@article { ISI:000227578700042, title = {Keggin ion mediated synthesis of hydrophobized pd nanoparticles for multifunctional catalysis}, journal = {Langmuir}, volume = {21}, number = {6}, year = {2005}, month = {MAR}, pages = {2408-2413}, publisher = {AMER CHEMICAL SOC}, type = {Article}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

Development of simple and reliable protocols for the synthesis of organically soluble catalytically active metal nanoparticles is an important aspect of research in nanomaterials. We demonstrate herein the formation of Pd nanoparticles by reduction of aqueous Pd(NO3)(2) by photoexcited Keggin ions (phosphotungstate anions). This results in the formation of Pd nanoparticles capped with with Keggin ions that render the particles negatively charged. The Keggin ion capped Pd nanoparticles may then be phase transferred into nonpolar organic solvents such as toluene by electrostatic complexation with cationic surfactants such as octadecylamine at the liquid-liquid interface. This results in a new class of catalyst wherein both the Pd core and Keggin ion shell may be used in a range of catalytic reactions leading to a truly multifunctional catalyst dispersible in organic solvents.

}, issn = {0743-7463}, doi = {10.1021/la047717a}, author = {Mandal, Sujata and Das, Amitava and Srivastava, R. and Sastry, M.} } @article { ISI:000230435900058, title = {Kinetic modeling of reductive alkylation of aniline with acetone using Pd/Al2O3 catalyst in a batch slurry reactor}, journal = {Industrial \& Engineering Chemistry Research}, volume = {44}, number = {14}, year = {2005}, month = {JUL}, pages = {5388-5396}, publisher = {AMER CHEMICAL SOC}, type = {Article}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

The kinetics of reductive alkylation of aniline with acetone was studied in a slurry reactor under isothermal conditions in a temperature range of 378-408 K using 3\% Pd/Al2O3 catalyst. Experimental data on concentration-time as well as hydrogen consumption-time profiles were obtained to study the effect of concentration of aniline, catalyst loading, and partial pressure of hydrogen. Separate controlled experiments were performed to understand the nature of the condensation reaction between aniline and acetone, which forms the Shiff{\textquoteright}s base intermediate. From the concentration-time profiles and the effect of reaction conditions, it was found that the noncatalytic equilibrium formation of the Shiff base intermediate was the slowest step in the multistep reaction sequence. Several rate equations were considered to fit the batch slurry reactor data, and rate models based on competitive dissociative adsorption of hydrogen and the reactive substrates in the rate-limiting catalytic steps were found to represent the experimental data. The kinetic parameters were evaluated by fitting the integral batch reactor data at different temperatures. The activation energies, heat of adsorption, and entropy of adsorption of all the reactant species were also evaluated.

}, issn = {0888-5885}, doi = {10.1021/ie049093+}, author = {Roy, D. and Jaganathan, Rengaswamy and Chaudhari, Raghunath V.} } @article { ISI:000227293600008, title = {Kinetics of the complete combustion of dilute propane and methyl ethyl ketone over Cr-doped ZrO2 catalyst}, journal = {Chemical Engineering Science}, volume = {60}, number = {6}, year = {2005}, month = {MAR}, pages = {1575-1581}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, type = {Article}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

The kinetics of the complete combustion of propane and methyl ethyl ketone (MEK) at very low concentration in air (0.45 and 0.4 mol\% in air, respectively) over Cr-doped ZrO2 (cubic) catalyst (Cr/Zr = 0.25) at different temperatures (485-673 K) in the kinetic control regime have been investigated. The combustion rate data could be fitted well to both the power law and redox (Mars-Van Krevelen) models. From the power law model, the apparent activation energy for the combustion of propane and MEK has been found to be 16.5 and 13.2 kcal mol(-1), respectively. Among the two models, the redox one, however, gave a better fit to the kinetic data for both the combustion of propane and MEK. (C) 2004 Elsevier Ltd. All rights reserved.

}, keywords = {combustion kinetics, combustion of methyl ethyl ketone, combustion of propane, Cr-doped ZrO2 (cubic) catalyst, methyl ethyl ketone, propane}, issn = {0009-2509}, doi = {10.1016/j.ces.2004.10.028}, author = {Choudhary, Vasant R. and Deshmukh, G. M.} } @article { ISI:000226471300007, title = {Kinetics of the complete combustion of dilute propane and toluene over iron-doped ZrO2 catalyst}, journal = {Energy \& Fuels}, volume = {19}, number = {1}, year = {2005}, month = {JAN}, pages = {54-63}, publisher = {AMER CHEMICAL SOC}, type = {Article}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

The kinetics of the complete combustion of propane and toluene at very low concentrations in air (0.45 and 0.3 mol \% in air, respectively) over iron-doped ZrO2 (cubic) catalyst (Fe/Zr = 0.25) at different temperatures (598-723 K) in kinetic control regime have been investigated. The combustion rate data could be fitted very well to both the power-law and redox (Mars-Van Krevelen) models. However, the redox model provided a better fit to the kinetic data for the propane combustion. It also showed a better fit to the toluene combustion data at the lower temperatures (623 K). The reaction order (with respect to the hydrocarbon), apparent activation energy, and frequency factor (from the power-law model) for the propane combustion were 0.96 (average), 21.16 kcal/mol, and 4.67 x 10(5) Mol g(-1) h(-1) kPa(-n), respectively, and those for the toluene combustion were 0.77 (average), 26.08 kcal/mol, and 1.48 x 10(7) mol g(-1) h(-1) kPa(-n), respectively.

}, issn = {0887-0624}, doi = {10.1021/ef0498871}, author = {Choudhary, Vasant R. and Deshmukh, G. M. and Mishra, D. P.} } @article { ISI:000232838800009, title = {Knowledge incorporated support vector machines to detect faults in Tennessee Eastman Process}, journal = {Computers \& Chemical Engineering}, volume = {29}, number = {10}, year = {2005}, month = {SEP}, pages = {2128-2133}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, type = {Article}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

A support vector machine with knowledge incorporation is applied to detect the faults in Tennessee Eastman Process, a benchmark problem in chemical engineering. The knowledge incorporated algorithm takes advantage of the information on horizontal translation invariance in tangent direction of the instances in dataset. This essentially changes the representation of the input data while training the algorithm. These local translations do not alter the class membership of the instances in the dataset. The results on binary as well as multiple fault detection justify the use of knowledge incorporation. (c) 2005 Elsevier Ltd. All rights reserved.

}, keywords = {fault detection, knowledge, support vector machines, Tennessee Eastman Process}, issn = {0098-1354}, doi = {10.1016/j.compchemeng.2005.06.006}, author = {Kulkarni, A. and Jayaraman, Valadi K. and Kulkarni, B. D.} } @article { ISI:000229478400004, title = {Kunitz trypsin inhibitor from chickpea (Cicer arietinum L.) that exerts anti-metabolic effect on podborer (Helicoverpa armigera) larvae}, journal = {Plant Molecular Biology}, volume = {57}, number = {3}, year = {2005}, month = {FEB}, pages = {359-374}, publisher = {SPRINGER}, type = {Article}, address = {VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS}, abstract = {

Chickpea (Cicer arietinum L.) seeds contain Bowman-Birk proteinase inhibitors, which are ineffective against the digestive proteinases of larvae of the insect pest Helicoverpa armigera. We have identified and purified a low expressing proteinase inhibitor (PI), distinct from the Bowman-Birk Inhibitors and active against H. armigera gut proteinases (HGP), from chickpea seeds. N-terminal sequencing of this HGP inhibitor revealed a sequence similar to reported pea (Pisum sativum) and chickpea alpha-L-fucosidases and also homologous to legume Kunitz inhibitors. The identity was confirmed by matrix assisted laser desorption ionization - time of flight analysis of tryptic peptides and isolation of DNA sequence coding for the mature protein. Available sequence data showed that this protein forms a distinct phylogenetic cluster with Kunitz inhibitors from Glycine max, Medicago truncatula, P. sativum and Canavalia lineata. The isolated coding sequence was cloned into a yeast expression vector and produced as a recombinant protein in Pichia pastoris. alpha-L-fucosidase activity was not detectable in purified or recombinant protein, by solution assays. The recombinant protein did not inhibit chymotrypsin or subtilisin activity but did exhibit stoichiometric inhibition of trypsin, comparable to soybean Kunitz trypsin inhibitor. The recombinant protein exhibited higher inhibition of total HGP activity as compared to soybean kunitz inhibitor, even though it preferentially inhibited HGP-trypsins. H. armigera larvae fed on inhibitor-incorporated artificial diet showed significant reduction in average larval weight after 18 days of feeding demonstrating potent antimetabolic activity. The over-expression of this gene in chickpea could act as an endogenous source of resistance to H. armigera.

