@article { ISI:000205747600006, title = {Extra-/intracellular biosynthesis of gold nanoparticles by an alkalotolerant fungus, trichothecium sp.}, journal = {Journal of Biomedical Nanotechnology}, volume = {1}, number = {1}, year = {2005}, month = {MAR}, pages = {47-53}, publisher = {AMER SCIENTIFIC PUBLISHERS}, type = {Article}, address = {25650 NORTH LEWIS WAY, STEVENSON RANCH, CA 91381-1439 USA}, abstract = {

The development of reliable, eco-friendly processes for the synthesis of nanoscale materials is an important aspect of nanotechnology. As part of our ongoing investigation into the use of fungi for nanoparticle synthesis, we report herein that depending on the reaction conditions of the fungus Trichothecium sp. with aqueous gold ions, gold nanoparticle synthesis can be controlled to occur either within the biomass or extracellularly. Moreover, we have found that reaction of gold ions with the Trichothecium sp. fungal biomass under stationary conditions results in the rapid extracellular formation of gold nanoparticles of spherical, rod-like and triangular morphology whereas reaction of the biomass under shaking conditions resulted in intracellular growth of the nanoparticles. It is believed that on changing the reaction conditions of the fungus with gold ions, the enzymes and proteins which are being released into the medium under stationary conditions do not get released under shaking conditions resulting in the formation of extracellular or intracellular gold nanoparticles respectively. The gold nanoparticles are not toxic to the cells and the cells continued to grow after the biosynthesis of the gold nanoparticles in both the cases.

}, keywords = {Biosynthesis, enzymes, Fungus, Gold, Morphology Control, Nanoparticles}, issn = {1550-7033}, doi = {10.1166/jbn.2005.012}, author = {Ahmad, Absar and Senapati, Satyajyoti and Khan, Mohammad Islam and Kumar, Rajiv and Sastry, Murali} } @article { ISI:000232129900020, title = {Synthesis of gold nanospheres and nanotriangles by the Turkevich approach}, journal = {Journal of Nanoscience and Nanotechnology}, volume = {5}, number = {10}, year = {2005}, month = {OCT}, pages = {1721-1727}, publisher = {AMER SCIENTIFIC PUBLISHERS}, type = {Article}, address = {25650 NORTH LEWIS WAY, STEVENSON RANCH, CA 91381-1439 USA}, abstract = {

Gold nanoparticles of triangular morphology possess interesting optical properties with potential application in medicine and infrared absorbing coatings, however, little is known about conditions that favor their growth. In this paper, we have reinvestigated a time-tested recipe for the formation of gold nanospheres by citrate reduction of aqueous gold ions under boiling conditions (Turkevich recipe). Our principle findings are that gold nanotriangle formation is kinetically controlled and is highly favored at low temperatures. Furthermore, the presence of chloride ions from the precursor chloroaurate ions plays a major role in promoting the growth of [111] oriented triangular/truncated triangular particles. The presence of bromide and iodide ions that possess the ability to replace surface-bound chloride ions inhibits triangle formation to varying degrees.

}, keywords = {Crystal growth, Gold, halides, nanospheres, nanotriangles, Temperature effect}, issn = {1533-4880}, doi = {10.1166/jnn.2005.192}, author = {Shankar, S. S. and Bhargava, S. and Sastry, Murali} } @article {17}, title = {Interfacial deposition of Ag on Au seeds leading to AucoreAgshell in organic media}, journal = {Journal of Colloid and Interface Science}, volume = {312}, number = {16}, year = {2007}, month = {AUG}, pages = {498-505}, publisher = {ACADEMIC PRESS INC ELSEVIER SCIENCE}, type = {Article}, address = {525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA}, keywords = {core-shell nanoparticles, Gold, HRTEM, interfacial seeded growth, Silver, XPS}, issn = {0021-9797}, doi = {10.1016/j.jcis.2007.03.032}, author = {Chandran, S. Prathap and Ghatak, J. and Satyam, P. V. and Sastry, Murall} } @article {17}, title = {Short synthesis of (+)-harzialactone A and (R)-(+)-4-hexanolide via proline-catalyzed sequential alpha-aminooxylation and horner-wadsworth-emmons olefination of aldehydes}, journal = {Tetrahedron-Asymmetry}, volume = {18}, number = {16}, year = {2007}, month = {AUG}, pages = {1795-1798}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, type = {Article}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

