02173nas a2200205   4500008004100000022001400041245010300055210006900158260011000227300001400337490000700351520135100358100002001709700002301729700001801752700001801770700003201788700002201820856012501842       2009                        eng d  a0959-942800aClickable SBA-15 mesoporous materials: synthesis, characterization and their reaction with alkynes0 aClickable SBA15 mesoporous materials synthesis characterization   aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcJAN  a1409-14160 v193 a<p>SBA-15 mesoporous silica has been functionalized with azidopropyl groups through both one-pot co-condensation and post-synthetic grafting. For both these methodologies, azidopropyltriethoxysilane was used to introduce the azidopropyl groups. The azidopropyl modified SBA-15 material synthesized by one-pot co-condensation had hexagonal crystallographic order, pore diameters up of 50 angstrom, and the content of azidopropyl groups was found to be 1.3 mmol g(-1). The presence of the azidopropyl group was confirmed by multinuclear ((13)C, (29)Si) solid state NMR and IR spectroscopy. Both these materials underwent very efficient Cu(I)-catalyzed azide alkyne ``click'' reaction (CuAAC) with a variety of alkynes. Nearly 85% of the azide present in the SBA-15 material was converted to the corresponding triazole when propargyl alcohol was used as the substrate. This methodology was also used to incorporate mannose into SBA-15. Incubation of this mannose labeled SBA-15 with fluorescein labeled Concanavalin-A led to the formation of a fluorescent silica-protein hybrid material. The ease of synthesis for the azide labeled SBA-15 material together with its ability to undergo very efficient chemoselective CuAAC in water would make it a very attractive platform for the development of covalently anchored catalysts, enzymes and sensors.</p>1 aMalvi, Bharmana1 aSarkar, Bibhas, R.1 aPati, Debasis1 aMathew, Renny1 aAjithkumar, Thalasseril, G.1 aGupta, Sayam, Sen  uhttps://library.ncl.res.in/content/clickable-sba-15-mesoporous-materials-synthesis-characterization-and-their-reaction-001623nas a2200193   4500008004100000022001400041245014900055210006900204260011000273300001400383490000700397520078300404100002301187700001901210700002001229700002201249700003001271856012801301       2010                        eng d  a1144-054600aClicking molecular hooks on silica nanoparticles to immobilize catalytically important metal complexes: the case of gold catalyst immobilization0 aClicking molecular hooks on silica nanoparticles to immobilize c  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcAUG  a2662-26700 v343 a<p>Gold mediated reactions have emerged as one of the best choices for affecting a variety of chemical transformations with a wide range of functional group tolerance. Application of such transformations to industrial processes necessitates immobilization of the Au ions into a matrix for easy separation of the catalyst after reaction. We report the synthesis and characterization of silica nanoparticles in which Au(III) has been immobilized through a 1,2,3-triazole linkage using an alkynalated picolinic acid exploiting ``click chemistry''. The Au( III) immobilized silica nanoparticle has been thoroughly characterized using FT-IR, C-13 CP MAS NMR and XPS. The utility of these particles as an easily separable catalyst for the Hashmi phenol synthesis is also reported.</p>1 aGanai, Anal, Kumar1 aBhardwaj, Rima1 aHotha, Srinivas1 aGupta, Sayam, Sen1 aPrasad, Bhagavatula L. V.  uhttps://library.ncl.res.in/content/clicking-molecular-hooks-silica-nanoparticles-immobilize-catalytically-important-metal-002126nas a2200217   4500008004100000022001400041245009900055210006900154260007100223300001400294490000700308520131800315100001801633700002201651700001601673700002601689700002101715700002001736700002201756856013001778       2012                        eng d  a1525-779700aControlled synthesis of O-glycopolypeptide polymers and their molecular recognition by lectins0 aControlled synthesis of Oglycopolypeptide polymers and their mol  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcMAY  a1287-12950 v133 a<p>The facile synthesis of high molecular weight water-soluble O-glycopolypeptide polymers by the ring-opening polymerization of their corresponding N-carboxyanhydride (NCA) in very high yield (overall yield &gt; 70%) is reported. The per-acetylated-O-glycosylated lysine-NCA monomers, synthesized using stable glycosyl donors and a commercially available protected amino acid in very high yield, was polymerized using commercially available amine initiators. The synthesized water-soluble glycopolypeptides were found to be alpha-helical in aqueous solution. However, we were able to control the secondary conformation of the glycopolypeptides (alpha-helix vs nonhelical structures) by polymerizing raceznic amino acid glyco NCAs. We have also investigated the binding of the glycopolypeptide poly(alpha-manno-O-lys) with the lectin Con-A using precipitation and hemagglutination assays as well as by isothermal titration calorimetry (ITC). The ITC results clearly show that the binding process is enthalpy driven for both alpha-helical and nonhelical structures, with negative entropic contribution. Binding stoichiometry for the glycopolypeptide poly(alpha-manno-O-lys) having a nonhelical structure was slightly higher as compared to the corresponding polypeptide which adopted an alpha-helical structure.