}, keywords = {Chickpea, Cicer arietinum, fucosidase, Helicoverpa armigera, Kunitz, Proteinase inhibitor}, issn = {0167-4412}, doi = {10.1007/s11103-004-7925-2}, author = {Srinivasan, A. and Giri, Ashok P. and Harsulkar, Abhay M. and Gatehouse, J. A. and Gupta, Vidya S.} } @article { ISI:000244614500012, title = {Kinetics of hexene-1 polymerization using [(N,N {\textquoteleft}-diisopropylbenzene)-2,3-(1,8-napthyl)-1,4-diazabutadiene] dibromonickel/methylaluminoxane catalyst system}, journal = {Journal of Polymer Science Part A-Polymer Chemistry}, volume = {45}, number = {6}, year = {2007}, month = {MAR}, pages = {1093-1100}, publisher = {JOHN WILEY \& SONS INC}, type = {Article}, address = {111 RIVER ST, HOBOKEN, NJ 07030 USA}, abstract = {

{Kinetics of hexene-1 polymerization was investigated using [(N,N{\textquoteright}-diiso-propylbenzene)2,3-(1,8-napthly)-1,4-diazabutadiene]/dibro monickel/methylaluminoxane catalyst. Experiments were performed at varying catalyst and monomer concentrations in the temperature range of -10 to 35 degrees C. First order time-conversion plot shows a downward curvature at temperatures of 20 degrees C and 35 degrees C indicating the presence of finite termination reactions. A nonlinear plot of degree of polymerization (P-n) with respect to conversion indicates occurrence of transfer reactions and slow initiation. The experimental molar masses are higher than predicted, which implies that a fraction of catalyst species could not be activated or is deactivated at the early stages of the reactions. The efficiency of the catalyst (Cat(eff)) varies from 0.77 to 0.89. The observed polydispersity of the poly(hexene-1) s is in the range of 1.18-1.48. The reaction order was found to be 1.11 with respect to catalyst. The Arrhenius plot obtained using the overall propagation rate constant, k(p), at five different temperatures (-10, 0, 10, 20, and 35 degrees C) was found to be linear with an activation energy

}, keywords = {Activation energy, chain transfer, degree of polymerization, hexene-1, kinetics (polym.), nickel (alpha-diimine)}, issn = {0887-624X}, doi = {10.1002/pola.21852}, author = {Subramanyam, Ummadisetty and Sivaram, Swaminathan} } @article { ISI:000246157400036, title = {Kinetics of reductive alkylation of p-phenylenediamine with methyl ethyl ketone using 3\% Pt/Al2O3 catalyst in a slurry reactor}, journal = {Industrial \& Engineering Chemistry Research}, volume = {46}, number = {10}, year = {2007}, month = {MAY}, pages = {3243-3254}, publisher = {AMER CHEMICAL SOC}, type = {Article}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

Intrinsic kinetics of reductive alkylation of p-phenylenediamine (PPDA) with methyl ethyl ketone (MEK) using 3\% Pt/Al2O3 catalyst was studied in a slurry reactor. The overall reaction involves a combination of parallel and consecutive reactions involving equilibrium noncatalytic (homogeneous) and catalytic (heterogeneous) steps. For the purpose of kinetic modeling, the effects of PPDA concentration, catalyst loading, agitation speed, and partial pressure of hydrogen were studied in a temperature range of 373-413 K. Quantitative criteria were used to ensure that the reaction occurred in the kinetic regime. Different rate equations have been considered based on the elementary steps involving catalytic and noncatalytic reactions, which lay stress on the different types of interactions occurring between the reactants and the active catalyst sites. The best-fit rate model has been proposed by rigorous optimization and model discrimination procedures, by simulating the experimental concentration-time data. For the best-fit model, the agreement between the predicted and experimental data was found to be very good over a wide range of operating conditions.

}, issn = {0888-5885}, doi = {10.1021/ie0608556}, author = {Patil, Narendra G. and Roy, Debdut and Chaudhari, Amit S. and Chaudhari, Raghunath V.} } @article { ISI:000254229100016, title = {Kinetic modeling of liquid phase autoxidation of cumene}, journal = {Chemical Engineering Journal}, volume = {137}, number = {2}, year = {2008}, month = {APR}, pages = {308-319}, publisher = {ELSEVIER SCIENCE SA}, type = {Article}, address = {PO BOX 564, 1001 LAUSANNE, SWITZERLAND}, abstract = {

A new kinetic model for the liquid phase autoxidation of cumene has been developed utilizing the existing knowledge about the traditional free-radical mechanism involving the initiation of the free-radicals, the chain propagation and transfer and the various modes of radical termination. Unlike previous work, in the re-organized reaction network an important cross-termination step replaces an often used but less likely one and a new derivation of the rate model has been provided. A base set of rate parameters for the elementary steps within this reaction network were chosen, many of them were same or very similar to those published in the literature, with a few critical ones re-estimated for correct match with directly observed kinetic data reported in the literature on cumene oxidation in bench scale reactors. Embedding this kinetic sub-model within a simple reaction engineering model for a single air-sparged continuous cumene oxidator, the liquid oxidate composition at the reactor exit could be predicted that compared closely with some limited published data from an industrial reactor. It is hoped that the kinetic model presented here would be a useful tool in the analysis and design of other autoxidation reactors as well with minor adaptations. (c) 2007 Elsevier B.V. All rights reserved.

}, keywords = {air-sparged continuous oxidator, cumene oxidation, free-radical mechanism, kinetic model, liquid phase autoxidation}, issn = {1385-8947}, doi = {10.1016/j.cej.2007.04.043}, author = {Bhattacharya, Arijit} } @article { ISI:000255905400010, title = {Kinetics of PbCrO(4) nanorod growth by oriented attachment at the air-water interface}, journal = {Journal of Physical Chemistry C}, volume = {112}, number = {20}, year = {2008}, month = {MAY}, pages = {7557-7561}, publisher = {AMER CHEMICAL SOC}, type = {Article}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

Oriented attachment is a new way of crystal growth to transform preformed nanoparticles into hierarchical assemblies. Here, we demonstrate the use of liquid-liquid interfaces toward the formation of PbCrO(4) nanoparticles and their subsequent time-dependent self-assembly at the air-water interface into nanorods by oriented attachment. EDAX and XPS analysis indicate the formation of stoichiometric PbCrO(4). TEM studies at different stages of aging reveal that the transformation from nanoparticles to nanorods is kinetically governed. HRTEM analysis indicates nanorod growth along the [110] plane. UV-visible spectra reveal the presence of peaks at 425 and 515 nm for nanorods, while for the nanoparticle sample, a single peak at 425 urn is evident. As formation of ultrathin films over a large area (typically equal to or greater than 1 mu m x 1 mu m) concomitantly accompanies this approach, it can be extended to other materials as well for nanostructured device applications.

}, issn = {1932-7447}, doi = {10.1021/jp801577y}, author = {Hawaldar, Ranjit R. and Sathaye, Shivaram D. and Harle, Arti S. and Gholap, Ramkrishna S. and Patil, Kashinath R.} } @article { ISI:000262582400008, title = {Kinetic evidence for the influence of subsurface oxygen on palladium surfaces towards CO oxidation at high temperatures}, journal = {Chemistry-an Asian Journal}, volume = {4}, number = {1}, year = {2009}, month = {OCT}, pages = {74-80}, publisher = {WILEY-V C H VERLAG GMBH}, address = {PO BOX 10 11 61, D-69451 WEINHEIM, GERMANY}, abstract = {

Transient state kinetics of the catalytic oxidation of CO with 0, on Pd-surfaces has been measured under isothermal conditions by using a molecular beam approach. Systematic studies were carried out as a function of reaction temperature and CO+O(2) composition. With sufficient kinetic evidence, we have demonstrated the positive influence of subsurface oxygen towards CO-adsorption and oxidation to CO, at high temperatures (600-900 K) on Pd-surfaces, and the likely electronic nature of the surface changes with oxygen in the subsurface. These studies also provide a direct proof for CO-adsorption with a significantly reactive sticking coefficient at high temperatures on Pd-surfaces exhibiting a significant subsurface O-coverage.

}, keywords = {Adsorption, kinetics, Oxidation, Palladium, surface analysis}, issn = {1861-4728}, doi = {10.1002/asia.200800278}, author = {Gopinath, Chinnakonda S. and Thirunavukkarasu, Kandasamy and Nagarajan, Sankaranarayanan} } @article { ISI:000268905100015, title = {Kinetics of arylation of 3-bromo-benzophenone with n-butylacrylate using NC palladacycle catalyst}, journal = {Journal of Molecular Catalysis A-Chemical}, volume = {309}, number = {1-2}, year = {2009}, month = {AUG}, pages = {111-116}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

The kinetics of arylation of n-butylacrylate (n-BA) with 3-bromo-benzophenone (BBP) using a monomeric palladacycle complex [Pd(ppy)(PPh(3))(OTs)](ppy=2-phenylpyridine) catalyst has been studied. The effect of concentration of the substrate, base (NaOAc), and catalyst was studied at three different temperatures (413-433 K). The rate was found to be first order with respect to catalyst, first order tending to zero order with respect to n-butylacrylate and NaOAc concentrations. The rate passed through a maximum with variation of BBP concentration. The observed results have been explained on the basis of formation of Pd species (PdX(2), PdX(3)(-), PdX(4)(2-), and Pd(2)X(6)(2-)) which are inactive for the Heck reaction. Various empirical rate equations were considered to fit the rate data and the best fitting model has been selected. The rates predicted by model were found to be in good agreement with the observed experimental data. (C) 2009 Elsevier B.V. All rights reserved.

}, keywords = {Arylation, Heck reaction, kinetics, Palladacycle}, issn = {1381-1169}, doi = {10.1016/j.molcata.2009.05.003}, author = {Atla, Shashi B. and Rajurkar, Kalpendra B. and Kelkar, Ashutosh A. and Chaudhari, Raghunath V.} } @article { ISI:000281430800001, title = {Kinetic model of TBP auto-regulation exhibits bistability}, journal = {Biology Direct}, volume = {5}, year = {2010}, month = {AUG}, pages = {50}, publisher = {BIOMED CENTRAL LTD}, address = {236 GRAYS INN RD, FLOOR 6, LONDON WC1X 8HL, ENGLAND}, abstract = {

Background: TATA Binding Protein (TBP) is required for transcription initiation by all three eukaryotic RNA polymerases. It participates in transcriptional initiation at the majority of eukaryotic gene promoters, either by direct association to the TATA box upstream of the transcription start site or by indirectly localizing to the promoter through other proteins. TBP exists in solution in a dimeric form but binds to DNA as a monomer. Here, we present the first mathematical model for auto-catalytic TBP expression and use it to study the role of dimerization in maintaining the steady state TBP level. Results: We show that the autogenous regulation of TBP results in a system that is capable of exhibiting three steady states: an unstable low TBP state, one stable state corresponding to a physiological TBP concentration, and another stable steady state corresponding to unviable cells where no TBP is expressed. Our model predicts that a basal level of TBP is required to establish the transcription of the TBP gene, and hence for cell viability. It also predicts that, for the condition corresponding to a typical mammalian cell, the high-TBP state and cell viability is sensitive to variation in DNA binding strength. We use the model to explore the effect of the dimer in buffering the response to changes in TBP levels, and show that for some physiological conditions the dimer is not important in buffering against perturbations. Conclusions: Results on the necessity of a minimum basal TBP level support the in vivo observations that TBP is maternally inherited, providing the small amount of TBP required to establish its ubiquitous expression. The model shows that the system is sensitive to variations in parameters indicating that it is vulnerable to mutations in TBP. A reduction in TBP-DNA binding constant can lead the system to a regime where the unviable state is the only steady state. Contrary to the current hypotheses, we show that under some physiological conditions the dimer is not very important in restoring the system to steady state. This model demonstrates the use of mathematical modelling to investigate system behaviour and generate hypotheses governing the dynamics of such nonlinear biological systems.