{In melts, ring polymers assume more compact conformations compared to linear chains with the same degree of polymerization N-r, i.e. R-r similar to N-r(nu) with nu approximate to 0.4, where R-r is the radius of gyration. Upon gradually substituting some of the ring polymers with linear chains, the ring molecules swell. In the limit of infinite dilution, their size scales as R-r similar to N-r(0.5). We present a scaling argument based on the blob model to capture this transition. Ring-linear blends are modeled as a semidilute solution of ring polymers in a theta-solvent consisting of linear chains. The model predicts that the size of the ring polymer remains unchanged up to the overlap concentration c(r)(*

}, keywords = {core-shell nanoparticles, Gold, HRTEM, interfacial seeded growth, Silver, XPS}, issn = {0957-4166}, doi = {10.1016/j.tetasy.2007.07.031}, author = {Kotkar, Shriram P. and Suryavanshi, Gurunath S. and Sudalai, Arumugarn} } @article { ISI:000244909500021, title = {Spider silk as an active scaffold in the assembly of gold nanoparticles and application of the gold-silk bioconjugate in vapor sensing}, journal = {Small}, volume = {3}, number = {3}, year = {2007}, month = {MAR}, pages = {466-473}, publisher = {WILEY-V C H VERLAG GMBH}, type = {Article}, address = {PO BOX 10 11 61, D-69451 WEINHEIM, GERMANY}, abstract = {

Spider silk is being viewed with interest by materials scientists due to its excellent resilience and mechanical properties. In this paper we show that spider silk is an excellent scaffold for the one-step synthesis and assembly of gold nanoparticles. Formation of a gold nanoparticle-spider-silk bioconjugate material is accomplished by simple reaction of the fibers with aqueous chloroauric acid. The gold nanoparticles thus formed are strongly bound to the spider-silk fiber surface enabling study of the electrical properties of the nano bioconjugate. Using the well-known contraction/expansion behavior of the fibers in solvents of varying polarity, we show that exposure of the gold nanoparticle-spider silk bioconjugate to vapors of methanol and chloroform leads to changes in electrical transport through the nanoparticles and thus, the possibility of developing a vapor sensor. The bioconjugate shows excellent response time and cycling efficiency to methanol vapors. The activation energy of electron transport from one gold nanoparticle to another in the nanobiocojugate was determined from temperature-dependent electron-transport measurements to be approximately 1.7 eV.

}, keywords = {bioconjugates, Gold, Nanoparticles, sensors, spider silk}, issn = {1613-6810}, doi = {10.1002/smll.200600413}, author = {Singh, Amit and Hede, Shantesh and Sastry, Murali} } @article { ISI:000261896400061, title = {Enhanced conversion efficiency in dye-sensitized solar cells based on ZnO bifunctional nanoflowers loaded with gold nanoparticles}, journal = {Applied Physics Letters}, volume = {93}, number = {24}, year = {2008}, month = {DEC}, pages = {Article No. 243108}, publisher = {AMER INST PHYSICS}, type = {Article}, address = {CIRCULATION \& FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA}, abstract = {

The ZnO nanoflowers loaded with gold (Au) nanoparticles (NPs) are synthesized by a hydrothermal route using mixed precursors and controlled conditions. The dye-sensitized solar cells based on the ZnO nanoflowers with Au NPs show power conversion efficiency of 2.5\%, which is considerably higher than that of ZnO nanoflowers without Au NPs. Detailed characterizations are performed, presented, and discussed.