</p>1 aPati, Debasis1 aShaikh, Ashif, Y.1 aDas, Soumen1 aNareddy, Pavan, Kumar1 aSwamy, Musti, J.1 aHotha, Srinivas1 aGupta, Sayam, Sen  uhttps://library.ncl.res.in/content/controlled-synthesis-o-glycopolypeptide-polymers-and-their-molecular-recognition-lectins-001167nas a2200193   4500008004100000022001400041245012200055210006900177260011000246300001400356490000700370520035600377100002100733700002000754700002000774700002800794700002200822856012900844       2013                        eng d  a1359-734500aCatalytic signal amplification using [Fe-III(biuret-amide)]-mesoporous silica nanoparticles: visual cyanide detection0 aCatalytic signal amplification using FeIIIbiuretamidemesoporous   aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcMAR  a2216-22180 v493 a<p>Catalytic signal amplification was used for the colorimetric detection of CN- in aqueous media by using the enzyme catalase in tandem with mesoporous silica nanoparticle based synthetic HRP enzyme mimic Fe-MSNs. Signal amplification up to a maximum of eight fold was observed for the reporter ``oxidized TMB'' with respect to the added CN- ion.</p>1 aPanda, Chakadola1 aDhar, Basab, B.1 aMalvi, Bharmana1 aBhattacharjee, Yudhajit1 aGupta, Sayam, Sen  uhttps://library.ncl.res.in/content/catalytic-signal-amplification-using-fe-iiibiuret-amide-mesoporous-silica-nanoparticles-002237nas a2200205   4500008004100000022001400041245012400055210006900179260007100248300001400319490000700333520144600340100002201786700001601808700001801824700002001842700002201862700002001884856012701904       2014                        eng d  a1525-779700aCationic charged helical glycopolypeptide using ring opening polymerization of 6-deoxy-6-azido-glyco-N-carboxyanhydride0 aCationic charged helical glycopolypeptide using ring opening pol  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcOCT  a3679-36860 v153 a<p>Glycopolypeptides with a defined secondary structure are of significance in understanding biological phenomena. Synthetic glycopolypeptides, or polypeptides featuring pendant carbohydrate moieties, have been of particular interest in the field of tissue engineering and drug delivery. In this work, we have synthesized charged water-soluble glycopolypeptides that adopt a helical conformation in water. This was carried out by the synthesis of a glyco-N-carboxyanhydride (glyco-NCA) containing an azide group at the sixth position of the carbohydrate ring. Subsequently, the NCA was polymerized to obtain azide-containing glycopolypeptides having good control over molecular weight and polydispersity index (PDI) in high yields. We were also able to control the incorporation of the azide group by synthesizing random co-glycopolypeptide containing 6-deoxy-6-azido and regular 6-OAc functionalized glucose. This azide functionality allows for the easy attachment of a bioactive group, which could potentially enhance the biological activity of the glycopolypeptide. We were able to obtain water-soluble charged glycopolypeptides by both reducing the azide groups into amines and using CuAAC with propargylamine. These charged glycopolypeptides were shown to have a helical conformation in water. Preliminary studies showed that these charged glycopolypeptides showed good biocompatibility and were efficiently taken up by HepG2 cells.</p>1 aShaikh, Ashif, Y.1 aDas, Soumen1 aPati, Debasis1 aDhaware, Vinita1 aGupta, Sayam, Sen1 aHotha, Srinivas  uhttps://library.ncl.res.in/content/cationic-charged-helical-glycopolypeptide-using-ring-opening-polymerization-6-deoxy-6-001631nas a2200181   4500008004100000022001400041245010800055210006900163260007100232300001200303490000600315520092400321100001601245700002001261700002001281700002201301856012601323       2016                        eng d  a2161-165300aControlled synthesis of end-functionalized mannose-6-phosphate glycopolypeptides for lysosome targeting0 aControlled synthesis of endfunctionalized mannose6phosphate glyc  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcJUL  a809-8130 v53 a<p>The ubiquitous expression of the mannose-6-phosphate receptor on the majority of human cells makes it a valid target in the quest to deliver therapeutics selectively to the lysosome. In this work end-functionalized polyvalent mannose-6-phosphate glycopolypeptides (M6P-GPs) with high molecular weights (up to 22 kDa) have been synthesized via NCA polymerization. These synthetic M6P-GPs were found to display minimal toxicity to cells in vitro and show exceptional selectivity for trafficking into lysosomes in various cell lines. Comparison of the cellular uptake behavior of M6P-GP and the corresponding mannose-GP polymer reveals that incorporation of the phosphate moiety at the 6-position of mannose completely alters its trafficking behavior and becomes exclusively lysosome specific. We also demonstrate that trafficking of M6P-GPs in mammalian cells is likely associated with the CI-MPR receptor pathway.