}, issn = {1745-6150}, doi = {10.1186/1745-6150-5-50}, author = {Gokhale, Sucheta A. and Roshan, Reema and Khetan, Vivek and Pillai, Beena and Gadgil, Chetan J.} } @article { ISI:000276206700037, title = {Kinetics of reductive alkylations of phenylenediamines: influence of substrates isomeric structure}, journal = {Chemical Engineering Science}, volume = {65}, number = {1, SI}, year = {2010}, note = {20th International Symposium on Chemical Reaction Engineering, Kyoto, JAPAN, SEP, 2008}, month = {JAN}, pages = {232-239}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

Reductive alkylation of ortho-, meta- and para-phenylenediamines (PDAs) with methyl ethyl ketone (MEK) has been studied in a semi-batch slurry reactor in the presence of a commercial 3\% Pt/Al(2)O(3) catalyst. It was observed that the PDA isomers differ remarkably from each other in their activity in reductive alkylation and product distribution. The activity was found to decrease in the following order: PPDA \> OPDA \> MPDA. To understand the substrate structure-activity correlation, the homogeneous equilibrium reactions involved in the alkylation step and the overall catalytic reactions were studied separately. Kinetics of reductive alkylation of PDAs with MEK as a solvent and alkylating agent with 3\% Pt/Al(2)O(3) catalyst was studied in a semi-batch slurry reactor over a temperature range of 373-453K and pressure range of 2.07-6.21 MPa. Semi-batch slurry reactor models were developed and kinetic parameters were estimated by fitting the integral batch reactor data at different temperatures to understand the influence of different reaction steps on the activity and selectivity of different products. Published by Elsevier Ltd.

}, keywords = {Batch, catalysis, kinetics, Multiphase reactions, Phenylenediamines, Reaction engineering, Reductive alkylation}, issn = {0009-2509}, doi = {10.1016/j.ces.2009.06.065}, author = {Roy, Debdut and Chaudhari, Amit S. and Chaudhari, Raghunath V.} } @article { ISI:000288434800016, title = {Kinetics studies and mechanism evolution of the epoxidation of styrene over nanoporous Au doped TS-1}, journal = {Polish Journal of Chemical Technology}, volume = {12}, number = {4}, year = {2010}, month = {JAN}, pages = {72-78}, publisher = {VERSITA}, address = {SOLIPSKA 14A-1, 02-482 WARSAW, POLAND}, abstract = {

{A kinetic investigation of the slurry phase epoxidation of styrene with hydrogen peroxide has been carried out, for the first time, over nanoporous Au doped TS-1 catalyst, in a batch reactor, in the temperature range of 313-333 K. It was found that product selectivity and the rate of reaction are greatly influenced by concentrations of styrene and hydrogen peroxide. Kinetics studies reveal that the mechanism of the reaction is of the {\textquoteleft}{\textquoteleft}Redox{\textquoteright}{\textquoteright} type. The rate equation

}, keywords = {Au/TS-1, epoxidation, kinetics, styrene, Styrene oxide}, issn = {1509-8117}, doi = {10.2478/v10026-010-0054-6}, author = {Saxena, Samidha and Dwivedi, Reena and Bhadauria, Sheenu and Chumbhale, Vilas R. and Prasad, Rajendra} } @article { ISI:000288015800010, title = {Kinetics of hydroformylation of 1-octene in ionic liquid-organic biphasic media using rhodium sulfoxantphos catalyst}, journal = {Chemical Engineering Science}, volume = {66}, number = {8}, year = {2011}, month = {APR}, pages = {1631-1639}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

Biphasic hydroformylation of 1-octene was performed using rhodium sulfoxantphos catalyst dissolved in [BuPy][BF(4)] ionic liquid. Preliminary experiments proved this system to retain the catalytic complex within the ionic liquid phase and to maintain a high selectivity towards the linear aldehyde (n:iso ratio of 30) over several cycles. Process parameter investigation showed a first order dependence of the initial rate with respect to the catalyst and 1-octene concentrations, but a more complex behavior with respect to hydrogen (fractional order) and carbon monoxide partial pressures (inhibition at high pressures). Different mathematical models were selected based on the trends observed and evaluated for data fitting. Also, rate models were derived from a proposed mechanism, using Christiansen matrix approach. To calculate concentrations of substrates in the catalytic phase as required by this kinetic modeling, solubility measurements were preformed for the gases (pressure drop technique), as well as for 1-octene and n-nonanal (thermogravimetry analysis). (C) 2011 Elsevier Ltd. All rights reserved.

}, keywords = {Biphasic catalysis, Butylpyridinium tetrafluoroborate, kinetics, Parameter identification, Reaction engineering, solubility}, issn = {0009-2509}, doi = {10.1016/j.ces.2010.12.040}, author = {Deshpande, R. M. and Kelkar, Ashutosh A. and Sharma, A. and Julcour-Lebigue, C. and Delmas, Henri} } @article { ISI:000293419700048, title = {Kinetics of nitric oxide adsorption on Pd(111) surfaces through molecular beam experiments: a quantitative study}, journal = {Journal of Physical Chemistry C}, volume = {115}, number = {31}, year = {2011}, month = {AUG}, pages = {15487-15495}, publisher = {AMER CHEMICAL SOC}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

A detailed kinetic picture derived by molecular beam studies of the adsorption-desorption of the NO/Pd(111) system is presented. Numerical simulations and detailed kinetic analysis show that the precursor state model of adsorption provides a valid picture of the sticking coefficient variation with surface coverage, especially at low temperatures. At higher temperatures, the precursor model gives way to the Langmuir molecular model of adsorption. All the parameters of the precursor state model have been quantified. Temperature programmed desorption (TPD) studies further show that there is a slight repulsive interaction between adsorbed NO molecules and there is only a negligible fraction of dissociated molecules on the surface for temperatures less than 500 K, as the Pd(111) surface is defect free. A Bragg-Williams (BW) lattice gas model with repulsive interactions, within the framework of mean field approach (MFA), is shown to describe the TPD spectra reasonably well.

}, issn = {1932-7447}, doi = {10.1021/jp203992r}, author = {Nagarajan, Sankaranarayanan and Thirunavukkarasu, Kandasamy and Gopinath, Chinnakonda S. and Prasad, Sudarsan D.} } @article { ISI:000309569200044, title = {Kernel morphometric traits in hexaploid wheat (Triticum aestivum L.) are modulated by intricate QTL x QTL and genotype x environment interactions}, journal = {Journal of Cereal Science}, volume = {56}, number = {2}, year = {2012}, month = {SEP}, pages = {432-439}, publisher = {ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD}, address = {24-28 OVAL RD, LONDON NW1 7DX, ENGLAND}, abstract = {

Wheat kernel size and shape influence its flour yield and market price. A hexaploid wheat population of 185 recombinant inbred lines was evaluated for five kernel morphometric traits namely, 1000-kernel weight, kernel length, width, length width ratio and factor form density in two diverse agro-climatic regions in India in five to eight year location combinations. Additive main effects and multiplicative interaction analysis revealed significant contributions from genotype (G) and genotype x environment (G x E) effects for these traits. Quantitative trait locus (QTL) analysis by composite interval mapping (CIM) was performed using a linkage map of 251 SSR markers and 59 QTLs distributed on 16 chromosomes were identified. The majority of the QTLs were located on the D genome (44.07\%) and the homeologous chromosomes of Group 2 (38.98\%). Stable QTLs detected in three or more year location combinations were identified for four traits. Multi-trait CIM showed 10 chromosomal regions harboring putative pleiotropic loci. Complexity in the genetic effects was further revealed by QTL analysis based on mixed-linear model that indicated 19 QTLs with significant individual effects (main-effect QTLs) and 14 QTL x QTL interactions. Five of these - nineteen main-effect QTLs and one of the fourteen QTL x QTL interactions showed environmental influence. (c) 2012 Elsevier Ltd. All rights reserved.

}, keywords = {Epistatic QTLs, Genotype x environment interactions, Kernel size and shape, Stable QTLs}, issn = {0733-5210}, doi = {10.1016/j.jcs.2012.05.010}, author = {Prashant, Ramya and Kadoo, Narendra Y. and Desale, Charushila and Kore, Prajakta and Dhaliwal, Harcharan Singh and Chhuneja, Parveen and Gupta, Vidya} } @article { ISI:000300999700014, title = {Kinetic analysis of 4-isopropylphenol hydrogenation over activated carbon-supported rhodium catalysts in supercritical carbon dioxide solvent}, journal = {Green Chemistry}, volume = {14}, number = {3}, year = {2012}, month = {Jan}, pages = {633-638}, publisher = {ROYAL SOC CHEMISTRY}, type = {Article}, address = {THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND}, abstract = {

Hydrogenation behavior of 4-isopropylphenol to 4-isopropylcyclohexanol over activated carbon-supported rhodium catalysts in supercritical carbon dioxide (scCO(2)) at 313 K was studied in a batch reactor and the results were compared with those in 2-propanol. Higher yields of cis-4-isopropylcyclohexanol were obtained in scCO(2) than in 2-propanol, and the formation of a byproduct, isopropylcyclohexane, was suppressed in scCO(2). The catalyst modification with hydrochloric or phosphoric acid enhanced the yield of cis-4-isopropylcyclohexanol in both scCO(2) and 2-propanol solvents. Kinetic analyses of the reaction profiles revealed higher reaction rates in scCO(2) than those in 2-propanol for the 4-isopropylcyclohexanol formation both by the direct hydrogenation of 4-isopropylphenol and by the consecutive hydrogenation of 4-isopropylcyclohexanone, and also revealed that the addition of hydrochloric acid increased the consecutive hydrogenation rate of 4-isopropylcyclohexanone to cis-4-isopropylcyclohexanol, which reduced the total reaction time needed for the complete hydrogenation of 4-isopropylphenol to 4-isopropylcyclohexanol.

