01561nas a2200193   4500008004100000022001400041245012900055210006900184260011000253300001400363490000600377520073000383100001901113700003101132700002601163700002401189700002601213856012801239       2008                        eng d  a1477-052000aSynthesis of polyhydroxy piperidines and their analogues: a novel approach towards selective inhibitors of alpha-glucosidase0 aSynthesis of polyhydroxy piperidines and their analogues a novel  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcJAN  a2587-25950 v63 a<p>Various polyhydroxy piperidine azasugars have been synthesized from precursors 18a and 18b, obtained in both enantiomeric forms from D-ribose. Out of these polyhydroxy piperidine azasugars, 22, 39 and 20 were found to be potent as well as selective inhibitors of a-glucosidase with K(i) values ranging as low as 1.07 mu M, 16.4 mu M, and 88.2 mu M, respectively. Replacement of the hydroxy methylene moiety of 19 (K(i) 33% at 1 mM) by an amino methylene moiety (32, K(i) 36.8 mu M) showed a remarkable increase in the activity (almost 30 times). Furthermore, increasing the lipophilicity of 33 by N-alkylation with a dodecyl group (36) showed a three-fold enhancement in the activity (K(i) 217 mu M to K(i) 72.3 mu M).</p>1 aPandey, Ganesh1 aBharadwaj, Kishor, Chandra1 aKhan, Mohammad, Islam1 aShashidhara, K., S.1 aPuranik, Vedavati, G.  uhttps://library.ncl.res.in/content/synthesis-polyhydroxy-piperidines-and-their-analogues-novel-approach-towards-selective-002163nas a2200253   4500008004100000022001400041245013100055210006900186260011700255300001000372490000600382520116900388653001601557653002201573653002601595653002701621653001501648100002401663700002001687700002601707700003101733700001501764856013001779       2009                        eng d  a0973-626300aInteraction of alpha-mannosidase from aspergillus fischeri with glycosidase inhibitors, metal ions and group specific reagents0 aInteraction of alphamannosidase from aspergillus fischeri with g  aSECTOR A-80, SCHEME NO 54, VIJAY NAGAR, A B ROAD, INDORE, 452 010 MP, INDIAbRESEARCH JOURNAL BIOTECHNOLOGYcNOV  a39-480 v43 a<p>As an initial step towards using alpha-mannosidase as a target against anticancer drugs, inhibition studies of a model enzyme, class II alpha-mannosidase from Aspergillus fischeri in presence of polyhydroxy piperidine derived glycosidase inhibitors, metal ions and amino acid specific reagents were carried out to reveal the sensitivity of the enzyme. Three of the derivatives (Compound 20, 32 and 39)(11) showed competitive inhibition (K(i) =45, 48 and 235 mu M) and the binding of the inhibitors to the enzyme was entropically driven. Among the metal ions checked, Cu(++) (K(i) = 21nm) and Se(++) ions (K(i) = 32 mu M) showed noncompetitive and Co(++) (K(i) = 1.195 mM) showed competitive inhibition of the enzyme activity with insignificant change in the secondary structure of the protein. The above studies exhibit the Potential of the enzyme in studying anticancer drugs. Treatment of the enzyme with group specific reagents showed the presence of carboxylate, Arg and Cys at the active site. Substrate protection studies and kinetics of the modified enzyme confirmed the above results. Trp and His at the active site were observed to be in proximity.</p>10aactive-site10aalpha-Mannosidase10aChemical modification10aGlycosidase inhibitors10ametal ions1 aShashidhara, K., S.1 aGaikwad, S., M.1 aKhan, Mohammad, Islam1 aBharadwaj, Kishor, Chandra1 aPandey, G.  uhttps://library.ncl.res.in/content/interaction-alpha-mannosidase-aspergillus-fischeri-glycosidase-inhibitors-metal-ions-and-001319nas a2200181   4500008004100000022001400041245020700055210006900262260011000331300001400441490000700455520044400462100002500906700003100931700002600962700003000988856011901018       2014                        eng d  a1477-052000aDivergent total synthesis of 1,6,8a-tri-epi-castanospermine and 1-deoxy-6,8a-di-epi-castanospermine from substituted azetidin-2-one (beta-lactam), involving a cascade sequence of reactions as a key step0 aDivergent total synthesis of 168atriepicastanospermine and 1deox  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcJUL  a7389-73960 v123 a<p>A divergent, short, and novel total synthesis of 1,6,8a-tri-epi-castanospermine (7) and 1-deoxy-6,8a-di-epi-castanospermine (8) has been developed via a common precursor, 15, obtained from D-mannitol derived beta-lactam. The key step involves a one pot cascade sequence of trimethyl sulfoxonium ylide based cyclization of epoxy sulfonamide 14 via epoxide ring opening, one carbon homologation followed by intramolecular cyclization.</p>1 aTiwari, Dipak, Kumar1 aBharadwaj, Kishor, Chandra1 aPuranik, Vedavati, G.1 aTiwari, Dharmendra, Kumar  uhttps://library.ncl.res.in/content/divergent-total-synthesis-168a-tri-epi-castanospermine-and-1-deoxy-68a-di-epi-0