</p>1 aDas, Soumen1 aParekh, Nimisha1 aMondal, Basudeb1 aGupta, Sayam, Sen  uhttps://library.ncl.res.in/content/controlled-synthesis-end-functionalized-mannose-6-phosphate-glycopolypeptides-lysosome01627nas a2200169   4500008004100000245008800041210006900129260000800198300001200206490000700218520102900225100001901254700002001273700002201293700002201315856012001337       2017                        eng d00aCatalytic macroporous biohydrogels made of ferritin-encapsulated gold nanoparticles0 aCatalytic macroporous biohydrogels made of ferritinencapsulated   cFEB  a225-2320 v823 aReported is a modular approach for the incorporation and stabilization of gold nanoparticles inside a three-dimensional macroporous hydrogel made of ferritin. The strategy, which involves the dynamic templating of surfactant H-1 domains, demineralization, and remineralization helps to overcome aggregation and degradation issues usually associated with bare-metal-based nanocatalysts. The catalytic activity of the so-synthesized bionanocomposite hydrogel was demonstrated in both nitroaldol (Henry) and nitroreduction model reactions in aqueous solution at room temperature. An interesting synergistic effect between basic residues of the protein and the gold nanoparticles was found in the nitroaldol reaction when carried out in water in the presence of a phase-transfer catalyst. Furthermore, the reduction of 4-nitrophenol and 4-nitroaniline catalyzed by the nanocomposite scaffold in the presence of NaBH4 proceeded significantly faster than that using other known Au- and Ag-based catalysts under similar conditions.1 aKumari, Sushma1 aHaring, Marleen1 aGupta, Sayam, Sen1 aDiaz, David, Diaz  uhttps://library.ncl.res.in/content/catalytic-macroporous-biohydrogels-made-ferritin-encapsulated-gold-nanoparticles02724nas a2200325   4500008004100000022001400041245014100055210006900196260000800265490000700273520157300280653002101853653004001874653004101914653002801955100001601983700002601999700002102025700002802046700002002074700002002094700001902114700001902133700002002152700002402172700003202196700002202228700002002250856012802270       2026                        eng d  a0935-964800aChirality transfer from covalent organic framework nanotubes to covalent organic framework films via chirality induction crystallization0 aChirality transfer from covalent organic framework nanotubes to   cAPR0 v383 a<p>
	We report the synthesis of homochiral crystalline covalent organic framework (COF) films that combine rigidity and porosity, offering significant promise for heterogeneous asymmetric catalysis. We prepared enantiopure COF films from achiral diamine and trialdehyde precursors using a chiral induction crystallization strategy. A Schiff-base reaction, catalyzed by a chiral acid, namely (R)- and (S)-camphorsulfonic acids (CSA) generated a beta-ketoenamine backbone with induced chirality. (R)- and (S)-camphorsulfonic acids direct the diamine-trialdehyde condensation and induce chirality during the nucleation of COF nanotubes, enabling their periodic arrangement and the formation of homochiral thin films. We successfully synthesized six distinct COF films with three different backbone functionalities: R-, S-TpAzo; R-, S-TpDPP; and R-, S-TpBDMe2, using the two enantiomers of the chiral camphorsulfonic acids. All films displayed strong circular dichroism signals and pronounced Cotton effects, confirming their enhanced enantiopurity. Both R- and S-TpAzo films exhibited the highest crystallinity, long-range order, and permanent porosity, making them particularly well-suited for catalytic applications. To demonstrate their utility, we encapsulated a bioinspired catalyst, (Et4N)2[FeIII(Cl)bTAML], within the chiral channels of the R- and S-TpAzo films. The resulting composite created a robust heterogeneous catalytic platform for the asymmetric epoxidation of alkenes, achieving excellent activity and enantioselectivity under ambient conditions.</p>
10achiral induction10acovalent organic framework nanotube10acovalent organic framework thin film10aheterogeneous catalysis1 aBag, Saikat1 aChatterjee, Debasmita1 aMahapatra, Rohan1 aSasmal, Himadri, Sekhar1 aKhatua, Arindam1 aGiri, Madhurima1 aPaul, Satyadip1 aShelke, Ankita1 aAlmasoud, Najla1 aAlomar, Taghrid, S.1 aAjithkumar, Thalasseril, G.1 aGupta, Sayam, Sen1 aBanerjee, Rahul  uhttps://library.ncl.res.in/content/chirality-transfer-covalent-organic-framework-nanotubes-covalent-organic-framework-films