}, issn = {1463-9262}, doi = {10.1039/c1gc16038a}, author = {Hiyoshi, Norihito and Sato, Osamu and Yamaguchi, Aritomo and Rode, Chandrashekhar V. and Shirai, Masayuki} } @article {43378, title = {Kinetic modeling and optimization of operating parameters for transvinylation of lauric acid}, journal = {International Journal of Chemical Kinetics}, volume = {44}, year = {2012}, month = {SEP}, pages = {624-634}, abstract = {The transition metal complex catalyzed transvinylation of carboxylic acid with vinyl acetate monomer is of significant interest to industry. The palladium complex catalyzed transvinylation of lauric acid using vinyl acetate monomer is a reversible reaction. In present article, design of experiments (DOE) statistics is used to study effects of various operating parameters on transvinylation of lauric acid. The kinetic parameters forward and backward rate constants and the thermodynamic parameters such as equilibrium constant and energy of activation of the transvinylation of lauric acid were estimated using the Dynochem model. The optimum operating parameters for the transvinylation of lauric acid were then predicted using the Dynochem model and verified by performing the actual experiments to validate the model. It was found that the experimental results match with the predicted one. (c) 2012 Wiley Periodicals, Inc. Int J Chem Kinet 44: 624634, 2012}, doi = {10.1002/kin.20704}, author = {Kamble, Sanjay P. and Manjarekar, Onkar and Mawale, Ravi and Kulkarni, Bhaskar D. and Chowdary, Naresh and Gupte, Milind Y. and Barve, Prashant P.} } @article { ISI:000304338300004, title = {Kinetic studies of amino acid-based surfactant binding to DNA}, journal = {Journal of Physical Chemistry B}, volume = {116}, number = {20}, year = {2012}, month = {MAY}, pages = {5831-5837}, publisher = {AMER CHEMICAL SOC}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

In this work, the binding kinetics of amino acid-based surfactants, presenting different linkers and head groups, with calf thymus (CT)-DNA was studied using stopped-flow fluorescence spectroscopy. The kinetic studies were carried out as a function of Na+ concentration and surfactant-to-DNA charge ratio. The surfactant binding on DNA took place in two consecutive steps, for which the corresponding first and second relative rate constants (k(1) and k(2)) were determined. The fast step was attributed to the surfactant binding to DNA and micelle formation in its vicinity, the slower step to DNA condensation and possible rearrangement of the surfactant aggregates. In general, both relative rate constants increase with surfactant concentration and decrease with the ionic strength of the medium. The architecture of the surfactant was found to have a significant impact on the kinetics of the DNA surfactant complexation. Surfactants with amide linkers showed larger relative rate constants than those with ester linkers. The variation of the relative rate constants with the head groups of the surfactants, alanine and proline, was found to be less obvious, being partially dependent on the surfactant concentration.

}, issn = {1520-6106}, doi = {10.1021/jp301069t}, author = {Santhiya, Deenan and Dias, Rita S. and Dutta, Sounak and Das, Prasanta Kumar and Miguel, Maria G. and Lindman, Bjorn and Maiti, Souvik} } @article { ISI:000305033900088, title = {Kinetics of hydrogenation of lauric acid in a batch slurry reactor using Ru-Sn/TiO2 catalyst}, journal = {Asian Journal of Chemistry}, volume = {24}, number = {6}, year = {2012}, month = {JUN}, pages = {2767-2771}, publisher = {ASIAN JOURNAL OF CHEMISTRY}, address = {11/100 RAJENDRA NAGAR, SECTOR 3,, SAHIBABAD 201 005, GHAZIABAD, INDIA}, abstract = {

Ru-Sn catalyst was prepared in-house by impregnation method. This catalyst was found to be stable for four recycles. The rate of hydrogenation of lauric acid (LAC) using Ru-Sn/TiO2 catalyst was found to be linearly dependent on catalyst loading, lauric acid concentration old hydrogen partial pressure. The rate data obtained from kinetic study were fitted to simple rate equation based on Langmuir-Hinshelwood (L-H) type model. Based on kinetic data the hydrogenation of lauric acid over Ru-Sn/TiO2 catalyst is proposed to occur by I dual site mechanism the activation energy for hydrogenation of lauric acid to lauryl alcohol (LAOH) using Rii-Sn/TiO2 catalyst was found to be 77.2 kJ/mol.

}, keywords = {Hydrogenation, kinetics, Langmuir-Hinshelwood model, Ru-Sn/TiO2 catalyst}, issn = {0970-7077}, author = {Shinde, S. B. and Deshpande, R. M.} } @article { ISI:000306193700016, title = {Kinetics of the Heck reaction in biphasic organic-ethylene glycol medium}, journal = {Reaction Kinetics Mechanisms and Catalysis}, volume = {106}, number = {2}, year = {2012}, month = {AUG}, pages = {457-473}, publisher = {SPRINGER}, address = {VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS}, abstract = {

PdCl2(bipy) was found to be an efficient and stable catalyst in biphasic medium (organic-glycol) for the Heck reaction. The kinetics of the Heck coupling of styrene with iodobenzene using the same catalyst was studied in a biphasic medium in a temperature range of 393-413 K. The rate was found to have a first order dependence tending to a fractional order, on the iodobenzene as well as catalyst concentration. The rate was found to have a complex dependence on the styrene concentration and passes through a maximum, showing typical substrate inhibition kinetics. The rate had a first order dependence on the base (morpholine) concentration. The trends observed for the influence of the different parameters on the activity of the catalyst are in agreement with the established mechanism for Heck reaction. An empirical rate model has been proposed to fit the observed rate data. The activation energy was found to be 72.91 kJ/mol. This is the first time that kinetic modeling of Heck reaction in a biphasic medium (organic-glycol) has been attempted.

}, keywords = {Biphasic catalysis, Heck reaction, kinetics, PdCl2(bipy) complex}, issn = {1878-5190}, doi = {10.1007/s11144-012-0437-1}, author = {Jagtap, Sangeeta Vijay and Deshpande, Raj Madhukar} } @article { ISI:000325949600005, title = {Kinetics and thermodynamics of glycans and glycoproteins binding to holothuria scabra lectin: a fluorescence and surface plasmon resonance spectroscopic study}, journal = {Journal of Fluorescence}, volume = {23}, number = {6}, year = {2013}, month = {NOV}, pages = {1147-1155}, publisher = {SPRINGER/PLENUM PUBLISHERS}, address = {233 SPRING ST, NEW YORK, NY 10013 USA}, abstract = {

Holothuria scabra produces a monomeric lectin (HSL) of 182 kDa. HSL showed strong antibacterial activity and induced bacterial agglutination under in vitro conditions, indicating its role in animals{\textquoteright} innate immune responses. Very few lectins have been reported from echinoderms and none of these lectins have been explored in detail for their sugar-binding kinetics. Affinity, kinetics and thermodynamic analysis of glycans and glycoproteins binding to HSL were studied by fluorescence and surface plasmon resonance spectroscopy. Lectin binds with higher affinity to O-linked than N-linked asialo glycans, and the affinities were relatively higher than that for sialated glycans and glycoproteins. T-antigen alpha-methyl glycoside was the most potent ligand having the highest affinity (Ka 8.32 x10(7) M-1). Thermodynamic and kinetic analysis indicated that the binding of galactosyl Tn-antigen and asialo glycans is accompanied by an enthalpic contribution in addition to higher association rate coupled by low activation energy for the association process. Presence of sialic acid or protein matrix inhibits binding. Higher affinity of HSL for O-glycans than N-glycans had biological implications; since HSL specifically recognizes bacteria, which have mucin or O-glycan cognate on their cell surfaces and play a major role in animal innate immunity. Since, HSL had higher affinity to T-antigen, makes it a useful tool for cancer diagnostic purpose.

}, keywords = {Holothuria scabra, Kinetic analysis, Lectin, Surface plasmon resonance spectroscopy, Thermodynamic properties}, issn = {1053-0509}, doi = {10.1007/s10895-013-1244-4}, author = {Gowda, Nagaraj M. and Gaikwad, Sushama M. and Khan, Mohammad Islam} } @article { ISI:000342315200005, title = {Kinetics of photocationically curable formulations involving glycerol diglycidyl ether and phenyl glycidyl ether}, journal = {Journal of Macromolecular Science Part A-Pure and Applied Chemistry}, volume = {51}, number = {10}, year = {2014}, month = {OCT}, pages = {788-795}, publisher = {TAYLOR \& FRANCIS INC}, address = {530 CHESTNUT STREET, STE 850, PHILADELPHIA, PA 19106 USA}, abstract = {

Kinetic analysis of formulations based on glycerol diglycidyl ether and phenyl glycidyl ether were carried out in the presence of sulfonium salt as initiator at 35 mW cm(-2) using photo differential scanning calorimeter and the final conversion was found to increase with an increase in phenyl glycidyl ether content. The effects of formulation monomer ratios at three different temperatures were studied. The variations in the observed kinetic parameters can be related to increase in mobility of reactive species with temperature, distance of counter ion from the propagating cationic center, as well as extent of crosslinking reaction which controlled the course and duration of the reaction. The applicability of autocatalytic kinetic model was also evaluated and the system underwent early gelation and the activation energy decreased with an increase in phenyl glycidyl ether content. Analysis of stable photocured films containing glycerol diglycidyl ether and phenyl glycidyl ether showed better thermal stability than rigid films obtained with glycerol diglycidyl ether.