}, keywords = {crystal growth from solution, Gold, II-VI semiconductors, Nanocomposites, Nanoparticles, solar cells, wide band gap semiconductors, zinc compounds}, issn = {0003-6951}, doi = {10.1063/1.3049131}, author = {Dhas, Vivek V. and Muduli, Subas and Lee, Wonjoo and Han, Sung-Hwan and Ogale, Satishchandra B.} } @article { ISI:000261559400012, title = {Natural gum reduced/stabilized gold nanoparticles for drug delivery formulations}, journal = {Chemistry-A European Journal}, volume = {14}, number = {33}, year = {2008}, month = {OCT}, pages = {10244-10250}, publisher = {WILEY-V C H VERLAG GMBH}, address = {PO BOX 10 11 61, D-69451 WEINHEIM, GERMANY}, abstract = {

{\textquoteleft}{\textquoteleft}Gellan Gum{\textquoteright}{\textquoteright}, widely used in food and confectionary industry as a thickening and gelling agent, has been employed as a reducing and stabilizing agent for the synthesis of gold nanoparticles. These nanoparticles display greater stability to electrolyte addition and pH changes relative to the traditional citrate and borohydride reduced nanoparticles. Subsequently these have been used to load anthracycline ring antibiotic doxorubicin hydrochloride. The drug loaded on these nanoparticles showed enhanced cytotoxic effects on human glioma cell lines LN-18 and LN-229.

}, keywords = {Apoptosis, Cytotoxicity, drug delivery, Gold, Nanostructures, natural gums}, issn = {0947-6539}, doi = {10.1002/chem.200801093}, author = {Dhar, Sheetal and Reddy, E. Maheswara and Shiras, Anjali and Pokharkar, Varsha and Bhagavatula L. V. Prasad} } @article { ISI:000266390000011, title = {Silver fused conducting fiber formation of Au-Ag core-shell nanoparticles mediated by ascorbic acid}, journal = {Plasmonics}, volume = {4}, number = {2}, year = {2009}, month = {JUN}, pages = {161-170}, publisher = {SPRINGER}, address = {233 SPRING ST, NEW YORK, NY 10013 USA}, abstract = {

In this paper, we report the spontaneous formation of fibrous structures consisting of assemblies of Au-Ag core-shell nanoparticles (NPs) from a solution consisting of Au-Ag core-shell NPs and l-ascorbic acid (AA). AA acted both as the reducing agent for the generation of NPs and also as the mediator for the formation of fibers. The process of fiber formation involved three steps-reduction of HAuCl(4) to Au NPs by AA, subsequent formation of Au-Ag core-shell NPs after addition of AgNO(3), and spontaneous formation of fibers from the mixtures in water. It took typically about 30 days to form complete fibers that are of lengths of several hundred micrometers to millimeters, although nanofibers started forming from the first day of solution preparation. The width of each of these fibers was typically about 1-4 A mu m with length of each segment of fiber bundle, on the order of 40 A mu m. Formation of fibers was also observed in absence of AgNO(3). These fibers consisted of Au NPs and polymer of AA degradation products and were not electrically conducting. Also, low concentrations of AgNO(3) produced fibers with low electrical conductivity. However, it was observed that increase in the amount of AgNO(3) leads to the formation of fibers that were electrically conducting with conductivity values in the range of metallic conductivity. Spectroscopic and electron microscopic investigations were carried out to establish the formation of fibers. The details of fiber formation mechanism under different conditions and electrical conductivities of the fibers are discussed in the article.

}, keywords = {Ascorbic acid, core-shell, Fiber, Gold, Nanoparticles, Silver}, issn = {1557-1955}, doi = {10.1007/s11468-009-9091-5}, author = {Murugadoss, A. and Kar, Manoranjan and Pasricha, Renu and Chattopadhyay, Arun} } @article { ISI:000277529700013, title = {NO reduction under diesel exhaust conditions over Au/Al2O3 prepared by deposition-precipitation method}, journal = {Journal of Molecular Catalysis A-Chemical}, volume = {322}, number = {1-2}, year = {2010}, month = {MAY}, pages = {90-97}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Gold supported on alumina was prepared by urea deposition-precipitation method and compared to silver supported on alumina for the selective catalytic reduction of NO by hydrocarbons under lean conditions. The catalyst showed activity in the reduction of NO and 100\% selectivity towards N-2 in the temperature range 300-350 degrees C. At higher temperature the NO conversion decreased due to competitive oxidative reactions of the reductants. XPS analysis confirmed the good stability of gold nanoparticles deposited on alumina. Infrared studies showed the formation of various adsorbed species (formates, carboxylates, ad-NOx and cyanide) on the catalyst surface. Addition of H-2 to the feed containing decane enhanced the formation of these species on the catalyst surface as well as the catalytic activity for the NO conversion to N-2. (C) 2010 Elsevier B.V. All rights reserved.

