Study of hydration of sarcosine, formation of its zwitterion and their different oligomers in aqueous media: a Raman spectroscopic and theoretical study - Sharma, Poornima; Singh, Dheeraj K.; Gupta, Vineet; Asthana, B. P.; Mishra, P. C.; Singh, Ranjan K. (Spectrochimica Acta Part A-Molecular and Biomolecular Spectroscopy, 2013)
{Raman spectra of the biologically important molecule sarcosine (SAR) (C3H7NO2) were studied experimentally in aqueous solution at different concentrations. These spectra were also calculated theoretically using density functional theory (DFT) at the B3LYP/6-31 1++G(d,p) level. Further, all the observed normal modes were assigned through potential energy distribution (PED). Geometry optimization of SAR produced its three conformers with slightly different energies. The lowest energy conformer of SAR was selected for a systematic solvation study wherein different numbers of water molecules (nW
Keywords: DFT calculations; Hydration; Oligomer; Raman spectra; Sarcosine; Zwitterion

Study of interatomic coulombic decay of Ne(H2O)(n) (n=1,3) clusters using equation-of-motion coupled-cluster method - Ghosh, Aryya; Pal, Sourav; Vaval, Nayana (Journal of Chemical Physics, 2013)
Interatomic Coulombic decay (ICD) is an efficient and ultrafast radiationless decay mechanism which can be initiated by removal of an electron from the inner-valence shell of an atom or molecule. Generally, the ICD mechanism is prevailed in weakly bound clusters. A very promising approach, known as CAP/EOM-CC, consists of the combination of complex absorbing potential (CAP) with the equation-of-motion coupled-cluster (EOM-CC) method, is applied for the first time to study the nature of the ICD mechanism. We have applied this technique to determine the lifetime of an auto-ionized, inner-valence excited state of the NeH2O, Ne(H2O)(2), and Ne(H2O)(3) systems. The lifetime is found to be very short and decreases significantly with the number of neighboring water molecules. (C) 2013 AIP Publishing LLC.

Sugar furanoid trans-vicinal diacid as a gamma-turn inducer: synthesis and conformational study - Vangala, Madhuri; Dhokale, Snehal A.; Gawade, Rupesh L.; Pattuparambil, Rajamohanan R.; Puranik, Vedavati G.; Dhavale, Dilip D. (Organic & Biomolecular Chemistry, 2013)
A simple method for the synthesis of a sugar furanoid trans vicinal diacid and its incorporation into the N-terminal tetrapeptide sequence (H-Phe-Trp-Lys-Thr-OH) to get glycopeptide 8 has been described. 2D NMR and MD simulation studies of 8 clearly show that the sugar diacid adopts a gamma-turn conformation towards the N-terminus.

Supplementation of medium with diammonium hydrogen phosphate enhanced the D-lactate dehydrogenase levels leading to increased D-lactic acid productivity - Singhvi, Mamata; Jadhav, Akanksha; Gokhale, Digambar V. (Bioresource Technology, 2013)
The production of D-lactic acid by Lactobacillus lactis RM2-24 was investigated using modified media to increase the efficiency of the fermentation process. The results indicated that the addition of 5 g/l peptone and 1 g/l (NH4)(2)HPO4 enhanced D-lactic acid production by 32%, as compared to that obtained from non supplemented media, with a productivity of 3.0 g/l/h. Lactate dehydrogenase (LDH) expression profile in these different media was studied which resulted in appearance of additional LDH isoform produced by cells when they were grown in HSYE supplemented with (NH4)(2)HPO4. The additional LDH appears to be L-LDH contributing to production of L-lactic acid in the fermented broth. This is totally new information in the lactic acid fermentation and could be very useful to industries engaged in D-lactic acid production. (c) 2013 Elsevier Ltd. All rights reserved.
Keywords: D(-) lactic acid production; Lactate dehydrogenase; Lactobacillus delbrueckii Uc-3; Lactobacillus lactis RM2-24

Supramolecular nanoparticles that target phosphoinositide-3-kinase overcome insulin resistance and exert pronounced antitumor efficacy - Kulkarni, Ashish A.; Roy, Bhaskar; Rao, Poornima S.; Wyant, Gregory A.; Mahmoud, Ayaat; Ramachandran, Madhumitha; Sengupta, Poulomi; Goldman, Aaron; Kotamraju, Venkata Ramana; Basu, Sudipta; Mashelkar, Raghunath Anant; Ruoslahti, Erkki; et al. (Cancer Research, 2013)
The centrality of phosphoinositide-3-kinase (PI3K) in cancer etiology is well established, but clinical translation of PI3K inhibitors has been limited by feedback signaling, suboptimal intratumoral concentration, and an insulin resistance ``class effect.'' This study was designed to explore the use of supramolecular nanochemistry for targeting PI3K to enhance antitumor efficacy and potentially overcome these limitations. PI3K inhibitor structures were rationally modified using a cholesterol-based derivative, facilitating supramolecular nanoassembly with L-alpha-phosphatidylcholine and DSPE-PEG [1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[amino(polythylen e glycol)]. The supramolecular nanoparticles (SNP) that were assembled were physicochemically characterized and functionally evaluated in vitro. Antitumor efficacy was quantified in vivo using 4T1 breast cancer and K-Ras(LSL/+)/Pten(fl/fl) ovarian cancer models, with effects on glucose homeostasis evaluated using an insulin sensitivity test. The use of PI103 and PI828 as surrogate molecules to engineer the SNPs highlighted the need to keep design principles in perspective; specifically, potency of the active molecule and the linker chemistry were critical principles for efficacy, similar to antibody-drug conjugates. We found that the SNPs exerted a temporally sustained inhibition of phosphorylation of Akt, mTOR, S6K, and 4EBP in vivo. These effects were associated with increased antitumor efficacy and survival as compared with PI103 and PI828. Efficacy was further increased by decorating the nanoparticle surface with tumor-homing peptides. Notably, the use of SNPs abrogated the insulin resistance that has been associated widely with other PI3K inhibitors. This study provides a preclinical foundation for the use of supramolecular nanochemistry to overcome current challenges associated with PI3K inhibitors, offering a paradigm for extension to other molecularly targeted therapeutics being explored for cancer treatment. (C)2013 AACR.

Switching the H-bonding network of a foldamer by modulating the backbone chirality and constitutional ratio of amino acids - Ramesh, Veera V. E.; Vijayadas, Kuruppanthara N.; Dhokale, Snehal A.; Gonnade, Rajesh G.; Rajamohanan, Pattuparambil R.; Sanjayan, Gangadhar J. (Organic & Biomolecular Chemistry, 2013)
This communication describes the folding propensity of a hetero-foldamer motif featuring proline (Pro) and anthranilic acid (Ant) residues in a 1:2:1 (alpha: beta: alpha) constitutional ratio. Structural investigations unequivocally suggest that the hydrogen-bonding network of this foldamer motif can be switched between 9-membered and 6-membered by modulating the backbone chirality and constitutional ratio of the amino acid residues.

Synergistic action of flavin containing NADH dependant azoreductase and cytochrome P450 monooxygenase in azoaromatic mineralization - Oturkar, Chetan C.; Othman, Munif A.; Kulkarni, Mahesh J.; Madamwar, Datta; Gawai, Kachru R. (RSC Advances, 2013)
An alkaliphilic strain Bacillus lentus Bl377 was isolated from contaminated soil of the textile area of Solapur, India. The strain was able to degrade almost 98% of recalcitrant azoic compounds by a mutually regulated process of azoreductase and a monooxygenase system. An enzyme activity study and a periodical carbon monoxide (CO) binding spectra study on a UV-visible spectrophotometer revealed that the intermediate amines formed by typical azoreduction (N=N cleavage), subsequently underwent hydroxylation by the cytochrome P450 monooxygenase (CYP450) system. Azoreductase was purified by chromatographic techniques and characterization by MALDI-TOF substantiated its identity as FMN containing NADH dependent azoreductase of 32 kDa in size. Surprisingly, purified azoreductase showed the highest activity at 80 degrees C and pH 8.0. An increase in the activity of superoxide dismutase after decolorization confirmed the signature of oxidative stress and its involvement in the dismutation of reactive metabolites. Intermediate metabolite analysis by HPLC, GC-MS and FTIR and the removal of total organic carbon (TOC) suggested the azoaromatics' degradation leads to mineralization via a TCA cycle.

Syntheses and determination of absolute configurations and biological activities of the enantiomers of the longtailed mealybug pheromone - Ramesh, Remya; Swaroop, Pandrangi Siva; Gonnade, Rajesh G.; Thirupath, Choppari; Waterworth, Rebeccah A.; Millar, Jocelyn G.; Reddy, D. Srinivasa (Journal of Organic Chemistry, 2013)
Preparation and assignment of absolute configurations to both enantiomers of the sex pheromone of the longtailed mealybug, an irregular monoterpenoid with extraordinary biological activity, has been completed. Comparison of the biological activities of both enantiomers and the racemate in field trials showed that the (S)-(+)-enantiomer was highly attractive to male mealybugs, strongly suggesting that female longtailed mealybugs produce this enantiomer. The (R)-(-)-enantiomer was benign, being neither attractive nor inhibitory.

Synthesis and antitubercular activity of amino alcohol fused spirochromone conjugates - Mujahid, Mohammad; Gonnade, Rajesh G.; Yogeeswari, P.; Sriram, D.; Muthukrishnan, Murugan (Bioorganic & Medicinal Chemistry Letters, 2013)
A series of 21 new amino alcohol fused spirochromone conjugates have been synthesized, characterized with analytical data and evaluated their antimycobacterial activity against Mycobacterium tuberculosis (virulent strain H37Rv) in vitro. Some of the compounds exerted significant inhibition, in particular, compound 4f found to be the most potent derivative exhibiting MIC = 3.13 mu g/mL. (C) 2013 Elsevier Ltd. All rights reserved.
Keywords: Amino alcohol; Antitubercular activity; Mycobacterium tuberculosis; Spirochromones

Synthesis and catalytic activity of monodisperse gold-mesoporous silica core-shell nanocatalysts - Sekhar, A. C. Sunil; Meera, C. J.; Kottavarithottil Ziyad; Gopinath, Chinnakonda S.; Vinod, C. P. (Catalysis Science & Technology, 2013)
Core-shell nanostructures, where gold nanoparticles of sub 10 nm size are successfully encapsulated inside porous silica spheres, have been prepared. The detailed characterization of the catalyst shows a high surface area and good mesoporosity. The sinter resistance of the catalyst under repeated cycles of the CO oxidation reaction is observed.

Synthesis and self-assembly of amphiphilic homoglycopolypeptide - Dhaware, Vinita; Shaikh, Ashif Y.; Kar, Mrityunjoy; Hotha, Srinivas; Sen Gupta, Sayam (Langmuir, 2013)
The synthesis of the amphiphilic homoglycopolypeptide was carried out by a combination of NCA polymerization and click chemistry to yield a well-defined Polypeptide having an amphiphilic carbohydrate on its side chain. The amphiphilicity of the carbohydrate was achieved by incorporation of an alkyl chain, at the C-6 position of the carbohydrate thus also rendering the homoglycopolypeptide amphiphilic. The homoglycopolypeptide formed multimicellar aggregates in water above a critical concentration of 0.9 mu M due to phase separation. The multimicellar aggregates were characterized by DLS, TEM, and AFM. It is proposed that hydrophobic interactions of the aliphatic chains at the 6-position of the sugar moieties drives the assembly of these rod-like homoglycopolypeptide into large;spherical aggregates. These multimicellar aggregates encapsulate both hydrophilic as well as hydrophobic dye as was confirmed by confocal microscopy. finally, amphiphilic random polypeptides containing 10% and 20% alpha-D-mannose in addition to glucose containing a, hydrophobic alkyl chain at its 6 position were synthesized by our methodology, and these polymers Were also found to assemble into spherical nanostructures. The spherical assemblies Of amphiphilic random glycopolypeptides containing 10% and 20% mannose were found to be surface bioactive and were found, to interact with the lectin Con-A.

Synthesis and structural studies of S-type/N-type-locked/frozen nucleoside analogues and their incorporation in RNA-selective, nuclease resistant 2 `-5 ` linked oligonucleotides - Erande, Namrata D.; Gunjal, Anita D.; Fernandes, Moneesha; Gonnade, Rajesh G.; Kumar, Vaijayanti A. (Organic & Biomolecular Chemistry, 2013)
2'-endo locked or frozen (S-type)/3'-endo locked or frozen (N-type) nucleoside analogues were synthesized. Conformational analysis based on (3)J(HH) and NOE measurements is presented which is further confirmed by X-ray crystal structural studies. 2'-5' isoDNA oligonucleotides (ON) were synthesized using these modified nucleoside analogues and UV-T-m studies of the resultant 2'-5' isoDNA : RNA duplexes reflect the site-and sequence-dependent effects and confirm that the S-type sugar conformations were preferred over the N-type sugar geometry in such duplexes.

Synthesis and X-ray single crystal structure of a cadmium(II) acetophenone thiosemicarbazone complex and its use as a single-source precursor for the preparation of CdS nanocrystallites and thin films - Palve, Anil M.; Joshi, Pranaya V.; Puranik, Vedavati G.; Garje, Shivram S. (Polyhedron, 2013)
{A cadmium(II) acetophenone thiosemicarbazone complex has been prepared and characterized by elemental analysis, infrared and nuclear magnetic resonance (H-1 and C-13H-1) spectroscopic techniques. Its single crystal structure has also been determined. The compound is found to be monoclinic, space group C2/c, with a = 12.1020(3) angstrom
Keywords: CdS; Nanocrystallites; Single source precursor; Thin films; Thiosemicarbazone complex

Synthesis of 3,5-Bis(acrylaldehyde) boron-dipyrromethene and application in detection of cysteine and homocysteine in living cells - Madhu, Sheri; Gonnade, Rajesh G.; Ravikanth, Mangalampalli (Journal Of Organic Chemistry, 2013)
Synthesis, characterization, and spectral and electrochemical properties of 3,5-bis(acrylaldehyde) BODIPY are described. The compound exhibited higher selectivity toward cysteine/homocysteine than toward other amino acids and thiol-containing compounds as shown by absorption and emission titration experiments and by experiments in living cells.

Synthesis of end-functionalized phosphate and phosphonate-polypeptides by ring-opening polymerization of their corresponding N-carboxyanhydride - Das, Soumen; Kar, Mrityunjoy; Sen Gupta, Sayam (Polymer Chemistry, 2013)
Phosphopolypeptides provide an interesting biomimetic analog for phosphorylated proteins that are involved in biomineralization. We have developed a high yielding synthesis of cysteine-based phosphate and phosphonate N-carboxyanhydride (NCA) by using the thiol-ene coupling reaction. These phosphate and phosphonate NCA monomers underwent polymerization using simple primary amine initiators to form well defined homophosphopolypeptides. Using a bifunctional initiator we were able to install a ``clickable'' alkyne or azide group at the end of the polypeptide chain. We were also able to successfully synthesize fully water-soluble phosphonate based polypeptides by hydrolysis of the corresponding phosphonate ester groups in the polypeptide. These water-soluble phosphopolypeptides adopt a random coil conformation at physiological pH.

Synthesis of low coercive BaFe12O19 hexaferrite for microwave applications in low-temperature cofired ceramic - Rane, Vivek A.; Meena, Sher Singh; Gokhale, Suresh P.; Yusuf, S. M.; Phatak, Girish J.; Date, Sadgopal K. (Journal of Electronic Materials, 2013)
Polycrystalline M-type barium hexaferrite (BaFe12O19) samples have been synthesized by solution combustion route at different pH and calcination conditions in order to reduce the coercivity for microwave applications in low-temperature cofired ceramic (LTCC) substrates. Structural, morphological, and magnetic properties of BaFe12O19 were studied by x-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), Raman spectroscopy, vibrating sample magnetometry (VSM), and Mossbauer spectroscopy. The formation of a single-phase hexagonal structure was confirmed by XRD. The Raman spectra reveal all characteristic peaks of BaFe12O19, illustrating the phase purity and crystal lattice symmetry of the synthesized material. Mossbauer spectra illustrate the existence of Fe3+ cations at all five crystallographic lattice sites. The microstructural features observed by FESEM disclose the growth of nanoregime particles into hexagonal platelet particles after calcination at temperatures from 800A degrees C to 1200A degrees C. The VSM results show a lower coercivity (1350 Oe to 3500 Oe) together with reasonably high saturation magnetization (55 emu/g to 60 emu/g) and a high bulk resistivity (> 10(9) Omega-cm) at room temperature. The dependence of magnetic and electrical properties on the preparation and processing conditions is also discussed.
Keywords: Barium hexaferrite; coercivity; LTCC; Mossbauer spectroscopy; Raman spectroscopy

Synthesis of pseudo-indoxyl derivatives via sequential Cu-catalyzed SNAr and Smalley cyclization - Goriya, Yogesh; Ramana, Chepuri V. (Chemical Communications, 2013)
ortho-Bromophenyl sec-alkyl/sec-alkenyl ketones, on reaction with sodium azide in the presence of copper salts, undergo sequential SNAr followed by Smalley cyclization to provide pseudo-indoxyl derivatives. Some of these pseudo-indoxyl derivatives exhibit interesting fluorescent properties and broad Stokes shifts.

Synthesis, steady-state, and femtosecond transient absorption studies of resorcinol bound ruthenium(ii)- and osmium(ii)-polypyridyl complexes on nano-TiO2 surface in water - Banerjee, Tanmay; Kaniyankandy, Sreejith; Das, Amitava; Ghosh, Hirendra Nath (Inorganic Chemistry, 2013)
The synthesis of two new ruthenium(II)- and osmium(II)-polypyridyl complexes 3 and 4, respectively, with resorcinol as the enediol anchoring moiety, is described. Steady-state photochemical and electrochemical studies of the two sensitizer dyes confirm strong binding of the dyes to TiO2 in water. Femtosecond transient absorption studies have been carried out on the dye–TiO2 systems in water to reveal <120 fs and 1.5 ps electron injection times along with 30% slower back electron transfer time for the ruthenium complex 3. However, the corresponding osmium complex 4 shows strikingly different behavior for which only a <120 fs ultrafast injection is observed. Most remarkably, the back electron transfer is faster as compared to the corresponding catechol analogue of the dye. The origin and the consequences of such profound effects on the ultrafast interfacial dynamics are discussed. This Article on the electron transfer dynamics of the aforesaid systems reinforces the possibility of resorcinol being explored and developed as an extremely efficient binding moiety for use in dye-sensitized solar cells.

Synthetic zipper peptide motif orchestrated via co-operative interplay of hydrogen bonding, aromatic stacking, and backbone chirality - Nair, Roshna V.; Kheria, Sanjeev; Rayavarapu, Suresh; Kotmale, Amol S.; Jagadeesh, Bharatam; Gonnade, Rajesh G.; Puranik, Vedavati G.; Rajamohanan, Pattuparambil R.; Sanjayan, Gangadhar J. (Journal of the American Chemical Society, 2013)
Here, we report on a new class of synthetic zipper peptide which assumes its three-dimensional zipper-like structure via a co-operative interplay of hydrogen bonding, aromatic stacking, and backbone chirality. Structural studies carried out in both solid- and solution-state confirmed the zipper-like structural architecture assumed by the synthetic peptide which makes use of unusually remote inter-residual hydrogen-bonding and aromatic stacking interactions to attain its shape. The effect of chirality modulation and the extent of noncovalent forces in the structure stabilization have also been comprehensively explored via single-crystal X-ray diffraction and solution-state NMR studies. The results highlight the utility of noncovalent forces in engineering complex synthetic molecules with intriguing structural architectures.

Thermodynamics and solvation dynamics of BIV TAR RNA-Tat peptide interaction - Goel, Teena; Kumar, Santosh; Maiti, Souvik (Molecular Biosystems, 2013)
The interaction of the trans-activation responsive (TAR) region of bovine immunodeficiency virus (BIV) RNA with the Tat peptide is known to play important role in viral replication. Despite being thoroughly studied through a structural point of view, the nature of binding between BIV TAR RNA and the BIV Tat peptide requires information related to its thermodynamics and the nature of hydration around the TAR-Tat complex. In this context, we carried out the thermodynamic study of binding of the Tat peptide to the BIV TAR RNA hairpin through different calorimetric and spectroscopic measurements. Fluorescence titration of 2-aminopurine tagged BIV TAR RNA with the Tat peptide gives their binding affinity. The isothermal titration calorimetric experiment reveals the enthalpy of binding between BIV TAR RNA and the Tat peptide to be largely exothermic with the value of -11.7 (SEM 0.2) kcal mol(-1). Solvation dynamics measurements of BIV TAR RNA having 2-AP located at the bulge region have been carried out in the absence and presence of the BIV Tat peptide using the time correlated single photon counting technique. The solvent cage around the Tat binding site of RNA appears to be more rigid in the presence of the Tat peptide as compared to the free RNA. The displacement of solvent and ions on RNA due to peptide binding influences the entropic contributions to the total binding energy.

Thermoresponsive and biodegradable dextran based microgels: synthesis and structural investigation - Ghugare, Shivkumar V.; Chiessi, Ester; Sakai, Victoria Garcia; Telling, Mark T. F.; Wadgaonkar, Prakash P.; Paradossi, Gaio (Macromolecular Symposia, 2013)
Nanostructured objects, often ranging from hundreds of nanometers to few microns, support a number of functions directly linked to their structural features. They are, or they will be, protagonists in biomedical applications where miniaturized activities are required. These include the interface with living systems as tissues and cells, where targeted release of drug molecules occurs, or molecular imaging methods monitoring the drug trafficking in specific cell districts. The potentials of such devices, far to be fully understood, will be assessed only when a close correlation of their functions with their structure will be established. In this contribution we present a dextran based microdevice responsive to temperature and biodegradable. Both thermoresponsivity and biodegradability are of relevance for the potential use as drug carrier and controlled release device. The temperature behaviour, overall structure and internal architectures have been addressed with different methods.
Polymer Networks Conference (PNG), WY, AUG 12-16, 2012
Keywords: Biomaterials; colloids; dynamic light scattering; hydrogels; p(NiPAAm)

Triazole-linked anthracenyl-appended calix[4]arene conjugate as receptor for Co(II): synthesis, spectroscopy, microscopy, and computational studies - Mummidivarapu, V. V. Sreenivasu; Hinge, Vijaya Kumar; Tabbasum, Khatija; Gonnade, Rajesh G.; Rao, Chebrolu P. (Journal of Organic Chemistry, 2013)
A new triazole-linked anthracenyl-appended calix[4]arene-1,3-diconjugate (L) has been synthesized and characterized, and its single crystal XRD structure has been established. Binding properties of L toward different biologically relevant metal ions have been studied by fluorescence and absorption spectroscopy in ethanol. L exhibits selective recognition of Co2+ and can detect down to a concentration of 55 ppb (0.92 mu M). The roles of the calix[4]arene platform as well as the preorganized binding core in L's selective recognition have been demonstrated by studying appropriate control molecules. The mode of binding of L with Co2+ has been modeled both by DFT and MD computational calculations. L and its Co2+ complex could be differentiated on the basis of the nanostructural features observed in AFM and TEM.

Two-stage fermentation process for enhanced mannitol production using Candida magnoliae mutant R9 - Savergave, Laxman S.; Gadre, Ramchandra V.; Vaidya, Bhalchandra K.; Jogdand, Vitthal V. (Bioprocess and Biosystems Engineering, 2013)
Mutants of Candida magnoliae NCIM 3470 were generated by treatment of ultra-violet radiations, ethyl methyl sulphonate and N-methyl-N'-nitro-N-nitrosoguanidine. Mutants with higher reductase activity were screened by means of 2,3,5-triphenyl tetrazolium chloride agar plate assay. Among the screened mutants, the mutant R9 produced maximum mannitol (i.e. 46 g l(-1)) in liquid fermentation medium containing 250 g l(-1) glucose and hence was selected for further experiments. Preliminary optimization studies were carried out on shake-flask level which increased the mannitol production to 60 g l(-1) in liquid fermentation medium containing 300 g l(-1) glucose. A two-stage fermentation process comprising of growth phase and production phase was employed. During the growth phase, glucose was supplemented and aerobic conditions were maintained. Thereafter, the production phase was initiated by supplementing fructose and switching to anaerobic conditions by discontinuing aeration and decreasing the speed of agitation. The strategy of two-stage fermentation significantly enhanced the production of mannitol up to 240 g l(-1), which is the highest among all fermentative production processes and corresponds to 81 % yield and 4 g l(-1) h(-1) productivity without formation of any by-product.
Keywords: Candida magnoliae; D-Mannitol; Mutagenesis; Strain improvement; Two-stage fermentation

Weak becomes strong: remarkable strength of C-H center dot center dot center dot pi hydrogen bond in the presence of O-H center dot center dot center dot O hydrogen bonds in the crystal stabilization - Sureshan, Kana M.; Gonnade, Rajesh G. (CrystEngComm, 2013)
We report crystallographic evidence for the significance of C-H center dot center dot center dot pi hydrogen bonds in the crystal stabilization of 1,4-di-O-benzoyl-myo-inositol. The strength of this otherwise weak hydrogen bond matches with the strength of O-H center dot center dot center dot O hydrogen bonds.

Xylitol production by cyberlindnera (Williopsis) saturnus, a tropical mangrove yeast from xylose and corn cob hydrolysate - Kamat, S.; Gaikwad, S.; Kumar, A. Ravi; Gade, Wasudeo N. (Journal of Applied Microbiology, 2013)
AimPotential for xylitol production from xylose and corn cob hydrolysate by a tropical mangrove yeast. Methods and ResultsIn the present study, 21 fungi were isolated from detritus-based mangrove wetlands along the Indian west coast. Of these, one yeast isolate had the ability to grow and assimilate xylose producing significant amounts of xylitol (3863gl(-1)). A maximum yield of 054gg(-1) was obtained after 144h of growth on xylose (150gl(-1)) and corn cob hydrolysate (CCH, containing 65gl(-1) xylose). Using biochemical and molecular methods, the yeast was identified as Cyberlindnera (Williopsis) saturnus. Preliminary characterization of enzymes in the cell-free extract revealed that while xylose reductase (XR) preferred NADPH to NADH as cofactor, xylitol dehydrogenase (XDH) was NAD specific. ConclusionsSignificant amounts of xylitol could be produced on CCH using C.saturnus isolated from tropical mangrove wetlands. The yeast has the potential to assimilate rather than ferment xylose as its XR has a preference for NADPH. Significance and Impact of the StudyMicrobes offer an economically viable and green approach for production of xylitol, an industrially important compound. A mangrove ecosystem with its battery of lignocellulolytic enzymes is an ideal location for isolating fungi capable of producing xylitol from agroindustrial waste such as CCH.
Keywords: corn cob hydrolysate; Cyberlindnera; mangrove; Williopsis; xylitol; Xylose; Yeast

1,8-Diazabicyclo[5.4.0]undec-7-ene (DBU): a highly efficient catalyst in glycerol carbonate synthesis - Munshi, Mudassir K.; Gade, Swapna M.; Mane, Manoj V.; Mishra, Deepti; Pal, Sourav; Vanka, Kumar; Rane, Vilas H.; Kelkar, Ashutosh A. (Journal of Molecular Catalysis A-Chemical, 2014)
Transesterification of dimethyl carbonate (DMC) with glycerol (GLY) was investigated using various amines as catalysts. Amidines like 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) and 1,5-diazabicyclo[4.3.0]non-5-ene (DBN) were found to be the best catalysts for this reaction. Best results: 98% conversion of GLY with 96% selectivity to GC (TON: 9408), were obtained with DBU as a catalyst. Effect of various reaction conditions on activity and selectivity were investigated using DBU as catalyst. The mechanism of the reaction was investigated with the help of H-1, C-13 and N-15 NMR analysis and OFT calculations. (C) 2014 Elsevier B.V. All rights reserved.
Keywords: DBU; Glycerol; Glycerol carbonate; transesterification

2-Aroylindoles from o-bromochalcones via Cu(I)-catalyzed SNAr with an azide and intramolecular nitrene C-H insertion - Goriya, Yogesh; Ramana, Chepuri V. (Chemical Communications, 2014)
A simple procedure for the synthesis of 2-aroylindole derivatives comprising a one-pot CuI-catalyzed SNAr reaction of o-bromochalconeswith sodium azide and subsequent intramolecular cyclization through nitrene C-H insertion has been developed. This protocol is also applicablewith the 2'-bromocinnamates giving the indole-2-carboxylates.

9-Fluorenemethanol: an internal electron donor to fine tune olefin polymerization activity - Gnanakumar, Edwin S.; Chokkapu, Eswara Rao; Kunjir, Shrikant; Ajithkumar, Thalasseril G.; Rajamohanan, P. R.; Chakraborty, Debashis; Gopinath, Chinnakonda S. (Dalton Transactions, 2014)
A new MgCl2 based molecular adduct has been synthesized with 9-fluorenemethanol (9FM) as a novel internal electron donor (IED), along with ethanol (EtOH) (MgCl2 center dot n9FM center dot xEtOH). The above molecular adduct has been subjected to a variety of structural, spectroscopic and morphological characterization techniques. The results of the solid state C-13 CPMAS NMR technique suggests the coordination of 9FM to MgCl2. Observation of a low angle diffraction peak at 2 theta = 5.7 degrees (d = 15.5 angstrom) underscores the coordination of 9FM along the z-axis, and ethanol in the molecular adduct. Active Ziegler-Natta catalysts were prepared by two different synthesis methods; the conventional method to obtain a high surface area active catalyst, and other one with 9FM as an integral part of the active catalyst in order to study the influence of 9FM as an IED over the active sites. The active catalysts were also characterized thoroughly with different analytical tools. The XRD results show (003) facets of delta-MgCl2 (alpha-MgCl2) for the conventional (non-conventional) titanated catalyst. Results of the ethylene polymerization activity study reveals that the conventionally prepared highly porous active catalyst shows 1.7-2.5 times higher activity than the non-conventional prepared catalyst; however, the latter shows a low molecular weight distribution and confirms the role of the Lewis base as an IED.

