01559nas a2200193   4500008004100000022001400041245013000055210006900185260011000254300001400364490000600378520072500384100002201109700002301131700002601154700002601180700002801206856013101234       2011                        eng d  a1477-052000aBicyclic amino acid-carbohydrate-conjugates as conformationally restricted hydroxyethylamine (HEA) transition-state isosteres0 aBicyclic amino acidcarbohydrateconjugates as conformationally re  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcSEP  a7300-73020 v93 a<p>This communication describes a general synthetic route to bicyclic amino acid-carbohydrate-conjugates, which would be useful as conformationally restricted hydroxyethylamine (HEA) transition-state isosteres. The synthesis was achieved in 12 steps starting from D-glucose. The striking features of this system are the bicyclic rigid core displaying an a-amino acid side chain and hydroxyethylamine moiety - both of which would be potentially important for receptor interactions, leading to various biomedical responses, as described in the literature. Crystal structure investigation suggested extensive intermolecular hydrogen-bonding interactions in this system, involving the backbone amide and hydroxyl groups.</p>1 aKale, Sangram, S.1 aChavan, Sanjay, T.1 aSabharwal, Sushma, G.1 aPuranik, Vedavati, G.1 aSanjayan, Gangadhar, J.  uhttps://library.ncl.res.in/content/bicyclic-amino-acid-carbohydrate-conjugates-conformationally-restricted-hydroxyethylamine-002335nas a2200229   4500008004100000022001400041245017300055210006900228260007100297300001400368490000700382520140600389100002101795700002601816700002301842700002201865700002301887700002601910700002601936700002301962856012001985       2012                        eng d  a0022-326300aAlpha-geminal dihydroxymethyl piperidine and pyrrolidine iminosugars: synthesis, conformational analysis, glycosidase inhibitory activity, and molecular docking studies0 aAlphageminal dihydroxymethyl piperidine and pyrrolidine iminosug  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcSEP  a7873-78820 v773 a<p>The Jocic-Reeve and Corey-Link type reaction of dichloromethyllithium with suitably protected 5-keto-hexofuranoses followed by treatment with sodium azide and sodium borohydride reduction gave 5-azido-5-hydroxylmethyl substituted hexofuranoses 7a-c with required geminal dihydroxymethyl group. Removal of protecting groups and converting the C-1 anomeric carbon into free hemiacetal followed by intramolecular reductive aminocyclization with in situ generated C5-amino functionality afforded corresponding 5C-dihydroxymethyl piperidine iminosugars 2a-c. Alternatively, removal of protecting groups in 7b and 7c and chopping of C1-anomeric carbon gave C2-aldehyde that on intramolecular reductive aminocyclization with CS-amino gave 4C-dihydroxyrnethyl pyrrolidine iminosugars 1b and 1c, respectively. On the basis of the H-1 NMR studies, the conformations of 2a/2b were assigned as C-4(1) and that of 2c as C-1(4). The glycosidase inhibitory activities of all five iminosugars were studied with various glycosidase enzymes and compared with natural o-g/uco-l-deoxynojirimycin (DNJ). All the five compounds were found to be potent inhibitors of rice alpha-glucosidase with K-i and IC50 values in the nanomolar concentration range. Iminosugars 2b and 1b were found to be more potent inhibitors than their parent iminosugar. These results were substantiated by in silico molecular docking studies.</p>1 aPawar, Nitin, J.1 aParihar, Vijay, Singh1 aChavan, Sanjay, T.1 aJoshi, Rakesh, S.1 aJoshi, Pranaya, V.1 aSabharwal, Sushma, G.1 aPuranik, Vedavati, G.1 aDhavale, Dilip, D.  uhttps://library.ncl.res.in/content/alpha-geminal-dihydroxymethyl-piperidine-and-pyrrolidine-iminosugars-synthesis-0