}, keywords = {Deposition-precipitation, Gold, In situ IR, NO reduction, XPS}, issn = {1381-1169}, doi = {10.1016/j.molcata.2010.02.024}, author = {Miguel, P. and Granger, P. and Jagtap, Neelam and Shubhangi B. Umbarkar and Dongare, Mohan K. and Dujardin, Christophe} } @article { ISI:000292852100017, title = {Gold catalyzed glycosidations for the synthesis of sugar acrylate/acrylamide hybrids and their utility}, journal = {Carbohydrate Research}, volume = {346}, number = {12, SI}, year = {2011}, month = {SEP}, pages = {1511-1518}, publisher = {ELSEVIER SCI LTD}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND}, abstract = {

Propargyl glyco 1,2-orthoesters were exploited for the efficient synthesis of interesting glycomonomers such as glyco-acrylates and acrylamides using gold catalysts. It was observed that propargyl glyco 1,2-orthoesters with hydroxyethyl acrylates gives very good yield of the corresponding glyco-acrylates in a single step in the presence of catalytic amount of gold(III) catalyst; whereas, gold catalyzed glycosidation reaction on hydroxyethyl acrylamides was found to yield the corresponding acrylamidoyl 1,2-orthoester which was then converted to the corresponding glycol-acrylamide in the presence of catalytic amount of TMSOTf. Synthesized glyco-acrylate/acrylamide monomers are shown to undergo thiolate addition as well as free radical polymerization (C) 2011 Elsevier Ltd. All rights reserved.

}, keywords = {carbohydrates, Glycoacrylamides, Glycoacrylates, Glycopolymers, glycosylation, Gold}, issn = {0008-6215}, doi = {10.1016/j.carres.2011.04.018}, author = {Thadke, Shivaji A. and Kar, Mritunjoy and Sen Gupta, Sayam and Hotha, Srinivas} } @article { ISI:000300606400030, title = {Green approach towards size controlled synthesis of biocompatible antibacterial metal nanoparticles in aqueous phase using lysozyme}, journal = {Current Nanoscience}, volume = {8}, number = {1}, year = {2012}, month = {FEB}, pages = {130-140}, publisher = {BENTHAM SCIENCE PUBL LTD}, address = {EXECUTIVE STE Y-2, PO BOX 7917, SAIF ZONE, 1200 BR SHARJAH, U ARAB EMIRATES}, abstract = {

Inspired by array of proteins present in nature, we choose lysozyme (hen egg protein) as a model system to synthesize nanoparticles of noble metals to understand the mechanism of interaction as well as to use them for potential applications such as potent antibacterial agents. Lysozyme is a very well studied biomolecule containing aromatic amino acids like tryptophan and tyrosine. Tyrosine has phenoxy group which is considered to be responsible for interacting with the metal ions. Lysozyme can be suitably modified by treatment with N-bromosuccinimide/N-acetylimidazole to obtain tight control over size distribution of nanoparticles. Here we report the direct synthesis of nanocrystals of gold and silver at controlled pH and light conditions without using any known reducing agents. Out of these, synthesis of gold nanoparticles is assisted by the presence of low concentration of Ag+ ions through the galvanic exchange. It is remarkable to note that the structure of protein is not changed drastically as seen by the FTIR studies. As-synthesized lysozyme capped nanoparticles prepared by this method are biocompatible and retain antibacterial property.