}, keywords = {autocatalytic kinetic model, Cationic photopolymerization, Glycidyl ether, Photo DSC}, issn = {1060-1325}, doi = {10.1080/10601325.2014.937124}, author = {Harikrishna, Reghunathan} } @article { ISI:000337930900028, title = {Kocuria indica sp nov., isolated from a sediment sample}, journal = {International Journal of Systematic and Evolutionary Microbiology}, volume = {64}, number = {3}, year = {2014}, month = {MAR}, pages = {869-874}, publisher = {SOC GENERAL MICROBIOLOGY}, address = {MARLBOROUGH HOUSE, BASINGSTOKE RD, SPENCERS WOODS, READING RG7 1AG, BERKS, ENGLAND}, abstract = {

An actinobacterial strain was isolated from a sediment sample from Chorao Island, in Goa province, India, and subjected to a taxonomic investigation. The isolate, designated NIO-1021(T), was a Gram-stain positive, aerobic, non-motile and coccoid. Strain NIO-1021(T) was identified as a member of the genus Kocuria by a polyphasic approach. Strain NIO-1021(T) could be differentiated from other members of the genus Kocuria on the basis of physiology and 16S rRNA gene sequence analysis. The 16S rRNA gene sequence similarity of strain NIO-1021(T) to the most closely related species, Kocuria marina KCTC 9943(T), was 98.6\% with 19 nt differences). Furthermore, DNA-DNA hybridization analysis revealed that the novel strain had lower relatedness with the type strains of other members of the genus Kocuria. The strain formed a monophyletic clade with K. marina with 100\% bootstrap values. The major phospholipids were phosphatidylglycerol, diphosphatidylglycerol and two unidentified lipids. The predominant menaquinone was MK-7(H-2). The major fatty acids were anteiso-C-15:0, iso-C-(16:0) and anteiso-C-17:0. The DNA G+C content of strain NIO-1021(T) was 60.5 mol\%. Chemotaxonomic and phylogenetic properties of the strain were consistent with its classification as representing a member of the genus Kocuria. On the basis of phenotypic, chemotypic and molecular characteristics, strain NIO-1021(T) is considered to represent a novel species of the genus Kocuria, for which the name Kocuria indica sp. nov. is proposed, with strain NIO-1021(T) (=NCIM 5455(T)=DSM 25126(T)=CCTCC AA 209050(T)) as the type strain.

}, issn = {1466-5026}, doi = {10.1099/ijs.0.052548-0}, author = {Dastager, Syed Gulam and Tang, Shan-Kun and Srinivasan, Krishnamurthi and Lee, Jae-Chan and Li, Wen-Jun} } @article { ISI:000346188400085, title = {Kinetic and mechanistic investigations of the Baylis-Hillman reaction in ionic liquids}, journal = {RSC Advances}, volume = {5}, number = {4}, year = {2015}, month = {NOV}, pages = {2994-3004}, publisher = {ROYAL SOC CHEMISTRY}, address = {THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND}, abstract = {

We report here a quantitative study of the kinetics and mechanism of the Baylis-Hillman reaction in the presence of ionic liquids as solvent media. Apparently, a simple Baylis-Hillman reaction can occur by two different exclusive mechanisms in ionic liquids. The delicate balance of these mechanisms is maintained by the ionic environment employed. The main features of the possible mechanism have been described here along with interesting kinetic consequences. The measurement of rate constants and activation energy parameters demonstrate that as the medium becomes basic, the order of the reaction changes from 1 to 2. An unexpected change in the mechanism of the reaction is observed with a change in the nature of the ionic liquid. The Linear Solvation Energy Relationship has also been used as an investigating tool to delineate the respective contributions of the cation and anion of the ionic liquid. The observation strongly dictates the dependency of the mechanism of the Baylis-Hillman reaction on the nature of the anion of the ionic liquids undertaken for this study.

}, issn = {2046-2069}, doi = {10.1039/c4ra14764b}, author = {Singh, Anshu and Kumar, Anil} } @article {43393, title = {Kinetic studies on an algal biofilm reactor for raw sewage water treatment}, journal = {Chemical Engineering \& Technology}, volume = {39}, year = {2016}, month = {SEP}, pages = {1629-1635}, abstract = {A packed-bed algae biofilm reactor was developed using porous and nonporous dual packings. The biofilm was cultivated on reticulated polyurethane foam cubes. The nonporous glass Raschig rings were taken as bed support that helps to remove generated gas from the system. The effect of variables such as column length-to-diameter ratio, catalyst cube dimension, and feed flow rate on the treatment of sewage water was studied. The reaction kinetics indicates that the nutrients uptake rate is dependent on both pore and film diffusion. The kinetics of uptake of nutrients follows a pseudo first-order reaction. From the pseudo reaction rate constant, Thiele modulus and effectiveness factor were calculated and a kinetic model equation for fractional nutrient uptake was developed in terms of operating variables. The model can predict the reaction rate with low deviation. The results obtained may be valuable for large-scale treatment of sewage water.}, doi = {10.1002/ceat.201500447}, author = {Gera, Gayatri S. and Yewalkar, Swati N. and Nene, Sanjay and Kulkarni, Bhaskar D. and Kamble, Sanjay P.} } @inbook {45814, title = {Kinetic model for extraction of betulinic acid by batch extraction from leaves of syzygium cumini (Jamun)}, booktitle = {Novel Water treatment and separation methods: simulation of chemical processew}, year = {2017}, pages = {179-190}, publisher = {Apple Academic Press}, organization = {Apple Academic Press}, chapter = {Kinetic model for extraction of betulinic acid by batch extraction from leaves of syzygium cumini (Jamun)}, abstract = {

Plants are one of the most important sources of medicines. Syzygium cumini known as {\textquotedblleft}jamun{\textquotedblright} in Hindi which is found in throughout India. The leaves are having promising therapeutic value with its various phyto constituents such as tannin, alkaloids, flavonoids, terpenoids, fatty acid, phenol, minerals, carbohydrates, and vitamins. All these phyto constituents are analyzed by qualitative analysis method. Betulinic acid is a naturally occurring pentacyclic triterpenoid compound. The medicinal application of betulinic acid is available for diabetes, cancer cell, and HIV. Betulinic acid shows more solubility for methanol. For extraction of betulinic acid, different extraction techniques like batch extraction and Soxhlet extraction techniques are used. The effect of various parameters like particle size, agitations speed, temperature, and solid loading is studied. To explain the extraction of biological material from plant sources different model equations are used which describes sorption isotherms of material. The experimental data of solid loading and temperature are best fitted by using second order Peleg{\textquoteright}s model. From this model the linearized Arrhenius equation was obtained and temperature dependency was 0.567 kJ/mol. The aim of this study is to find out the best kinetic model for extraction and experimental data shows the good agreement of betulinic acid with methanol which justifies batch extraction process.

}, doi = {10.1201/9781315225395}, author = {Admane, S. V. and Gaikwad, S. G. and Chavan, S. M.} } @article {43805, title = {Kinetic profile and catalytic activity of transition metal-based ionic liquids for reduction of nitroarenes via in situ formation of nanoparticles}, journal = {Chemistryselect}, volume = {2}, year = {2017}, month = {AUG}, pages = {6833-6843}, type = {Article}, abstract = {

The experimentally determined apparent rate constant (k(app)) shows that the [BmIm](2)[PdCl4] and [BmIm](2)[NiCl4] act as effective catalysts for the reduction of nitroarenes to aminoarenes in the presence of NaBH4. The TEM, XPS, XRD and dynamic light scattering studies show that there is in situ formation of Pd and Ni metal Nanoparticles (NPs) from the reduction of [BmIm](2)[PdCl4] and [BmIm](2)[NiCl4], respectively which are responsible for the enhancement in the catalytic activity. Thus, in the presence of the ionic liquid stabilized metal NPs show higher catalytic activity in comparison to the NPs stabilized with other capping agents as reported. The order of k(app) as 1) PNP \> 2-BrPNP \> 2-APNP and 2) PNP \> ONP \> 2-NR for reduction of nitroarenes using [BmIm](2)[PdCl4] and [BmIm](2)[NiCl4] and its correlation explained on the basis of electronic structure and hydrogen bonding ability of nitroarenes. The thermodynamic parameters such as E-a, Delta H-$\#$, Delta S-$\#$ and Delta G($\#$) are in agreement with the surface catalyzed reduction reaction of PNP in the presence of NPs as catalyst. The kapp values illustrated the reduction reaction follow the LangmuirHinshelwood (L-H) mechanism.