Acid-base cooperative catalysis over mesoporous nitrogen-rich carbon - Goyal, Reena; Sarkar, Bipul; Lucas, Nishita; Bordoloi, Ankur (ChemCatChem, 2014)
WOx nanoclusters (2-3 nm) embedded on a mesoporous nitrogen-rich carbon material were synthesized by using novel methodology. This material was very effectively capitalized as a new carbon-based acid-base cooperative catalyst for sequential acetal hydrolysis and Knoevenagel condensation reactions. The protocol was also explored for the nitroaldol condensation reaction.
Keywords: cooperative catalysts; Knoevenagel condensation; mesoporous materials; Nanostructures; nitro aldol reaction

Activated nitrogen doped graphene shell towards electrochemical oxygen reduction reaction by its encapsulation on Au nanoparticle (Au@N-Gr) in water-in-oil ``nanoreactors'' - Dhavale, Vishal M.; Gaikwad, Sachin S.; Kurungot, Sreekumar (Journal of Materials Chemistry A, 2014)
Encapsulation of nitrogen doped graphene on Au nanoparticle (Au@N-Gr) could be accomplished through a water-in-oil emulsion technique, where the emulsion droplets act as `nanoreactors' and the redox reaction inside the droplets results in the formation of core-shell nanoparticles. The encapsulation of N-Gr on a small quantity of Au (N-Gr : Au wt ratio of 90 : 10) made the N-Gr layer more conductive and active towards electrochemical oxygen reduction reaction (ORR). The enhanced conductivity helped the system narrow down the ohmic overpotential, and direct electronic interactions between the Au and Gr layers brought in a favourable positive shift to the onset potential for ORR. Encapsulation has helped N-Gr reduce the overpotential by similar to 121 mV as compared to N-Gr alone. Apart from this, the oxygen reduction kinetics of Au@N-Gr also appeared to be superior to N-Gr and Au nanoparticles as separate entities due to greater involvement of the preferred 4-electron reduction pathway. At -0.3 V (vs. Hg/HgO), the percentage of hydrogen peroxide (H2O2) (a product formed from the undesirable 2-electron reduction pathway) was found to be 16.5% for Au@Gr, where Au was covered with undoped Gr, which gets reduced to a significantly low level of 6.5% for Au@N-Gr. Au and N-Gr as separate entities give yield of H2O2 as 52.2 and 47.7%, respectively. From these, it can be concluded that the coverage of N-Gr on Au helps decrease the yield of H2O2 drastically apart from the benefits of synergistic interactions in reducing both ohmic and activation overpotentials.

Acyl-transfer reactions in molecular crystals: reactivity correlation with crystal structure - Gonnade, Rajesh G.; Shashidhar, Mysore S. (Acta Crystallographica A‐Foundation and Advances, 2014)
Keywords: crystal engineering; intermolecular interactions; solid-state reactions

Additive induced capture of elusive polymorphs of conformationally flexible Sulfonamides/Sulfoesters - Shaikh, Samir Rashid; Gawade, Rupesh L.; Chakravarty, Debamitra K.; Puranik, Vedavati G.; Gonnade, Rajesh (Acta Crystallographica A‐Foundation and Advances, 2014)
Keywords: additive induced polymorphism; intermolecular interactions; phase transition

Ambient oxidation of benzene to phenol by photocatalysis on Au/Ti0.98V0.02O2: role of holes - Devaraji, Perumal; Sathu, Naveen K.; Gopinath, Chinnakonda S. (ACS Catalysis, 2014)
A potential photocatalyst with 2 atom % vanadium incorporated into the 1 lattice of disordered mesoporous titania, Ti0.98V0.02O2, (TV2) was synthesized. Au was deposited on TV2 (Au/TV2) through a photodeposition method. Structural, microscopy, and spectroscopy techniques support the incorporation of vanadium into the TiO2 lattice, and Au was deposited on the surfaces of TV2. Photocatalytic oxidation of benzene was conducted at ambient temperature under UV and/or visible light to demonstrate the catalytic activity of the Au/TV2 catalyst. The TV2 lattice exhibits a quantum jump in benzene to phenol oxidation compared to that of TiO2, highlighting the importance of V for oxidation. Introduction of Au onto TV2 further increases the benzene to phenol oxidation and phenol yield by a factor of 2 under UV light compared to those of bare TV2. No significant phenol production was observed in visible light with or without gold, indicating the role of gold is indirect toward charge separation and electron storage. Nano gold clusters on TV2 selectively store photoexcited electrons and in turn maximize holes utilization on TiO2. The high photocatalytic activity of Au/TV2 is mainly attributed to the presence of Schottky junctions, disordered mesoporosity, and short diffusion lengths for charge carriers.
Keywords: nano gold; phenol; Photocatalysis; Schottky junction; titania; Vanadium

Antifungal dimeric chalcone derivative kamalachalcone E from Mallotus philippinensis - Kulkarni, Roshan R.; Tupe, Santosh G.; Gample, Suvarna P.; Chandgude, Macchindra G.; Sarkar, Dhiman; Deshpande, Mukund V.; Joshi, Swati P. (Natural Product Research, 2014)
From the red coloured extract (Kamala) prepared through acetone extraction of the fresh whole uncrushed fruits of Mallotus philippinensis, one new dimeric chalcone (1) along with three known compounds 1-(5,7-dihydroxy-2,2,6-trimethyl-2H-1-benzopyran-8-yl)-3-phenyl-2-propen -1-one (2), rottlerin (3) and 4 `-hydroxyrottlerin (4) were isolated. The structure of compound 1 was elucidated by 1D and 2D NMR analyses that included HSQC, HMBC, COSY and ROESY experiments along with the literature comparison. Compounds 1-4 were evaluated for antifungal activity against different human pathogenic yeasts and filamentous fungi. The antiproliferative activity of the compounds was evaluated against Thp-1 cell lines. Compounds 1 and 2 both exhibited IC50 of 8, 4 and 16 mu g/mL against Cryptococcus neoformans PRL518, C. neoformans ATCC32045 and Aspergillus fumigatus, respectively. Compound 4, at 100 mu g/mL, showed 54% growth inhibition of Thp-1 cell lines.
Keywords: 4 `-hydroxyrottlerin; antifungal; dimeric chalcone; kamalachalcone E; Mallotus philippinensis; rottlerin

Antimicrobial activity of a new series of Bis(isoxazoline),Bis(isoxazole)and their derivatives - Gajbhiye, Jayant M.; Chopade, A. U. (International Journal of Chemical and Physical Sciences, 2014)
A series of 1,1-bis [2-hydroxy-3-(5’-aryl-isoxazoline-3-yl)-5-methyl phenyl] methane and 1,1-bis [2-hydroxy-3-(5’-aryl-isoxazol-3-yl)-5-methyl phenyl] methane derivatives were evaluated for their antimicrobial activity against some selected pathogenic micro-organisms such as Gram-positive bacteria, Staphylococcus aureus, Citrobacter frundii, Bacillus megatherium and Gram-negative bacteria Staphyloccus aureus, Escherichia coli, Proteus mirabilis, Pseudomonas aeruginosa, Enterobacter aerogenes, Salmonella typhi, Proteus vulgaris.

Asymmetric vinylogous mannich reaction of silyloxy furans with N-tert-butanesulfinyl ketimines - Rao, V. U. Bhaskara; Jadhav, Amol P.; Garad, Dnyaneshwar N.; Singh, Ravi P. (Organic Letter, 2014)
A highly regio- and diastereoselective TMSOTf promoted vinylogous Mannich reaction for the synthesis of chiral quaternary 3-aminooxindole butenolides from 2-silyloxy furans and chiral ketimines is described. The method is found to be very efficient and also provides a facile access to sterically challenging 3-aminooxindole butenolides bearing two quaternary centers in continuation. Further, the versatility of the method is demonstrated by the 1,4-addition of nucleophiles on the sterically congested butenolide substructure..

Biocatalyst mediated functionalization of salannin, an insecticidal limonoid - Haldar, Saikat; Kolet, Swati P.; Dandekar, Devdutta S.; Kale, Balaji S.; Gonnade, Rajesh G.; Thulasiram, Hirekodathakallu V. (RSC Advances, 2014)
Transformation of salannin, an insecticidal C-seco limonoid was investigated using a fungal system, Cunninghamella echinulata. Salannin was efficiently converted into two metabolites, where the C-17 furan moiety was transformed into gamma-hydroxybutenolide (salanninolide) and N-(2-hydroxyethyl)-alpha,beta-unsaturated-gamma-lactam (salanninactam) analogues. Present studies have indicated salanninolide to be a metabolite in the C-seco limonoid biosynthetic pathway.

Blue luminescent graphene quantum dots by photochemical stitching of small aromatic molecules: fluorescent nanoprobes in cellular imaging - Gokhale, Rohan; Singh, Pooja (Particle & Particle Systems Characterization, 2014)
Blue fluorescent graphene quantum dots (GQDs) are synthesized from small haloaromatic molecules by laser photochemistry. The process involves a bottom-up photochemical stitching mechanism of the free radicals generated by irradiation of ultraviolet photons (lambda = 248 nm) on o-dichlorobenzene. The GQDs are further demonstrated to be of importance as fluorescent nanoprobes in bioimaging of cells.image
Keywords: bioimaging; free radicals; graphene quantum dots; photochemical stitching; UV laser

Capturing a novel metastable polymorph of the anticancer drug gefitinib - Thorat, Shridhar H.; Patwadkar, Manjusha V.; Gonnade, Rajesh G.; Vaidhyanathan, R. (CrystEngComm, 2014)
Gefitinib, a life-extending anticancer drug, exhibits solvent-mediated conformational polymorphism to yield stable (form I) and novel metastable (form II) polymorphs. Crystal structure analysis revealed 3D isostructurality in the molecular organization of the polymorphs, and the metastable polymorph undergoes a crystal-to-crystal thermal phase transition to the stable polymorph.

Cationic charged helical glycopolypeptide using ring opening polymerization of 6-deoxy-6-azido-glyco-N-carboxyanhydride - Shaikh, Ashif Y.; Das, Soumen; Pati, Debasis; Dhaware, Vinita; Sen Gupta, Sayam; Hotha, Srinivas (Biomacromolecules, 2014)
Glycopolypeptides with a defined secondary structure are of significance in understanding biological phenomena. Synthetic glycopolypeptides, or polypeptides featuring pendant carbohydrate moieties, have been of particular interest in the field of tissue engineering and drug delivery. In this work, we have synthesized charged water-soluble glycopolypeptides that adopt a helical conformation in water. This was carried out by the synthesis of a glyco-N-carboxyanhydride (glyco-NCA) containing an azide group at the sixth position of the carbohydrate ring. Subsequently, the NCA was polymerized to obtain azide-containing glycopolypeptides having good control over molecular weight and polydispersity index (PDI) in high yields. We were also able to control the incorporation of the azide group by synthesizing random co-glycopolypeptide containing 6-deoxy-6-azido and regular 6-OAc functionalized glucose. This azide functionality allows for the easy attachment of a bioactive group, which could potentially enhance the biological activity of the glycopolypeptide. We were able to obtain water-soluble charged glycopolypeptides by both reducing the azide groups into amines and using CuAAC with propargylamine. These charged glycopolypeptides were shown to have a helical conformation in water. Preliminary studies showed that these charged glycopolypeptides showed good biocompatibility and were efficiently taken up by HepG2 cells.

CH3NH3PbI(3-x)(BF4)(x): molecular ion substituted hybrid perovskite - Nagane, Satyawan; Bansode, Umesh P.; Game, Onkar S.; Chhatre, Shraddha; Ogale, Satishchandra (Chemical Communications, 2014)
A molecular ion (BF4-) substituted hybrid perovskite CH3NH3PbI(3-x)(BF4)(x) is synthesized. The substituted perovskite shows significant enhancement in electrical conductivity at low frequencies and improved photoresponse under AM1.5 illumination as compared to the perovskite (CH3NH3PbI3).

Characterization, non-isothermal decomposition kinetics and photocatalytic water splitting of green chemically synthesized polyoxoanions of molybdenum containing phosphorus as hetero atom - D'Cruz, Bessy; Samuel, Jadu; George, Leena (Thermochimica Acta, 2014)
In here, the green synthesis and thermal characterization of a novel polyoxoanions of molybdenum containing phosphorus as hetero atom are reported. The composition and morphology of the nanorods were established by fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA) and inductively coupled plasma atomic emission spectroscopic (ICP-AES) techniques. Thermal properties of the nanoparticles were investigated by non-isothermal analysis under nitrogen atmosphere. The values activation energy of each stage of thermal decomposition for all heating rates was calculated by Flynn-Wall-Ozawa (FWO) and Kissinger-Akahira-Sunnose (KAS) methods. Invariant kinetic parameter (IKP) method and master plot methodmere also used to evaluate the kinetic parameters and mechanism for the thermal decomposition of cetylpyridinium phosphomolybdate (CPM). Photocatalytic water oxidation mechanism using CPM catalyst in the presence of platinum (Pt) co-catalyst enhances the H-2 evolution and was found to be 1.514 mmol/g/h. (C) 2014 Elsevier B.V. All rights reserved.
Keywords: Keggin structure; Master plot method; Polyoxometalate; Water oxidation

Chiron approach to formal synthesis of both antipodes of cis 3-hydroxypipecolic acid - Chavan, Subhash P.; Khairnar, Lalit B.; Chavan, Prakash N.; Dumare, Nilesh B.; Kalbhor, Dinesh B.; Gonnade, Rajesh G. (Tetrahedron Letters, 2014)
The efficient and practical formal syntheses of both enantiomers of cis 3-hydroxypipecolic acid were accomplished from cis aziridine-2-carboxylate as the common synthetic precursor. The key steps involved are stereo and regioselective aziridine ring opening, reductive cyclization and selective N-debenzylation over O-debenzylation reactions. (C) 2014 Elsevier Ltd. All rights reserved.
Keywords: 3-Hydroxypipecolic acid; Aziridine ring opening; Aziridine-2-carboxylate; Piperidine alkaloids; Selective debenzylation

Cocrystals/salts of Furosemide : Interesting case of colour cocrystal polymorphism - Sangtani, Ekta; Jha, Kunal; Munshi, Parthapratim; Gonnade, Rajesh (Acta Crystallographica A‐Foundation and Advances, 2014)
Keywords: Color cocrystal polymorphism; Sandwich assembly; Stacking interactions

Comparison of sodium zirconium phosphate and calcium zirconium phosphate structures for the retention of fluoride - Dey, Ambarish; Das Gupta, Amit; Basu, Debrata; Ambashta, Ritu D.; Wattal, P. K.; Kumar, Sanjiv; Body, Monique; Rajamohanan, P. R. (Journal of Radioanalytical and Nuclear Chemistry, 2014)
Fluoride anion interaction has been explored for the first time to investigate how the structure of sodium zirconium phosphate (NZP) and calcium zirconium phosphate (CZP) can be altered in its presence. Different compositions were made by adding NaF and CaF2 in CZP and NZP matrices respectively. Fluoride interaction differs with NZP and CZP structure as suggested by F-NMR data. The addition of fluoride to the NZP or CZP structure enables to stabilize the structure at a low temperature of 600-700 A degrees C under microwave conditions.
Keywords: F-NMR; Fluoride characterization; Microwave; NZP; PIGE

Complex absorbing potential based equation-of-motion coupled cluster method for the potential energy curve of CO2- anion - Ghosh, Aryya; Vaval, Nayana; Pal, Sourav; Bartlett, Rodney J. (Journal of Chemical Physics, 2014)
The equation-of-motion coupled cluster method employing the complex absorbing potential has been used to investigate the low energy electron scattering by CO2. We have studied the potential energy curve for the (2)Pi(u) resonance states of CO2- upon bending as well as symmetric and asymmetric stretching of the molecule. Specifically, we have stretched the C-O bond length from 1.1 angstrom to 1.5 angstrom and the bending angles are changed between 180 degrees and 132 degrees. Upon bending, the low energy (2)Pi(u) resonance state is split into two components, i.e., (2)A(1), B-2(1) due to the Renner-Teller effect, which behave differently as the molecule is bent. (c) 2014 AIP Publishing LLC.

Computational investigation on the catalytic activity of Rh-6 and Rh4Ru2 clusters towards methanol activation - Ghatak, Kamalika; Sengupta, Turbasu; Krishnamurty, Sailaja; Pal, Sourav (Theoretical Chemistry Accounts, 2014)
Catalysis of molecular activation of small molecules through scission of strong chemical bonds is one of the major challenges faced by chemists. More specifically, activation of the strong C-H and O-H bonds of various alcohols, especially methanol, is one of the various important intermediate steps of key organic reactions. Our present work explores a suitable metal cluster catalyst towards methanol dissociation. In particular, we have examined the effect of ruthenium doping (Rh:Ru = 2:1) on the catalytic activity of Rh-6 cluster towards methanol dissociation. Density functional theory-based calculations illustrate two competitive pathways for methanol dissociation, which are via O-H and C-H bond breaking. Both the pathways are found to be energetically favourable in the presence of bimetallic and mono-metallic clusters. Importantly, energy barrier for O-H bond dissociation reduces considerably in doped cluster as compared to pure Rh-6 cluster and is smaller than the values reported for a number of other small metallic clusters.
Keywords: Bimetallic Clusters; Density Functional Theory (DFT); Doping; Methanol Activation; Rhodium Clusters

Concise account of the chemistry of valuable alkyl(methyl)maleic anhydrides - Deore, Prashant S.; Haval, Kishan P.; Gadre, Smita R.; N. P. Argade (Synthesis-Stuttgart, 2014)
A large number of significant bioactive natural and synthetic alkyl(methyl)maleic anhydrides are known in the contemporary literature. A broad range of suitably functionalized substrates have been tailored to accomplish concise and efficient syntheses of an array of alkyl(methyl)maleic anhydrides employing a variety of elegant synthetic strategies. This review presents a brief literature account of the isolation and activity of these important target compounds with a special emphasis on their synthesis.
Keywords: alkyl(methyl)maleic anhydrides; bioactivity; dimethylmaleic anhydride; isolation; nucleophilic reactions; Total synthesis

Conformational modulation of peptide secondary structures using beta-aminobenzenesulfonic acid - Kale, Sangram S.; Kunjir, Shrikant M.; Gawade, Rupesh L.; Puranik, Vedavati G.; Rajamohanan, P. R.; Sanjayan, Gangadhar J. (Chemical Communications, 2014)
This communication describes the influence of beta-aminobenzenesulfonic acid ((S)Ant) on the conformational preferences of hetero foldamers. The designed (Aib-(S)Ant-Aib)(n) and (Aib-(S)Ant-Pro)(n) oligomers display a well-defined folded conformation featuring intramolecular mixed hydrogen bonding (7/11) and intra-residual (6/5) H-bonding interactions, respectively.

Conformational transitions of cinnamoyl CoA reductase 1 from leucaena leucocephala - Sonawane, Prashant D.; Khan, Bashir Mohammad; Gaikwad, Sushama M. (International Journal of Biological Macromolecules, 2014)
Conformational transitions of cinnamoyl CoA reductase, a key regulatory enzyme in lignin biosynthesis, from Leucaena leucocephala (L1-CCRH1) were studied using fluorescence and circular dichroism spectroscopy. The native protein possesses four trp residues exposed on the surface and 66% of helical structure, undergoes rapid structural transitions at and above 45 C and starts forming aggregates at 55 C. LI-CCRH1 was transformed into acid induced (pH 2.0) molten globule like structure, exhibiting altered secondary structure, diminished tertiary structure and exposed hydrophobic residues. The molten globule like structure was examined for the thermal and chemical stability. The altered secondary structure of Ll -CCRH1 at pH 2.0 was stable up to 90 C. Also, in presence of 0.25 M guanidine hydrochloride (GdnHCI), it got transformed into different structure which was stable in the vicinity of 2 M GdnHCI (as compared to drastic loss of native structure in 2 M GdnHC1) as seen in far UV-CD spectra. The structural transition of LI-CCRH1 at pH 2.0 followed another transition after readjusting the pH to 8.0, forming a structure with hardly any similarity to that of native protein. (C) 2013 Elsevier B.V. All rights reserved.
Keywords: Aggregation Cinnamoyl CoA reductase; Conformation; Molten globule; Thermostability; Unfolding

Contemporary avenues in catalytic P-H bond addition reaction: a case study of hydrophosphination - Koshti, Vijay; Gaikwad, Shahaji R.; Chikkali, Samir H. (Coordination Chemistry Reviews, 2014)
Remarkable advances and current state-of-the-art developments in catalytic hydrophosphination of alkenes and alkynes are reviewed. The challenges in constructing a C P bond with a special emphasis on metal catalysed (asymmetric) hydrophosphination are highlighted. Only those systems that unambiguously proceed via P H bond addition across a C-C/X (X = O, N, S) multiple bond have been covered in this overview. Reviewed examples support the assumption that either strongly chelating ligands or reaction products that act as ligands, enhance the rate of hydrophosphination. The asymmetric variant of this transformation allows installation of p-chiral [enantiomeric excess (ee) up to 82%] as well as C-chiral (ee up to 99%) centres. The limited spectroscopic, mechanistic data and OFT calculations point at two distinctly different mechanisms. In case of hydrophosphination, the metal undergoes oxidative addition and reductive elimination steps (in general), thus changing the oxidation state from M(0) to M(II) and back to M(0). Whereas in asymmetric hydrophosphination it is proposed that the oxidation state of the metal remains unaltered throughout the catalytic cycle. The examples described in this overview showcase the real power of catalytic hydrophosphination in constructing various phosphorus compounds, which may initiate a new era in organo-phosphorus chemistry. (C) 2014 Elsevier B.V. All rights reserved.
Keywords: Alkynes; Asymmetric hydrophosphination; Hydrophosphination; Metal catalyzed hydrophosphination; Olefins; P-H bond addition

Correlation of the solid-state reactivities of racemic 2,4(6)-di-O-benzoyl-myo-inositol 1,3,5-orthoformate and its 4,4 `-bipyridine cocrystal with their crystal structures - Tamboli, Majid I.; Bahadur, Vir; Gonnade, Rajesh G.; Shashidhar, Mysore S. (Acta Crystallographica Section C-Structural Chemistry, 2014)
Racemic 2,4(6)-di-O-benzoyl-myo-inositol 1,3,5-orthoformate, C21H18O8, (1), shows a very efficient intermolecular benzoyl-group migration reaction in its crystals. However, the presence of 4,4 `-bipyridine molecules in its cocrystal, C21H18O8 center dot C10H8N2, (1)center dot BP, inhibits the intermolecular benzoyl-group transfer reaction. In (1), molecules are assembled around the crystallographic twofold screw axis (b axis) to form a helical self-assembly through conventional O-H center dot center dot center dot O hydrogen-bonding interactions. This helical association places the reactive C6-O-benzoyl group (electrophile, El) and the C4-hydroxy group (nucleophile, Nu) in proximity, with a preorganized El center dot center dot center dot Nu geometry favourable for the acyl transfer reaction. In the cocrystal (1)center dot BP, the dibenzoate and bipyridine molecules are arranged alternately through OH center dot center dot center dot N interactions. The presence of the bipyridine molecules perturbs the regular helical assembly of the dibenzoate molecules and thus restricts the solid-state reactivity. Hence, unlike the parent dibenzoate crystals, the cocrystals do not exhibit benzoyl-transfer reactions. This approach is useful for increasing the stability of small molecules in the crystalline state and could find application in the design of functional solids.
Keywords: acyl transfer; cocrystal; crystal structure; design of functional solids; helical assembly; hydrogen bonding; myo-inositol; solid-state reactions

Coupled cluster methods for autoionisation resonances - Sajeev, Y.; Ghosh, A.; Vaval, N.; Pal, S. (International Reviews in Physical Chemistry, 2014)
The quantum chemical calculation of autoionisation resonances in many-electron systems is a highly challenging task due to the ionisation continuum involved. Recently, advances were reported where conventionally used ab initio codes can be employed to compute autoionisation resonances. This is made possible by the use of analytical continuation tools such as complex scaling and complex absorbing potential (CAP) in the electronic structure codes. We review the formulation and the use of complex scaling and CAP in coupled cluster methods for the electron correlated calculation of energy position and autoionisation decay rate of resonance states. The application of analytically continued coupled cluster method for the correlated calculation of interatomic or intermolecular Coulombic decay process is also discussed.
Keywords: autoionisation resonances; complex absorbing potential; complex scaling; equation-of-motion coupled cluster; Fock space multi-reference-coupled cluster; intermolecular Coulombic decay

Crystal-to-crystal thermal phase transformation of polymorphs of isomeric 2,3-naphthalene diol ditoluates: mechanism and implications for molecular crystal formation and melting - Tamboli, Majid I.; Krishnaswamy, Shobhana; Gonnade, Rajesh G.; Shashidhar, Mysore S. (Crystal Growth & Design, 2014)
Isomeric para- (1) and meta- (2) ditoluate derivatives of naphthalene 2,3-diol exhibited polymorphism producing three (Forms 1I, 1II, 1III) and two (Forms 2I, 2II) polymorphs each, respectively, depending on the solvent and conditions of crystallization. Crystal forms 1I, 1II, and 2I could be obtained repeatedly, whereas crystal forms 1III and 2II were obtained (separately) in one of the crystallization experiments, each. All the crystal forms were stable at ambient conditions, except for Form 2II, which disintegrated to a powder over 45 days. In contrast, the ortho-ditoluate (3) of naphthalene 2,3-diol did not exhibit polymorphism; it yielded fibrous chiral crystals from different solvents/conditions. Crystal structure analysis of all these polymorphs revealed dominance of energetically similar weak intermolecular interactions such as CH center dot center dot center dot O, CH center dot center dot center dot pi, pi center dot center dot center dot pi, and their interplay in molecular aggregation resulting in polymorphic modifications. Differential scanning calorimetry (DSC), hot stage microscopy, single crystal and powder X-ray diffraction measurements revealed crystal-to-crystal thermal transformation of Forms 1I and 1II crystals to Form 1III crystals and Form 2II crystals to Form 2I crystals. The transformation of Form 1I and Form 1II crystals to Form 1III crystals can be viewed as progressive destabilization of the crystal lattice during heating and converting to metastable phase, whereas the conversion of Form 2II to Form 2I crystals can be considered as reorganization of an unstable crystalline phase to a stable crystalline phase. Hence comparative studies of the structure of stable, metastable, or transient crystals and crystal-to-crystal transformations involving these forms could aid in unraveling the process of crystallization.

Cu(II) conjugation along the transformation of a vitamin K-3 derivative to a dinaphthoquinone methide radical - Badave, Kirti D.; Patil, Shalaka S.; Khan, Ayesha A.; Srinivas, Darbha; Butcher, Raymond J.; Gonnade, Rajesh G.; Puranik, Vedavati G.; Pinjari, Rahul V.; Gejji, Shridhar P.; Rane, Sandhya Y. (New Journal of Chemistry, 2014)
1,1'-Methide-bi-vitamin K-3 (B) has been isolated as a dinaphthoquinone methide radical (DNQM) by the transformation of 1-imino(acetylhydrazino)-vitamin K-3 (A). The transformation follows a biomimetic activation pathway mediated via Cu(II) ion catalyzed oxidative coupling. Single crystal X-ray and electron spin resonance (ESR) experiments combined with density functional calculations elucidate the ``resonance structure'' of the DNQM radical (B). Fluorescence investigations reveal that DNQM facilitates interaction with the cysteine residue. As compared to the parent substrate, B shows a depletion in the level of GSH, triggering apoptosis in HeLa cells.