}, keywords = {Antibacterial, Biocompatible, Gold, lysozyme, Nanoparticles, Silver}, issn = {1573-4137}, author = {Kumar, Umesh and Ranjan, Amaresh K. and Sharan, Chandrashekhar and Hardikar, Anandwardhan A. and Pundle, Archana and Poddar, Pankaj} } @article { ISI:000331828400019, title = {Enhanced mineralization of gaseous organic pollutant by photo-oxidation using Au-Doped TiO2/MCM-41}, journal = {Water Air and Soil Pollution}, volume = {225}, number = {2}, year = {2014}, month = {FEB}, pages = {1847}, publisher = {SPRINGER}, type = {Article}, address = {VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS}, abstract = {

The synthesis, characterization, and photocatalytic evaluation of titania-loaded MCM-41 with and without Au doping are reported in the present study. The samples were characterized by powder XRD, TEM, low temperature N-2 adsorption/desorption, UV-Vis, and FTIR. UV-induced vapor-phase photo-oxidation of acetone was used as a probe reaction to study the role of Au in mineralization of volatile organic compounds (VOCs), viz. acetone at different concentrations. The doping of Au in titania-loaded MCM-41 resulted in the decrease of BET surface area, total pore volume, and average pore size. UV-Vis diffuse reflectance spectra of Au-doped titania-loaded MCM-41 showed the red shift in their absorption bands compared to titania-loaded MCM-41. The activity of mineralization of acetone by photocatalysis for 2 \% Au-doped titania-loaded MCM-41 was found to be similar to 1.6 times higher than titania-loaded MCM-41. The presence of cocatalytic nanosized gold might be responsible for their enhanced activity on account of the delayed recombination of electron/hole pair. Although, almost complete mineralization of acetone was observed irrespective of the initial concentration of acetone in air (up to 3.72 mol\%) by all the catalysts, 2 wt.\% Au-doped titania-loaded MCM-41 has shown the most enhanced activity.

}, keywords = {Acetone, Doping, Gold, Mineralization of VOCs, Photo-oxidation, TiO2/MCM-41}, issn = {0049-6979}, doi = {10.1007/s11270-013-1847-z}, author = {Tangale, Nilesh P. and Belhekar, Anuja A. and Kale, Kishor B. and Awate, Shobhana V.} } @article { ISI:000336107400002, title = {Living plant-mediated synthesis of different shaped gold nanoparticles}, journal = {Nanoscience and Nanotechnology Letters}, volume = {6}, number = {4}, year = {2014}, month = {APR}, pages = {279-283}, publisher = {AMER SCIENTIFIC PUBLISHERS}, address = {26650 THE OLD RD, STE 208, VALENCIA, CA 91381-0751 USA}, abstract = {

We demonstrate extracellular green synthesis of gold nanoparticles with different shapes and sizes by using live Prosopis juliflora L. seedling. The conversion of ionic to metallic gold nanoparticles by P. juliflora seedling was carried out in short period. The formed nanoparticles were characterized by UV, TEM, Diffraction and EDS. TEM shows well dispersed particles of different shapes and sizes. The percentage of different shapes of nanoparticles was calculated, most of the particles were spherical in shape (75\%). The triangle nanoparticles were 10\%, followed by squares (8\%), hexagonal (5\%) and rods (2\%). The diffraction shows the formed nanoparticles are crystalline in nature and EDS confirms the formed nanoparticles are of gold. This shows P. juliflora seedling can synthesis different shapes of well dispersed nanoparticles.

}, keywords = {Gold, Nanoparticles, Prosopis juliflora, Shapes, synthesis, TEM}, issn = {1941-4900}, doi = {10.1166/nnl.2014.1756}, author = {Raju, D. and Paneliya, Nikita and Mehta, Urmil J.} } @article { ISI:000337617500028, title = {Plasmon-enhanced photocurrent generation from click-chemically modified graphene}, journal = {Chemistry-A European Journal}, volume = {20}, number = {24}, year = {2014}, month = {JUN}, pages = {7402-7409}, publisher = {WILEY-V C H VERLAG GMBH}, address = {BOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANY}, abstract = {

The visible-light response of Au nanoparticles (AuNPs) assembled on rGO through different molecular bridges was investigated by transient photocurrent generation. We prepared rGO with two self-assembled monolayers (SAMs), one linear and the other with aromatic triazoles through a click cycloaddition reaction. A fivefold photocurrent enhancement was observed for triazole linkers over the aminopropyltrimethoxysilane (APTMS) linker. Cyclic voltammetry (CV) and impedance measurements also suggest fast electron transfer on account of the low resistance offered by the click-modified rGO surface whereby introduction of triazoles offers the efficient bridge between the donor AuNPs and acceptor rGO.

