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

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.

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-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

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 > 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.

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-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

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.

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-6-0