CVD synthesis of graphene nanoplates on MgO support - Jugade, Ravin M.; Sharma, Shalini; Gokhale, Suresh (Materials Science-Poland, 2014)
Synthesis of graphene directly on MgO has been carried out and the structural properties of the obtained material have been investigated. Few-layered graphene was produced by simple thermal decomposition of methane over MgO powder at 950 A degrees C in a CVD reactor. The samples were purified by 10 N HNO3 treatment, and studied by TEM, Raman spectroscopy, EDAX and SEM. TEM clearly indicated the formation of graphene. EDAX showed that the purified sample contained only carbon and no traces of MgO. The characteristic Raman features of graphene were also seen as D-band at 1316 cm(-1), G-band at 1602 cm(-1), and a small 2D-band at 2700 cm(-1) in the Raman spectra. The strong D-band suggests that the graphene possess large number of boundary defects. The small 2D-band indicates the formation of few-layered graphene.
Keywords: graphene; magnesium oxide; nanographene

Design and development of POCN-pincer palladium catalysts for C-H bond arylation of azoles with aryl iodides - Khake, Shrikant M.; Soni, Vineeta; Gonnade, Rajesh G.; Punji, Benudhar (Dalton Transactions, 2014)
{Well-defined and efficient POCN-ligated palladium complexes have been developed for the direct C H bond arylation of azoles with aryl iodides. The phosphinite-amine pincer ligands 1-(R2PO)-C6H4-3-((CH2NPr2)-Pr-i) 1R2POCNIPr2-H; R = `Pr (1a)

Design of efficient metal-free organic dyes having an azacyclazine scaffold as the donor fragment for dye-sensitized solar cells - Biswas, Abul Kalam; Barik, Sunirmal; Sen, Anik; Das, Amitava; Ganguly, Bishwajit (Journal of Physical Chemistry C, 2014)
The energy conversion efficiency of dye-sensitized solar cells derived from organic dye molecules has seen immense interest recently. In this work, we report a series of organic donor molecules with enhanced energy conversion efficiency using ?-spacers and cyanoacrylic acid as an anchoring group (2-6). Density functional theory (DFT) and time-dependent DFT calculations of these molecules have been performed to examine their electronic structures and absorption spectra before and after binding to the semiconductor titanium dioxide surface. The computational results suggest that dyes 4 and 6 have a larger driving force (Delta G(inject) = -1.66 and -1.80 eV, respectively) and light-harvesting efficiency (LHE = 0.99) in the series of donor molecules studied. Thus, these dyes should possess a larger short-circuit photocurrent density (J(sc)) compared to the other examined dyes. The reported Delta G(inject) (-1.62 eV) and LHE (0.98) for compound 1, calculated with the same level of theory, were lower than those of the designed 4 and 6 dyes. Furthermore, the DFT calculations showed that the open-circuit photovoltage (V-oc) is improved with the vertical dipole moment and number of photoinjected electrons for 4 and 6. Dyes 4 and 6 are expected to exhibit high solar-energy-to-electricity conversion.

Design, synthesis and cytotoxicity of novel N-benzylpiperidin-4-one oximes on human cervical cancer cells - Dindulkar, Someshwar D.; Bhatnagar, Ira; Gawade, Rupesh L.; Puranik, Vedavati G.; Kim, Se-Kwon; Anh, Dong Hyun; Parthiban, Paramasivam; Jeong, Yeon Tae (Journal of Chemical Sciences, 2014)
A series of fifteen diversified N-benzylpiperidin-4-one oximes were synthesized and characterized by their NMR spectral data. Additionally, single-crystal XRD analysis was performed for the representative symmetrically and unsymmetrically substituted molecules. All the synthesized oximes from unsymmetrical ketones existed as E-isomer as witnessed by their NMR and XRD data. Among the synthesized target compounds that evaluated for their in vitro cytotoxicity against human cervical carcinoma (HeLa) cells, five compounds were potent with IC50 < 17 mu M. 1-Benzyl-2,6-bis(4-isopropylphenyl)-3-methylpiperidin-4-one oxime 3c with an IC50 of 13.88 mu M was found to be the best active compound as depicted by the microscopic analysis.
Keywords: Cytotoxicity; HeLa cells; N-benzylpiperidin-4-one oximes; single-crystal XRD

Determination of optimum values of descriptors to set filters for synthetic tri-pyrrole derivatives (prodiginines) against multi drug resistant strain of plasmodium falciparum - Masand, Vijay H.; Mahajan, Devidas T.; Pourbasheer, Eslam; Hadda, Taibi Ben; Chauhan, Harsh; Gajbhiye, Jayant M.; Alafeefy, A. M. (Current Research in Drug Discovery, 2014)
Abstract: In the present study, we have carried out extensive non-linear Quantitative-Structure Activity Relationship (QSAR) analysis to correlate in vitro anti-malarial activity against multi drug resistant strain of Plasmodium falciparum. Forty-three synthetic prodiginines with different structural features were used for their potential antimalarial activity. Linear, bilinear, biexponential and parabolic equations were developed. These equations were compared to determine the optimum values of descriptors for very useful and easily interpretable descriptors. The optimum values of these descriptors could be helpful in finding and optimizing a good lead compound. Obtained correlations reveal that various factors like lipophilicity, molecular weight and number of bonds have non-linear relation with the anti-malarial activity. Keywords: Prodiginines, Anti-Malarial Activity, Optimum/Desirability Values, Hybrid Inverse-QSAR

Diels-alder reaction of tropones with arynes: synthesis of functionalized benzobicyclo[3.2.2]nonatrienones - Thangaraj, Manikandan; Bhojgude, Sachin Suresh; Bisht, Rajesh H.; Gonnade, Rajesh G.; Biju, Akkattu T. (Journal of Organic Chemistry, 2014)
A new procedure for the mild, practical, and scalable Diels–Alder reaction of tropones with arynes is reported. Differently substituted tropones undergo selective [4 + 2] cycloaddition with arynes generated in situ by the fluoride-induced 1,2-elimination of 2-(trimethylsilyl)aryl triflates, allowing the formation of functionalized benzobicyclo[3.2.2]nonatrienone derivatives in moderate to good yields. In addition, the photophysical properties of the cycloadducts are presented.

Differential antibiosis against helicoverpa armigera exerted by distinct inhibitory repeat domains of capsicum annuum proteinase inhibitors - Joshi, Rakesh S.; Gupta, Vidya S.; Giri, Ashok P. (Phytochemistry, 2014)
Plant defensive serine proteinase inhibitors (Pis) are known to have negative impact on digestive physiology of herbivore insects and thus have a crucial role in plant protection. Here, we have assessed the efficacy and specificity of three previously characterized inhibitory repeat domain (IRD) variants from Capsicum annuum PIs viz., IRD-7, -9 and -12 against gut proteinases from Helicoverpa armigera. Comparative study of in silico binding energy revealed that IRD-9 possesses higher affinity towards H. armigera serine proteinases as compared to IRD-7 and -12. H. armigera fed on artificial diet containing 5 TIU/g of recombinant IRD proteins exhibited differential effects on larval growth, survival rate and other nutritional parameters. Major digestive gut trypsin and chymotrypsin genes were down regulated in the IRD fed larvae, while few of them were up-regulated, this indicate alterations in insect digestive physiology. The results corroborated with proteinase activity assays and zymography. These findings suggest that the sequence variations among Pis reflect in their efficacy against proteinases in vitro and in vivo, which also could be used for developing tailor-made multi-domain inhibitor gene(s). (C) 2014 Elsevier Ltd. All rights reserved.
Keywords: Capsicum annuum; Helicoverpa armigera; Inhibitory repeat domain; Proteases; Proteinase inhibitors

Differential transcriptional activity of SAD, FAD2 and FAD3 desaturase genes in developing seeds of linseed contributes to varietal variation in alpha-linolenic acid content - Rajwade, Ashwini V.; Kadoo, Narendra Y.; Borikar, Sanjay P.; Harsulkar, Abhay M.; Ghorpade, Prakash B.; Gupta, Vidya S. (Phytochemistry, 2014)
Linseed or flax (Linum usitatissimum L.) varieties differ markedly in their seed a-linolenic acid (ALA) levels. Fatty acid desaturases play a key role in accumulating ALA in seed. We performed fatty acid (FA) profiling of various seed developmental stages of ten Indian linseed varieties including one mutant variety. Depending on their ALA contents, these varieties were grouped under high ALA and low ALA groups. Transcript profiling of six microsomal desaturase genes (SAD1, SAD2, FAD2, FAD2-2, FAD3A and FAD3B), which act sequentially in the fatty acid desaturation pathway, was performed using real-time PCR. We observed gene specific as well as temporal expression pattern for all the desaturases and their differential expression profiles corresponded well with the variation in FA accumulation in the two groups. Our study points to efficient conversion of intermediate FAs [stearic (SA), oleic (OA) and linoleic acids (LA)] to the final product, ALA, due to efficient action of all the desaturases in high ALA group. While in the low ALA group, even though the initial conversion up to OA was efficient, later conversions up to ALA seemed to be inefficient, leading to higher accumulation of OA and LA instead of ALA. We sequenced the six desaturase genes from the ten varieties and observed that variation in the amino acid (AA) sequences of desaturases was not responsible for differential ALA accumulation, except in the mutant variety TL23 with very low (<2%) ALA content. In TL23, a point mutation in the FAD3A gene resulted into a premature stop codon generating a truncated protein with 291 AA. (C) 2013 Elsevier Ltd. All rights reserved.
Keywords: ALA; Fatty acid desaturases; Fatty acids; Flax; Gene expression; Linseed

Disordered mesoporous TiO2-xNx+Nano-Au: an electronically integrated nanocomposite for solar H-2 generation - Sivaranjani, Kumarsrinivasan; Rajaambal, Sivaraman; Das, Tanmay; Roy, Kanak; Bhattacharyya, Somnath; Gopinath, Chinnakonda S. (ChemCatChem, 2014)
We report on H-2 generation by photocatalysis driven by simulated white light by electronically integrated Au nanoparticles with multifunctional, disordered mesoporous TiO2-xNx (Au-NT) nanocomposites. Solar H-2 generation (1.5 mmolh(-1)g(-1)) from aqueous methanol has been demonstrated with Au-NT nanocomposites. The water splitting activity of Au-NT is attributed to the 21.1 ps lifetime of charge carriers observed from fluorescence lifetime measurements, which indicates a high electron-injection efficiency from nano-Au to the conduction band of TiO2, and hence charge separation as well as utilization. This is directly supported by the observation of a high photoluminescence emission intensity with Au-NT that highlights the energy transfer from nano-Au to TiO2. The p-n heterojunction observed between the Au (001) and TiO2 (101) facets helps to-wards the higher charge separation and their utilization. A low mesochannel depth (< 10 nm) associated with disordered mesoporous TiO2-xNx helps the charge carriers to move towards the surface for redox reactions and hence charge utilization. Visible-light absorption, as a result of the surface plasmon resonance of nano-Au, is observed in a broad range between 500 and 750 nm, which helps in harvesting visible-light photons. Finally, electronically integrated nano-Au with TiO2-xNx in Au-NT is evident from Raman and X-ray photoelectron spectroscopy measurements. All of these factors help to achieve a high rate of H-2 production. It is likely that a higher rate of H-2 production than that reported here is feasible by strategically locating Au clusters in porous TiO2 to generate hot spots through electronic integration.
Keywords: heterogeneous catalysis; Hydrogen; mesoporous materials; photochemistry; water splitting

Distinctive PdCl2-mediated transformation of Fe-based metallogels into metal-organic frameworks - Aiyappa, Harshitha Barike; Saha, Subhadeep; Garai, Bikash; Thote, Jayshri; Kurungot, Sreekumar; Banerjee, Rahul (Crystal Growth & Design, 2014)
Simple, efficient conversion of viable Fe3+-based metallogels into Fe-metal-organic frameworks (MOFs) has been achieved by PdCl2-mediated gel degradation. The metallogels and the resulting MOFs have been characterized, and a probable mechanism for the event has been elucidated.

Donor decomposition by lewis acids in Ziegler-Natta catalyst systems: a computational investigation - Kumawat, Jugal; Gupta, Virendra Kumar; Vanka, Kumar (Organometallics, 2014)
The development of new donors (Lewis bases, usually containing oxygen atoms) is one of the chief areas of research in Ziegler-Natta (ZN) olefin polymerization systems. The addition of such donors has led to improvement in the activity and selectivity of ZN systems. However, in order for the donor to be effective, it has to be chemically stable and resistant to decomposition by Lewis acidic species such as AlEt3. Discussed in the current work is the chemical stability of different ester donors, including aromatic benzoate donors and the silyl ester-a promising new donor class in ZN systems. Full quantum chemical calculations with density functional theory (DFT) indicate that esters can undergo decomposition through different pathways upon interaction with species such as the AlEt3 dimer: Al2Et6. Moreover, the studies show that the active, supported titanium catalyst species can cause donor decomposition and, in fact, is likely to be the greater threat to donor decomposition than Al2Et6. This explains why the addition of excess donors can lead to the poisoning of the active site in ZN systems. We have also computationally investigated means of improving the silyl ester donors in order to make them more robust and resilient to donor decomposition by Al2Et6 and the supported active titanium species.

Effect of method of preparation on hydrodesulphurization activity of Co- or Ni-promoted MoS2/SBA-15 catalysts - Garg, Shelu; Soni, Kapil; Prasad, V. V. D. N.; Kumar, Manoj; Bhaskar, Thallada; Gupta, J. K.; Dhar, G. Murali; Gopinath, Chinnakonda S. (Journal of Chemical Sciences, 2014)
Ordered mesoporous material SBA-15 was synthesized and used as a support for the preparation of molybdenum sulphide catalysts through precipitation from homogeneous solution (PFHS) technique with the Mo content varying from 2-12 wt%. The prepared catalysts were evaluated for thiophene hydrodesulphurizadon catalytic activities at 400 degrees C. Catalysts prepared through PFHS method resulted in highly dispersed MoS2 catalysts, which were inferred from powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), low temperature oxygen chemisorptions (LTOC) and BET surface area analysis. The relationship between XPS intensity ratio, oxygen chemisorption and catalytic activities is discussed in terms of highly dispersed nano particles of MoS2 and its consequence in accommodating more promoted atoms at the edge sites.
21st National Symposium on Catalysis (CATSYMP), CSIR Indian Inst Chem Technol, Hyderabad, INDIA, FEB 11-13, 2013
Keywords: HDS; MoS2; PFHS method; promotional effects; SBA-15

Effect of self-assembly on triiodide diffusion in water based polymer gel electrolytes: an application in dye solar cell - Soni, S. S.; Fadadu, K. B.; Vekariya, R. L.; Debgupta, Joyashish; Patel, K. D.; Gibaud, A.; Aswal, Vinod K. (Journal of Colloid and Interface Science, 2014)
The preparation of ordered polymer gels from the amphiphilic block copolymers, Pluronic (R) F77, P123 and polyethylene glycol in the presence of ionic liquid, iodine and organic additives is presented. At 35%(w/w) concentration these copolymers (F77 and P123) self-assembled into cubic liquid crystalline phase in aqueous solution and characterized by using SAXS and AFM measurements. The effects of micellar aggregation formed by polymers on the ionic transport and triiodide diffusion have been studied by electro-chemistry and SANS experiments. The ionic migration or triiodide diffusion through these polymer gels is found to be affected by the PEO/PPO content in the polymer backbone. These gels were successfully employed as an electrolyte in a dye sensitized solar cell. A remarkable solar to electricity conversion efficiency and good stability was obtained using Pluronic (R) F77 based gel, which is attributed to its thermoreversible sol to gel transition. (C) 2014 Elsevier Inc. All rights reserved.
Keywords: Amphiphilic block copolymer; Dye solar cell; Micellar nanochannels; SANS; SAXS; Self-assembly; Water based gel electrolytes

Effect of SnO2/Al2O3 ratio of Si-based MFI on its acidity and hydrophobicity: application in selective hydroxyalkylation of p-cresol - Garade, Ajit C.; Malwadkar, A. V.; Niphadkar, P. S.; Jha, Ratnesh Kumar; Joshi, P. N.; Rode, C. V. (Catalysis Communications, 2014)
Silica based MR type molecular sieves with various SnO2/Al2O3 ratios were synthesized from gels having molar compositions SiO2:xSnO(2):yAl(2)O(3):0.23(TPA)(2)O:35H(2)O where 0 <= x <= 0.02 and 0 <= y <= 0.01. Recyclable, Al-free Sn-MFI catalyst showed 31% conversion of formaldehyde with 100% selectivity to 2,2'-methylenebis(4-methylphenol) in hydroxyalkylation of p-cresol with formaldehyde on account of moderate acidity and higher hydrophobicity. (C) 2013 Elsevier B.A. All rights reserved.
Keywords: Al-27 MAS NMR; Hydroxyalkylation; Molecular sieves; p-Cresol; Stannosilicate

Efficient synthesis of 9-aryldihydrophenanthrenes by a cascade reaction involving arynes and styrenes - Bhojgude, Sachin Suresh; Bhunia, Anup; Gonnade, Rajesh G.; Biju, Akkattu T. (Organic Letters, 2014)
A mild, general, and transition-metal-free protocol for the synthesis of 9,10-dihydrophenanthrenes is reported. The aryne generated by the fluoride-induced,1,2-elimination of 2-(trimethylsilyl)aryl triflates undergoes an efficient cascade reaction initiated by the Diels-Alder reaction with the differently substituted styrenes leading to the formation of 9-aryl-9,10-dihydrophenanthrene derivatives in moderate to good yields.

Efficient synthesis of glycerol carbonate/glycidol using 1,8-diazabicyclo [5.4.0] undec-7-ene (DBU) based ionic liquids as catalyst - Munshi, Mudassir K.; Biradar, Pradeep S.; Gade, Swapna M.; Rane, Vilas H.; Kelkar, Ashutosh A. (RSC Advances, 2014)
Transesterification of dimethyl carbonate with glycerol to glycerol carbonate has been catalyzed efficiently using basic ionic liquids as catalysts. Activity of all the ILs tested is very high and the best result (96% conversion with 82% selectivity to glycerol carbonate and 18% selectivity to glycidol) was obtained using IL1 as catalyst. The effect of catalyst loading has significant influence on the selectivity pattern. The higher activity of the ionic liquid is explained with a plausible mechanism based on the co-operative effect of both cation and anion.

Electrokinetic properties of PMAA functionalized NiFe2O4 nanoparticles synthesized by thermal plasma route - Bhosale, Shivaji V.; Mhaske, Pravin; Kanhe, N.; Navale, A. B.; Bhoraskar, S. V.; Mathe, V. L.; Bhatt, S. K. (Solid State Physics: Proceedings of the 58th Dae Solid State Physics Symposium 2013, PTS A & B, 2014)
The magnetic nickel ferrite (NiFe2O4) nanoparticles with an average size of 30nm were synthesised by Transferred arc DC Thermal Plasma route. The synthesized nickel ferrite nanoparticles were characterized by TEM and FTIR techniques. The synthesized nickel ferrite nanoparticles were further functionalized with PMAA (polymethacrylic acid) by self emulsion polymerization method and subsequently were characterized by FTIR and Zeta Analyzer. The variation of zeta potential with pH was systematically studied for both PMAA functionalized (PNFO) and uncoated nickel ferrite nanoparticles (NFO). The IEP (isoelectric points) for PNFO and NFO was determined from the graph of zeta potential vs pH. It was observed that the IEP for NFO was at 7.20 and for PNFO it was 2.52. The decrease in IEP of PNFO was attributed to the COOH functional group of PMAA.
Keywords: IEP; NiFe2O4; PMAA; Thermal plasma; Zeta potential

Electronic structure-sunlight driven water splitting activity correlation of (Zn1-yGay)(O1-zNz) - Rajaambal, Sivaraman; Yadav, A. K.; Jha, Shambhu Nath; Bhattacharyya, Dibyendu; Gopinath, Chinnakonda S. (Physical Chemistry Chemical Physics, 2014)
(Zn1-yGay)(O1-zNz) (y <= 0.10; z <= 0.15) solid solutions have been investigated for their electronic structure and visible light photocatalytic activity, and a correlation was found between them. (Zn1-yGay)(O1-zNz) with ZnO as the major component have been synthesized by a solution combustion method in 10 minutes using simple raw materials. The local structures of Zn K edge and Ga K edge, and changes in the chemical environment with the incorporation of Ga and N in ZnO were determined by EXAFS study. EXAFS and XRD results suggested the dissolution of GaN in the ZnO lattice. The homogeneity of the solid solution was demonstrated from HRTEM studies. Photoluminescence studies revealed the creation of a new band at the top of the ZnO valence band (VB), and thus the broadening of the VB of (Zn1-yGay)(O1-zNz) or a decrease in the band gap was attributed to the origin of visible light absorption. UV-Vis spectral studies showed light absorption up to 550 nm, which directly supports the VB broadening. Predominant oxygen vacancies and high photocorrosion observed for ZnO were fully suppressed for (Zn1-yGay)(O1-zNz) , indicating the minimization of defects, and thus more sustainability under irradiation conditions. The bare solid solution exhibited reasonable and promising activity for solar hydrogen evolution and photoelectrochemical current generation at 0 V. The present work explained factors such as the preparation method, single phase structure with the stabilization of integral parts, homogeneity in the structure, compensation of oxygen vacancies, and suppression of the density of recombination centres that play a pivotal role in realizing solar energy harvesting.

Electronically and catalytically functional carbon cloth as a permeable and flexible counter electrode for dye sensitized solar cell - Tathavadekar, Mukta; Biswal, Mandakini; Agarkar, Shruti A.; Giribabu, Lingamallu; Ogale, Satishchandra (Electrochimica Acta, 2014)
In this work we demonstrate that a conducting carbon cloth obtained by one-step pyrolysis of easily available cellulose fabric competes favorably with the commonly employed expensive platinum/FTO system as a counter electrode for dye sensitized solar cell (DSSC). In view of the low carbonization temperature (1000 degrees C) which forbids full graphitization, the nature of carbon in this case is represented by topologically randomly assembled nanoscale graphene units (turbostratic carbon). This morphology has high density of edge states and oxygen containing surface groups rendering multitude of catalytic sites for the reduction of I-3(-). Moreover the cloth is permeable to the dye and/or liquid electrolyte and its absorption properties also help retain the electrolyte. A fairly high efficiency of 5.8% is achieved using such cloth as a counter electrode as against 7% with the conventional Pt/FTO system. Moreover, the permeable property of the cloth eliminates a complete step of drilling hard TCO substrates for final dispensing of electrolyte into the device and the sealing process is also facile. In fact even the dye can be dispensed through the cloth. Finally, the flexibility of the carbon cloth can adapt easily to flexible/wearable DSSC designs. (C) 2014 Elsevier Ltd. All rights reserved.
Keywords: conducting carbon cloth; counter electrode; DSSC; without drilling

Electrostatics determine vibrational frequency shifts in hydrogen bonded complexes - Dey, Arghya; Mondal, Sohidul Islam; Sen, Saumik; Ghosh, Debashree; Patwari, G. Naresh (Physical Chemistry Chemical Physics, 2014)
The red-shifts in the acetylenic C-H stretching vibration of C-H center dot center dot center dot X (X = O, N) hydrogen-bonded complexes increase with an increase in the basicity of the Lewis base. Analysis of various components of stabilization energy suggests that the observed red-shifts are correlated with the electrostatic component of the stabilization energy, while the dispersion modulates the stabilization energy.

Engineering of the tat pathway and chaperons - Ghosh, Deepanjan; Ramasamy, Sureshkumar (Acta Crystallographica A‐Foundation and Advances, 2014)
Keywords: Protein transport; Signal sequence; Tat Pathway

Enhanced catalytic activity of polyethylenedioxythiophene towards tri-iodide reduction in DSSCs via 1-dimensional alignment using hollow carbon nanofibers - Anothumakkool, Bihag; Game, Onkar S.; Bhange, Siddheshwar N.; Kumari, Tanya; Ogale, Satishchandra B.; Kurungot, Sreekumar (Nanoscale, 2014)
Here, we report a highly conducting 1-dimensionally (1-D) aligned polyethylenedioxythiophene (PEDOT) along the inner and outer surfaces of a hollow carbon nanofiber (CNF) and its application as a counter electrode in a dye sensitized solar cell (DSSC). The hybrid material (CP-25) displays a conversion efficiency of 7.16% compared to 7.30% for the standard Pt counter electrode, 4.48% for bulk PEDOT and 5.56% for CNF. The enhanced conversion efficiency of CP-25 is attributed to the accomplishment of high conductivity and surface area of PEDOT through the 1-D alignment compared to its bulk counterpart. Reduced charge transfer resistance and high conductivity of CP-25 could be proven by cyclic voltammetry, impedance analysis and Tafel experiments. Further, through a long-term stability test involving efficiency profiling for 20 days, it is observed that CP-25 possesses excellent durability compared to the bulk PEDOT.

Enhancement in the field emission behavior of graphene in N-2/O-2 high vacuum ambience - Suryawanshi, S. R.; Kolhe, Pankaj S.; Gavhane, D. S.; Patil, S. S.; Chavan, P. G.; More, Mahendra A.; Late, Dattatray J. (2014 27th International Vacuum Nanoelectronics Conference (IVNC), 2014)
Herein we report, pressure dependent field emission (FE) behaviour of a few-layer graphene emitter. Gas dependent FE properties have been investigated in ultra high vacuum (UHV), as well as in N-2 and O-2 ambience at base pressure similar to 1x10(-6) torr. Interestingly, the graphene emitter when operated in N-2/O-2 ambience exhibits lower turn-on field and higher emission current density, as compared to the UHV conditions. The emission current stability investigated at preset value of similar to 1 mu A over the period of more than 2 hrs is found better in the N2 ambience and is characterized by fewer fluctuations, in contrast to the behaviour in the O-2 ambience. The observed enhanced electron emission behavior in N-2/O-2 ambience is attributed to modulation of the work function of graphene emitter.
27th International Vacuum Nanoelectronics Conference (IVNC), Engelberg, SWITZERLAND, JUL 06-10, 2014
Keywords: graphene; Pressure Dependent Field Emission

Enhancement of CO2 uptake in iso-reticular Co based zeolitic imidazolate frameworks via metal replacement - Panda, Tamas; Gupta, Krishna M.; Jiang, Jianwen; Banerjee, Rahul (CrystEngComm, 2014)
Three Co based Zeolitic Imidazolate Frameworks (Co-ZIF-68, -69 and -81) which adopt a GME topology with high porosity have been synthesized. These Co-ZIFs show high CO2 (273 K/298 K) uptake compared to their isostructural Zn based analogues, which has been proved experimentally as well as by ab initio calculations.

Evaluation of genetic variability in Symplocos laurina Wall. from two biodiversity hotspots of India - Bhagwat, Rasika M.; Banu, Sofia; Dholakia, Bhushan B.; Kadoo, Narendra Y.; Lagu, Meena D.; Gupta, Vidya S. (Plant Systematics and Evolution, 2014)
Symplocos laurina Wall., an important medicinal tree species, is one of the pioneering plants for establishment of shola forest ecosystem. We analyzed 208 accessions of S. laurina from 13 populations belonging to three ecoregions in India namely, Western Ghats, Eastern Ghats and Northeast India, to comment on the genetic diversity and population structure of the species. Of the 100 inter simple sequence repeat primers screened, eight were selected based on their clear and reproducible polymorphic patterns. These eight ISSR primers produced on an average 1,014 bands from 208 accessions, of which 6.58 % were rare bands, 55.96 % were shared bands and 37.46 % were similar bands. The primers, UBC835 and UBC880, amplified the highest number of polymorphic loci (16), while the primer UBC852 amplified the least number of amplicons (9). The values for total genetic diversity (H-T) and the average heterozygosity (H-S) were 0.3407 and 0.2263, respectively; while the coefficient of genetic differentiation (G(ST)) was 0.3358. Within-population variance was higher (68 %) than among-population variance (17 %), indicating high intra-population genetic diversity. These populations were grouped according to their geographical location in cluster analysis. Mantel test also showed significant positive correlation between genetic and geographical distances. The present study revealed the importance of the Palghat gap in South India in shaping the distribution of genetic diversity in S. laurina.
Keywords: Biodiversity hotspots; Genetic diversity; ISSR; Palghat gap; Symplocos laurina

Evaluation of n-type ternary metal oxide NiMn2O4 nanomaterial for humidity sensing - Gawli, Yogesh; Badadhe, Satish S.; Basu, Aniruddha; Guin, Debanjan; Shelke, Manjusha V.; Ogale, Satishchandra (Sensors and Actuators B-Chemical, 2014)
Synthesis of mono-dispersed oleic acid (OA) capped NiMn2O4 (NMO) nanoparticles and their use for humidity sensing is reported. Oleic acid capped NMO (NMO-cOA) nanoparticles are synthesized from nickel oleate and manganese oleate complex. NiMn2O4 is obtained by removing oleic acid capping at 500 degrees C in air. X-ray diffraction analysis shows formation of pure NiMn2O4 phase which is also confirmed by HRTEM-SAED analysis. The TEM analysis also shows that the nanoparticles are nearly mono-dispersed. Doctor bladed films of NMO nanoparticles are seen to exhibit excellent humidity sensing property. The resistivity is seen to change by two orders with humidity change from 11% RH to 92% RH with fairly good linearity over the entire range. The response and recovery times are also fast. (C) 2013 Elsevier B.V. All rights reserved.
Keywords: Humidity; Impedance; Nanoparticles; NiMn2O4; Oleic acid; Sensor

Extracellular biosynthesis of gadolinium oxide (Gd2O3) nanoparticles, their biodistribution and bioconjugation with the chemically modified anticancer drug taxol - Khan, Shadab Ali; Gambhir, Sanjay; Ahmad, Absar (Beilstein Journal of Nanotechnology, 2014)
As a part of our programme to develop nanobioconjugates for the treatment of cancer, we first synthesized extracellular, protein-capped, highly stable and well-dispersed gadolinium oxide (Gd2O3) nanoparticles by using thermophilic fungus Humicola sp. The biodistribution of the nanoparticles in rats was checked by radiolabelling with Tc-99m. Finally, these nanoparticles were bioconjugated with the chemically modified anticancer drug taxol with the aim of characterizing the role of this bioconjugate in the treatment of cancer. The biosynthesized Gd2O3 nanoparticles were characterized by UV-vis spectroscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoemission spectroscopy (XPS). The Gd2O3-taxol bioconjugate was confirmed by UV-vis spectroscopy and fluorescence microscopy and was purified by using high performance liquid chromatography (HPLC).
Keywords: bioconjugation; biodistribution; gadolinium oxide; humicola sp; transmission electron microscopy

Facile esterification of carboxylic acid using amide functionalized benzimidazolium dicationic ionic liquids - Muskawar, Prashant Narayan; Thenmozhi, K.; Gajbhiye, Jayant M.; Bhagat, Pundlik Rambhau (Applied Catalysis A-General, 2014)
Herein, we report the synthesis of a new series of amide functionalized dicationic benzimidazolium based ionic liquids (DBimILs) and appraised their efficacy towards perceptive esterification of carboxylic acids with alkyl/allyl/aryl halides in presence of triethylamine. The amide groups present in this new series of DBimILs are expected to form hydrogen bonding with the carboxylic acids and this could facilitate the esterification reactions under mild conditions devoid of any added catalyst or organic solvent. The plausible mechanism for the enhanced catalytic activity in presence of this new series of ILs has been proposed. The corresponding alkyl/allyl/aryl esters isolated from this reaction were of high purity after simple extraction, which wipe out the necessity for further purification. This protocol addresses clean methodology and the efficient recyclability as well as reusability of the catalyst. (C) 2014 Elsevier B.V. All rights reserved.
Keywords: Benzimidazolium; Dicationic ionic liquids; Esterification; Homogenous catalysis

Facile gamma radiolytic synthesis of synergistic Co3O4-rGO nanocomposite: direct use in photocatalytic water splitting - Gupta, Bhavana; Melvin, Ambrose A.; Matthews, Tom; Dash, S.; Tyagi, A. K. (Materials Research Express, 2014)
Nanostructured Co3O4 was synthesized through a gamma (gamma)-radiolysis technique using alcoholic (iso-propanol) salt solutions of cobalt ions with and without suspended graphene oxide (GO) nanoparticles, respectively. Formation of Co3O4 accompanied with GO reduction takes place simultaneously (in situ) upon.-ray exposure carried out at a rate of 5.1 KGy h(-1). Reduction of GO and formation of Co3O4 were confirmed by XRD, Raman and UV-vis spectroscopy. XRD and HRTEM results supports the embedding of nano-crystalline Co3O4 in an amorphous matrix. Relatively larger crystallites of cobalt oxide obtained in the presence of rGO proved to be a decisive supporting material for the directional growth of Co3O4. Electrochemical characterization established the fact that rGO is indeed considered as a proficient medium for electrochemical electron transfer process. Photo-assisted H-2 generation studies using Co3O4 and Co3O4-rGO nano-composite yielded 3 and 30 mu mol h(-1) g(-1) of hydrogen (H-2) generation, respectively, supports the action of rGO as an electron trap.
Keywords: nano cobalt oxide; photocatalytic hydrogen production; Reduced graphene oxide

Facile method for the synthesis of Co-core Au-shell nanohybrid - Sardar, Debasmita; Neogi, S. K.; Bandyopadhyay, Sanjoy; Satpati, Biswarup; Jain, Ruchi; Gopinath, Chinnakonda S.; Bala, Tanushree (New Journal Of Chemistry, 2014)
Heterostructured Co-Au core-shell nanoparticles have been synthesized by reducing AuCl4- ions on cobalt nanoparticles after a minor but effective modification of cobalt surface by an amine. The core shell morphology is emphatically confirmed by thorough investigation through UV-Vis spectroscopy, X-ray photoelectron spectroscopy (XPS), and transmission electron microscopic analysis (TEM). The chemical composition and topography were determined using STEM-HAADF analysis and EFTEM imaging. Fourier transform infrared (FTIR) spectroscopy confirms the surface modification of Co nanoparticles and the interactions involved between the ligands and the core and shell metals at various steps of the synthetic process. The magnetic properties confirm the material to be superparamagnetic in nature.