}, doi = {10.1002/slct.201701601}, author = {Thawarkar, Sachin R. and Khupse, Nageshwar D. and Kumar, Anil} } @article {45687, title = {Kinetics and thermodynamics of transpeptidation catalysed by Bacillus subtilis gamma glutamyl transferase}, journal = {Indian Journal of Biochemistry and Biophysics }, volume = {54 }, year = {2017}, month = {JUN}, pages = {109-113}, type = {Article}, abstract = {Gamma glutamyl transferases (GGT) catalyse the removal (deglutamylation) of the terminal gamma-glutamate residue from compounds such as glutathione and poly-gamma-glutamic acid and its transfer either to a water molecule (hydrolysis) or to a peptide/amino acid (transpeptidation). We analysed the kinetics of Bacillus subtilis GGT (BsGGT) catalysed transpeptidation using gamma-glutamyl-(3-carboxyl)-4-nitroaniline as the gamma-glutamate-donor and glycylglycine (Gly-Gly) as the gamma-glutamate acceptor. Addition of Gly-Gly improved the affinity (Km) of the enzyme for gamma-glutamyl-(3-carboxyl)-4-nitroaniline by nearly 25 times with negligible impact on the rate of deglutamylation (V-max). The asymmetric changes in the kinetic parameters improved the specificity constant (K-cat/K-m.) by about 43 times. BsGGT catalysed transpeptidation was pronounced in conditions that are unfavorable for hydrolysis. Maximum transpeptidation occurred near neutral pH and when the concentration of the gamma-glutamate-donor substrate is lower. The effect of Gly-Gly on the kinetics of BsGGT is contrastingly different from that observed for eukaryotic GGTs. In the case of mammalian GGTs, the addition of Gly-Gly increases both Km and k(cat); and, the specificity constant (K-cat/K-m) remains unaltered}, author = {Balakrishna, Sharath and Prabhune, Asmita A.} } @article {45770, title = {Kocuria indica sp. nov., isolated from a sediment sample (vol 64, pg 869, 2014)}, journal = {International Journal of Systematic and Evolutionary Microbiology}, volume = {67}, year = {2017}, month = {MAY}, pages = {1620}, type = {Correction}, chapter = {1620}, issn = {1466-5026}, doi = {10.1099/ijsem.0.002077}, author = {Dastager, Syed G. and Tang, Shan-Kun and Srinivasan, Krishnamurthi and Lee, Jae-Chan and Li, Wen-Jun} } @article {45526, title = {Kinetic investigation for the catalytic reduction of nitrophenol using ionic liquid stabilized gold nanoparticles}, journal = {RSC Advances}, volume = {8}, year = {2018}, month = {NOV}, pages = {38384-38390}, type = {Article}, abstract = {We demonstrate the synthesis of gold nanoparticles (AuNP) stabilized by 1-butyl-3-hexadecyl imidazolium bromide (Au@[C4C16Im]Br) and their use as a catalyst for the reduction of nitrophenol. The AuNPs show excellent stability in presence of [C4C16Im]Br ionic liquids for the reduction of 4-nitrophenol and 2-nitrophenol using NaBH4 as a reducing agent. The detailed kinetics for the reduction of 4-nitrophenol and 2-nitrophenol were investigated and the catalytic activity of Au@[C4C16Im]Br was evaluated. The pseudo first-order rate constant (kapp) values for 4-nitrophenol was observed to be greater than that of 2-nitrophenol and explained on the basis of hydrogen bonding present in 2-nitrophenol. Au@[C4C16Im]Br showed good separability and reusability and hence, it can be used for the complete reduction of nitrophenols in multiple cycles. The Langmuir{\textendash}Hinshelwood reaction mechanism is elucidated for reduction of 4-nitrophenol by Au@[C4C16Im]Br nanocatalyst on the basis of the kapp values. The thermodynamic activation parameters such as activation energy, enthalpy of activation and entropy of activation were determined and explained using the temperature dependent kinetics for the reduction of nitrophenol using Au@[C4C16Im]Br. The above results reveal that the Au@[C4C16Im]Br nanocatalyst demonstrates excellent catalytic performance for the reduction of nitrophenol by NaBH4 at room temperature. }, doi = {10.1039/c8ra07404f}, author = {Thawarkar, S.R. and Thombare, B. and Munde, B.S. and Khupse, N.D.} } @article {44201, title = {Kinetic promotion of methane hydrate formation by combining anionic and silicone surfactants: scalability promise of methane storage due to prevention of foam formation}, journal = {Journal of Chemical Thermodynamics}, volume = {117}, year = {2018}, month = {FEB}, pages = {248-255}, type = {Article}, abstract = {

Methane storage in its solid hydrate form has recently come up as a rather attractive and low risk option for large scale storage of the gas owing to its mild storage conditions, high gas retention capacity and benign (non-explosive) character. However, it has its fair share of limitations with the slow rate of hydrate formation being one of the most prominent. The addition of surfactants like Sodium dodecyl sulfate (SDS) to the hydrate forming system significantly speeds up the process of methane hydrate formation but the large amount of foam generated by these surfactants during the process of hydrate formation and dissociation stands as a major roadblock towards the scaling up of the technology. In the current work, a small amount of a silicon based surfactant has been proposed to be used as antifoam in conjunction with an anionic surfactant SDS to eliminate the foam generation while at the same time promote the kinetics of methane hydrate formation. The idea is simple, cost effective and can be a potential game-changer in the quest to develop a commercially scalable hydrate based methane storage technology. (C) 2017 Elsevier Ltd.

}, keywords = {Antifoam, Gas hydrate, kinetics, Methane storage, scale-up, Silicone surfactant}, issn = {0021-9614}, doi = {10.1016/j.jct.2017.09.029}, author = {Bhattacharjee, Gaurav and Barmecha, Vivek and Kushwaha, Omkar S. and Kumar, Rajnish} } @article {44372, title = {Kitchen grinder: a tool for the synthesis of metal-organic frameworks towards size selective dye adsorption}, journal = {Crystengcomm}, volume = {20}, year = {2018}, month = {MAY}, pages = {2486-2490}, abstract = {In this report, we present a simple, swift mechanochemical synthesis of metal-organic frameworks (MOFs) using a kitchen grinder. By adopting this tool, we could synthesize ZIF-8, CuBTC, and MIL-100(Fe) in multi gram-scale and successfully employ MIL-100(Fe)-KG for the efficient (ca. 98\%) removal of an organic dye (methylene blue) from aqueous solution. In particular, we demonstrated the significance of pore aperture for effective dye adsorption by comparing the adsorption behaviours of ZIF-8-KG and MIL-100(Fe)-KG. We believe that this approach could be of economic interest towards the green synthesis of porous adsorbents for waste-water treatment.}, doi = {10.1039/c8ce00333e}, author = {Samal, Mahalaxmi and Panda, Jagannath and Biswal, Bishnu P. and Sahu, Rojalin} } @article {45355, title = { KLTL-MCM-41 micro-mesoporous composite as a solid base for the hydrogenation of sugars }, journal = {Catalysis Science \& Technology}, volume = {8}, year = {2018}, month = {DEC}, pages = { 6429-6440}, type = {Article}, abstract = {An approach to the synthesis of KLTL-MCM-41 micro-mesoporous composites of varying SiO2/Al2O3 molar ratio (20-8) was designed by following green technology. The synthesis was based on the recycling of waste mother liquor containing preformed KLTL zeolite crystals and unutilized reagents. The micro-mesoporous composites consist of KLTL zeolite crystals preformed through hydrothermal treatment in the first step. In the second step, the siliceous mother liquor was transformed into mesoporous MCM-41. The physico-chemical properties of the KLTL-MCM-41 micro-mesoporous composites were determined by PXRD, ICP-OES, FTIR, CO2-TPD, Al-27 MAS-NMR, TEM-EDX, HRTEM, and N-2 adsorption-desorption measurements. The mesopores properties of the KLTL-MCM-41 composites depended on the SiO2/Al2O3 molar ratio. The characterization results led to the following conclusions with decreasing SiO2/Al2O3 molar ratio: 1) decreasing order of the mesophase, 2) decreasing wall thickness of the mesopores, and 3) decreasing BET surface area and pore volume. Al-27 MAS-NMR spectra showed that only tetrahedrally coordinated aluminium was contained in zeolite KLTL. Moreover, the total amount and the strength of the basic sites of the KLTL-MCM-41 micro-mesoporous composites owing to the exchangeable potassium content (Al/K ratio approximate to 1) decreased in the order: 8 MMC > 10 MMC > 15 MMC > 20 MMC. The catalytic activity of the synthesized micro-mesoporous samples as a solid base was tested for the hydrogenation of xylose to sugar alcohols}, issn = {2044-4753}, doi = {10.1039/c8cy01716f}, author = {Tangale, Nilesh P. and Niphadkar, Prashant S. and Joshi, Praphulla N. and Dhepe, Paresh L.} } @article {44377, title = {Knowledge, attitude and practice of antibiotic use and antimicrobial resistance: a study post the {\textquoteright}Red Line{\textquoteright} initiative}, journal = {Current Science}, volume = {114}, year = {2018}, month = {MAY}, pages = {1866-1877}, abstract = {Antimicrobial resistance (AMR) is propagated by irrational use of antibiotics by healthcare practitioners and the uninformed public. This study assessed a select cohort of 504 urban Indians for their knowledge, awareness and practice of antibiotic use and AMR. Forty seven per cent were unaware of the differences between over-the-counter drugs and antibiotics. One in four believes that dose-skipping does not contribute to AMR. One in ten tends to self-medicate. One in five bought medicines without prescription or started an antibiotic course by calling a doctor. Our results mandate educational campaigns, stewardship and surveillance at the national level for prudent antimicrobial use in the Indian community.}, doi = {10.18520/cs/v114/i09/1866-1877}, author = {Banerjee, Deepanwita and Raghunathan, Anu} } @article {45553, title = {Kinetics of cinnamaldehyde hydrogenation in four phase system}, journal = {Chemical Engineering Journal}, volume = {377}, year = {2019}, month = {DEC}, pages = {Article Number: UNSP 120512}, type = {Article}, abstract = {

The kinetics of cinnamaldehyde hydrogenation in four phase system viz. gas (hydrogen)-liquid (cinnamaldehyde + toluene)-liquid (aqueous KOH)-solid (catalyst, 5\% Pt/C), [GLLS] system has been studied in this work. As reported, addition of aqueous alkali in hydrogenation of unsaturated aldehydes like cinnamaldehyde shifts selectivity towards unsaturated alcohol, cinnamyl alcohol. The promotion action by alkali metals for improving selectivity towards cinnamyl alcohol involves changes in the adsorption mechanism of the cinnamaldehyde in a way that CO bond get preferentially hydrogenated. In cinnamaldehyde hydrogenation in presence of promoters two different catalytic sites can be considered, each for CO and CC bond hydrogenation. In accordance with this consideration and as demonstrated in various studies on hydrogenation of unsaturated aldehydes, further hydrogenation of intermediate-cinnamyl alcohol (CC bond hydrogenation) occurs on Pt only sites while cinnamaldehyde and intermediate hydrocinnamaldehyde (both involving CO bond hydrogenation) are hydrogenated on catalytic sites affected by promoters. This preferential adsorption and hydrogenation through CO bond leads to the increased selectivity of cinnamyl alcohol. Although, many authors have studied cinnamaldehyde hydrogenation using various promoters, there are very few reports on kinetics in which this two site approach behind promotion action has been considered. The effect of various operating parameters on the rates of hydrogenation was studied and the two site Langmuir-Hinshelwood type of kinetic model was used for evaluating the kinetic parameters by fitting experimental data. The thermodynamic model for estimating the solubility of hydrogen in the reaction mixture was incorporated with this kinetic model.