}, keywords = {Gold, graphene, Nanoparticles, photophysics, surface plasmon resonance}, issn = {0947-6539}, doi = {10.1002/chem.201400403}, author = {Yenchalwar, Sandeep G. and Devarapalli, Rami Reddy and Deshmukh, Ashvini B. and Shelke, Manjusha V.} } @article { ISI:000336464400074, title = {Protein mediated synthesis of Au-Ag bimetallic nanoparticles}, journal = {Materials Letters}, volume = {124}, year = {2014}, month = {JUN}, pages = {271-274}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

There is growing need to develop environment friendly method for synthesis of bimetallic nanoparticle that do not use toxic chemicals during their synthesis process. Here, we report synthesis of Au-Ag bimetallic nanoparticles by using macerase enzyme as reducing agent at different temperatures. Bimetallic nanoparticles were synthesized at 80 and 90 degrees C. The intensity of formation of nanoparticles was more at 80 degrees C. The bimetallic nanoparticles are characterized by using UV-vis, TEM and EDAX. The TEM study shows the inner gold and outer silver bimetallic nanoparticles. The formed nanoparticles are 4-20 nm in size and spherical in shape. EDAX confirms the formed bimetallic nanoparticles are of gold and silver. (C) 2014 Elsevier B.V. All rights reserved.

}, keywords = {Enzyme, Gold, Macerase, Particles, Silver, synthesis}, issn = {0167-577X}, doi = {10.1016/j.matlet.2014.03.087}, author = {Raju, D. and Mendapara, Ritul and Mehta, Urmil J.} } @article { ISI:000344330800015, title = {Role of nanointerfaces in Cu- and Cu plus Au-based near-ambient-temperature CO oxidation catalysts}, journal = {ChemCatChem}, volume = {6}, number = {11}, year = {2014}, month = {NOV}, pages = {3116-3124}, publisher = {WILEY-V C H VERLAG GMBH}, address = {BOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANY}, abstract = {

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}, issn = {1867-3880}, doi = {10.1002/cctc.201402581}, author = {Gnanakumar, Edwin S. and Naik, Jarpla Madhusudhan and Manikandan, Marimuthu and Raja, Thirumalaiswamy and Gopinath, Chinnakonda S.} } @article { ISI:000358370700007, title = {Identifying solid luminogens through gold-catalysed intramolecular hydroarylation of alkynes}, journal = {European Journal of Organic Chemistry}, number = {22}, year = {2015}, month = {AUG}, pages = {4860-4867}, publisher = {WILEY-V C H VERLAG GMBH}, address = {POSTFACH 101161, 69451 WEINHEIM, GERMANY}, abstract = {

The identification of a new class of luminogens based on pyrrolo-quinoxaline embedded coumarin (PQC) structures is reported. The reaction relies on the gold-catalyzed hydroarylation reaction of appropriately substituted aryl alkynoates that produces molecules that exhibit solvatochromism and aggregation-induced emission enhancement (AIEE) phenomena. The application of PQCs for live cell imaging has also been demonstrated.

}, keywords = {Cell imaging, Dyes/pigments, fluorescence, Gold, Luminescence, Solvatochromism}, issn = {1434-193X}, doi = {10.1002/ejoc.201500503}, author = {Shaikh, Aslam C. and Shalini, S. and Vaidhyanathan, Ramanathan and Mane, Manoj V. and Barui, Ayan Kumar and Patra, Chitta Ranjan and Venkatesh, Yeduru and Bangal, Prakriti Ranjan and Patil, Nitin T.} } @article { ISI:000350116200014, title = {Robustness screen in enantioselective catalysis enabled generation of enantioenriched heterocyclic scaffolds in one pot}, journal = {Chemistry-A European Journal}, volume = {21}, number = {9}, year = {2015}, month = {FEB}, pages = {3580-3584}, publisher = {WILEY-V C H VERLAG GMBH}, address = {BOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANY}, abstract = {

Enantioselective catalysis has emerged as a powerful synthetic paradigm and has accelerated the development of new methods to make diverse chiral molecules. Generally, these reactions are very sensitive to the steric and electronic environment present in the catalyst as well as the substrates. With this scenario, the presence of an additional component in the reaction mixture is expected to add complexity in achieving the enantioselective variants. Herein, we report that various enantioenriched molecules could be obtained from multiple starting materials in one pot. The reaction of aminoaromatics A with alkynols B-1, B-2, B-3...B-n with a Au-I/chiral BrOnsted acid catalyst afforded AB(1)*, AB(2)*, AB(3)*...AB(n)*; while, the reaction of alkynols B with aminoaromatics A(1), A(2), A(3)...A(n) under the same reaction conditions gave A(1)B*, A(2)B*, A(3)B*...A(n)B*.