Facile single-step synthesis of nitrogen-doped reduced graphene oxide-Mn3O4 hybrid functional material for the electrocatalytic reduction of oxygen - Bag, Sourav; Roy, Kanak; Gopinath, Chinnakonda S.; Raj, C. Retna (ACS Applied Materials & Interfaces, 2014)
Development of efficient electrocatalyst based on non-precious metal that favors the four-electron pathway for the reduction of oxygen in alkaline fuel cell is a challenging task. Herein, we demonstrate a new facile route for the synthesis of hybrid functional electrocatalyst based on nitrogen-doped reduced graphene oxide (N-rGO) and Mn3O4 with pronounced electrocatalytic activity towards oxygen reduction reaction (ORR) in alkaline solution. The synthesis involves one-step in situ reduction of both graphene oxide (GO) and Mn(VII), growth of Mn3O4 nanocrystals and nitrogen doping onto the carbon framework using a single reducing agent, hydrazine. The X-ray photoelectron (XPS), Raman and FTIR spectral, and X-ray diffraction measurements confirm the reduction of GO and growth of nanosized Mn3O4. The XPS profile reveals that N-rGO has pyridinic (40%), pyrrolic (53%), and pyridine N oxide (7%) types of nitrogen. The Mn3O4 nanoparticles are single crystalline and randomly distributed over the wrinkled N-rGO sheets. The hybrid material has excellent ORR activity and it favors the 4-electron pathway for the reduction of oxygen. The electrocatalytic performance of the hybrid catalyst is superior to the N-rGO, free Mn3O4 and their physical mixture. The hybrid material shows an onset potential of -0.075 V, which is 60-225 mV less negative than that of the other catalyst tested. It has excellent methanol tolerance and high durability. The catalytic current density achieved with the hybrid material at 0.1 mg cm(-2) is almost equivalent to that of the commercial Pt/C (10%). The synergistic effect of N-rGO and Mn3O4 enhances the overall performance of the hybrid catalyst. The nitrogen in N-rGO is considered to be at the interface to bridge the rGO framework and Mn3O4 nanoparticles and facilitates the electron transfer.
Keywords: electrocatalysis; hybrid material; Mn3O4; nitrogen-doped graphene; oxygen reduction; synergistic effect

Facile synthesis of the isoquinoline alkaloids doryanine and oxyhydrastinine - Jangir, Ravi; Gadre, Smita R.; N. P. Argade (Synthesis-Stuttgart, 2014)
Starting from 4,5-(methylenedioxy)homophthalic acid, a concise and efficient synthesis of the isoquinoline alkaloids dory-anine and oxyhydrastinine is described via the corresponding homophthalimide utilizing a one-pot regioselective reductive dehydration and catalytic hydrogenation pathway.
Keywords: dehydration; homophthalic acid; homophthalimide; isoquinoline alkaloids; regioselective reduction

Ferromagnetic tetranuclear Cu(II) complex: catecholase and phenoxazinone synthase activities - Mitra, Merry; Kundu, Tanay; Kaur, Gurpreet; Sharma, Gyaneswar; Choudhury, Angshuman Roy; Singh, Yogesh; Ghosh, Rajarshi (Acta Crystallographica A‐Foundation and Advances, 2014)
Keywords: catalysis; Ferromagnetic; Tetranuclear copper

Fe-TAML encapsulated inside mesoporous silica nanoparticles as peroxidase mimic: femtomolar protein detection - Kumari, Sushma; Dhar, Basab B.; Panda, Chakadola; Meena, Abhishek; Sen Gupta, Sayam (ACS Applied Materials & Interfaces, 2014)
Peroxidase, such as horseradish peroxidase (HRP), conjugated to antibodies are routinely used for the detection of proteins via an ELISA type assay in which a critical step is the catalytic signal amplification by the enzyme to generate a detectable signal. Synthesis of functional mimics of peroxidase enzyme that display catalytic activity which far exceeds the native enzyme is extremely important for the precise and accurate determination of very low quantities of proteins (fM and lower) that is necessary for early clinical diagnosis. Despite great advancements, analyzing proteins of very low abundance colorimetrically, a method that is most sought after since it requires no equipment for the analysis, still faces great challenges. Most reported HRP mimics that show catalytic activity greater than native enzyme (similar to 40-fold) are based on metal/metal-oxide nanoparticles such as Fe3O4. In this paper, we describe a second generation hybrid material developed by us in which approximately 25 000 alkyne tagged biuret modified Fetetraamido macrocyclic ligand (Fe-TAML), a very powerful small molecule synthetic HRP mimic, was covalently attached inside a 40 nm mesoporous silica nanopartide (MSN). Biuret-modified Fe-TAMLs represent one of the best small molecule functional mimics of the enzyme HRP with reaction rates in water close to the native enzyme and operational stability (pH, ionic strength) far exceeding the natural enzyme. The catalytic activity of this hybrid material is around 1000-fold higher than that of natural HRP and 100-fold higher than that of most metal/metal oxide nanoparticle based HRP mimics reported to date. We also show that using antibody conjugates of this hybrid material it is possible to detect and, most importantly, quantify femtomolar quantities of proteins colorimetrically in an ELISA type assay. This represents at least 10-fold higher sensitivity than other colorimetric protein assays that have been reported using metal/metal oxide nanoparticles as HRP mimic. Using a human IgG expressing cell line, we were able to demonstrate that the protein of interest human IgG could be detected from a mixture of interfering proteins in our assay.
Keywords: colorimetrically; immuno assay; MSN; peroxidase mimic; signal amplification

First iodocyclization reaction of allene-thioureas: an efficient approach to bicyclic beta-lactams - Garud, Dinesh R.; Jadhav, Amol R.; Lahore, Santosh V.; Kahar, Nilesh M.; Joshi, Rohini R.; Joshi, Ramesh A.; Koketsu, Mamoru (Tetrahedron Letters, 2014)
The regioselective iodocyclization reaction of allene-thioureas is described, for the first time, for the synthesis of bicyclic beta-lactams. The substitution at the allenyl part heavily influenced the iodocyclization reaction. The iodocyclization reaction of the unsubstituted allene-thioureas afforded six-membered 3-thia-1-dethiacephems whereas, the substituted allene-thiourea afforded seven-membered thiazepines along with five-membered isopenams. (C) 2014 Elsevier Ltd. All rights reserved.
Keywords: Allene; beta-Lactams; Iodocyclization; Regioselective; thiourea

Flexible dicarboxylate based pillar-layer metal organic frameworks: differences in structure and porosity by tuning the pyridyl based N, N ` linkers - Dey, Rajdip; Bhattacharya, Biswajit; Pachfule, Pradip; Banerjee, Rahul; Ghoshal, Debajyoti (CrystEngComm, 2014)
{Dicarboxylate supported metal organic hybrids of Co(II), Zn(II) and Cd(II) have been synthesized using two different pyridyl based N, N' linkers having Schiff base functionalized site. The use of flexible dicarboxylate glutarate in designing such frameworks has created a marked diversity in topology. The different N, N' donor linkers also played an active part in the channel modification in the synthesized MOFs. The structural and topological diversity has been analyzed from the single crystal X-ray structure. Five compounds, {[Co(azpy)(glut)]center dot(CH3OH)}(n) (1), {[Co(meazpy)(glut)(H2O)(2)]center dot (H2O)(3)

Formation of a pseudo-beta-hairpin motif utilizing the Ant-Pro reverse turn: consequences of stereochemical reordering - Nair, Roshna V.; Kotmale, Amol S.; Dhokale, Snehal A.; Gawade, Rupesh L.; Puranik, Vedavati G.; Rajamohanan, Pattuparambil R.; Sanjayan, Gangadhar J. (Organic & Biomolecular Chemistry, 2014)
Herein, we report a special case of pseudo-beta-hairpin formation by tetrapetide sequences featuring a two-membered Ant Pro dipeptide motif (Ant = anthranilic acid and Pro = proline) at the loop region. These folded structures uniquely feature the presence of C9- and C17-H-bonding patterns at reverse turn and interstrand regions, respectively. Their hairpin nucleation and folding propensities have been expounded using solution and solid state studies of distinct stereochemically altered sequences.

Formation of a room temperature stable Fe-V(O) complex: reactivity toward unactivated C-H bonds - Ghosh, Munmun; Singh, Kundan K.; Panda, Chakadola; Weitz, Andrew; Hendrich, Michael P.; Collins, Terrence J.; Dhar, Basab B.; Sen Gupta, Sayam (Journal of American Chemical Society, 2014)
An Fe-V(O) complex has been synthesized from equimolar solutions of (Et4N)(2)[Fe-III(Cl)(biuretamide)] and mCPBA in CH3CN at room temperature. The Fe-V(O) complex has been characterized by UV-vis, EPR, Mossbauer, and HRMS and shown to be capable of oxidizing a series of alkanes having C-H bond dissociation energies ranging from 99.3 kcal mol(-1) (cyclohexane) to 84.5 kcal mori (cumene). Linearity in the Bell-Evans-Polayni graph and the finding of a large kinetic isotope effect suggest that hydrogen abstraction is engaged the rate-determining step.

Functional isoDNA aptamers: modified thrombin binding aptamers with a 2'-5'-linked sugarphosphate backbone (isoTBA) - Gunjal, Anita D.; Fernandes, Moneesha; Erande, Namrata D.; Rajamohanan, P. R.; Kumar, Vaijayanti A. (Chemical Communications, 2014)
The regioisomeric 3'-deoxy-2'-5'-linked thrombin binding DNA aptamers (isoTBAs) were chemically synthesized and their ability to form unimolecular anti-parallel G-quadruplexes in the presence of K+ ions was evaluated. These modified sequences retain the function of the native thrombin binding aptamer (TBA), exhibit better stability against exonuclease and are capable of slowing down the process of blood clotting.

Functionally engineered egg albumen gel for quasi-solid dye sensitized solar cells - Kelkar, Sarika A.; Pandey, Komal; Agarkar, Shruti A.; Saikhedkar, Nidhi; Tathavadekar, Mukta; Agrawal, Ishita; Gundloori, Rathna V. N.; Ogale, Satishchandra (ACS Sustainable Chemistry & Engineering, 2014)
In this report, we demonstrated an interesting application of a bioderived material for the dye sensitized solar cells (DSSCs). Egg white, the clear liquid in a hen's egg, which possesses a remarkable gelling/cross-linking ability, was applied in the form of a gel electrolyte in a DSSC architecture to enhance its durability. A hybrid gel composed of poly(acrylic acid), polyaniline and egg albumen was synthesized, and the cell efficiency, stability and durability of the corresponding DSSC device were studied in detail. The dye sensitized solar cell with the egg albumen based electrolyte demonstrated a conversion energy efficiency of 4.6%. Further, a chemically modified egg albumen with ethylenediaminetetraacetic dianhydride showed improved cross-linking, microstructural and conductivity properties of the gel, and yielded a remarkable 5.75% conversion efficiency. Electrochemical impedance spectroscopy data showed favorable characteristics for charge transport through the modified gel and supported the efficiency observations very well.
Keywords: dye sensitized solar cells; Egg albumen; gel electrolyte

General approach to N-heterocyclic carbenes with a fused tetracyclic core: ligands for suzuki-miyaura cross-coupling reaction - Sutar, Revannath L.; Kumar, Vinod; Shingare, Rahul D.; Thorat, Shridhar; Gonnade, Rajesh G.; Reddy, D. Srinivasa (European Journal of Organic Chemistry, 2014)
The synthesis of an N-heterocyclic carbene (NHC) based on a tetracyclic scaffold by using simple, general, and scalable chemistry is disclosed. The developed route is suitable for introducing multiple substitutions on the tetracyclic scaffold. The utility of the present NHC as a ligand in the Suzuki-Miyaura cross-coupling reaction is demonstrated with a low catalyst loading.
Keywords: C-C coupling; carbenes; Homogeneous catalysis; N ligands; synthetic methods

Genesis of enhanced photoactivity of CdS/Ni-x nanocomposites for visible-light-driven splitting of water - Devi, Suman; Korake, Prakash V.; Achary, Srungarpu N.; Gupta, Narencira M. (International Journal of Hydrogen Energy, 2014)
A series of CdS/Ni-x nanocomposite photocatalysts, containing ca. 0.6-15 wt% Ni, were synthesized using a one-step hydrothermal method and characterized for their crystallographic, morphological, interfacial, and optical properties. Rietveld refinement of powder XRD data revealed the coexistence of wurtzite (hexagonal) and zinc blende (cubic) phases of CdS in ratios dependent on Ni content. Only a fraction of Ni existed as a secondary phase of NiS while the majority occupied the lattice positions of hexagonal CdS. Whereas up to 10-fold enhancement in H-2 evolution compared with pure CdS was observed for samples containing similar to 1.5-4.5 wt% Ni, samples with smaller or larger Ni content displayed poor activity for visible-light-induced splitting of water in presence of sulfide-sulphite ions as sacrificial electron donors. In contrary to recent findings, our study reveals that the enhanced CdS photoactivity is not a result of charge transfer between p-type NiS and n-type CdS, Ni-induced visible-region absorbance, or the coating of CdS particles by non-photoactive NiS. Instead, the preparation-dependent hexagonal/cubic CdS phase boundaries and particle morphology may play a crucial role. Additionally, certain Ni-doping-induced sub-bandgap shallow energy levels contribute to charge carrier separation. Copyright (C) 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.
Keywords: CdS/Ni-x nanocomposites; Dominant hexagonal facets; Enhanced photoactivity; Hydrogen evolution; Phase boundary effects; water splitting

Geometry-dependent lifetime of Interatomic coulombic decay using equation-of-motion coupled cluster method - Ghosh, Aryya; Vaval, Nayana (Journal of Chemical Physics, 2014)
Electronically excited atom or molecule in an environment can relax via transferring its excess energy to the neighboring atoms or molecules. The process is called Interatomic or Intermolecular coulombic decay (ICD). The ICD is a fast decay process in environment. Generally, the ICD mechanism predominates in weakly bound clusters. In this paper, we have applied the complex absorbing potential approach/equation-of-motion coupled cluster (CAP/EOMCCSD) method which is a combination of CAP and EOMCC approach to study the lifetime of ICD at various geometries of the molecules. We have applied this method to calculate the lifetime of ICD in Ne-X; X = Ne, Mg, Ar, systems. We compare our results with other theoretical and experimental results available in literature. (C) 2014 AIP Publishing LLC.

Green chemical incorporation of silicon into polyoxoanions of molybdenum: characterization, thermal kinetics study and their photocatalytic water splitting activity - D'Cruz, Bessy; Samuel, Jadu; George, Leena (RSC Advances, 2014)
Cetylpyridinium silicomolybdate (CSM) nanorods were successfully synthesized by applying green chemistry principles using sodium molybdate and a structure directing cationic surfactant, cetyl pyridinium chloride (CPC) at room temperature. The composition and morphology of the nanorods were established by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TG) and inductively coupled plasma atomic emission spectroscopic (ICP-AES) techniques. The thermal decomposition kinetics of CSM nanorods were investigated by a non-isothermal thermogravimetric analyzer at various heating rates. The thermal decomposition of CSM occurred in two stages. The activation energies of the first and second stages of thermal decomposition for all heating rates have been estimated using the iso-conventional methods of Flynn-Wall-Ozawa (FWO) and Kissinger-Akahira-Sunose (KAS) and the results are found to be in good agreement with each other. The invariant kinetic parameter (IKP) method and master plot method were also used to evaluate the kinetic parameters and mechanism for the thermal decomposition of CSM. The photocatalytic water oxidation mechanism using the CSM catalyst in the presence of platinum (Pt) co-catalyst enhances the H-2 evolution and was found to be 1.946 mmol g(-1) h(-1).

Green chemistry approach to styrene from ethylbenzene and air on MnxTi1-xO2 catalyst - Negi, Sanjay Singh; Venugopalan, Aswathy Thareparambil; Raja, Thirumalaiswamy; Singh, Anand Pal; Gopinath, Chinnakonda S. (RSC Advances, 2014)
Styrene (ST) is an industrially important commodity chemical, and design of a suitable catalyst, which provides high ethyl benzene (EB) conversion and styrene selectivity at Lower temperature with sustainable activity, is one of the major challenges in the field of heterogeneous catalysis. Manganese incorporated in titania (MnxT1-xO2) anatase Lattice, prepared via the solution combustion method, was evaluated for oxidative dehydrogenation (ODH) of EB with O-2 or air. MnxTi1-xO2 catalysts were characterized by different physiochemical methods. Up to 15% Mn could be introduced into the TiO2 Lattice. TEM and XRD indicate disordered mesoporosity, further confirmed by adsorption isotherm analysis. MnxTi1-xO2 catalysts were evaluated for ST synthesis from EB using air or oxygen as oxidant between 440 and 570 degrees C. Reaction conditions have been varied systematically, such as catalyst composition, and EB/air/O-2 flow. MnxTi1-xO2 shows sustainable 55% styrene yield for 45 h without deactivation under optimum conditions. A thorough analysis of spent catalysts demonstrates the conversion of initial anatase phase MnxTi1-xO2 to Mn3O4 supported on the rutile (R) phase of TiO2. The above change occurs in the first few hours of reaction and the Mn3O4 on R-TiO2 phase is the active phase of the catalyst and responsible for sustainable activity for Longer duration.

Green synthesis of novel polyoxoanions of tungsten containing phosphorus as a heteroatom: characterization, non-isothermal decomposition kinetics and photocatalytic activity - D'Cruz, Bessy; Samuel, Jadu; Sreedhar, Mulloor Kesavapillai; George, Leena (New Journal of Chemistry, 2014)
Synthesis of cetylpyridinium phosphotungstate (CPW) nanospheres was carried out by using sodium tungstate and a structure directing cationic surfactant, cetyl pyridinium chloride (CPC), at room temperature by applying green chemistry principles. The composition and morphology of the nanospheres were established by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), thermogravimetric analysis (TGA) and inductively coupled plasma atomic emission spectroscopic (ICP-AES) techniques. Thermal properties of the nanoparticles were investigated by nonisothermal analysis under a nitrogen atmosphere at four different heating rates 10, 15, 20 and 25 degrees C min(-1). The thermal decomposition of CPW occurred in two stages. The activation energy values at each stage of thermal decomposition for all heating rates were calculated by Flynn-Wall-Ozawa (FWO) and Kissinger-Akahira-Sunnose (KAS) methods. The invariant kinetic parameter (IKP) method and the master plot method were also used to evaluate the kinetic parameters and mechanism for the thermal decomposition of CPW. The photocatalytic water oxidation mechanism using a CPW catalyst in the presence of a platinum (Pt) co-catalyst enhances the H-2 evolution, which was found to be 2.0 mmol g(-1) h(-1).

High performance all-organic flexural piezo-FET and nanogenerator via nanoscale soft-interface strain modulation - Dhakras, Dipti; Gawli, Yogesh; Chhatre, Shraddha; Wadgaonkar, Prakash; Ogale, Satishchandra (Physical Chemistry Chemical Physics, 2014)
Flexural strain fields are encountered in a wide variety of situations and invite novel device designs for their effective use in sensing, actuating, as well as energy harvesting (nanogenerator) applications. In this work we demonstrate an interesting all-organic device design comprising an electrospun P(VDF-TrFE) fiber-mat built directly on a conducting PANI film, which is also grown on a flexible PET substrate, for flexural piezo-FET and nanogenerator applications. Orders of magnitude stronger modulation of electrical transport in PANI film is realized in this device as compared to the case of a similar device but with a uniform spin-coated P(VDF-TrFE) film. We find that in the flexural mode of operation, the interaction between the laterally modulated nanoscale strain field distributions created by the fibers and the applied coherent strain field strongly influences the carrier transport in PANI. The transport modulation is suggested to occur due to strain-induced conformational changes in P(VDF-TrFE) leading to changes in carrier localization-delocalization. We further show that the fiber-mat based device system also works as an efficient nanogenerator capable of delivering power for low power applications.

Highly efficient chiral resolution of DL-arginine by cocrystal formation followed by recrystallization under preferential-enrichment conditions - Iwama, Sekai; Kuyama, Kazunori; Mori, Yuko; Manoj, Kochunnoonny; Gonnade, Rajesh G.; Suzuki, Katsuaki; Hughes, Colan E.; Williams, P. Andrew; Harris, Kenneth D. M.; Veesler, Stephane; Takahashi, Hiroki; Tsue, Hirohito; et al. (Chemistry-A European Journal, 2014)
An excellent chiral symmetry-breaking spontaneous enantiomeric resolution phenomenon, denoted preferential enrichment, was observed on recrystallization of the 1:1 cocrystal of dl-arginine and fumaric acid, which is classified as a racemic compound crystal with a high eutectic ee value (>95%), under non-equilibrium crystallization conditions. On the basis of temperature-controlled video microscopy and in situ time-resolved solid-state (CNMR)-C-13 spectroscopic studies on the crystallization process, a new mechanism of phase transition that can induce preferential enrichment is proposed.
Keywords: Amino acids; chiral resolution; cocrystals; Crystal growth; phase transitions

Highly efficient one-pot multi-component synthesis of alpha-aminophosphonates and bis-alpha-aminophosphonates catalyzed by heterogeneous reusable silica supported dodecatungstophosphoric acid (DTP/SiO2) at ambient temperature and their antitubercular eval - Mulla, Shafeek Abdul Rashid; Pathan, Mohsinkhan Y.; Chavan, Santosh S.; Gample, Suvarna P.; Sarkar, Dhiman (RSC Advances, 2014)
A highly efficient one-pot multi-component reaction (MCR) protocol over DTP/SiO2 has been developed for the synthesis of alpha-aminophosphonate derivatives (4a-x) in excellent yields. The alpha-aminophosphonate derivatives were for the first time evaluated for their antitubercular activity against the M. tuberculosis H37Ra (MTB) strain. An evaluation of the data on the cytotoxicity and antimicrobial activity shows that 4n and 4v are promising antitubercular agents.

Highly regioselective C4-hydrazinylation of 2,4-dichloroquinolines: expedient synthesis of aminoquinoline substituted pyrrolidin-2,5-diones via hydrazinylquinolines - Kumar, Gopal Senthil; Zeller, Matthias; Gonnade, Rajesh Ghanshyam; Prasad, Kamam Jayarampillai Rajendra (Tetrahedron Letters, 2014)
A new class of hydrazinylquinoline regio-isomers has been synthesized through SNAr reaction of 2,4-dichloroquinolines with hydrazine hydrate. The reaction stops at the mono-substitution product with high regioselectivity at the C-4 rather than C-2 position of dichloroquinolines. The hydrazinylquinolines were subsequently converted into aminoquinoline substituted pyrrolidin-2,5-diones in the presence of Eaton's reagent. (C) 2014 Elsevier Ltd. All rights reserved.
Keywords: 5-diones; Eaton's reagent; Hydrazinylquinolines; Pyrrolidin-2; Regioisomers; SNAr reaction

Homogeneous photochemical water oxidation by biuret-modified Fe-TAML: evidence of Fe-V(O) intermediate - Panda, Chakadola; Debgupta, Joyashish; Diaz, David Diaz; Singh, Kundan K.; Gupta, Sayam Sen; Dhar, Basab B. (Journal of the American Chemical Society, 2014)
{Water splitting, leading to hydrogen and oxygen in a process that mimics natural photosynthesis, is extremely important for devising a sustainable solar energy conversion system. Development of earth-abundant, transition metal-based catalysts that mimic the oxygen-evolving complex of photosystem II, which is involved in oxidation of water to O-2 during natural photosynthesis, represents a major challenge. Further, understanding the exact mechanism, including elucidation of the role of active metal-oxo intermediates during water oxidation (WO), is critical to the development of more efficient catalysts. Herein, we report Fe-III complexes of biuret-modified tetra-amidomacrocyclic ligands (Fe-TAML; 1a and 1b) that catalyze fast, homogeneous, photochemical WO to give OD with moderate efficiency (maximum TON = 220

Homogeneous water oxidation using peroxidase mimic [Fe-III(biuret-amide)] and analyte detection via signal amplification - Panda, C.; Dhar, B. B.; Ghosh, Munmun; Malvi, Bharmana; Bhattacharjee, Yudhajit; Sengupta, S. (Journal of Biological Inorganic Chemistry, 2014)
16th International Conference on Biological Inorganic Chemistry (ICBIC), Grenoble, FRANCE, JUL 22-26, 2013

Hydrogen bonding interaction between active methylene hydrogen atoms and an anion as a binding motif for anion recognition: experimental studies and theoretical rationalization - Agarwalla, Hridesh; Jana, Kalyanashis; Maity, Arunava; Kesharwani, Manoj K.; Ganguly, Bishwajit; Das, Amitava (Journal of Physical Chemistry A, 2014)
Two new reagents, having similar spatial arrangements for hydrogen atoms of the active methylene functionalities, were synthesized and interactions of such reagents with different anionic analytes were studied using electronic spectroscopy as well as by using 1H and 31P NMR spectroscopic methods. Experimental studies revealed that these two reagents showed preference for binding to F– and OAc–. Detailed theoretical studies along with the above-mentioned spectroscopic studies were carried out to understand the contribution of the positively charged phosphonium ion, along with methylene functionality, in achieving the observed preference of these two receptors for binding to F– and OAc–. Observed differences in the binding affinities of these two reagents toward fluoride and acetate ions also reflected the role of acidity of such methylene hydrogen atoms in controlling the efficiencies of the hydrogen bonding in anion–Hmethylene interactions. Hydrogen bonding interactions at lower concentrations of these two anionic analytes and deprotonation equilibrium at higher concentration were observed with associated electronic spectral changes as well as visually detectable change in solution color, an observation that is generally common for other strong hydrogen bond donor functionalities like urea and thiourea. DFT calculations performed with the M06/6-31+G**//M05-2X/6-31G* level of theory showed that F– binds more strongly than OAc– with the reagent molecules. The deprotonation of methylene hydrogen atom of receptors with F– ion was observed computationally. The metal complex as reagent showed even stronger binding energies with these analytes, which corroborated the experimental results.