}, doi = {10.1016/j.cej.2018.11.210}, author = {Khan, M. and Joshi, S. and Ranade, V.} } @article {45489, title = {Kinetics of hydroformylation of 1-decene using carbon-supported ossified HRh(CO)(TPPTS)(3) catalyst}, journal = {International Journal of Chemical Kinetics}, volume = {51}, year = {2019}, month = {FEB}, pages = {112-122}, type = {Article}, abstract = {

The kinetics of hydroformylation of 1-decene has been investigated using a carbon-supported ossified HRh(CO)(TPPTS)(3)/Ba catalyst in a temperature range of 343-363 K. The effect of concentration of 1-decene, catalyst loading, partial pressure of H-2 and CO, and stirring speed on the reaction rate has been investigated. A first-order dependence was observed for catalyst concentration and hydrogen partial pressure. The rate showed a typical case of substrate inhibition for high 1-decene concentration. The rate varied with a linear dependence on P-CO up to a CO partial pressure of 5-6 MPa in contrast to the general trends; for most of the rhodium-phosphine catalyzed hydroformylation reactions, severe inhibition of rate is observed with an increase in CO pressure. A rate equation has been proposed, which was found to be in good agreement with the observed rate data within the limit of experimental errors. The kinetic parameters and activation energy values have been reported.

}, keywords = {1-decene, Hydroformylation, kinetics, ossification, supported ossified}, issn = {0538-8066}, doi = {10.1002/kin.21234}, author = {Pagar, Nitin S. and Deshpande, Raj M.} } @article {46316, title = {Kinetics of hydrogenation of aqueous levulinic acid over bimetallic Ru-Ni/MMT catalyst}, journal = {Industrial \& Engineering Chemistry Research}, volume = {58}, year = {2019}, month = {OCT }, pages = {19803-19817}, type = {Article}, abstract = {

gamma-Valerolactone is one of the value-added products obtained from levulinic acid hydrogenation, having tremendous applications in fuels and chemicals. In this work, several monometallic and bimetallic compositions of Ru and Ni were prepared and evaluated for levulinic acid hydrogenation in an aqueous medium. The optimum composition of 0.5 wt \% Ru and 5 wt \% Ni on MMT was found to achieve 91\% levulinic acid conversion with complete selectivity to gamma-valerolactone within 5 h at 220 degrees C and 250 psig H-2 pressure. XPS and H-2-TPR studies clearly showed that the electronic interactions between Ru-Ni leading to the synergism enhanced the catalytic efficiency of the Ru-Ni bimetallic catalyst. The average metal particle size by HRTEM was found to be in the range of 1.5-4.5 nm, having mixed cubic, oval, and spherical morphology, dispersed on the surface as well as within the layers of MMT. NH3-TPD showed a higher acidity due to both Lewis and Bronsted sites of the 0.5 wt \% Ru-5 wt \% Ni/MMT catalyst than individual MMT and monometallic catalysts. The presence of higher Lewis acidic sites preferred selective formation of GVL. Reaction kinetics was studied to propose the rate equation for this reaction based on which a plausible reaction pathway is proposed involving a first step dehydration of levulinic acid to an alpha-angelica lactone intermediate which then undergoes hydrogenation by dissociatively adsorbed H-2 to form gamma-valerolactone. The stability of our catalyst was proved by its recycle studies as well as by a hot filtration test.

}, issn = {0888-5885}, doi = {10.1021/acs.iecr.9b03748}, author = {Kasar, Gayatri B. and Medhekar, Rucha S. and Bhosale, P. N. and Rode, V, Chandrashekhar} } @article {47026, title = {Kinetic and biocompatibility investigation on the catalytic ring opening polymerization of L-lactide in bulk using cyclic Bu2Sn initiators derived from ethylene glycol, pentaerythritol and cloisite 30B}, journal = {Polyhedron}, volume = {175}, year = {2020}, month = {JAN }, pages = {114202}, type = {Article}, abstract = {

In the present work, considering a green approach, PLLA was synthesized by the ring-opening polymerization of L-LA using various cyclic initiators (2,2-dibutyl-2-stanna-1,3-dioxacyclo ethane (1), spirocyclic tin (3) and cloisite modified tin (5)). PLLA was characterized by size exclusion chromatography, differential scanning calorimetry, H-1 and C-13 NMR, XRD and MALDI-TOF. The molecular weight distribution was narrow (\<1.5) for both low and high molecular weights (\>85,000 g/mol). An X-ray study showed the crystalline nature of PLLA, irrespective of the different types of initiators and polymerization conditions. A kinetic investigation showed that all polymerizations were first order with respect to the monomer and no termination reactions occurred during the polymerization. MALDI-TOF spectra of PLLA chains doped with Na+ and K+ cations show that the PLLA prepared using initiators 1 and 3 have hydroxyl and carboxyl end groups without incorporation of tin. The MALDI-TOF spectrum of PLLA prepared using initiator 5 also enabled the simultaneous detection of the linear and cyclic structure of PLLA without tin. Biocompatible and biodegradable PLLA was obtained, which could be used for biomedical applications. (C) 2019 Elsevier Ltd. All rights reserved.

}, keywords = {Cloisite modified tin, Cyclic tin initiator, MALDI-TOF, Poly (L-Lactide), Spirocyclic}, issn = {0277-5387}, doi = {10.1016/j.poly.2019.114202}, author = {Mohite, Kavita K. and Garnaik, Baijayantimala} } @article {46889, title = {Kinetics of hydroformylation of camphene using rhodium-phosphite catalyst}, journal = {International Journal of Chemical Kinetics}, volume = {52}, year = {2020}, month = {JUL}, pages = {485-495}, type = {Article}, abstract = {

Kinetics of hydroformylation of camphene was investigated in the presence of [Rh(CO)(2)(acac)]/P(OPh)(3) catalyst in a temperature range of 363-383 K. The influence of parameters such as stirring speed, camphene, catalyst, ligand concentrations, and partial pressures of H-2 and CO on the activity and selectivity of the catalyst has been studied. The rate showed a first-order dependence with respect to catalyst and camphene concentrations. The effect of partial pressure of hydrogen showed fractional order dependence. The plots of rate versus excess ligand, that is, (P(OPh)(3)) concentration and rate versus CO partial pressure passed through maxima and showed typical substrate/ligand inhibited kinetics. An empirical rate equation has been proposed and found to be in good agreement with the observed rate data. The kinetic parameters and activation energy were also evaluated.

}, keywords = {camphene, homogeneous, Hydroformylation, kinetics, rhodium-phosphite}, issn = {0538-8066}, doi = {10.1002/kin.21364, Early Access Date = APR 2020}, author = {Pagar, Nitin S. and Rajurkar, Kalpendra B. and Deshpande, Raj M.} } @article {46661, title = {Kinetics of 1-decene hydroformylation in an aqueous biphasic medium using a water-soluble Rh-sulfoxantphos catalyst in the presence of a cosolvent}, journal = {International Journal of Chemical Kinetics}, volume = {53}, year = {2021}, month = {MAR}, pages = {333-344}, type = {Article}, abstract = {

The kinetics of hydroformylation of 1-decene has been studied in an aqueous biphasic medium using a water-soluble Rh-sulfoxantphos catalyst in the presence of N-methyl pyrrolidone as a cosolvent at 383-403 K. The rate was found to be first order, with concentrations of catalyst and olefin and partial order, with concentrations of hydrogen in the liquid phase. The plot of rate versus excess ligand and CO concentrations passed through maxima, indicating negative order dependence at higher concentrations. These trends have been interpreted based on the established hydroformylation mechanism. High selectivity towards the linear aldehyde was maintained (n: iso ratio \> 30). An empirical rate equation has been proposed which was found to be in good agreement with the observed rate data within the experimental error. The activation energy was evaluated to be 74.76 kJ/mol.

}, keywords = {1\&\#8208, aqueous\&\#8208, biphasic, cosolvent, decene, Hydroformylation, kinetics, rh\&\#8208, sulfoxantphos}, issn = {0538-8066}, doi = {10.1002/kin.21446, Early Access Date = OCT 2020}, author = {Pagar, Nitin S. and Deshpande, Raj M.} } @article {48365, title = {K3PO4-promoted cycloannulation of (E)-beta-Iodovinyl Sulfones with ortho-Hydroxy-chalcones/cinnamates for the synthesis of 2,3,4-trisubstituted 4h-benzopyran derivatives}, journal = {Advanced Synthesis \& Catalysis}, volume = {364}, year = {2022}, month = {DEC }, pages = {4080-4087}, type = {Article}, abstract = {

K3PO4-mediated cycloannulation of (E)-beta-iodovinyl sulfones with ortho-hydroxy chalcones/ortho-hydroxy cinnamates has been realized to access 2,3,4-trisubstituted-4H-benzopyran derivatives. A metal-free tandem oxa-Michael addition and cycloannulation allows the diversity-oriented synthesis of the corresponding 3-sulfonyl-4H-benzopyrans in good to high yields. More importantly, one-pot three-component reaction between (E)-beta-iodovinyl sulfones, 2-hydroxybenzaldehydes, and phosphonium ylides has been established for the synthesis of 4H-chromene derivatives in moderate to good yields. Notably, this metal-free process features a broad substrate scope and easy elaboration into numerous multifaceted chromene products, including bioactive estrone-derivative. The present protocol is sustainable at the gram scale reactions, and post-synthetic applications were also demonstrated. A plausible mechanism is also presented on the basis of existing experimental results.