}, keywords = {chiral Bronsted acid, Enantioselectivity, Gold, molecular scaffolds, robustness screen}, issn = {0947-6539}, doi = {10.1002/chem.201406045}, author = {Bagle, Pradip N. and Shinde, Valmik S. and Patil, Nitin T.} } @article { ISI:000372759100036, title = {Amelioration of excision wounds by topical application of green synthesized, formulated silver and gold nanoparticles in albino Wistar rats}, journal = {Materials Science \& Engineering C-Materials for Biological Applications}, volume = {62}, year = {2016}, month = {MAY}, pages = {293-300}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Wound healing, a complex biological process, has attained a lot of attention as dermatologists are primarily interested in stimulated wound closure without formation of scar or a faint scar. The recent upsurgence of nanotechnology has provided novel therapeutic materials in the form of silver and gold nanoparticles which accelerate the wound healing process. The effect of formulated nanoparticles using Coleus forskohlii root extract (green synthesized) has been tried out for ameliorating full thickness excision wounds in albino Wistar male rats. The evaluation of in vivo activity of nanoparticles in wound healing was carried out on open wounds made by excision on the dorsal sides of albino Wistar rats under anesthesia, and the healing of the wounds was assessed. Histological aspects of the healing process were studied by a HE (Hematoxylin and Eosin) staining method to assess various degrees of re-epithelialization and the linear alignment of the granulation tissue whereas Van Gieson{\textquoteright}s histochemical staining was performed to observe collagen fibers. The healing action shown by the formulated nanoparticles was remarkable during the early stages of wound healing, which resulted in the substantial reduction of the whole healing period. Topical application of formulated gold nanoparticles was found to be more effective in suppressing inflammation and stimulating re-epithelialization compared to silver nanoparticles during the healing process. The results throw light on the amelioration of excision wounds using nanoparticles which could be a novel therapeutic way of improving wound healing in clinical practice. The mechanism of advanced healing action of both types of nanoparticles could be due to their antimicrobial, antioxidant and anti-inflammatory properties. (C) 2016 Elsevier B.V. All rights reserved.