Identification and expression profiling of helicoverpa armigera microRNAs and their possible role in the regulation of digestive protease genes - Lomate, Purushottam R.; Mahajan, Neha S.; Kale, Sandip M.; Gupta, Vidya S.; Giri, Ashok P. (Insect Biochemistry and Molecular Biology, 2014)
The present investigation is an effort to determine the possible roles of microRNAs (miRNAs) in the regulation of protease gene expression in Helicoverpa armigera upon exposure to plant protease inhibitors (PIs). Using Illumina platform, deep sequencing of 12 small RNA libraries was performed from H. armigera larvae fed on artificial diet (AD) or recombinant Capsicum annuum PI-7 (rCanPI-7) incorporated diet, at various time intervals (0.5, 2, 6, 12, 24, and 48 h). Sequencing data were analyzed with miRDeep2 software; a total of 186 unique miRNAs were identified from all the 12 libraries, out of which 96 were conserved while 90 were novel. These miRNAs showed all the conserved characteristics of insect miRNAs. Homology analysis revealed that most of the identified miRNAs were insect-specific, and more than 50 miRNAs were Lepidoptera-specific. Several candidate miRNAs (conserved and novel) were differentially expressed in rCanPI-7 fed larvae as compared to the larvae fed on AD. H. armigera miRNAs were found to have target sites in several protease genes as well as in protease regulation related genes such as serine PI and immune reactive PI. As expected, negative correlation in the relative abundance miRNAs and their target mRNAs was evident from qualitative real time polymerase chain reaction analysis. The investigation revealed potential roles of miRNAs in H. armigera protease gene regulation. (C) 2014 Elsevier Ltd. All rights reserved.
Keywords: Deep sequencing; Helicoverpa armigera; miRNAs; Protease gene regulation; Protease inhibitors

IFN-gamma signaling maintains skin pigmentation homeostasis through regulation of melanosome maturation - Natarajan, Vivek T.; Ganju, Parul; Singh, Archana; Vijayan, Vinaya; Kirty, Kritika; Yadav, Shalini; Puntambekar, Shraddha; Bajaj, Sonali; Dani, Prachi P.; Kar, Hemanta K.; Gadgil, Chetan J.; Natarajan, Krishnamurthy; et al. (Proceedings of the National Academy of Sciences of the United States of America, 2014)
Cellular homeostasis is an outcome of complex interacting processes with nonlinear feedbacks that can span distinct spatial and temporal dimensions. Skin tanning is one such dynamic response that maintains genome integrity of epidermal cells. Although pathways underlying hyperpigmentation cascade are recognized, negative feedback regulatory loops that can dampen the activated melanogenesis process are not completely understood. In this study, we delineate a regulatory role of IFN-gamma in skin pigmentation biology. We show that IFN-gamma signaling impedes maturation of the key organelle melanosome by concerted regulation of several pigmentation genes. Withdrawal of IFN-gamma signal spontaneously restores normal cellular programming. This effect in melanocytes is mediated by IFN regulatory factor-1 and is not dependent on the central regulator microphthalmia-associated transcription factor. Chronic IFN-gamma signaling shows a clear hypopigmentation phenotype in both mouse and human skin. Interestingly, IFN-gamma KO mice display a delayed recovery response to restore basal state of epidermal pigmentation after UV-induced tanning. Together, our studies delineate a new spatiotemporal role of the IFN-gamma signaling network in skin pigmentation homeostasis, which could have implications in various cutaneous depigmentary and malignant disorders.
Keywords: detanning; gene regulation; interferon; melanin

Immune response to chemically modified proteome - Bhat, Shweta; Mary, Sheon; Banarjee, Reema; Giri, Ashok P.; Kulkarni, Mahesh J. (Proteomics Clinical Applications, 2014)
Both enzymatic and nonenzymatic PTMs of proteins involve chemical modifications. Some of these modifications are prerequisite for the normal functioning of cell, while other chemical modifications render the proteins as neo-self antigens, which are recognized as non-self leading to aberrant cellular and humoral immune responses. However, these modifications could be a secondary effect of autoimmune diseases, as in the case of type I diabetes, hyperglycemia leads to protein glycation. The enigma of chemical modifications and immune response is akin to the chick-and-egg paradox. Nevertheless, chemical modifications regulate immune response. In some of the well-known autoimmune diseases such as rheumatoid arthritis, systemic lupus erythematosus, and multiple sclerosis, chemically modified proteins act as autoantigens forming immune complexes. In some instances, chemical modifications are also involved in regulating immune response during pathogen infection. Further, the usefulness of proteomic analysis of immune complexes is briefly discussed.
Keywords: Autoantibody; Autoimmune diseases; Immune complex; Immunoproteomics; PTMs

In situ pH management for microbial culture in shake flasks and its application to increase plasmid yield - Sanil, Reenu; Maralingannavar, Vishwanathgouda; Gadgil, Mugdha (Journal of Industrial Microbiology & Biotechnology, 2014)
Shake flasks are widely used to culture microorganisms, but they do not allow for pH control without additional infrastructure. In the presence of a carbon source like glucose, culture pH typically decreases due to overflow metabolism and can limit the growth of microorganisms in shake flasks. In this study, we demonstrate the use of magnesium hydroxide-loaded pH managing hydrogels (m-pHmH) for in situ base release to counter the decrease in culture pH in shake flasks using Escherichia coli as a model organism, in both complex and mineral salts medium. Base release from m-pHmH is shown to increase with decreasing pH (22-fold increase in release rate from pH 8 to 5), thus providing feedback from culture pH. The addition of m-pHmH resulted in better pH maintenance and higher biomass yields of E. coli K12 in media containing glucose as a carbon source. The use of m-pHmH with additional buffer resulted in pH being maintained above 6.9 while pH decreases below 5 without m-pHmH. We demonstrate one application of such in situ pH management to increase the volumetric plasmid yield from E. coli in shake flask culture. In situ glucose release through a hydrogel to mimic fed-batch culture along with the addition of m-pHmH resulted in a 395 % increase in volumetric plasmid yield to 38 mu g/ml in shake flask culture.
Keywords: In situ pH control; Magnesium hydroxide; pH-responsive base release; Shake flask culture

In1-XGaXN@ZnO: a rationally designed and quantum dot integrated material for water splitting and solar harvesting applications - Rajaambal, Sivaraman; Mapa, Maitri; Gopinath, Chinnakonda S. (Dalton Transactions, 2014)
The highly desirable combination of the visible light absorption properties of In1-xGaxN Quantum dots (QD) along with the multifunctionality of ZnO into a single integrated material was prepared for solar harvesting. This is the first report on InGaN QD integrated with ZnO (InGaN@ZnO), synthesized by a highly reproducible, simple combustion method in 15 min. Structural, microstructural and electronic integration of the nitride and oxide components of InGaN@ZnO was demonstrated by appropriate characterization methods. Self-assembly of InGaN QD is induced in growing nascent zinc oxo nanoclusters taking advantage of the common wurtzite structure and nitrogen incorporation at the expense of oxygen vacancies. Direct integration brings about a single phase structure exhibiting extensive visible tight absorption and high photostability. InGaN@ZnO suggests synergistic operation of tight harvesting and charge conducting components for solar H-2 generation without using any co-catalyst or sacrificial agent, and a promising photocurrent generation at 0 V under visible light illumination. The present study suggests a direct integration of QD with the host matrix and is a potential method to realize the advantages of QDs.

Influence of starting precursors and synthesis methods on the physiochemical properties of zirconia - Gaydhankar, T. R.; Jha, Ratnesh Kumar; Nikalje, M. D.; Waghmare, K. J. (Materials Research Bulletin, 2014)
Under identical and judiciously pre-optimized synthesis conditions, the influence of different combinations of zirconium sources and/or post treatment conditions on structural properties, thermal stability, phase composition and morphology of zirconia has been investigated. High surface area tetragonal zirconia could be synthesized in a cost-effective manner from 1 M solution of zirconium oxynitrate at pH 11 using aqueous ammonia solution as a precipitant when calcined at 400 degrees C for 3 h. Irrespective of the preparation method, pH and starting precursor, zirconia samples prepared without digestion contained dominant monoclinic phase with some traces of tetragonal phase when calcined at 700 degrees C. Even though there is linear decrease in surface area with increase in the crystallite size for each sample as a function of calcination temperature, no co-relation between the surface area and crystallite size could be achieved. SEM images show agglomerated and irregular shape particles between 10 to 20 mu m. (C) 2014 Elsevier Ltd. All rights reserved.
Keywords: Oxides; Sol-gel chemistry; Thermogravimetric analysis (TGA)

Insecticidal potential of defense metabolites from ocimum kilimandscharicum against helicoverpa armigera - Singh, Priyanka; Jayaramaiah, Ramesha H.; Sarate, Priya; Thulasiram, Hirekodathakallu V.; Kulkarni, Mahesh J.; Giri, Ashok P. (Plos One, 2014)
Genus Ocimum contains a reservoir of diverse secondary metabolites, which are known for their defense and medicinal value. However, the defense-related metabolites from this genus have not been studied in depth. To gain deeper insight into inducible defense metabolites, we examined the overall biochemical and metabolic changes in Ocimum kilimandscharicum that occurred in response to the feeding of Helicoverpa armigera larvae. Metabolic analysis revealed that the primary and secondary metabolism of local and systemic tissues in O. kilimandscharicum was severely affected following larval infestation. Moreover, levels of specific secondary metabolites like camphor, limonene and beta-caryophyllene (known to be involved in defense) significantly increased in leaves upon insect attack. Choice assays conducted by exposing H. armigera larvae on O. kilimandscharicum and tomato leaves, demonstrated that O. kilimandscharicum significantly deters larval feeding. Further, when larvae were fed on O. kilimandscharicum leaves, average body weight decreased and mortality the larvae increased. Larvae fed on artificial diet supplemented with O. kilimandscharicum leaf extract, camphor, limonene and beta-caryophyllene showed growth retardation, increased mortality rates and pupal deformities. Digestive enzymes of H. armigera - namely, amylase, protease and lipase- showed variable patterns after feeding on O. kilimandscharicum, which implies striving of the larvae to attain required nutrition for growth, development and metamorphosis. Evidently, selected metabolites from O. kilimandscharicum possess significant insecticidal activity.

Intermediate hamiltonian fock space multireference coupled cluster approach to core excitation spectra - Dutta, Achintya Kumar; Gupta, Jitendra; Vaval, Nayana; Pal, Sourav (Journal of Chemical Theory and Computation, 2014)
The Fock space multireference coupled cluster (FSMRCC) method provides an efficient approach for the direct calculation of excitation energies. In intermediate Hamiltonian (IH-FSMRCC) formulation, the method is free from intruder state problems and associated convergence difficulties, even with a large model space. In this paper, we demonstrate that the IH-FSMRCC method with suitably chosen model space can be used for the accurate description of core excitation spectra of molecules, and our results are in excellent agreement with the experimental values. We have investigated the effect of choice of model space on the computed results. Unlike the equation-of-motion (EOM)-based method, the IH-FSMRCC does not require any special technique for convergence and in singles and doubles approximation gives a performance comparable to that of the standard EOMEE-CCSD method, even better in some of the cases.

Investigation of C-C bond formation mediated by bombyx mori silk fibroin materials - Kuehbeck, Dennis; Ghosh, Munmun; Sen Gupta, Sayam; Diaz, David Diaz (ACS Sustainable Chemistry & Engineering, 2014)
The formation of C-C bonds is a prerequisite for all life on earth. Understanding the role of proteins in mediating the formation of these bonds is important for understanding biological mechanisms in evolution, as well as for designing ``green catalysts''. In this work, the ability of silk fibroin (SF) proteins to mediate selective C-C bond formation under mild conditions was comprehensively evaluated and compared between different SF-based materials and other proteins. Aqueous SF solution (ASFS), freeze-dried SF (FDSF), mesoporous SF (MPSF), and SF hydrogel (SFHG) materials were prepared and characterized by a variety of techniques including, among others, FE-SEM, ICP-OES, FT-IR, and TGA. The nitroaldol (Henry) reaction, Knoevenagel condensation, and direct aldol reaction were used as models for this study, in which the recovery and reusability of the protein was also evaluated.
Keywords: Aldol-like reactions; C-C Bond formation; Knoevenagel condensation; Proteins; Silk fibroin

Ionization-induced tautomerization in cytosine and effect of solvation - Das, Tamal; Ghosh, Debashree (Journal of Physical Chemistry A, 2014)
The recent observation of excitation-induced tautomerization in gas-phase cytosine motivated us to investigate the possibility of facile tautomerization in ionized cytosine and the effect of solvation on the tautomerization barriers. The tautomerization mechanisms were characterized at the density functional theory (DFT)omega B97X-D and coupled-cluster singles and doubles (CCSD) levels of theory. Vertical and adiabatic ionization energies (VIEs and AIEs, respectively) of the tautomers of cytosine and the microsolvated species were calculated with the equation-of-motion ionization-potential coupled-cluster (EOM-IP-CCSD) method. We observed that, in microsolvated cytosine, the solvatochromic shifts of the VIEs can be both blue- and red-shifted depending on the tautomers. This is explained by the analysis of the charge dipole interactions between the cytosine and water molecules. We noticed that, upon ionization, gas-phase tautomerization barriers are reduced by 0-4 kcal/mol, whereas microsolvated (with one water) tautomerization barriers are reduced by 4-5 kcal/mol. We also investigated the tautomerization process in solvation using a continuum model with one active water molecule in the quantum mechanical region. We noticed that, even though bulk solvation has a significant effect on ionization energies, its effect on the ionization-induced tautomerization barrier is minimal.

Large magnetocaloric effect, moment, and coercivity enhancement after coating Ni nanoparticles with Ag - Srinath, Sanyadanam; Poddar, Pankaj; Das, Raja; Sidhaye, Deepti; Bhagavatula L. V. Prasad; Gass, James; Srikanth, Hariharan (ChemPhysChem, 2014)
We observe a large magnetocaloric effect in monodisperse Ni and NicoreAgshell nanoparticles in the superparamagnetic region. The organically passivated Ni nanospheres show a large magnetic entropy change of 0.9 J kg(-1)K for a 3 T magnetic field change. In comparison to the surfactant-coated Ni nanoparticles, the NicoreAgshell nanoparticles show an enhanced coercivity, magnetization, and magnetocaloric effect (1.3 kgK for a 3 T magnetic field change). The coercivity at 10 K increases from 360 Oe for Ni nanoparticles to nearly 610 Oe for NicoreAgshell particles. This large enhancement is attributed to the enhanced inter-particle interaction, which is mediated by the metallic shell, over the relatively weaker dipolar interaction in the surfactant-coated Ni nanoparticles, and to modification of the surface spin structure.
Keywords: anisotropy; core-shell; magnetic properties; Nanoparticles; superparamagnetic

Large scale synthesis of graphene quantum dots (GQDs) from waste biomass and their use as an efficient and selective photoluminescence on-off-on probe for Ag+ ions - Suryawanshi, Anil; Biswal, Mandakini; Mhamane, Dattakumar; Gokhale, Rohan; Patil, Shankar; Guin, Debanjan; Ogale, Satishchandra (Nanoscale, 2014)
Graphene quantum dots (GQDs) are synthesized from bio-waste and are further modified to produce amine-terminated GQDs (Am-GQDs) which have higher dispersibility and photoluminescence intensity than those of GQDs. A strong fluorescence quenching of Am-GQDs (switch-off) is observed for a number of metal ions, but only for the Ag+ ions is the original fluorescence regenerated (switch-on) upon addition of L-cysteine.

Layer-separated distribution of nitrogen doped graphene by wrapping on carbon nitride tetrapods for enhanced oxygen reduction reactions in acidic medium - Unni, SreeKuttan M.; Illathvalappil, Rajith; Gangadharan, Pranav K.; Bhange, Siddheshwar N.; Kurungot, Sreekumar (Chemical Communications, 2014)
Layer-separated 3D nitrogen doped graphene (NG) with an accessible interstitial surface and modulated activity characteristics for oxygen reduction in acidic medium could be prepared by wrapping NG sheets on in situ generated carbon nitride (CNx) tetrapods.

Leucaena sp recombinant cinnamyl alcohol dehydrogenase: purification and physicochemical characterization - Patel, Parth; Gupta, Neha; Gaikwad, Sushama M.; Agrawal, Dinesh C.; Khan, Bashir Mohammad (International Journal of Biological Macromolecules, 2014)
Cinnamyl alcohol dehydrogenase is a broad substrate specificity enzyme catalyzing the final step in monolignol biosynthesis, leading to lignin formation in plants. Here, we report characterization of a recombinant CAD homologue (LICAD2) isolated from Leucaena leucocephala. LICAD2 is 80 kDa homodimer associated with non-covalent interactions, having substrate preference toward sinapaldehyde with K-cat/K-m of 11.6 x 10(6) (M-1 s(-1)), and a possible involvement of histidine at the active site. The enzyme remains stable up to 40 C, with the deactivation rate constant (K-d*) and half-life (t(1/2)) of 0.002 and 5 h, respectively. LICAD2 showed optimal activity at pH 6.5 and 9 for reduction and oxidation reactions, respectively, and was stable between pH 7 and 9, with the deactivation rate constant (K-d*) and half-life (t(1/2)) of 7.5 x 10(-4) and 15 h, respectively. It is a Zn-metalloenzyme with 4 Zn2+ per dimer, however, was inhibited in presence of externally supplemented Zn2+ ions. The enzyme was resistant to osmolytes, reducing agents and non-ionic detergents. (C) 2013 Elsevier B.V. All rights reserved.
Keywords: Cinnamyl alcohol dehydrogenase (CAD); Metalloenzyme; Substrate specificity

Lignocellulose processing: a current challenge - Singhvi, Mamata S.; Chaudhari, Shivani; Gokhale, Digambar V. (RSC Advances, 2014)
Lignocellulosic biomass, of which inedible crops are a renewable source, is expected to become one of the key renewable energy resources in the near future, to deal with global warming and the depletion of conventional fossil fuel resources. It also holds the key to supplying society's basic needs for the sustainable production of chemicals and fuels without impacting the human food supply. Despite this, the production of 2nd generation biofuels and chemicals has not yet been commercialized. Therefore, the challenges involved in the production of lignocellulosic biomass derived fuels and chemicals must be addressed. The search for economic pretreatment methods has been recognized as one of the main hurdles for the processing of biomass to biofuels and chemicals. The conversion of all biomass components, lignin in particular, would greatly contribute to the economic viability of biomass based processes for 2nd generation biofuels and chemicals. The highly organized crystalline structure of cellulose presents an obstacle to its hydrolysis. Hydrolysis of lignocellulose carbohydrates into fermentable sugars requires a number of different biomass degrading enzymes such as cellulases and hemicellulases. Still, a number of technical and scientific issues within pretreatment and hydrolysis remain to be solved. Depending on the raw material and pretreatment technology, the enzyme mixtures must be designed to degrade biomass carbohydrates. Rapid advances in enzyme, microbial and plant engineering would provide the necessary breakthroughs for the successful commercialization of biomass derived fuels and chemicals.

Mapping of copper oxidation state using high pressure x-ray photoelectron spectroscopy - Kowalska, J.; Gopinath, Chinnakonda S. (Acta Physica Polonica A, 2014)
The interaction of O-2 with polycrystalline foil of Cu, from ultra high vacuum to 1 mbar and up to 773 K has been investigated. The study were performed by using the high pressure X-ray photoelectron spectroscopy (electron spectroscopy for chemical analysis) ultraviolet photoelectron spectroscopy system. In this work the results of mapping copper oxidation states as a function of temperature at 1 mbar O-2 have been presented.

Matrix-assisted laser desorption/ionization mass spectrometry analysis of dimethyl arginine isomers from urine - Bhattacharya, Nivedita; Singh, Ajeet; Ghanate, Avinash; Phadke, Gayatri; Parmar, Dharmesh; Dhaware, Deepika G.; Basak, Trayambak; Sengupta, Shantanu; Panchagnula, Venkateswarlu (Analytical Methods, 2014)
Isomeric asymmetric and symmetric dimethyl arginine (ADMA and SDMA respectively) residues are excreted in urine and are putative markers of cardiovascular and chronic kidney diseases. In this work, we demonstrate simultaneous and quantitative detection of endogeneous ADMA and SDMA from urine samples of healthy subjects using MALDI-TOF MS without any chromatographic separation. The DMA isomers yielded [M + H](+) ions along with their product ions formed due to MALDI in-source fragmentation. The precursor ions were validated using MALDI-TOF MS/MS as well as direct injection ESI-Q-TOF MS/MS. ADMA and SDMA generated unique product ions at similar to m/z 46 and similar to m/z 172 respectively in the MS-mode itself. These were advantageously used for full scan-mode absolute quantification of the isomeric metabolites. The m/z observed for all the ions was within 10 ppm mass accuracy. The calibration method was established by generating internal standard normalized peak area-based concentration response curves using synthetic standards. Good linearities (R-2 > 0.95) with acceptable intra-assay, inter-assay variation (within 15% RSD) and excellent recoveries were observed for quality control samples. Finally, endogeneous concentrations of the metabolites were determined in urine from healthy subjects (n = 11). ADMA and SDMA were found to be in the range of 1.6-8 mu M and 2.9-9.1 mu M in urine and were in agreement with previously reported physiological levels.

Mechanical downsizing of a gadolinium(iii)-based metal-organic framework for anticancer drug delivery - Kundu, Tanay; Mitra, Shouvik; Patra, Prasun; Goswami, Arunava; Diaz, David Diaz; Banerjee, Rahul (Chemistry-A European Journal, 2014)
A Gd-III-based porous metal-organic framework (MOF), Gd-pDBI, has been synthesized using fluorescent linker pDBI (pDBI=(1,4-bis(5-carboxy-1H-benzimidazole-2-yl)benzene)), resulting in a three-dimensional interpenetrated structure with a one-dimensional open channel (1.9x1.2nm) filled with hydrogen-bonded water assemblies. Gd-pDBI exhibits high thermal stability, porosity, excellent water stability, along with organic-solvent and mild acid and base stability with retention of crystallinity. Gd-pDBI was transformed to the nanoscale regime (ca. 140nm) by mechanical grinding to yield MG-Gd-pDBI with excellent water dispersibility (>90min), maintaining its porosity and crystallinity. In vitro and in vivo studies on MG-Gd-pDBI revealed its low blood toxicity and highest drug loading (12wt%) of anticancer drug doxorubicin in MOFs reported to date with pH-responsive cancer-cell-specific drug release.
Keywords: ball-milling; doxorubicin; drug delivery; metal-organic frameworks; nanocarriers

Molecular recognition pattern of cytotoxic alkaloid vinblastine with multiple targets - Pandya, Prateek; Agarwal, Lokesh Kr; Gupta, Neelima; Pal, Sourav (Journal of Molecular Graphics & Modelling, 2014)
Vinblastine (VLB), a cytotoxic alkaloid is used extensively against various cancer types and the crystal structure of its tubulin complex is already known. Multitarget affinity of vinblastine has been investigated and the nature of binding with biological receptors namely, duplex DNA and Human serum albumin (HSA) has been compared to the binding characteristics of its known complex with natural high affinity receptor tubulin using molecular docking and QM-MM calculations. VLB is found to interact with DNA as well as HSA protein, though, with weaker affinity as compared to tubulin. Analysis of various docked complexes revealed that the H-bonds and cation-pi bonds do not have significant contribution to the binding interactions and despite its large size, VLB remains in relaxed conformation and fits in the hydrophobic regions on the receptors. (C) 2014 Elsevier Inc. All rights reserved.
Keywords: Drug-DNA interactions; Drug-protein binding; Human serum albumin; Molecular docking; Multitarget affinity; QM-MM calculation; Vinblastine

Multicomponent reactions involving phosphines, arynes and aldehydes - Bhunia, Anup; Kaicharla, Trinadh; Porwal, Digvijay; Gonnade, Rajesh G.; Biju, Akkattu T. (Chemical Communications, 2014)
Although nucleophilic phosphine-catalysis is a powerful tool for the construction of various carbocycles and heterocycles, the reactions in which phosphines are incorporated into the final product are rare, and the reports on phosphine addition to highly electrophilic arynes are scarce. Herein, we report the phosphine triggered multicomponent reaction of arynes and aldehydes, which takes place via the formal [3+2] cycloaddition of an initially generated 1,3-phosphonium zwitterion from phosphines and arynes with aldehydes. The reaction resulted in the formation of a diverse range of stable pentacovalent phosphoranes in good yields based on the benzooxaphosphole system.

Myo-Inositol 1,3-acetals as early intermediates during the synthesis of cyclitol derivatives - Gurale, Bharat P.; Sardessai, Richa S.; Shashidhar, Mysore S. (Carbohydrate Research, 2014)
Synthetic sequences starting from commercially available myo-inositol necessarily involve protection-deprotection strategies of its six hydroxyl groups. Several strategies have been developed/attempted over the last several decades leading to the synthesis of naturally occurring phosphoinositols, their analogs, and cyclitol derivatives. Of late, myo-inositol 1,3-acetals, which can be obtained by the reductive cleavage of myo-inositol orthoesters have emerged as early intermediates for the synthesis of phosphorylated and other inositol derivatives. This mini-review is an attempt to illustrate the economy and convenience of using myo-inositol 1,3-acetals as early intermediates during syntheses from myo-inositol. (C) 2014 Elsevier Ltd. All rights reserved.
Keywords: Acetal; Cyclitol; Inositol; Protecting group; Signal transduction

Nanocomposite of silver and thermo-associating polymer by a green route: a potential soft-hard material for controlled drug release - Gupta, Nivika R.; Bhagavatula L. V. Prasad; Gopinath, Chinnakonda S.; Badiger, Manohar V. (RSC Advances, 2014)
Major research efforts are continuously being made to look for alternative, environment friendly green chemicals for the synthesis of nanoparticles in place of conventional and hazardous reducing agents such as sodium borohydride and hydrazine. We report here on the synthesis and characterization of AgNPs using a thermo-associating polymer namely, carboxymethyl guar grafted poly(ethylene oxide-co-propylene oxide) [CMG-g-PEPO]. The polymer acts as both reducing agent as well as stabilizing/capping agent. The formation of AgNPs with polymer was confirmed by UV/Vis spectroscopy and the TEM images indicated the size of nanoparticles to be in the range of 10-20 nm. We also demonstrated the use of these nanoparticles in the controlled release of doxorubicin hydrochloride (Dox), an anticancer drug. The binding of Dox onto the polymer and AgNPs was investigated by XPS and Raman spectroscopy which indicates that a charge-transfer mechanism is operative between the Dox and polymer holding both the entities together. The first synthesis of AgNPs using non-toxic thermo-associating polymer and subsequent release of Dox with body temperature (37 degrees C) as a trigger is the highlight of the present work.

Nature of the active site in ziegler-natta olefin polymerization catalysis systems - a computational investigation - Kumawat, Jugal; Gupta, Virendra Kumar; Vanka, Kumar (European Journal of Inorganic Chemistry, 2014)
Pull quantum chemical calculations with density functional theory (DET) show that a principal role of donors in Ziegler-Nana (ZN) oh-din polymerization catalysts is to coordinate to the metal center at the active sites on the MgCl2 surface. Thereby, the behavior of the catalyst is modulated to favor insertion over termination and, thus, polymerization occurs. This is shown to be true for a range of different donors. The calculations indicate that active sites that feature anionic chloride ligands at the titanium center (the conventional model for the active site) would lead to lower-molecular-weight riolymers. If an -OC2H5 group were present instead of a chloride ligand, the active site would much more effectively produce long chain polymers. Therefore, the current work provides important new insights into the nature of the ZN polymerization process.
Keywords: Alkene polymerization; Density functional calculations; heterogeneous catalysis; Insertion; Polymers

New Ru(II)/Os(II)-polypyridyl complexes for coupling to TiO2 surfaces through acetylacetone functionality and studies on interfacial electron-transfer dynamics - Banerjee, Tanmay; Biswas, Abul Kalam; Sahu, Tuhin Subhra; Ganguly, Bishwajit; Das, Amitava; Ghosh, Hirendra Nath (Dalton Transactions, 2014)
New Ru(II)- and Os(II)-polypyridyl complexes have been synthesized with pendant acetylacetone (acac) functionality for anchoring on nanoparticulate TiO2 surfaces with a goal of developing an alternate sensitizer that could be utilized for designing an efficient dye-sensitized solar cell (DSSC). Time-resolved transient absorption spectroscopic studies in the femtosecond time domain have been carried out. The charge recombination rates are observed to be very slow, compared with those for strongly coupled dye molecules having catechol as the anchoring functionality. The results of such studies reveal that electron-injection rates from the metal complex-based LUMO to the conduction band of TiO2 are faster than one would expect for an analogous complex in which the chromophoric core and the anchoring moiety are separated with multiple saturated C-C linkages. Such an observation is rationalized based on computational studies, and a relatively smaller spatial distance between the dye LUMO and the TiO2 surface accounted for this. Results of this study are compared with those for analogous complexes having a gem-dicarboxy group as the anchoring functionality for covalent binding to the TiO2 surface to compare the role of binding functionalities on electron-transfer dynamics.