}, keywords = {(E)-beta-Iodovinyl sulfones, Benzopyrans, Cycloannulation, ortho-Hydroxy Chalcones, Sulfones}, issn = {1615-4150}, doi = {10.1002/adsc.202200763}, author = {Reddy, Raju Jannapu and Kumar, Jangam Jagadesh and Krishna, Gamidi Rama} } @article {48117, title = {Kinetic model of GPCR-G protein interactions reveals allokairic modulation of signaling}, journal = {Biophysical Journal}, volume = {121}, year = {2022}, month = {FEB}, pages = {122}, type = {Meeting Abstract}, issn = {0006-3495}, author = {Culhane, Kelly and Gupte, Tejas and Madhugiri, Indrani and Gadgil, Chetan and Sivaramakrishnan, Sivaraj} } @article {48352, title = {Kinetic study on alkylation of hydroquinone with methanol over SO3H functionalized Bronsted acidic ionic liquids}, journal = {Canadian Journal of Chemical Engineering}, volume = {100}, year = {2022}, month = {OCT}, pages = {2986-2996}, type = {Article}, abstract = {

O-alkylation of a dihydric phenol (i.e., hydroquinone) with methanol in presence of benzoquinone catalyzed by double SO3H functionalized Bronsted acidic ionic liquids (i.e., 1,3-disulphonic acid imidazolium hydrogen sulphate, 1,3-disulphonic acid benzimidazolium hydrogen sulphate, and sulphuric acid) is studied in a batch reactor. The sensitivity of activity and selectivity with reaction time, temperature, speed of agitation, and catalyst loading was examined. The plausible reaction pathways proposed based on the experimental observations and detailed kinetic investigation are performed by assuming a homogeneous reaction phase. The kinetic parameters, such as pre-exponential factor and activation energy, are estimated for both ionic liquids and sulphuric acid by considering all competitive reactions, and comparative results were presented. An extended form of the Arrhenius equation is used to estimate the kinetic parameters for the reaction which showed curvature in lnk against a 1/T plot. The model prediction with the estimated kinetic parameters is in good agreement with the experimental data, which confirmed the model validity in the experimental operating range. It was found that ionic liquid has a potential application in the synthesis of a selective monoalkylated product of hydroquinone. The kinetic analysis performed is found to be useful in the understanding of process behaviour.

}, keywords = {4-Methoxyphenol, Hydroquinone, ionic liquids, Kinetic analysis, O-alkylation}, issn = {0008-4034}, doi = {10.1002/cjce.24307}, author = {Bhongale, V. Priyanka and Amonkar, Amogh A. and Joshi, Sunil S. and Mali, Nilesh A.} } @article {48235, title = {Kupyaphores are zinc homeostatic metallophores required for colonization of Mycobacterium tuberculosis}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {119}, year = {2022}, month = {FEB}, pages = {e2110293119}, type = {Article}, abstract = {

Mycobacterium tuberculosis (Mtb) endures a combination of metal scarcity and toxicity throughout the human infection cycle, contributing to complex clinical manifestations. Pathogens counteract this paradoxical dysmetallostasis by producing specialized metal trafficking systems. Capture of extracellular metal by siderophores is a widely accepted mode of iron acquisition, and Mtb iron-chelating siderophores, mycobactin, have been known since 1965. Currently, it is not known whether Mtb produces zinc scavenging molecules. Here, we characterize low-molecular-weight zinc-binding compounds secreted and imported by Mtb for zinc acquisition. These molecules, termed kupyaphores, are produced by a 10.8 kbp biosynthetic cluster and consists of a dipeptide core of ornithine and phenylalaninol, where amino groups are acylated with isonitrilecontaining fatty acyl chains. Kupyaphores are stringently regulated and support Mtb survival under both nutritional deprivation and intoxication conditions. A kupyaphore-deficient Mtb strain is unable to mobilize sufficient zinc and shows reduced fitness upon infection. We observed early induction of kupyaphores in Mtb-infected mice lungs after infection, and these metabolites disappeared after 2 wk. Furthermore, we identify an Mtb-encoded isonitrile hydratase, which can possibly mediate intracellular zinc release through covalent modification of the isonitrile group of kupyaphores. Mtb clinical strains also produce kupyaphores during early passages. Our study thus uncovers a previously unknown zinc acquisition strategy of Mtb that could modulate host-pathogen interactions and disease outcome.

}, keywords = {metallophore, nutritional immunity, tuberculosis, zinc}, issn = {0027-8424}, doi = {10.1073/pnas.2110293119}, author = {Mehdiratta, Kritee and Singh, Shubham and Sharma, Sachin and Bhosale, Rashmi S. and Choudhury, Rahul and Masal, Dattatraya P. and Manocha, Alzu and Dhamale, Bhushan Dilip and Khan, Naseem and Asokachandran, Vivekanand and Sharma, Pooja and Ikeh, Melanie and Brown, Amanda C. and Parish, Tanya and Ojha, Anil K. and Michael, Joy Sarojini and Faruq, Mohammed and Medigeshi, Guruprasad R. and Mohanty, Debasisa and Reddy, D. Srinivasa and Natarajan, Vivek T. and Kamat, Siddhesh S. and Gokhale, Rajesh S.} } @article {49255, title = {Kinetic H2S/CO2 selectivity in an exceptionally sterically hindered amine membrane}, journal = {JOURNAL OF MATERIALS CHEMISTRY A}, volume = {12}, year = {2024}, month = {OCT }, pages = {29138-29144}, type = {Journal Article}, keywords = {Absorption, COMPOSITE MEMBRANES, GAS STREAMS, H2S, Thin-Film}, issn = {2050-7488}, doi = {10.1039/d4ta04997g}, author = {Rao, Shraavya and Deng, Xuepeng and Zou, Changlong and Prasad, Babul and Han, Yang and Lin, Li-Chiang and Ho, W. S. Winston} } @article {49050, title = {Kinetic model of hydrogenation of glucose to sorbitol on a Ni/Bentonite catalyst}, journal = {Industrial and Engineering Chemistry Research}, volume = {63}, year = {2024}, month = {MAR }, pages = {4771-4781}, type = {Article}, abstract = {

In the present work, we studied the hydrogenation of glucose to sorbitol using a nickel/bentonite catalyst. The Ni/bentonite catalyst was prepared by the wet impregnation method and characterized by different methods to understand the catalyst surface morphology, surface area, metal content, pore size, etc. Different reaction parameters such as temperature, hydrogen pressure, metal loading, catalyst loading, and agitation speed were studied to achieve a glucose conversion of 96.8\% and a sorbitol selectivity of 95.3\%. The reusability test was performed to examine the stability of the catalyst. The kinetic models such as the Eley-Rideal and Langmuir-Hinshelwood-Hougen-Watson models were used to study the hydrogenation of glucose and activation energy required for the reaction.

}, issn = {0888-5885}, doi = {10.1021/acs.iecr.3c03808}, author = {Pandya, Harmitkumar and Vinod, Chathakudath Prabhakaran and Rathod, Virendra and Kantam, Mannepalli Lakshmi} } @article {49821, title = {Ketenimine multicomponent strategy for multifaceted amidine functionalization of peptides on the solid phase}, journal = {Angewandte Chemie-International Edition}, volume = {64}, year = {2025}, month = {SEP}, type = {Article}, abstract = {

The amidine group and its derivatives serve as proteolytically stable bioisosteres of the peptide bond, and their selective incorporation into peptides attributes significant chemical and biological features. This study introduces an efficient synthesis of amidine-containing peptides by a copper-catalyzed, solid-phase-compatible multicomponent reaction (MCR), leveraging ketenimine intermediates that are generated in situ. Through the reaction of sulfonyl azides with terminal alkynes and a wide variety of amines, we establish the robust on-resin synthesis of delta/epsilon-amidine amino acids, arginine isologues, fluorescently labeled peptides, drug-peptide hybrids, and PEGylated derivatives. This strategy notably supports a wide range of peptide modifications, including side chain alteration, amine functionalization, and peptide macrocyclization through both backbone and side chain groups, as well as incorporating aromatic scaffolds into the peptide backbone. The methodology demonstrates broad substrate tolerance, compatibility with peptide chemistry protocols, and access to complex motifs, including pharmacophores and imaging tags, all within a single reaction platform. Our results underscore the synthetic versatility and functional applicability of ketenimine-based MCRs for advanced peptide modification, expanding the chemical space of peptide medicinal chemistry and therapeutics.

}, keywords = {Amidines, multicomponent reactions, peptide modification, Peptide-small molecule hybrids, Solid phase peptide synthesis}, issn = {1433-7851}, doi = {10.1002/anie.202509854}, author = {Bodake, Supriya Mahadev and Marelli, Udaya Kiran} } @article {49418, title = {Kinetic investigation on palladium-catalyzed carbonylation of allyl alcohol}, journal = {International Journal of Chemical Kinetics}, volume = {57}, year = {2025}, month = {OCT}, pages = {153-163}, type = {Article}, abstract = {

Palladium-catalyzed carbonylation of allyl alcohol to 3-butenoic acid has been investigated. A significant effect of halide promoters, p-tolylsulfonic acid (TsOH), water, solvents, and PPh3 concentration activity and selectivity has been studied. Detailed kinetics of this reaction was investigated in a temperature range of 363-383 K. The influence of parameters such as stirring speed, allyl alcohol, catalyst, benzyltriethylammonium chloride (BTEAC), TsOH concentrations, and CO partial pressures on the activity and selectivity has been studied. An empirical rate equation was suggested and found to be fairly consistent with observed rate data. In addition, the activation energy and kinetic parameters were evaluated.

}, keywords = {allyl alcohol, Carbonylation, halide promoters, kinetics, Mechanism, Palladium}, issn = {0538-8066}, doi = {10.1002/kin.21767}, author = {Tonde, Sunil S. and Rajurkar, Kalpendra B. and Pagar, Nitin S.} }