}, keywords = {collagen, Gold, green synthesis, Nanopraticles, wound Healing}, issn = {0928-4931}, doi = {10.1016/j.msec.2016.01.069}, author = {Naraginti, Saraschandra and Kumari, P. Lakshmi and Das, Raunak Kumar and Sivakumar, A. and Patil, Sagar Hindurao and Andhalkar, Vaibhav Vilas} } @article {43959, title = {Gold nanoconjugates reinforce the potency of conjugated cisplatin and doxorubicin}, journal = {Colloids and Surfaces B: Biointerfaces}, volume = {160}, year = {2017}, month = {DEC}, pages = {254-264}, type = {Journal Article}, abstract = {Osteosarcoma or osteogenic sarcoma is the most common and prevalent cancerous tumor of bone and occurs especially in children and teens. Recent treatment strategy includes a combination of both chemotherapy and surgeries. Although, the use of single drug-based chemotherapy treatment remains unsatisfactory. Therefore, combinatorial therapy has emerged as a potential strategy for treatment with limited side- effects. Here, we evaluated the combinatorial anticancerous effect of cisplatin (CIS) and doxorubicin (DOX) bioconjugated bromelain encapsulated gold nanoparticles (B-AuNPs conjugated CIS and DOX) in the treatment of osteosarcoma. The synthesized B-AuNPs conjugated CIS and DOX were characterized by various characterization techniques like UV{\textendash}vis spectroscopy, TEM, DLS and zeta potential to ensure the synthesis, size, shape, size distribution and stability. Drug loading efficiency bioconjugation of CIS and DOX was ensured by UV{\textendash}vis spectroscopy. Bioconjugation of CIS and DOX was further confirmed using UV{\textendash}vis spectroscopy, TEM, DLS, Zeta potential and FT-IR analysis. The combinatorial effect of CIS and DOX in B-AuNPs conjugated CIS and DOX showed highly improved potency against MG-63 and Saos-2 cells at a very low concentration where primary osteoblasts didn{\textquoteright}t show any cytotoxic effect. The apoptotic effect of B-AuNPs conjugated CIS and DOX on osteosarcoma and primary osteoblasts cells were analyzed by increased permeability of the cell membrane, condensed chromatin and deep blue fluorescent condensed nucleus. The results clearly showed that B-AuNPs conjugated CIS and DOX significantly improved the potency of both the chemotherapeutic drugs by delivering them specifically into the nucleus of cancer cells through caveolae-dependent endocytosis. Thus, the greater inhibitory effect of combinatorial drugs (B-AuNPs conjugated CIS and DOX) over single drug based chemotherapy would be of great advantage during osteosarcoma treatment. }, keywords = {cells, chemotherapy, Cytology, Cytotoxicity, Drug interactions, dynamic light scattering, Gold, Molecular Biology, Platinum Compounds}, doi = {10.1016/j.colsurfb.2017.09.017}, author = {Iram, S.}, editor = {Zahera, M.} } @article {46628, title = {Apparent umpolung reactivity of indole through [Au]-catalysed cyclisation and lewis-acid-mediated allylation}, journal = {Chemistry-A European Journal}, volume = {26}, year = {2020}, month = {DEC}, pages = {17171-17175}, type = {Article}, abstract = {

The sequential functionalization of indole C2 and C3 in an umpolung fashion was executed with a predesigned substrate and choice of reagents. The developed method comprises gold-catalysed alkynol cycloisomerisation/intramolecular addition of C2 of indole and subsequent BF3.OEt2-mediated regioselective C3 allylation, resulting in the synthesis of the functionalized indoloisoquinolinone scaffold. The reaction involves 5-endo-alkynol cycloisomerisation and the dearomative addition of indole C2 to the intermediate oxocarbenium cation, which results in two equilibrating fused and spiropentacyclic intermediates, which upon treatment with allyl silane in the presence of BF3.OEt2, undergo selective indole C3 allylation. Other nucleophiles, such as hydride, azide and indole, were also found to be compatible with this process.

}, keywords = {Allylation, cyclization, domino reactions, Gold, umpolung}, issn = {0947-6539}, doi = {10.1002/chem.202003441, Early Access Date = NOV 2020}, author = {Shinde, Mahesh H. and Ramana, Chepuri V.} } @article {48405, title = {Silver dependent enantiodivergent gold(i) catalysed asymmetric intramolecular hydroamination of alkenes: a theoretical study}, journal = {Catalysts}, volume = {12}, year = {2022}, month = {NOV}, pages = {1392}, type = {Article}, abstract = {

We report a theoretical study of the first silver-dependent enantiodivergent gold-catalysed reaction. The combination of a single chiral binuclear gold(I) chloride complex and silver perchlorate catalyses the asymmetric intramolecular hydroamination of alkenes and affords both enantiomers of the products by applying a simple solvent change from toluene to methanol. A gold-silver chloride adduct that occurs only in methanol appears to control the enantioinversion. If one gold atom coordinates and activates the alkene moiety, the other gold is included in an adduct with silver chloride, which coordinates a methanol solvent molecule and further interacts with the amine function. If the use of toluene implies free anions and affords (S)-enantiomer, methanol allows a proximal interaction with the amine, leads to an opposite stereodifferentiation of the two diastereomeric intermediates during the final protodeauration step and results in the (R)-enantiomer.

}, keywords = {alkene, enantiodivergent catalysis, Gold, hydroamination, Silver}, doi = {10.3390/catal12111392}, author = {Dixit, Ruchi and Sharma, Himanshu and Agbossou-Niedercorn, Francine and Vanka, Kumar and Michon, Christophe} }