N-Heterocyclic carbene-catalyzed enantioselective synthesis of functionalized cyclopentenes via alpha,beta-unsaturated acyl azoliums - Mondal, Santigopal; Yetra, Santhivardhana Reddy; Patra, Atanu; Kunte, Sunita S.; Gonnade, Rajesh G.; Biju, Akkattu T. (Chemical Communications, 2014)
Highly enantioselective NHC-organocatalyzed synthesis of functionalized cyclopentenes proceeding via alpha,beta-unsaturated acyl azolium intermediates is reported. The organocascade reaction of modified enals with malonic ester derivatives having a gamma-benzoyl group involves the Michael-intramolecular aldol-beta-lactonization-decarboxylation sequence to deliver cyclopentenes in good yields and excellent ee values.

Nitrogen-doped graphene interpenetrated 3D Ni-nanocages: efficient and stable water-to-dioxygen electrocatalysts - Dhavale, Vishal M.; Gaikwad, Sachin S.; George, Leena; Devi, R. Nandini; Kurungot, Sreekumar (Nanoscale, 2014)
Herein, we report the synthesis of a nitrogen-doped graphene (NGr) interpenetrated 3D Ni-nanocage (Ni-NGr) electrocatalyst by a simple water-in-oil (w/o) emulsion technique for oxidation of water to dioxygen. Correlation of adsorption of NGr and subsequent interpenetration through the specific surface plane of nickel particles as well as the concomitant interaction of N and C with Ni in the nano-regime has been investigated. Apart from the benefits of the synergistic interactions between Ni, N, and C, the overall integrity of the structure and its intra-molecular connectivity within the framework help in achieving better oxygen evolution characteristics at a significantly reduced overpotential. The engineered Ni-NGr nanocage displays a substantially low overpotential of similar to 290 mV at a practical current density of 20 mA cm(-2) in 0.1 M KOH. In comparison, NGr and Ni-particles as separate entities give overpotentials of similar to 570 and similar to 370 mV under similar conditions. Moreover, the long term stability of Ni-NGr was investigated by anodic potential cycling for 500 cycles and an 8.5% increment in the overpotential at 20 mA cm(-2) was observed. Additionally, a chronoamperometric test was performed for 15 h at 20 mA cm(-2), which highlights the better sustainability of Ni-NGr under the actual operating conditions. Finally, the quantitative estimation of evolved oxygen was monitored by gas chromatography and was found to be 70 mmol h(-1) g(-1) of oxygen, which is constant in the second cycle as well.

Non-coding RNA interact to regulate neuronal development and function - Iyengar, Bharat R.; Choudhary, Ashwani; Sarangdhar, Mayuresh A.; Venkatesh, K. V.; Gadgil, Chetan J.; Pillai, Beena (Frontiers in Cellular Neuroscience, 2014)
The human brain is one of the most complex biological systems, and the cognitive abilities have greatly expanded compared to invertebrates without much expansion in the number of protein coding genes. This suggests that gene regulation plays a very important role in the development and function of nervous system, by acting at multiple levels such as transcription and translation. In this article we discuss the regulatory roles of three classes of non-protein coding RNAs (ncRNAs)-microRNAs (miRNAs), piwi-interacting RNA (piRNAs) and long-non-coding RNA (lncRNA), in the process of neurogenesis and nervous function including control of synaptic plasticity and potential roles in neurodegenerative diseases. miRNAs are involved in diverse processes including neurogenesis where they channelize the cellular physiology toward neuronal differentiation. miRNAs can also indirectly influence neurogenesis by regulating the proliferation and self renewal of neural stem cells and are dysregulated in several neurodegenerative diseases. miRNAs are also known to regulate synaptic plasticity and are usually found to be co-expressed with their targets. The dynamics of gene regulation is thus dependent on the local architecture of the gene regulatory network (GRN) around the miRNA and its targets. piRNAs had been classically known to regulate transposons in the germ cells. However, piRNAs have been, recently, found to be expressed in the brain and possibly function by imparting epigenetic changes by DNA methylation. piRNAs are known to be maternally inherited and we assume that they may play a role in early development. We also explore the possible function of piRNAs in regulating the expansion of transposons in the brain. Brain is known to express several lncRNA but functional roles in brain development are attributed to a few lncRNA while functions of most of the them remain unknown. We review the roles of some known lncRNA and explore the other possible functions of lncRNAs including their interaction with miRNAs.
Keywords: gene expression regulation; lncRNA; miRNA; network-motifs; piRNA

Nonstoichiometric calcium pyrophosphate: a highly efficient and selective catalyst for dehydration of lactic acid to acrylic acid - Ghantani, Vidhya C.; Dongare, Mohan K.; Shubhangi B. Umbarkar (RSC Advances, 2014)
Calcium phosphate catalysts were prepared by co-precipitation method using calcium nitrate and mixtures of ammonium and different sodium phosphates as calcium and phosphate precursors, respectively. Depending on the phosphate precursor, the pH of the synthesis mixture changed during the catalyst precipitation. The catalyst characterisation by XRD and ICP revealed the formation of a calcium pyrophosphate structure with varying Ca/P ratio from 1.02 to 0.76 which could be correlated to the different pH of the synthesis solutions. Vapour phase dehydration of lactic acid to acrylic acid was carried out using these calcium pyrophosphate catalysts. Non-stoichiometric calcium pyrophosphate catalyst with Ca/P ratio 0.76 was found to be the most efficient catalyst among the synthesized series with 100% lactic acid conversion and 78% acrylic acid selectivity at 375 degrees C. The higher selectivity for acrylic acid has been correlated to the increased acidity and reduced basicity of non-stoichiometric calcium pyrophosphate compared to other stoichiometric pyrophosphates. In situ FTIR studies showed the formation of a higher amount of calcium lactate on non-stoichiometric compared to stoichiometric pyrophosphate leading to higher selectivity for acrylic acid.

Novel fluorescence probe for estimation of cysteine/histidine in human blood plasma and recognition of endogenous cysteine in live Hct116 cells - Reddy, Upendar G.; Agarwalla, Hridesh; Taye, Nandaraj; Ghorai, Suvankar; Chattopadhyay, Samit; Das, Amitava (Chemical Communications, 2014)
A new Cu(II)-complex is used as a ``Turn-On'' luminescence probe for specific detection of endogenous Cys in live Hct116 cells and Cys present in human blood plasma without any interference from other amino acids, especially GSH and Hcy. Difference in the mechanistic pathway for Cys and His recognition is discussed.

NOx reduction at near ambient temperatures and under lean-burn conditions on modified pd surfaces - Roy, Kanak; Gopinath, Chinnakonda S. (ChemCatChem, 2014)
Palladium surfaces that are modified with O atoms in the subsurface broaden the NO reduction temperature regime up to 325 K with O-2-rich NO+H-2+O-2 compositions. Compared to virgin Pd surfaces, up to 150% higher deNO(x) catalytic activity was observed with modified Pd surfaces at the reaction maximum. Molecular beam instrument and ambient-pressure photoelectron spectroscopy were employed to follow the kinetic and surface changes. These results open up a possibility to realize the cold-start reduction of NOx (deNO(x)). DeNO(x) activity reported in the literature with supported Pd catalysts after a simple calcination in air compares well with our present observations. Surface modification is likely to demonstrate a high potential for other catalytic reactions at relatively low temperatures.
Keywords: heterogeneous catalysis; nitrogen; oxygen; Palladium; surface chemistry

Nucleophilic ring-opening of benzoxazinones by dbu: some observations - Baravkar, Sachin B.; Roy, Arup; Gawade, Rupesh L.; Puranik, Vedavati G.; Sanjayan, Gangadhar J. (Synthetic Communications, 2014)
This communication demonstrates the formation of an unusual nucleophilic ring opening of benzoxazinones by 1,8-diazabicycloundec-7-ene (DBU). This observation contradicts the intrinsic feature of a hindered nonnucleophilic base like DBU. Confirmation of the product was achieved via single-crystal X-ray diffraction studies.
Keywords: Benzoxazinones; caprolactam; DBU; HATU

Oligomer-salt derived 3D, heavily nitrogen doped, porous carbon for Li-ion hybrid electrochemical capacitors application - Gokhale, Rohan; Aravindan, Vanchiappan; Yadav, Prasad; Jain, Srashti; Phase, Deodatta; Madhavi, Srinivasan; Ogale, Satishchandra (Carbon, 2014)
3D high surface area porous carbon is seen to form via self assembly of porous graphene sheets by direct pyrolysis of an oligomer salt tailored for the realization of molecular level activation. The oligomer salt was derived from 4-amino benzoic acid as the monomer by a facile free radical polymerization process. Incorporation of the functional groups (-COONa) eliminate the need for any external activating agents (KOH, ZnCl2, etc.) and also render high degree of sub-nanoscale homogeneity. This oligomer derived carbon (ODC) exhibits efficient performance in non-aqueous charge storage application namely Li-ion hybrid electrochemical capacitor (Li-HEC) owing to its high surface area, 3D interconnectivity and an appropriate pore size distribution. The Li-HEC fabricated with ODC based electrodes delivered a maximum energy density of similar to 63 Wh kg(-1) with spinel L4Ti5O12 as the anode. (C) 2014 Elsevier Ltd. All rights reserved.

One-pot synthesis of 5-hydroxymethylfurfural by cellulose hydrolysis over highly active bimodal micro/mesoporous H-ZSM-5 catalyst - Nandiwale, Kakasaheb Y.; Galande, Nitish D.; Thakur, Pratika; Sawant, Sanjay D.; Zambre, Vishal P.; Bokade, Vijay V. (ACS Sustainable Chemistry & Engineering, 2014)
Direct synthesis of 5-hydroxymethylfurfural (5-HMF), a useful renewable biofuel and biochemical, was systematically studied by hydrolysis of microcrystalline cellulose over Bimodal-HZ-5 zeolite. Bimodal-HZ-5 zeolite obtained by post-synthesis modification of H-ZSM-5 with desilication was found to be a potential heterogeneous catalyst with 67% cellulose conversion and 46% yield of 5-HMF. Bimodal-HZ-5 was observed to be reusable for four cycles, without any loss in activity. The detailed optimization of process parameters and catalyst reusability are also presented. The present study opens a new avenue for the renewable one-pot synthesis of 5-HMF, a valuable product.
Keywords: 5-Hydroxymethylfurfural; Biomodal-HZ-5; glucose; Hydrolysis; Microcrystalline cellulose

Partitioned EOMEA-MBPT(2): an efficient N-5 scaling method for calculation of electron affinities - Dutta, Achintya Kumar; Gupta, Jitendra; Pathak, Himadri; Vaval, Nayana; Pal, Sourav (Journal of Chemical Theory and Computation, 2014)
We present an N-5 scaling modification to the standard EOMEA-CCSD method, based on the matrix partitioning technique and perturbative approximations. The method has lower computational scaling and smaller storage requirements than the standard EOMEA-CCSD method and, therefore, can be used to calculate electron affinities of large molecules and clusters. The performance and capabilities of the new method have been benchmarked with the standard EOMEA-CCSD method, for a test set of 20 small molecules, and the average absolute deviation is only 0.03 eV. The method is further used to investigate electron affinities of DNA and RNA nucleobases, and the results are in excellent agreement with the experimental values.

Pd-Phosphinesulfonate bravely battles the ``vinyl halide insertion copolymerization'' barricade - Gaikwad, Shahaji R.; Deshmukh, Satej S.; Chikkali, Samir H. (Journal of Polymer Science Part A-Polymer Chemistry, 2014)
This overview provides insights into the current state-of-the-art solutions to insertion copolymerization of functional olefinic monomers. The challenges in insertion copolymerization of functional olefinic monomers, with a special emphasis on vinyl halides, are highlighted. The crucial design of the Pd-phosphinesulfonate [Pd(PO)] enables up to 3.6 mol % incorporation of vinyl fluoride (VF) in an ethylene-VF copolymerization reaction. In a significant development, insertion copolymerization of industrially relevant functional olefin, that is, vinyl chloride (VC), was unambiguously ascertained, and a detectable amount of VC (0.4 mol %) was incorporated (at the chain end). In a detailed investigation, the in situ existence of (PO)PdH species during the polymerization was revealed, and it was demonstrated that these are indeed responsible for VC incorporation. (c) 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 1-6
Keywords: functional olefin; insertion copolymerization; palladium catalyst; phosphinesulfonate; vinyl chloride

Permeation of lipidated protein in bilayer using unbiased simulations reveals signature motif for protein-membrane binding - Thukral, Lipi; Sengupta, Durba; Gokhale, Rajesh S. (Biophysical Journal, 2014)
58th Annual Meeting of the Biophysical-Society, San Francisco, CA, FEB 15-19, 2014

Perturbative approximation to hybrid equation of motion coupled cluster/effective fragment potential method - Ghosh, Debashree (Journal of Chemical Physics, 2014)
Hybrid quantum mechanics/molecular mechanics (QM/MM) methods provide an attractive way to closely retain the accuracy of the QM method with the favorable computational scaling of the MM method. Therefore, it is not surprising that QM/MM methods are being increasingly used for large chemical/biological systems. Hybrid equation of motion coupled cluster singles doubles/effective fragment potential (EOM-CCSD/EFP) methods have been developed over the last few years to understand the effect of solvents and other condensed phases on the electronic spectra of chromophores. However, the computational cost of this approach is still dominated by the steep scaling of the EOM-CCSD method. In this work, we propose and implement perturbative approximations to the EOM-CCSD method in this hybrid scheme to reduce the cost of EOM-CCSD/EFP. The timings and accuracy of this hybrid approach is tested for calculation of ionization energies, excitation energies, and electron affinities of microsolvated nucleic acid bases (thymine and cytosine), phenol, and phenolate. (C) 2014 AIP Publishing LLC.

Pharmacokinetic modeling of caco-2 cell permeability using genetic programming (GP) method - Vyas, Renu; Goel, Purva; Karthikeyan, Muthukumarasamy; Tambe, S. S.; Kulkarni, B. D. (Letters in Drug Design & Discovery, 2014)
An accurate prediction of the pharmacokinetic properties of orally administered drugs is of paramount importance in pharmaceutical industry. Caco-2 cell permeability is a well established parameter for assessing the drug absorption profiles of lead molecules. Due to the restrictions on animal testing, prohibitive in situ models and ethical issues, the development of predictive models is essential. Genetic programming (GP) is an artificial intelligence (AI)-based exclusively data driven modeling paradigm. Given an example input-output data, it searches and optimizes, both the structure and parameters of a well fitting linear/non-linear input-output model. Despite this novelty, GP has not been widely exploited in drug design. Accordingly, in this study we propose a GP based approach for the in silico prediction of Caco-2 cell permeability using a diverse set of molecules. The predictions yielded a high magnitude for the training and test set correlation coefficient with low RMSE, indicating accurate Caco-2 permeability prediction and generalization performance by the GP model. The predictions were better or comparable to artificial neural networks (ANN) and support vector regression (SVR) methods. The GP based modeling approach illustrated will find diverse applications in (QSAR, QSPR and QSTR) modeling for the virtual screening of large libraries.
Keywords: ADME modeling; Caco-2 cell permeability; genetic programming; MLP; SVR

Photochromic metal organic frameworks for inkless and erasable printing - Garai, Bikash; Banerjee, Rahul (Acta Crystallographica A‐Foundation and Advances, 2014)
Keywords: Erasable Printing; Inkless Printing; metal organic framework

Photo-enhanced field emission studies of tapered CdS nanobelts - Chavan, Padmakar G.; More, Mahendra A.; Joag, Dilip S.; Badadhe, Satish S.; Mulla, Imtiaz S. (2014 27th International Vacuum Nanoelectronics Conference (IVNC), 2014)
Field emission and photo-enhanced field emission characteristics of single crystalline tapered CdS nanobelts have been investigated. The turn-on field for the emission current density of similar to 0.1 mu A/cm(2) is found to be similar to 2.1 V/mu m, which is much lower than reported values for various CdS nanostructures. The photo-enhanced field emission current shows a reproducible photo-switching behavior with rise in current level nearly four times that of its initial preset value (similar to 1 mu A) which is found to be very remarkable. Possible mechanism of photo-enhanced field emission is discussed.
27th International Vacuum Nanoelectronics Conference (IVNC), Engelberg, SWITZERLAND, JUL 06-10, 2014
Keywords: Current stability; field emission; Nanobelts; Photoswitching

Photophysical, bandstructural, and textural properties of o-FeNbO4 in relation to its cocatalyst-assisted photoactivity for water oxidation - Babu, Robin; Kelkar, Sarika A.; Kashid, Vikas; Achary, Srungarpu N.; Salunke, Hemant G.; Gupta, Narendra M. (RSC Advances, 2014)
In this study, a relationship between physicochemical, photophysical and photocatalytic properties of hydrothermally synthesized orthorhombic iron niobate (FeNbO4) is investigated. o-FeNbO4 displayed a multi-regime optical absorbance, which was ascribed to at least two distinct phenomena: (i) bandgap (similar to 3.4 eV) excitation giving rise to UV absorbance and (ii) energy transitions involving disorder-induced sub-bandgap donor or acceptor states leading to visible light absorbance. The preparation-dependent distortion in the crystal lattice and the existence of closely spaced inter-bandgap energy states were corroborated by powder X-ray diffraction, photoluminescence, thermoluminescence, and Raman spectroscopy studies. The first principles electronic structure elucidation and photoelectrochemical measurements supported a wide bandgap for FeNbO4, in contrast to the narrow bandgap reported previously. Correspondingly, a small photocurrent density was observed for FeNbO4 (similar to 2 to 3 mu A cm(-2)) under 1 sun illumination, suggesting the availability of a smaller cross section of photogenerated charge pairs. Following these band characteristics, while no H-2 evolution was observed, FeNbO4 gave rise to particle size-dependent O-2 evolution during visible light irradiation of water in the presence of electron scavengers, the samples loaded with NiO as cocatalyst showing better activity. Further, the transmission electron microscopy examination revealed the dominant exposure of (011) facets of FeNbO4, besides a significant heterogeneity of inter-domain boundaries. Overall, our results confirm that the photoactivity of metal/oxide nanocomposites is governed by a combination of factors, such as: grain morphology, microstructure, surface adsorption states, and the localized inter-bandgap energy states. Our study also reveals that, in contrast to prevalent assumptions, the wavelength at the absorption edge may not represent the true band-to-band energy gap of metal oxide semiconductors, which is relevant to their photocatalytic activity.

Photosensitive field emission study of SnS2 nanosheets (27th International Vacuum Nanoelectronics Conference ) - Joshi, Padmashree D.; Joag, Dilip S.; Rout, Chandra Shekhar; Late, Dattatray J. (2014 27TH International Vacuum Nanoelectronics Conference (IVNC), 2014)
SnS2 nanosheets (SnS(2)NSs), synthesized by one-step hydrothermal reaction, are subjected to Field Emission (FE) studies. For synthesis, specific concentrations of Na2SnO3 and thioamide solution are used. The FE study is carried out in all metal Ultra High Vacuum (UHV) chamber in planar diode configuration at a base pressure of similar to 10(-8) torr. A maximum current density of 110 mu A/cm(2) was attainable. The turn on field required to draw a current density of 1 mu A/cm(2) is found to be 2.6 V/mu m. A separate study was carried out to investigate the photosensitivity of the emitter by illuminating the specimen under visible light. In dark, the FN plot is non-linear, indicative of semiconductor nature of the emitter. However, on illumination, the FN plot is observed to be linear. This remarkable change can be explained by the photoconductivity imparted on illumination. The field at the tip is high in presence of light, than in dark, due to enhanced conductivity. It is also observed that on switching ON the light, the FE current increases almost instantaneously. Repetitive switching is observed at a fixed applied voltage, generating current pulses. The visible light soaking of the sample is carried out by illuminating the lamp for more than 100 minutes, where the current seems to saturate. On switching off the lamp the emission current decayed almost to its initial value exponentially. The photosensitivity has been studied for different wavelengths in the visible spectra. The maximum photosensitive field emission is observed for green filter. With this photoresponse, it is envisaged that SnS2 nanosheets are a potential candidate for optoelectronic applications of field emitters.
Keywords: field emission; photosensitivity; Photoswitching

Polarization switching characteristics of 0.5BaTi(0.8)Zr(0.2)O(3)-0.5Ba(0.7)Ca(0.3)TiO(3) lead free ferroelectric thin films by pulsed laser deposition - Kolekar, Y. D.; Bhaumik, A.; Shaikh, P. A.; Ramana, C. V.; Ghosh, K. (JOURNAL OF APPLIED PHYSICS, 2014)
We report on the ferroelectricity for morphotropic-phase-boundary lead (Pb) free 0.5BaTi(0.8)Zr(0.2)O(3)-0.5Ba(0.7)Ca(0.3)TiO(3) (0.5BZT-0.5BCT) thin films. Thin films were grown on Pt/Ti/SiO2/Si substrate using pulsed laser deposition. Raman spectroscopic data combined with the X-ray diffraction analyses confirm body centered tetragonal crystallographic structure 0.5BZT-0.5 BCT thin films on Pt/Ti/SiO2/Si. Polarization studies demonstrate that these 0.5BZT-0.5BCT films exhibit a large remnant and saturation polarization of 37 mu C/cm(2) and 40 mu C/cm(2), respectively, with a coercive field of 140 kV/cm. A correlation between polarization dynamics, structural distortion, and phonon vibration is established. The splitting of X-ray diffraction peak of the thin film in the 2 theta range of 44.5 degrees to 46.5 degrees represents high degree of tetragonality. The tetragonality factor calculated by Rietveld analysis was found to be 0.006 and can be a major cause for the increased remnant polarization value. It is established from Raman spectra that the non-centrosymmetricity due to the displacement of Ti/Zr ions from its octahedral position is related to the peak position as well as the broadening of the A(1) (LO) optical phonon mode. This increase of broadness in the thin film causes an increase in the dipole moment of the unit cell and, hence, the net increase in polarization values. (C) 2014 AIP Publishing LLC.

Poly (3,4-ethylenedioxythiophene) (PEDOT) and poly (3,4-ethylenedioxythiophene)-few walled carbon nanotube (PEDOT-FWCNT) nanocomposite based thin films for Schottky diode application - Gupta, Bhavana; Mehta, Minisha; Melvin, Ambrose A.; Kamalakannan, R.; Dash, Sitaram; Kamruddin, M.; Tyagi, A. K. (Materials Chemistry and Physics, 2014)
Transparent, conductive films of poly (3,4-ethylenedioxythiophene) (PEDOT) and poly (3,4-ethylenedioxythiophene)-few walled carbon nanotube (PEDOT-FWCNT) nanocomposite were synthesized by in-situ oxidative polymerization and investigated for their Schottky diode property. The prepared films were characterized by UV-Vis spectroscopy, thermal gravimetric analysis (TGA), surface resistivity, cyclic voltametery, scanning electron microscopy (SEM) and high resolution transmission electron microscopy (HRTEM). SEM reveals the formation of homogeneous and adhesive polymer films while HRTEM confirms the uniform wrapping of polymer chains around the nanotube walls for PEDOT-FWCNT film. Improved thermal stability, conductivity and charge storage property of PEDOT in the presence of FWCNT is observed. Among different compositions, 5 wt. % of FWCNT is found to be optimum with sheet resistance and transmittance of 500 Omega sq(-1) and 77%, respectively. Moreover, the electronic and junction properties of polymer films were studied and compared by fabricating sandwich type devices with a configuration of Al/PEDOT or PEDOT-FWCNT nanocomposite/indium tin oxide (ITO) coated glass. The measured current density-voltage characteristics show typical rectifying behavior for both configurations. However, enhanced rectification ratio and higher forward current density is observed in case of PEDOT-FWCNT based Schottky diode. Furthermore, reliability test depicts smaller hysteresis effect and better performance of PEDOT-FWCNT based diodes. (C) 2014 Elsevier B.V. All rights reserved.
Keywords: Composite materials; Electrical properties; Polymer; Thin films

Post-synthetically modified porous covalent framework (PCF) for high proton conduction - Samanta, Partha; Desai, Aamod; Anothumakkool, Bihag; Shirolkar, Mandar; Karmakar, Avishek; Kurungot, Sreekumar; Ghosh, Sujit (Acta Crystallographica A‐Foundation and Advances, 2014)
Keywords: Porous Covalent Framework; Post-synthetic Modification; proton conduction

Prediction of higher heating value of solid biomass fuels using artificial intelligence formalisms - Ghugare, Suhas B.; Tiwary, S.; Elangovan, V.; Tambe, S. S. (Bioenergy Research, 2014)
The higher heating value (HHV) is an important property defining the energy content of biomass fuels. A number of proximate and/or ultimate analysis based predominantly linear correlations have been proposed for predicting the HHV of biomass fuels. A scrutiny of the relationships between the constituents of the proximate and ultimate analyses and the corresponding HHVs suggests that all relationships are not linear and thus nonlinear models may be more appropriate. Accordingly, a novel artificial intelligence (AI) formalism, namely genetic programming (GP) has been employed for the first time for developing two biomass HHV prediction models, respectively using the constituents of the proximate and ultimate analyses as the model inputs. The prediction and generalization performance of these models was compared rigorously with the corresponding multilayer perceptron (MLP) neural network based as also currently available high-performing linear and nonlinear HHV models. This comparison reveals that the HHV prediction performance of the GP and MLP models is consistently better than that of their existing linear and/or nonlinear counterparts. Specifically, the GP- and MLP-based models exhibit an excellent overall prediction accuracy and generalization performance with high (> 0.95) magnitudes of the coefficient of correlation and low (< 4.5 %) magnitudes of mean absolute percentage error in respect of the experimental and model-predicted HHVs. It is also found that the proximate analysis-based GP model has outperformed all the existing high-performing linear biomass HHV prediction models. In the case of ultimate analysis-based HHV models, the MLP model has exhibited best prediction accuracy and generalization performance when compared with the existing linear and nonlinear models. The AI-based models introduced in this paper due to their excellent performance have the potential to replace the existing biomass HHV prediction models.
Keywords: Artificial intelligence; Artificial neural networks; Biomass fuels; genetic programming; Higher heating value; Multilayer perceptron

Preferential growth of Au on CdSe quantum dots using langmuir-blodgett technique - Das, Subhasis; Satpati, Biswarup; Chauhan, Himani; Deka, Sasanka; Gopinath, Chinnakonda S.; Bala, Tanushree (RSC Advances, 2014)
Oleyl amine capped CdSe quantum dots (QD) were synthesised by hot injection technique. These QDs formed a self-assembled monolayer on an aqueous subphase of a Langmuir-Blodgett (LB) trough. Here, in this report we introduced a simple but very efficient route to form a metal (Au)-QD hybrid nanostructure via the LB technique. In this method, the metal counterpart of the hybrid nanostructure could be deposited exclusively on one side of the QDs. The formation of stable monolayer of QDs was evidenced from a surface pressure-area (P-A) isotherm. The development of gold tip was confirmed and monitored by detailed TEM study on the monolayer deposited on TEM grids from the LB trough. Other characterizations like UV-Vis spectroscopy, FTIR, XPS and EDX also suggested the same. Oleyl amine was shown to act both as a reducing agent as well as a capping agent in this strategy.

Preparation and characterization of silver particulate films on softened polystyrene and poly(4-vinylpyridine) blends - Gurumurthy, S. C.; Pattabi, Manjunatha; Krishna, Shreedhar; Gaikwad, A. B. (Journal of Materials Science-Materials In Electronics, 2014)
Results of the investigations carried out on the optical properties of silver particulate films deposited at a rate of 0.4 nm/s on softened polystyrene and poly(4-vinylpyridine) (P4VP) blends held at 455 K are reported. Under the conditions of deposition, a sub-surface particulate structure is expected. It had been shown earlier that the morphology of the sub-surface particulate structure is dependent on polymer-metal interaction. In the present studies, an inert polymer like polystyrene (PS) is blended with an interacting polymer P4VP. The optical studies on the silver particulate films deposited on softened blends of PS/P4VP have been carried out. The results show a shift in plasmon resonance to higher wavelength with increasing P4VP concentration of the blends in comparison to that of the films deposited on pure PS. An X-ray photoelectron spectroscopy study at two different electron take off angles indicates the formation of subsurface particulate structures for films deposited on blends.

Preparation of pyrazole carboxylic acid analogues as anti-mycobacterial drug candidates - Gajbhiye, Jayant M. (WO2014174457 A1, 2014)
The present invention relates to the pyrazole carboxylic acid analogues of Formula (1) or stereoisomers, or esters or pharmaceutically acceptable salts thereof, as potent anti- mycobacterial agents. Formula Further it discloses the pharmaceutical composition comprising compounds of Formula-I for the treatment of mycobacterial infections.

Probing the folding induction ability of orthanilic acid in peptides: some observations - Roy, Arup; Kotmale, Amol S.; Gawade, Rupesh L.; Puranik, Vedavati G.; Rajamohanan, P. R.; Sanjayan, Gangadhar J. (RSC Advances, 2014)
This paper describes the ability of orthanilic acid (2-aminobenzenesulfonic acid, (S)Ant) to promote folding when introduced in a peptide sequence. Three peptide sequences, containing orthanilic acid (SAnt) with a sulfonamide moiety in the turn segment, have been synthesized in the solution phase using suitable coupling agents, and their structural aspects investigated using NMR and X-ray crystallographic studies. Solid- and solution-state conformational analyses reveal that the peptide sequences containing orthanilic acid in their backbone exist in a folded conformation featuring long-range 15-membered ring H-bonding.

Protecting group free and scalable approach towards total synthesis of (-)-venlafaxine - Chavan, Subhash P.; Pawar, Kailash P.; Garai, Sumanta (RSC Advances, 2014)
A protecting group free asymmetric total synthesis of (-)-venlafaxine is reported. The strategy employs Sharpless epoxidation and regio-selective epoxide ring opening by an in situ generated Gilman reagent as key steps. This paper reports a 53% overall yield in 6 steps for total synthesis of (-)-venlafaxine.

