@article { ISI:000244732800019, title = {Stereoselective synthesis of 3-alkylidene/alkylazetidin-2-ones from azetidin-2,3-diones}, journal = {Tetrahedron}, volume = {63}, number = {11}, year = {2007}, month = {MAR}, pages = {2524-2534}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, type = {Article}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

Azetidin-2,3-diones have been used as synthons for the synthesis of C-3 alkylidene/alkylazetidin-2-ones. Some of the 3-alkylazetidin-2-ones are well known for their cholesterol absorption inhibitor activity. A regio and stereoselective Grignard reaction on a keto group followed by dehydration using PPh3/CCl4 reagent is a key step in this synthesis. Hydrogenation of the 3-alkylideneazetidin-2-ones provided stereoselectively cis-3-alkylazetidin-2-ones in very good yields. (c) 2006 Published by Elsevier Ltd.

}, keywords = {3-diones, azetidin-2, azetidin-2-ones, beta-lactam, Grignard reaction}, issn = {0040-4020}, doi = {10.1016/j.tet.2006.12.010}, author = {Tiwari, Dharmendra Kumar and Shaikh, Ashif Y. and Pavase, Laxmikant S. and Gumaste, Vikas K. and Deshmukh, Abdul Rakeeb A. S.} } @article { ISI:000288386700006, title = {Synthesis of glycopolypeptides by the ring opening polymerization of O-glycosylated-alpha-amino acid N-carboxyanhydride (NCA)}, journal = {Polymer Chemistry}, volume = {2}, number = {4}, year = {2011}, month = {FEB}, pages = {805-811}, publisher = {ROYAL SOC CHEMISTRY}, address = {THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND}, abstract = {

The novel synthesis of O-glycosylated lysine-NCA from a stable glycosyl donor and a commercially available protected amino acid in very high yield is reported. These O-glycosylated lysine-NCA monomers underwent ring opening polymerization using simple primary amine initiators to form well defined, high molecular weight homoglycopolypeptides and diblock co-glycopolypeptides. The synthesis of azide labelled end functionalized glycopolypeptides and amphiphilic diblock copolypeptides is also reported. This methodology represents an easy and practical route to the synthesis of O-glycosylated polypeptides with 100\% glycosylation.

}, issn = {1759-9954}, doi = {10.1039/c0py00412j}, author = {Pati, Debasis and Shaikh, Ashif Y. and Hotha, Srinivas and Sen Gupta, Sayam} } @article { ISI:000319185100004, title = {Synthesis and self-assembly of amphiphilic homoglycopolypeptide}, journal = {Langmuir}, volume = {29}, number = {19}, year = {2013}, month = {MAY}, pages = {5659-5667}, publisher = {AMER CHEMICAL SOC}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

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

}, issn = {0743-7463}, doi = {10.1021/la400144t}, author = {Dhaware, Vinita and Shaikh, Ashif Y. and Kar, Mrityunjoy and Hotha, Srinivas and Sen Gupta, Sayam} }