Protecting-group-free diastereoselective total synthesis of (+/-)-6-epi-cleistenolide and chemoenzymatic synthesis of (-)-6-epi-cleistenolide - Mahajan, Pankaj S.; Gonnade, Rajesh G.; Mhaske, Santosh B. (European Journal of Organic Chemistry, 2014)
A short, efficient, practical, and protecting-group-free diastereoselective total synthesis of (+/-)-6-epi-cleistenolide (1) has been achieved in five steps in 60% overall yield. The use of a chemoenzymatic approach also gave (-)-6-epi-cleistenolide (1) (>99.9% ee). The Achmatowicz reaction, chemoselective oxidation of a hemiacetal, diastereoselective 1,3-anti reduction of alpha-hydroxy ketone, and enzymatic resolution of a 1,3-diol are the key features of this linear total synthesis. The synthetic strategy demonstrated in this paper could be extended for an asymmetric total synthesis of (-)-cleistenolide (1) and related biologically active natural products.
Keywords: Asymmetric synthesis; diastereoselectivity; Enzyme catalysis; Lipases; Oxygen heterocycles; Total synthesis

Proteomic analysis of human plasma in chronic rheumatic mitral stenosis reveals proteins involved in the complement and coagulation cascade - Mukherjee, Somaditya; Jagadeeshaprasad, Mashanipalya G.; Banerjee, Tanima; Ghosh, Sudip K.; Biswas, Monodeep; Dutta, Santanu; Kulkarni, Mahesh J.; Pattari, Sanjib; Bandyopadhyay, Arun (Clinical Proteomics, 2014)
Background: Rheumatic fever in childhood is the most common cause of Mitral Stenosis in developing countries. The disease is characterized by damaged and deformed mitral valves predisposing them to scarring and narrowing (stenosis) that results in left atrial hypertrophy followed by heart failure. Presently, echocardiography is the main imaging technique used to diagnose Mitral Stenosis. Despite the high prevalence and increased morbidity, no biochemical indicators are available for prediction, diagnosis and management of the disease. Adopting a proteomic approach to study Rheumatic Mitral Stenosis may therefore throw some light in this direction. In our study, we undertook plasma proteomics of human subjects suffering from Rheumatic Mitral Stenosis (n = 6) and Control subjects (n = 6). Six plasma samples, three each from the control and patient groups were pooled and subjected to low abundance protein enrichment. Pooled plasma samples (crude and equalized) were then subjected to in-solution trypsin digestion separately. Digests were analyzed using nano LC-MSE. Data was acquired with the Protein Lynx Global Server v2.5.2 software and searches made against reviewed Homo sapiens database (UniProtKB) for protein identification. Label-free protein quantification was performed in crude plasma only.

Proteomics of arsenic stress in the gram-positive organism Exiguobacterium sp PS NCIM 5463 - Sacheti, Poonam; Patil, Rajendra; Dube, Ankita; Bhonsle, Hemangi S.; Thombre, Dipalee; Marathe, Sayali; Vidhate, Ravindra; Wagh, Priyanka; Kulkarni, Mahesh J.; Rapole, Srikanth; Gade, Wasudeo N. (Applied Microbiology and Biotechnology, 2014)
The general responses of microorganisms to environmental onslaughts are modulated by altering the gene expression pattern to reduce damage in the cell and produce compensating stress responses. The present study attempts to unravel the response of the Gram-positive Exiguobacterium sp. PS NCIM 5463 in the presence of [As(III)] and arsenate [As(V)] using comparative proteomics via two-dimension gel electrophoresis (2-DE) coupled with identification of proteins using matrix-assisted laser desorption/ionisation (MALDI-TOF/MALDI-TOF/TOF). Out of 926 Coomassie-stained proteins, 45 were differentially expressed (p < 0.05). Considering the resolution and abundance level, 24 spots (peptides) were subjected to MALDI analysis, identified and categorised into several functional categories, viz., nitrogen metabolism, energy and stress regulators, carbohydrate metabolism, protein synthesis components and others. A functional role of each protein is discussed in Exiguobacterium sp. PS 5463 under arsenic stress and validated at their transcript level using a quantitative real-time polymerase chain reaction. Unlike previous reports that unravel the responses toward arsenic stress in Gram-negative organisms, the present study identified new proteins under arsenic stress in a Gram-positive organism, Exiguobacterium sp. PS NCIM 5463, which could elucidate the physiology of organisms under arsenic stress.
Keywords: Arsenic; Exiguobacterium; proteomics; Stress; Transcriptomics

Pseudo-homogeneous kinetic model for esterification of acetic acid with propanol isomers over dodecatungstophosphoric acid supported on montmorillonite k10 - Gurav, Hanumant R.; Nandiwale, Kakasaheb Y.; Bokade, Vijay V. (Journal of Physical Organic Chemistry, 2014)
Esterification of acetic acid with propanol isomers such as isopropanol and naEuropropanol was carried out over dodecatungstophosphoric acid (DTPA), dodecamolybdophosphoric acid ammonium salt hydrate, and sodium tungstate hydrated purified supported on montmorillonite K10, which were characterized by powder XaEuroray diffraction, BrunaueraEuro'EmmettaEuro'Teller, and temperature programmed ammonia desorption. A pseudoaEurohomogeneous (PaEuroH) kinetic model was established for esterification of acetic acid with propanol isomers over DTPA supported on montmorillonite K10. Effects of various parameters such as reaction time, speed of agitation, particle size, temperature, percent catalyst loading, molar ratio and mixture of propanol isomer were investigated in detail. The 20% (w/w) DTPA/K10 was found to be an optimum solid catalyst with 82% naEuropropanol and 53% isopropanol conversion with 100% selectivity toward propyl acetate. The 20% (w/w) DTPA/K10 catalyst was found to be reusable for three cycles. The reaction follows secondaEuroorder kinetics with activation energies of 25.53aEuro?kJaEuro?mol(a?'1) and 28.15aEuro?kJaEuro?mol(a?'1) for isopropanol and naEuropropanol, respectively. PseudoaEurohomogeneous kinetic model fitted with R-2 value of trend line 0.999. This implies that esterification reaction is kinetically controlled owing to high activation energy. Copyright a (c) 2013 John Wiley & Sons, Ltd.
Keywords: Acetic acid; dodecatungstophosphoric acid; Esterification; kinetic model; montmorillonite K10

Quantum confinement controlled solar hydrogen production from hydrogen sulfide using a highly stable CdS0.5Se0.5/CdSe quantum dot-glass nanosystem - Apte, Sanjay K.; Garaje, Sunil N.; Naik, Sonali D.; Waichal, Rupali P.; Baeg, Jin-Ook; Kale, Bharat B. (Nanoscale, 2014)
We have demonstrated unique CdS0.5Se0.5 and CdSe quantum dot-glass nanosystems with quantum confinement effect. The stable, monodispersed CdS0.5Se0.5 and CdSe quantum dots (QDs) of size 2 to 12 nm have been grown in a germanate glass matrix by a simple melt quench technique at moderate temperature. XRD and Raman studies show formation of hexagonal CdS0.5Se0.5 and CdSe in the glass matrix. The quantum confinement of CdS0.5Se0.5 and CdSe was studied using TEM and UV-Vis spectroscopy. The band gap of the glass nanosystem was tuned from 3.6 to 1.8 eV by controlling the CdS0.5Se0.5 quantum dot size in the glass matrix. It can be further tuned to 1.68 eV using growth of CdSe quantum dots in the glass matrix. Considering the tuneable band gap of the CdS0.5Se0.5 and CdSe quantum dot-glass nanosystem for the visible light absorption, a study of size tuneable photocatalytic activity for hydrogen generation from hydrogen sulfide splitting was performed under visible light irradiation for the first time. The utmost hydrogen evolution, i.e. 8164.53 and 7257.36 mu mol h(-1) g(-1) was obtained for the CdS0.5Se0.5 and CdSe quantum dot-glass nanosystems, respectively. The apparent quantum yield (AQY) was observed to be 26% and 21% for the CdS0.5Se0.5 and CdSe quantum dot-glass nanosystems, respectively. It is noteworthy that the present glass nanosystem as a photocatalyst was found to be very stable as compared to naked powder photocatalysts.

Rapid access to benzoxaphospholes and their spiro analogues by a three-component coupling involving arynes, phosphines, and activated ketones - Bhunia, Anup; Roy, Tony; Gonnade, Rajesh G.; Biju, Akkattu T. (Organic Letters, 2014)
An operationally simple multicomponent coupling involving in situ generated arynes from 2 (trimethylsilyl)aryl triflates, phosphines, and various acyclic and cyclic activated carbonyl compounds has been developed. The reaction proceeds via a formal [3 + 2] cycloaddition mode giving access to differently substituted (spiro)benzoxaphosphole derivatives in moderate to good yields Mild reaction conditions. a broad scope. and the possibility of varying all the three-components are the notable features of the present reaction.

Rapid efficient synthesis and characterization of silver, gold, and bimetallic nanoparticles from the medicinal plant plumbago zeylanica and their application in biofilm control - Salunke, Gayatri R.; Ghosh, Sougata; Kumar, R. J. Santosh; Khade, Samiksha; Vashisth, Priya; Kale, Trupti S.; Chopade, Snehal; Pruthi, Vikas; Kundu, Gopal; Bellare, Jayesh R.; Chopade, Balu Ananda (International Journal of Nanomedicine, 2014)
Background: Nanoparticles (NPs) have gained significance in medical fields due to their high surface-area-to-volume ratio. In this study, we synthesized NPs from a medicinally important plant - Plumbago zeylanica. Materials and methods: Aqueous root extract of P. zeylanica (PZRE) was analyzed for the presence of flavonoids, sugars, and organic acids using high-performance thin-layer chromatography (HPTLC), gas chromatography-time of flight-mass spectrometry (GC-TOF-MS), and biochemical methods. The silver NPs (AgNPs), gold NPs (AuNPs), and bimetallic NPs (AgAuNPs) were synthesized from root extract and characterized using ultraviolet-visible spectra, X-ray diffraction (XRD), energy-dispersive spectrometry (EDS), transmission electron microscopy (TEM), and dynamic light scattering (DLS). The effects of these NPs on Acinetobacter baumannii, Staphylococcus aureus, and Escherichia coli biofilms were studied using quantitative biofilm inhibition and disruption assays, as well as using fluorescence, scanning electron microscopy, and atomic force microscopy. Results: PZRE showed the presence of phenolics, such as plumbagin, and flavonoids, in addition to citric acid, sucrose, glucose, fructose, and starch, using HPTLC, GC-TOF-MS, and quantitative analysis. Bioreduction of silver nitrate (AgNO3) and chloroauric acid (HAuCl4) were confirmed at absorbances of 440 nm (AgNPs), 570 nm (AuNPs), and 540 nm (AgAuNPs), respectively. The maximum rate of synthesis at 50 degrees C was achieved with 5 mM AgNO3 within 4.5 hours for AgNPs; and with 0.7 mM HAuCl4 within 5 hours for AuNPs. The synthesis of AgAuNPs, which completed within 90 minutes with 0.7 mM AgNO3 and HAuCl4, was found to be the fastest. Fourier-transform infrared spectroscopy confirmed bioreduction, while EDS and XRD patterns confirmed purity and the crystalline nature of the NPs, respectively. TEM micrographs and DLS showed about 60 nm monodispersed Ag nanospheres, 20-30 nm Au nanospheres adhering to form Au nanotriangles, and about 90 nm hexagonal blunt-ended AgAuNPs. These NPs also showed antimicrobial and antibiofilm activity against E. coli, A. baumannii, S. aureus, and a mixed culture of A. baumannii and S. aureus. AgNPs inhibited biofilm in the range of 96%-99% and AgAuNPs from 93% to 98% in single-culture biofilms. AuNPs also showed biofilm inhibition, with the highest of 98% in S. aureus. AgNPs also showed good biofilm disruption, with the highest of 88% in A. baumannii. Conclusion: This is the first report on rapid and efficient synthesis of AgNPs, AuNPs and AgAuNPs from P. zeylanica and their effect on quantitative inhibition and disruption of bacterial biofilms.
Keywords: AgAuNPs; AgNPs; AuNPs; biofilm inhibition and disruption; GC-TOF-MS; P. zeylanica

Relativistic equation-of-motion coupled-cluster method for the double-ionization potentials of closed-shell atoms - Pathak, Himadri; Ghosh, Aryya; Sahoo, B. K.; Das, B. P.; Vaval, Nayana; Pal, Sourav (Physical Review A, 2014)

Remarkable efficiency of a pin-II proteinase inhibitor sans two conserved disulfide bonds is due to enhanced flexibility and hydrogen bond density in the reactive site loop - Joshi, Rakesh S.; Mishra, Manasi; Tamhane, Vaijayanti A.; Ghosh, Anirban; Sonavane, Uddhavesh; Suresh, C. G.; Joshi, Rajendra; Gupta, Vidya S.; Giri, Ashok P. (Journal of Biomolecular Structure & Dynamics, 2014)
Capsicum annuum (L.) expresses diverse potato type II family proteinase inhibitors comprising of inhibitory repeat domain (IRD) as basic functional unit. Most IRDs contain eight conserved cysteines forming four disulfide bonds, which are indispensible for their stability and activity. We investigated the functional significance of evolutionary variations in IRDs and their role in mediating interaction between the inhibitor and cognate proteinase. Among the 18 IRDs encoded by C. annuum, IRD-7, -9, and -12 were selected for further characterization on the basis of variation in their reactive site loop, number of conserved cysteine residues, and higher theoretical G(bind) for interaction with Helicoverpa armigera trypsin. Moreover, inhibition kinetics showed that IRD-9, despite loss of some of the disulfide bonds, was a more potent proteinase inhibitor among the three selected IRDs. Molecular dynamic simulations revealed that serine residues in the place of cysteines at seventh and eighth positions of IRD-9 resulted in an increase in the density of intramolecular hydrogen bonds and reactive site loop flexibility. Results of the serine residues chemical modification also supported this observation and provided a possible explanation for the remarkable inhibitory potential of IRD-9. Furthermore, this natural variant among IRDs showed special attributes like stability to proteolysis and synergistic inhibitory effect on other IRDs. It is likely that IRDs have coevolved selective specialization of their structure and function as a response towards specific insect proteases they encountered. Understanding the molecular mechanism of pest protease-plant proteinaceous inhibitor interaction will help in developing effective pest control strategies.An animated interactive 3D complement (I3DC) is available in Proteopedia at http://proteopedia.org/w/Journal:JBSD:39
Keywords: Capsicum annuum; Helicoverpa armigera; Proteases; Proteinase inhibitor

Removal of carbonate ion through cellulose fiber supported solid membrane - Gaikwad, Abaji G. (Journal of Engineered Fibers and Fabrics, 2014)
A novel fiber supported solid membrane was prepared by chemical modification of cellulose fiber with tartaric acid, 8-hydroxyquinoline and magnesium carbonate for removal of bicarbonate ion. Loading effect of tartaric acid, magnesium metal ion and 8-hydroxyquinoline over cellulose fiber was studied for removal of carbonate ion. The selective removal of carbonate, sulfate, phosphate, and nitrate ions through fiber supported solid membrane was investigated. The removal of carbonate ion with/without bubbling of CO2 was determined in source and receiving phases.

Resistance through inhibition: ectopic expression of serine protease inhibitor offers stress tolerance via delayed senescence in yeast cell - Joshi, Rakesh S.; Tanpure, Rahul S.; Singh, Rajan Kumar; Gupta, Vidya S.; Giri, Ashok P. (Biochemical and Biophysical Research Communications, 2014)
Protease inhibitors have been known to confer multiple stress tolerance in transgenic plants. We have assessed growth of yeast (Pichia pastoris GS115) strains expressing inhibitory repeat domains (PpIRD(+)) of previously characterized Capsicum annuum protease inhibitors under high salt, heavy metal and oxidative stress. PpIRD(+) strains exhibited multiple stress tolerance and showed differential molecular responses at transcriptional and translational level on exposure to stress inducing agents like heavy metal, high salt and H2O2. PpIRD(+) strains display significant reduction in metacaspase (Yca1) activity, the key enzyme in apoptosis, indicates the possibility of cross reactivity of IRDs (serine protease inhibitor) with cysteine proteases. PpIRD(+) and Saccharomyces cerevisiae knockout with Yca1 (Delta Yca1) strain showed similar growth characteristics under stress, which indicated the delayed senescence due to cellular metacaspase inhibition. Molecular docking study showed a close proximity of IRDs reactive site and the active site of metacaspase in the complex that signified their strong interactions. Maintenance of GAPDH activity, primary target of metacaspase, in PpIRD(+) strain evidenced the inhibition of metacaspase activity and survival of these cells under stress. This report demonstrates a potential molecular mechanism of protease inhibitor-based multiple stress tolerance in yeast strains. (C) 2014 Elsevier Inc. All rights reserved.
Keywords: Metacaspase; Multiple stress tolerance; protease inhibitor; Yeast

Role of cation-anion cooperation in the selective synthesis of glycidol from glycerol using DABCO-DMC ionic liquid as catalyst - Munshi, Mudassir K.; Gade, Swapna M.; Rane, Vilas H.; Kelkar, Ashutosh A. (RSC Advances, 2014)
Transesterification of dimethyl carbonate with glycerol has been investigated using 1,4-diazabicyclo [2.2.2] octane (DABCO) based ionic liquid as a catalyst. DABCO reacted with dimethyl carbonate to form ionic liquid as the reaction progressed. Though the basicity of DABCO based ionic liquid was lower than that of DABCO, the catalytic activity and selectivity to glycidol was higher with DABCO based ionic liquid as a catalyst, indicating that basicity may not be the only criterion in deciding activity and selectivity of the reaction. The cooperative effect of the cation and anion of the ionic liquid is responsible for the observed results. The best results (97% glycerol conversion with 83% selectivity to glycidol and 17% selectivity to glycerol carbonate) were obtained using DABCO based ionic liquid as a catalyst. A plausible mechanism involving the role of both the cation and anion of the ionic liquid has been proposed.

Role of nanointerfaces in Cu- and Cu plus Au-based near-ambient-temperature CO oxidation catalysts - Gnanakumar, Edwin S.; Naik, Jarpla Madhusudhan; Manikandan, Marimuthu; Raja, Thirumalaiswamy; Gopinath, Chinnakonda S. (ChemCatChem, 2014)
Disordered mesoporous Cu-doped ceria-zirconia (Cu0.1Ce0.85Zr0.05O2), and gold deposited (Au/Cu0.1Ce0.85Zr0.05O2) catalysts were synthesized and evaluated for CO oxidation. Onset of CO oxidation activity, and 50% (100%) CO2 formation occurs at room temperature (RT), and 77 (120)degrees C, respectively, with Cu0.1Ce0.85Zr0.05O2. A small amount of gold on Cu0.1Ce0.85Zr0.05O2 induces the sustainable oxidation catalysis around RT. Onset of copper reduction temperature decreases from 110 degrees C on Cu0.1Ce0.85Zr0.05O2 to 48 degrees C with Au/Cu0.1Ce0.85Zr0.05O2, highlighting the direct interaction between Cu and Au through a Cu-Au interface. Au particles with a (00 1) facet deposit on an oxygen-deficient site of (111) facet of CeO2-ZrO2. Any decrease in surface Cu-content with increasing Au-content further supports the Au-Cu-Ce/Zr interface interactions. Nanointerfaces of Au clusters on Cu next to oxygen-deficient sites of CeO2-ZrO2 facilitate all the elementary steps of the CO + O-2 reaction to occur in close proximity at ambient conditions.
Keywords: carbon monoxide; Gold; heterogeneous catalysis; Oxidation; redox

Scaling behavior of resistive switching in epitaxial bismuth ferrite heterostructures - Rana, Abhimanyu; Lu, Haidong; Bogle, Kashinath A.; Zhang, Qi; Vasudevan, Rama; Thakare, Vishal; Gruverman, Alexei; Ogale, Satishchandra; Valanoor, Nagarajan (Advanced Functional Materials, 2014)
Resistive switching (RS) of (001) epitaxial multiferroic BiFeO3/La0.67Sr0.33MnO3/SrTiO3 heterostructures is investigated for varying lengths scales in both the thickness and lateral directions. Macroscale current-voltage analyses in conjunction with local conduction atomic force microscopy (CAFM) reveal that whilst both the local and global resistive states are strongly driven by polarization direction, the type of conduction mechanism is different for each distinct thickness regime. Electrode-area dependent studies confirm the RS is dominated by an interface mechanism and not by filamentary formation. Furthermore, CAFM maps allow deconvolution of the roles played by domains and domain walls during the RS process. It is shown that the net polarization direction, and not domain walls, controls the conduction process. An interface mechanism based on barrier height and width alteration due to polarization reversal is proposed, and the role of electronic reconstruction at the interface is further investigated.

Second generation, arginine-rich (R-X `-R)(4)-type cell-penetrating alpha-omega-alpha-peptides with constrained, chiral omega-amino acids (X `) for enhanced cargo delivery into cells - Patil, Kiran M.; Naik, Rangeetha J.; Vij, Manika; Yadav, Amit K.; Kumar, Vaijayanti A.; Ganguli, Munia; Fernandes, Moneesha (Bioorganic & Medicinal Chemistry Letters, 2014)
The syntheses of novel N-aminoalkyl proline-derived spacers (X') in polycationic (R-X'-R)-motif cell-penetrating alpha-omega-alpha-peptides are described as improved molecular transporters and their structural features studied by CD. FACS analysis shows enhanced cellular uptake and confocal microscopy indicates predominantly cytoplasmic localization. The oligomers are efficient at transporting pDNA into cells. The chirality together with the hydrophobicity and flexibility derived from the spacer chain are found to have marked influence on the cell-penetrating and cargo delivery properties of the cell-penetrating peptides (CPPs). The peptides containing N-(3-aminopropyl)-D-proline spacers are found to be the best at cell penetration and cargo delivery in the present study. (C) 2014 Elsevier Ltd. All rights reserved.
Keywords: (R-X-R)-motif; alpha-omega-alpha-Peptide; Cell-penetrating peptide; Constrained chiral amino acid; Peptidomimetics

Selection of phytase producing yeast strains for improved mineral mobilization and dephytinization of chickpea flour - Pable, A.; Gujar, P.; Khire, Jayant Malhar (Journal of Food Biochemistry, 2014)
Among 600 yeast isolates screened for phytase production, five (Zygosaccharomyces bisporusNCIM 3265 and 3296, Williopsis saturnusNCIM 3298, Zygosaccharomyces priorionusNCIM 3299 and Schizosaccharomyces octosporusNCIM 3297) were selected as potential phytase producers. Phytase activity was found to be cell wall associated with temperature and pH optima of 50C and 4.0, respectively. Highest phytase production was attained in cane juice medium as compared with other media used. Addition of phytase to chickpea flour significantly enhanced mineral mobilization by approximately 20-28%, 26-37% and 24-42% for Zn2+, Fe2+ and Ca2+, respectively, and decreased phytic acid content by about 75-88%.

Simple and efficient synthesis of isocoumarins and alkylidenephthalides from 3-(1-hydroxycarbethoxy/alkyl)phthalides with a DEAD/PPh3/TBHP system - Gadakh, Sunita K.; Sudalai, Arumugam (RSC Advances, 2014)
A facile and novel approach to the synthesis of 3-carbethoxy-isocoumarins and 3-alkylidenephthalides is described. The methodology employs DEAD/PPh3/TBHP as the reagent system proceeding through unprecedented 1,2-shift intramolecular ring expansion or simple elimination depending upon substituents present on 3-substituted phthalides, with broader substrate scope. This strategy is amply demonstrated in the short synthesis of bioactive molecules such as cytogenin and (Z)-3-butylidene-7-hydroxy-5-methoxyphthalide.

Size quantization effects on interfacial electron transfer dynamics in Ru(II)-polypyridyl complex sensitized ZnO QDs - Verma, Sandeep; Das, Amitava; Ghosh, Hirendra N. (Journal of Physical Chemistry C, 2014)
Quantum-size confinement in semiconductor material offers size based tunability of interband gap energy as well as intraband sublevels. In this work, size quantization of wide bandgap ZnO quantum dots has been explored in the study of interfacial charge separation reaction using a catechol functionalized Ru(II)polypyridyl complex as a photosensitizer molecule. Femtosecond time-resolved transient absorption studies have revealed multiple electron injection events based on discrete conduction band states of ZnO QDs. The electron injection rates have been rationalized for quantum confinement effects owing to different sizes of ZnO QDs. Furthermore, the size dependency of the intrinsic lifetime of electrons injected into discrete energy levels of ZnO QDs has been revealed in charge recombination reaction with the Ru(III)polypyridyl complex cation. The charge recombination dynamics reveals a competing trend of carrier confinement and carrier leak upon reducing particle size. This study shows the optimization of finite size effects in achieving better interfacial charge separation at the dye/semiconductor interface.

Soft colloidal scaffolds capable of elastic recovery after large compressive strains - Rajamanickam, Raja; Kumar, Sushma; Kumar, Deepak; Ghosh, Shankar; Kim, Jong Chul; Tae, Giyoong; Sen Gupta, Sayam; Kumaraswamy, Guruswamy (Chemistry of Materials, 2014)
Assemblies of inorganic or glassy particles are typically brittle and cannot sustain even moderate deformations. This restricts the use of such materials to applications where they do not experience significant loading or deformation. Here, we demonstrate a general strategy to create centimeter-size macroporous monoliths, composed primarily (>90 wt %) of colloidal particles, that recover elastically after compression to about one-tenth their original size. We employ ice templating of an aqueous dispersion of particles, polymer, and cross-linker such that cross-linking happens in the frozen state. This method yields elastic composite scaffolds for starting materials ranging from nanoparticles to micron-sized dispersions of inorganics or glassy lattices. The mechanical response of the monoliths is also qualitatively independent of polymer type, molecular weight, and even cross-linking chemistry. Our results suggest that the monolith mechanical properties arise from the formation of a unique hybrid microstructure, generated by cross-linking the polymer during ice templating. Particles that comprise the scaffold walls are connected by a cross-linked polymeric mesh. This microstructure results in soft monoliths, with moduli similar to O (10(4) Pa), despite the very high particle content in their walls. A remarkable consequence of this microstructure is that the monolith mechanical response is entropic in origin: the modulus of these scaffolds increases with temperature over a range of 140 K. We show that interparticle connections formed by cross-linking during ice templating determine the monolith modulus and also allow relative motion between connected particles, resulting in entropic elasticity.

Solar photocatalytic degradation of methylene blue using doped TiO2 nanoparticles - Bhosale, R. R.; Pujari, S. R.; Muley, G. G.; Patil, S. H.; Patil, K. R.; Shaikh, M. F.; Gambhire, A. B. (Solar Energy, 2014)
Doped-TiO2 nanoparticles (M:TiO2: Fe, Zn, Zr, Sb, Ce and nM:TiO2: B, C, N, P, S) with anatase structure were prepared by sol-gel method and characterized by X-ray diffraction (XRD), Transmission electron microscopy (TEM), X-ray photoelectron spectra (XPS), Brunauer-Teller method (BET), UV-Vis diffuses reflectance spectroscopy (DRS). Results revealed that the anatase structure is highly stable for all doped TiO2 prepared compounds with enhancement in the surface area. UV-Vis diffuse reflectance spectra showed that these dopants were responsible for narrowing the band gap of TiO2 and shifting its optical response from ultraviolet to visible-light region. The photocatalytic activities of these multi-doped TiO2 catalysts were investigated by degradation methylene blue in aqueous solution under solar-light illumination. The results showed an appreciable enhancement in the photoactivity of the C-doped TiO2 as compared to other multi-doped TiO2 because of the formation of Ti+3 species which prevent the recombination of electron-hole pairs in C-doped TiO2. (C) 2014 Elsevier Ltd. All rights reserved.
Keywords: Carbon; iron; Methylene blue; Solar photocatalysis

Sol-gel assisted fabrication of collagen hydrolysate composite scaffold: a novel therapeutic alternative to the traditional collagen scaffold - Ramadass, Satiesh Kumar; Perumal, Sathiamurthi; Gopinath, Arun; Nisal, Anuya; Subramanian, Saravanan; Madhan, Balaraman (ACS Applied Materials & Interfaces, 2014)
Collagen is one of the most widely used biomaterial for various biomedical applications. In this Research Article, we present a novel approach of using collagen hydrolysate, smaller fragments of collagen, as an alternative to traditionally used collagen scaffold. Collagen hydrolysate composite scaffold (CHCS) was fabricated with sol-gel transition procedure using tetraethoxysilane as the silica precursor. CHCS exhibits porous morphology with pore sizes varying between 380 and 780 mu m. Incorporation of silica conferred CHCS with controlled biodegradation and better water uptake capacity. Notably, 3T3 fibroblast proliferation was seen to be significantly better under CHCS treatment when compared to treatment with collagen scaffold. Additionally, CHCS showed excellent antimicrobial activity against the wound pathogens Staphylococcus aureus, Bacillus subtilis, and Escherichia coli due to the inherited antimicrobial activity of collagen hydrolysate. In vivo wound healing experiments with full thickness excision wounds in rat model demonstrated that wounds treated with CHCS showed accelerated healing when compared to wounds treated with collagen scaffold. These findings indicate that the CHCS scaffold from collagen fragments would be an effective and affordable alternative to the traditionally used collagen structural biomaterials.
Keywords: collagen; collagen hydrolysate; scaffold; sol-gel; tissue engineering; wound Healing

Solid-state NMR investigations of a MgCl2 center dot 4(CH3)(2)CHCH2OH molecular adduct: a peculiar case of reversible equilibrium between two phases - Thushara, K. S.; Ajithkumar, Thalasseril G.; Rajamohanan, P. R.; Gopinath, Chinnakonda S. (Journal of Physical Chemistry A, 2014)
MgCl2 center dot xROH molecular adducts are extensively employed as a support material for Ziegler-Natta polyolefin catalysis. However, their structural properties are not well understood. Recently, we reported on the preparation of an isobutanol adduct, MgCl2 center dot 4(CH3)(2)CHCH2OH (MgiBuOH) (Dalton Trans. 2012, 41, 11311), which is very sensitive to the preparation conditions, such as the temperature and refluxing time. For the present study, the structural properties of MgiBuOH adducts prepared under different conditions have been investigated thoroughly by solid-state NMR and nonambient XRD. Formation of two phases has been confirmed, and in situ variable temperature solid-state NMR measurements confirm the coexistence of two phases as well as the oscillation from one to another phase. It is expected that such molecular adducts could have a significant role in organic transformation reactions due to an oscillating structural component. An understanding of phase oscillation with the Mg2+ ion as the central metal ion might shed some light toward understanding various biological and structural functions.

Status of membrane distillation for water and wastewater treatment-a review - Pangarkar, Bhausaheb L.; Sane, Mukund G.; Parjane, Saroj B.; Guddad, Mahendra (Desalination and Water Treatment, 2014)
Membrane distillation (MD) is a promising separation technique for water treatment. It is a nonisothermal process known since 1963. However, this technology still needs to be developed for its industrial implementation for different purposes. This paper presents a status review of MD based on the available published literatures and on preliminary analysis. The review covers the concept, membranes and modules design, configurations, performance parameters, fouling phenomena, the heat and mass transfer phenomena, applications, energy assessment, heat integration, and Memstill technology of MD process. Earlier study indicates that the permeate quality obtained by MD is stable and practically independent on the feed concentrations. The permeate flux is strongly affected by the feed temperature, feed flow rate, vacuum pressure in vacuum MD, and the boundary layer heat transfer coefficient. The permeate flux obtained in the literature of MD process is disagree by an order of enormity and hence better experimental work is needed. The less attention was found in the literature towards the removal of organic and inorganic toxic constituents from the groundwater by MD process.
Keywords: Fouling; Membrane configuration; Membrane design; Membrane distillation; wastewater

Steady state fluorescence studies of wild type recombinant cinnamoyl CoA reductase (Ll-CCRH1) and its active site mutants - Sonawane, Prashant; Vishwakarma, Rishi Kishore; Singh, Somesh; Gaikwad, Sushama M.; Khan, Bashir Mohammad (Journal of Fluorescence, 2014)
Fluorescence quenching and time resolved fluorescence studies of wild type recombinant cinnamoyl CoA reductase (Ll-CCRH1), a multitryptophan protein from Leucaena leucocephala and 10 different active site mutants were carried out to investigate tryptophan environment. The enzyme showed highest affinity for feruloyl CoA (K (a) = 3.72 x 10(5) M-1) over other CoA esters and cinnamaldehydes, as determined by fluorescence spectroscopy. Quenching of the fluorescence by acrylamide for wild type and active site mutants was collisional with almost 100 % of the tryptophan fluorescence accessible under native condition and remained same after denaturation of protein with 6 M GdnHCl. In wild type Ll-CCRH1, the extent of quenching achieved with iodide (f (a) = 1.0) was significantly higher than cesium ions (f (a) = 0.33) suggesting more density of positive charge around surface of trp conformers under native conditions. Denaturation of wild type protein with 6 M GdnHCl led to significant increase in the quenching with cesium (f (a) = 0.54), whereas quenching with iodide ion was decreased (f (a) = 0.78), indicating reorientation of charge density around trp from positive to negative and heterogeneity in trp environment. The Stern-Volmer plots for wild type and mutants Ll-CCRH1 under native and denatured conditions, with cesium ion yielded biphasic quenching profiles. The extent of quenching for cesium and iodide ions under native and denatured conditions observed in active site mutants was significantly different from wild type Ll-CCRH1 under the same conditions. Thus, single substitution type mutations of active site residues showed heterogeneity in tryptophan microenvironment and differential degree of conformation of protein under native or denatured conditions.
Keywords: Active site mutants; Cinnamoyl CoA reductase; fluorescence; Ligand binding; Solute quenching

Stereospecific synthetic approach towards tamiflu using the ramberg-backlund reaction from cysteine hydrochloride - Chavan, Subhash P.; Chavan, Prakash N.; Gonnade, Rajesh G. (RSC Advances, 2014)
The stereospecific formal synthesis of Tamiflu from L-cysteine hydrochloride as the chiral source is described. The notable feature of the present strategy is the Ramberg-Backlund reaction and Sharpless-Reich protocol as the key chemical transformations to access the cyclohexene skeleton of Tamiflu.

Stress inducible proteomic changes in capsicum annuum leaves - Mahajan, Neha S.; Mishra, Manasi; Tamhane, Vaijayanti A.; Gupta, Vidya S.; Giri, Ashok P. (Plant Physiology and Biochemistry, 2014)
Herbivore attack induces defense responses in plants, activating several signaling cascades. As a result, molecules deterrent to the herbivores are produced and accumulated in plants. Expression of defense mechanism/traits requires reorganization of the plant metabolism, redirecting the resources otherwise meant for growth. In the present work, protein profile of Capsicum annuum leaves was examined after herbivore attack/induction. Majority of proteins identified as differentially accumulated, were having roles in redox metabolism and photosynthesis. For example, superoxide dismutase and NADP oxidoreductase were upregulated by 10- and 6-fold while carbonic anhydrase and fructose-1,6-bisphosphatase were downregulated by 9- and 4-fold, respectively. Also, superoxide dismutase, NADPH quinone oxidoreductase and NADP dependent isocitrate dehydrogenase transcripts showed a higher accumulation in induced leaf tissues at early time points. In general, proteins having role in defense and damage repair were upregulated while those involved in photosynthesis appeared downregulated. Thus metabolic reconfiguration to balance defense and tolerance was evident in the stress-induced leaves. (C) 2013 Elsevier Masson SAS. All rights reserved.
Keywords: Capsicum annuum; Oxidative stress; Wounding

Structural investigations of porous MgCl2-2-butanol molecular adduct as support for olefin polymerization - Thushara, K. S.; Ajithkumar, Thalasseril G.; Rajamohanan, P. R.; Gopinath, Chinnakonda S. (Applied Catalysis A-General, 2014)
A new heterogeneous Ziegler-Natta (Z-N) catalyst support material, MgCl2 center dot 4(CH3CH(OH)CH2CH3) (Mg2BuOH) has been synthesized. 2-Butanol, a linear, secondary alcohol was chosen for the generation of an active MgCl2 support which results in a Z-N catalyst with TiCl4. Significant feature of this work is the formation of rod shaped molecular adduct with highly porous character. Adduct material is characterized by XRD, TG-DTA, Raman spectroscopy, solid-state NMR and SEM. Activity of the Z-N catalyst supported on Mg2BuOH for ethylene polymerization is comparable with that of commercially available heterogeneous Z-N catalyst. However, there is scope to improve the activity by optimizing textural properties. (C) 2013 Elsevier B.V. All rights reserved.
Keywords: heterogeneous catalysis; MgCl2; Molecular adduct; NMR; Polyolefin; Ziegler-Natta catalyst

Structure function attributes of gold nanoparticle vaccine association: effect of particle size and association temperature - Barhate, Ganesh A.; Gaikwad, Sushama M.; Jadhav, Suresh S.; Pokharkar, Varsha B. (International Journal of Pharmaceutics, 2014)
Many biotherapeutic applications of gold nanoparticles make use of conjugated or adsorbed protein moieties. Physical parameters of association such as particle size, morphology, surface chemistry and temperature influences the protein-nanoparticle association and thereby their interaction with the biological environment. In present study, effect of size of chitosan reduced gold nanoparticles (CsAuNPs) and association temperature on structure and function of tetanus toxoid (TT) vaccine has been investigated. CsAuNPs were synthesized in the sizes of 20 + 3, 40 + 5 and 80 + 7 nm followed by loading of TT. Binding process of CsAuNPs with TT was investigated at their predetermined micro molar concentrations. Upon binding of TT onto CsAuNPs, particle surface was characterized using X-ray photoelectron spectroscopy. CD spectroscopic evaluation of TT bound 20 nm CsAuNPs led to 75% reduction in secondary structure of TT and thereby compromised immune function. Binding of TT with 40 and 80 nm sized CsAuNPs did not cause significant modifications in secondary structure or function of TT. Thermodynamic studies using temperature dependent fluorescence spectroscopy revealed an increase in association constants with the temperature. Based on thermodynamic data three phases in CsAuNPs and TT association process were traced. Samples from these distinct phases were also investigated for immunological recognition. Ex-vivo interaction of TT-CsAuNPs with TT positive and negative sera followed by relative change in particle size and zeta potential was studied. The findings here suggests prominent role of particle size and association temperature on adsorbed TT structure and function. Such studies may help in engineering functional nanotherapeutics. (C) 2014 Elsevier B.V. All rights reserved.
Keywords: Association thermodynamics; Gold nanoparticle; Nanoparticle protein interaction; Structure function studies; Vaccine formulation

Subtilase from Beauveria sp.: conformational and functional investigation of unusual stability - Dalal, Sayli A.; More, Snehal V.; Shankar, Shiv; Laxman, Ryali Seeta; Gaikwad, Sushama M. (European Biophysics Journal With Biophysics Letters, 2014)
Retention of total activity of the subtilisin-like serine protease from Beauveria sp. MTCC 5184 (Bprot) in the vicinity of (1) 3 M GdnHCl for 12 h, (2) 50 % methanol and dimethyl sulfoxide each for 24 h, and (3) proteolytic enzymes (trypsin, chymotrypsin, and proteinase K) for 48 h led to expect the enzyme to be a kinetically stable protein. Also, the structure of the protein was stable at pH 2.0. Biophysical characterization and conformational transitions were monitored using steady-state and time-resolved fluorescence, FTIR, and CD spectroscopy. Single tryptophan in the protein exists as two conformers, in hydrophobic and polar environment. The secondary structure of Bprot was stable in 3 M GdnHCl as seen in far-UV CD spectra. The active fraction of Bprot obtained from size-exclusion chromatography in the presence of GdnHCl (1.0-3.0 M) eluted at reduced retention time. The peak area of inactive or denatured protein with the same retention time as that of native protein increased with increasing concentration of denaturant (1.0-4.0 M GdnHCl). However, the kinetics of GdnHCl-induced unfolding as studied from intrinsic fluorescence revealed k (unf) of native protein to be 5.407 x 10(-5) s(-1) and a half-life of 3.56 h. The enzyme is thermodynamically stable in spite of being resistant to the denaturant, which could be due to the effect of GdnHCl imparting rigidity to the active fraction and simultaneously unfolding the partially unfolded protein that exists in equilibrium with the folded active protein. Thermal and pH denaturation of Bprot exhibited interesting structural transitions.
Keywords: Beauveria; Chemical denaturation; Conformational transitions; Serine protease; Subtilase; Thermal denaturation; Thermodynamic stability

Superior grafting and state-of-the-art interfacial electron transfer rates for newly designed geminal dicarboxylate bound ruthenium(II)- and osmium(II)-polypyridyl dyes on TiO2 nanosurface - Banerjee, Tanmay; Biswas, Abul Kalam; Reddy, Upendar G.; Sahu, Tuhin Subhra; Das, Amitava; Ganguly, Bishwajit; Ghosh, Hirendra Nath (Journal of Physical Chemistry C, 2014)
Two new Ru(II)-/Os(II)-polypyridyl based sensitizer dyes with geminal dicarboxylic acid group as the binding unit for superior grafting of the dye to TiO2 have been designed and synthesized. Steady-state photochemical studies of the two sensitizer dyes in presence of TiO2 in water confirm strong binding of the dyes to TiO2. Femtosecond transient absorption studies of these newly synthesized dyes on TiO2 nanosurface have been carried out in water and the results have been compared with those for the corresponding 4,4'-dicarboxy-2,2'-bipyridine analogues of the dyes. While the charge recombination rates are considerably slower, interestingly, the electron injection rates are very fast for multiple saturated C-C linkages present between the chromophoric core and the anchoring moiety. The origin and the consequences of such profound effects on the ultrafast interfacial dynamics are discussed. This is the first report on the ultrafast transient absorption studies of dyes with geminal dicarboxylic acid binding groups, which we believe will add significantly to the present research efforts toward the development of robust and efficient dyes for use in dye solar applications.

Surface studies on benzophenone doped PDMS microstructures fabricated using KrF excimer laser direct write lithography - Kant, Madhushree Bute; Shinde, Shashikant D.; Bodas, Dhananjay S.; Patil, K. R.; Sathe, V. G.; Adhi, K. P.; Gosavi, S. W. (Applied Surface Science, 2014)
his paper discusses microfabrication process for benzophenone doped polydimethylsiloxane (PDMS) using laser lithography. KrF excimer laser of 248 nm with 20 ns pulse width at repetition rate of 1 Hz was used for microfabrication of undoped and benzophenone doped PDMS. The doped-PDMS shows sensitivity below 365 nm, permitting processing under ambient light. The analysis of etch depth revealed that doped PDMS shows self developable sensitivity at lower fluence of similar to 250 mJ/cm(2). The unexposed and exposed surface was studied using Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy and Scanning electron microscopy (SEM). Spectrocopic analysis indicated increase in C-O, C=O, Si-O-3 and Si-O-4 bonding at the expense of Si-C and Si-O-2 bonds of PDMS. In case of laser exposed doped-PDMS, removal of benzophenone from probe depth of spectroscopy was observed. Whereas the surface morphology of exposed and unexposed doped-PDMS was observed to be same, indicating clean development of PDMS micropattems. The present study indicates that addition of 3.0 wt.% benzophenone in PDMS enhance self development sensitivity of PDMS. The self developable results on doped-PDMS are quite encouraging for its potential use in point of care Lab-On-Chip applications, for fabricating micropattems using direct write laser lithography technology.
Keywords: Direct write laser lithography; Microfabrication; micropatterning; Poly(dimethylsiloxane) (PDMS)

Sustainable polyacetals from isohexides - Rajput, B. S.; Gaikwad, S. R.; Menon, Shamal K.; Chikkali, Samir H. (Green Chemistry, 2014)
A single step synthetic protocol to access a small family of renewable diacetals was established. The resultant chiral diacetals are valuable building blocks in pharmaceuticals and materials science. To demonstrate their synthetic competence, isohexide-diacetals (2a-c) were subjected to acetal metathesis polymerization and the corresponding polymers (poly2a-c) were isolated as white solids with molecular weights in the range 3200-27 600 (g mol(-1)). The semi-crystalline polymers displayed glass transition temperatures between 38-65 degrees C and melting temperatures in the range 103-156 degrees C. The isohexide derived polyacetats are stable under practical washing and rinsing conditions but degrade in slightly acidic media.

Syntheses, X-ray structures, catalytic activity and magnetic properties of two new coordination polymers of Co(II) and Ni(II) based on benzenedicarboxylate and linear N,N `-donor Schiff base linkers - Bhattacharya, Biswajit; Maity, Dilip Kumar; Pachfule, Pradip; Colacio, Enrique; Ghoshal, Debajyoti (Inorganic Chemistry Frontiers, 2014)
{Two isostructural coordination polymers based on Co(II) and Ni(II), {[M(azpy)(3)(p-bdc)(2)(H2O)(4)]center dot(CH3OH)(2)(H2O)(3)}(n) [where M = Co (1) and Ni (2); azpy = N,N'-bis-pyridin-4-ylmethylene-hydrazine and p-bdc = 1,4-benzenedicarboxylate], have been synthesized using mixed ligand systems at room temperature and characterized by single-crystal X-ray diffraction and other physicochemical methods. Structure determination reveals that both the complexes crystallize in the monoclinic space group C2/c and exhibit one-dimensional (1D) ladder like structures constructed by p-bdc and azpy ligands in which Schiff base (azpy) linkers serve as a bridging as well as pendent ligands. These pendent ligands are involved in H-bonding and pi-pi interactions with lattice water, methanol molecules and bridging azpy ligands, to form the 3D supramolecular structure. Notably, both the frameworks efficiently catalyze the Knoevenagel condensation reactions of a wide range of substituted benzaldehydes with active methylene compounds in heterogeneous medium under environmentally friendly conditions and the products were obtained in excellent yields. These catalysts were also found to exhibit excellent recyclability and re-usability without any significant loss of activity. A variable temperature magnetic study of both compounds was carried out and their magnetic properties justified on the basis of their crystal structure.

Synthesis and characterization of azoxy based mesogenic diols - Mulani, Khudbudin Baban; Ganjave, Nitin V.; Chavan, Nayaku (Indian Journal of Chemistry Section B-Organic Chemistry Including Medicinal Chemistry, 2014)
Azoxy based rigid mesogenic diols have been synthesized using two steps. Phenol/cresol is used as starting material. Synthesized diols are characterized by IR, H-1 and C-13 NMR, and mass spectroscopic methods. Thermal properties have been determined by thermo gravimetric analysis method and crystallinity patterns have been obtained by wide angle X-ray diffiactogram. Substituted phenol (methyl) is used to study the effect of substitution on physical and thermal properties of rigid azoxy mesogenic diol. The detailed characterization of azoxy based rigid diols is reported in this communication, which is highly useful for fundamental and applied research, particularly in liquid crystals and liquid crystalline polymers. The experimental results reveal that phenol based rigid mesogenic diols have high thermal stability and degree of crystallinity than methyl substituted rigid mesogenic diols.
Keywords: Azoxy; degree of crystallinity; diol; mesogen; phenol; thermal stability

Synthesis and characterization of triad based rigid mesogenic diols derived from hydroquinone and 4-hydroxybenzoic acid - Mulani, Khudbudin Baban; Ganjave, Nitin V.; Chavan, Nayaku (Indian Journal of Chemistry Section B-Organic Chemistry Including Medicinal Chemistry, 2014)
Triad based rigid mesogenic diols have been synthesized by four step synthesis method using protection-deprotection method. Hydroquinone and 4-hydroxy benzoic acid have been used as starting materials. Synthesized diols have been characterized by IR, H-1 and C-13 NMR, and mass spectroscopic methods. Thermal properties have been determined by thermo gravimetric analysis method and degree of crystallinity have been measured by wide angle X-ray technique. Substituted hydroquinones (methyl and chloro) have been used to study the effect of substitution on physical and thermal properties. Synthesis of rigid mesogenic diol monomer using p-hydroxy benzoic acid and hydroquinone is reported, which is a facile route. Hydrolysis of diacetate derivatives of rigid mesogenic diols is performed in good yields, even though two types of ester groups present in the same moiety, aromatic and aliphatic. The experimental results reveal that hydroquinone based rigid triad mesogenic diol have high thermal stability and degree of crystallinity as compared to methyl-and chloro-substituted rigid triad mesogenic diols.
Keywords: degree of crystallinity; ester hydrolysis; Mesogenic diols; spectral properties; Thermal properties

Synthesis and luminescence of graphene-nano calcium sulphide composite - Sharma, Geeta; Patil, K. R.; Gosavi, S. W. (Materials Chemistry and Physics, 2014)
Graphene-nanocrystalline calcium sulphide has been synthesized using in-situ reduction of calcium salt and graphene oxide. Graphene oxide was prepared using Hummer's method. Surface morphology and crystal structure of samples were observed by transmission electron microscopy (TEM) and X-Ray diffraction (XRD). Ultra thin graphene and graphene oxide sheets with size ranging between tens to several hundreds of square nanometers are observed in TEM images. The TEM micrographs of G-CaS show that CaS particles are embedded in graphene sheets and the average particle size of CaS particles in the composite is less than 50 nm. The reduction in the intensity of various functional groups in FTIR spectrum also confirms the formation of graphene. The UV-Visible spectra of CaS shows absorption peak at 220 nm with a small shoulder at 250 nm whereas in G-CaS 220 nm absorption peak has reduced intensity and the shoulder at 250 nm has now shifted to 270 nm due to modification in the defect structure of CaS by graphene. CaS and G-CaS shows photoluminescence emission at 470 nm (lambda(exc.) = 375 nm) and 440 nm (lambda(exc.) = 350 nm) respectively, however emission intensity of G-CaS is relatively lower than CaS. Although the emission intensity is found to be lower than CaS, addition of CaS to graphene in G-CaS complex has made graphene luminescent. XPS spectra also indicate reduction of various oxygen containing functional groups in highly reduced graphene oxide and G-CaS. (C) 2014 Elsevier B.V. All rights reserved.
Keywords: Luminescence; Nanostructures; powder diffraction; Precipitation

Synthesis, characterization and in vitro study of biocompatible cinnamaldehyde functionalized magnetite nanoparticles (CPGF Nps) for hyperthermia and drug delivery applications in breast cancer - Wani, Kirtee D.; Kadu, Brijesh S.; Mansara, Prakash; Gupta, Preeti; Deore, Avinash V.; Chikate, Rajeev C.; Poddar, Pankaj; Dhole, Sanjay D.; Kaul-Ghanekar, Ruchika (Plos One, 2014)
Cinnamaldehyde, the bioactive component of the spice cinnamon, and its derivatives have been shown to possess anticancer activity against various cancer cell lines. However, its hydrophobic nature invites attention for efficient drug delivery systems that would enhance the bioavailability of cinnamaldehyde without affecting its bioactivity. Here, we report the synthesis of stable aqueous suspension of cinnamaldehyde tagged Fe3O4 nanoparticles capped with glycine and pluronic polymer (CPGF NPs) for their potential application in drug delivery and hyperthermia in breast cancer. The monodispersed superparamagnetic NPs had an average particulate size of similar to 20 nm. TGA data revealed the drug payload of similar to 18%. Compared to the free cinnamaldehyde, CPGF NPs reduced the viability of breast cancer cell lines, MCF7 and MDAMB231, at lower doses of cinnamaldehyde suggesting its increased bioavailability and in turn its therapeutic efficacy in the cells. Interestingly, the NPs were non-toxic to the non-cancerous HEK293 and MCF10A cell lines compared to the free cinnamaldehyde. The novelty of CPGF nanoparticulate system was that it could induce cytotoxicity in both ER/PRpositive/Her2 negative (MCF7) and ER/PRnegative/Her2 negative (MDAMB231) breast cancer cells, the latter being insensitive to most of the chemotherapeutic drugs. The NPs decreased the growth of the breast cancer cells in a dose-dependent manner and altered their migration through reduction in MMP-2 expression. CPGF NPs also decreased the expression of VEGF, an important oncomarker of tumor angiogenesis. They induced apoptosis in breast cancer cells through loss of mitochondrial membrane potential and activation of caspase-3. Interestingly, upon exposure to the radiofrequency waves, the NPs heated up to 41.6 degrees C within 1 min, suggesting their promise as a magnetic hyperthermia agent. All these findings indicate that CPGF NPs prove to be potential nano-chemotherapeutic agents in breast cancer.

Synthesis of an efficient heteroatom-doped carbon electro-catalyst for oxygen reduction reaction by pyrolysis of protein-rich pulse flour cooked with SiO2 nanoparticles - Gokhale, Rohan; Unni, SreeKuttan M.; Puthusseri, Dhanya; Kurungot, Sreekumar; Ogale, Satishchandra (Physical Chemistry Chemical Physics, 2014)
Development of a highly durable, fuel-tolerant, metal-free electro-catalyst for oxygen reduction reaction (ORR) is essential for robust and cost-effective Anion Exchange Membrane Fuel Cells (AEMFCs). Herein, we report the development of a nitrogen-doped (N-doped) hierarchically porous carbon-based efficient ORR electrocatalyst from protein-rich pulses. The process involves 3D silica nanoparticle templating of the pulse flour(s) followed by their double pyrolysis. The detailed experiments are performed on gram flour (derived from chickpeas) without any in situ/ex situ addition of dopants. The N-doped porous carbon thus generated shows remarkable electrocatalytic activity towards ORR in the alkaline medium. The oxygen reduction on this material follows the desired 4-electron transfer mechanism involving the direct reduction pathway. Additionally, the synthesized carbon catalyst also exhibits good electrochemical stability and fuel tolerance. The results are also obtained and compared with the case of soybean flour having higher nitrogen content to highlight the significance of different parameters in the ORR catalyst performance.

Synthesis of ciprofloxacin-conjugated poly(L-lactic acid) polymer for nanofiber fabrication and antibacterial evaluation - Parwe, Sharad P.; Chaudhari, Priti N.; Mohite, Kavita K.; Selukar, Balaji S.; Nande, Smita S.; Garnaik, Baijayantimala (International Journal of Nanomedicine, 2014)
Ciprofloxacin was conjugated with polylactide (PLA) via the secondary amine group of the piperazine ring using PLA and 7-(4-(2-Chloroacetyl) piperazin-1-yl)-1-cyclopropyl-6-fluoro-1, 4-dihydro-4-oxoquinoline-3-carboxylic acid. Zinc prolinate, a biocompatible catalyst was synthesized, characterized, and used in ring opening polymerization of L-lactide. Five different kinds of OH-terminated poly(L-lactide) (two-, three-, four-, six-arm, star-shaped) homopolymers were synthesized by ring opening polymerization of L-lactide in the presence of dodecanol, glycerol, pentaerythritol, dipentaerythritol as initiator and zinc prolinate as a catalyst. The structures of the polymers and conjugates were thoroughly characterized by means of gel permeation chromatography, matrix-assisted laser desorption/ionization-time of flight mass spectrometry, and nuclear magnetic resonance spectroscopy. PLA (molecular weight = 100,000) and ciprofloxacin conjugated PLA were used for fabrication of nonwoven nanofiber mat (diameter ranges; 150-400 nm) having pore size (62-102 nm) using electrospinning. The microbiological assessment shows that the release of ciprofloxacin possesses antimicrobial activity. The drug-release behavior of the mat was studied to reveal potential application as a drug delivery system. The result shows that the ciprofloxacin release rates of the PLA conjugate nonwoven nanofiber mat could be controlled by the drug loading content and the release medium. The development of a biodegradable ciprofloxacin system, based on nonwoven nanofiber mat, should be of great interest in drug delivery systems.
Keywords: antibacterial activity; ciprofloxacin conjugated polylactides; CP-PLA; drug release; electrospinning; MDR; nonwoven nanofibers; zinc prolinate

Synthesis of green nano iron particles (GnIP) and their application in adsorptive removal of As(III) and As(V) from aqueous solution - Prasad, Kumar Suranjit; Gandhi, Pooja; Selvaraj, Kaliaperumal (Applied Surface Science, 2014)
{The present study reports a new approach to synthesise nano iron particles using leaf extract of Mint (Mentha spicata L.) plant. The synthesised GnIPs were subjected to detailed adsorption studies for removal of arsenite and arsenate from aqueous solution of defined concentration. Iron nanoparticles synthesised using leaf extract showed UV-vis absorption peaks at 360 and 430 nm. TEM result showed the formation of polydispersed nanoparticles of size ranging from 20 to 45 nm. Nanoparticles were found to have core-shell structure. The planer reflection of selected area electron diffraction (SAED) and XRD analysis suggested that iron particles were crystalline and belonged to fcc (face centred cubic) type. Energy-dispersive X-ray analysis (EDAX) shows that Fe was an integral component of synthesised nanoparticles. The content of Fe in nanoparticles was found to be 40%, in addition to other elements like C (16%), 0 (19%) and Cl (23%). FT-IR study suggested that functional groups like NH
Keywords: Adsorption; Arsenate; Arsenite; Iron nanoparticles; kinetics; M. spicata L.

Synthesis, structure, spectral, electrochemical and sensing properties of 3-amino boron-dipyrromethene and its derivatives - Ganapathi, Emandi; Madhu, Sheri; Chatterjee, Tamal; Gonnade, Rajesh G.; Ravikanth, Mangalampalli (Dyes and Pigments, 2014)
We report the synthesis of 3-amino boron-dipyrromethene (3-amino BODIPY) by treating 3-bromo boron-dipyrromethene (3-bromo BODIPY) initially with sodium azide in acetonitrile followed by tri-phenylphosphine(PPh3)/H2O in tetrahydrofuran in three steps under mild reaction conditions. In this reaction, 3-azido BODIPY which formed in the first step was not isolated but the 3-iminophosphorane BODIPY which formed in the second step was isolated and characterized crystallographically. The 3-amino BODIPY was characterized by various spectroscopic and X-ray analytical techniques. To test the reactivity of amine functionality on BODIPY core, we prepared 1-(meso-anisyl BODIPY)-3-phenyl urea/thiourea derivatives under simple reaction conditions. Our studies indicated that 1-(meso-anisyl BODIPY)-3-pheny thiourea can act as specific chemodosimetric sensor for Hg2+ ion and 1-(meso-anisyl BODIPY)-3-phenyl urea as colorimetric and ratiometric sensor for F- ion. (C) 2013 Elsevier Ltd. All rights reserved.
Keywords: 3-Amino boron dipyrromethene; Chemodosimeter; F sensor; Fluorescent probes; Iminophosphorane BODIPY; Mercury(II) sensor