Chemo-enzymatic synthesis of a divalent sialyl Lewisx ligand with restricted flexibility
摘要:
To study the influence of the entropic factor in cluster cooperative effects, a divalent sialyl Lewis(x) ligand with restricted flexilbility was chemo-enzymatically synthesized. First, a cyclized precursor with both glucosamine residues bridged together by a succinyl group was readily obtained in 42% yield by treatment of 2,2-bis(benzyloxymethyl)-1,3-bis(3,4,6-tri-O-acetyl-2-amino-2-deoxy-beta-D-glucopyranosyloxy)-propane with succinyl chloride. After deacetylation, this precursor was subjected to stepwise enzymatic elongation utilizing successively, soluble galactosyltransferase, then recombinant sialyltransferase and fucosyltransferase; the latter enzymes immobilized on Ni2+-Agarose, to afford, after debenzylation, a divalent sialyl Lewis(+) ligand of restricted flexibility. in 45% overall yield. Following the same enzymatic sequence, a totally flexible ligand, required as a reference compound for evaluation of inhibitory activity toward selectins, was also prepared from 2,2(bis-benzyloxymethyl)-1,3-bis(2-acetamido-2-deoxy-beta-D-glucopyranosyloxy)-propane, as well as both related divalent Lewis' molecules lacking the sialic acids, the rigid one and the flexible one. (C) 2003 Elsevier Science Ltd. All rights reserved.
Chemo-enzymatic synthesis of a divalent sialyl Lewisx ligand with restricted flexibility
摘要:
To study the influence of the entropic factor in cluster cooperative effects, a divalent sialyl Lewis(x) ligand with restricted flexilbility was chemo-enzymatically synthesized. First, a cyclized precursor with both glucosamine residues bridged together by a succinyl group was readily obtained in 42% yield by treatment of 2,2-bis(benzyloxymethyl)-1,3-bis(3,4,6-tri-O-acetyl-2-amino-2-deoxy-beta-D-glucopyranosyloxy)-propane with succinyl chloride. After deacetylation, this precursor was subjected to stepwise enzymatic elongation utilizing successively, soluble galactosyltransferase, then recombinant sialyltransferase and fucosyltransferase; the latter enzymes immobilized on Ni2+-Agarose, to afford, after debenzylation, a divalent sialyl Lewis(+) ligand of restricted flexibility. in 45% overall yield. Following the same enzymatic sequence, a totally flexible ligand, required as a reference compound for evaluation of inhibitory activity toward selectins, was also prepared from 2,2(bis-benzyloxymethyl)-1,3-bis(2-acetamido-2-deoxy-beta-D-glucopyranosyloxy)-propane, as well as both related divalent Lewis' molecules lacking the sialic acids, the rigid one and the flexible one. (C) 2003 Elsevier Science Ltd. All rights reserved.
Chemo-enzymatic synthesis of a divalent sialyl Lewisx ligand with restricted flexibility
作者:Fabrice Bintein、Claudine Augé、André Lubineau
DOI:10.1016/s0008-6215(03)00129-0
日期:2003.5
To study the influence of the entropic factor in cluster cooperative effects, a divalent sialyl Lewis(x) ligand with restricted flexilbility was chemo-enzymatically synthesized. First, a cyclized precursor with both glucosamine residues bridged together by a succinyl group was readily obtained in 42% yield by treatment of 2,2-bis(benzyloxymethyl)-1,3-bis(3,4,6-tri-O-acetyl-2-amino-2-deoxy-beta-D-glucopyranosyloxy)-propane with succinyl chloride. After deacetylation, this precursor was subjected to stepwise enzymatic elongation utilizing successively, soluble galactosyltransferase, then recombinant sialyltransferase and fucosyltransferase; the latter enzymes immobilized on Ni2+-Agarose, to afford, after debenzylation, a divalent sialyl Lewis(+) ligand of restricted flexibility. in 45% overall yield. Following the same enzymatic sequence, a totally flexible ligand, required as a reference compound for evaluation of inhibitory activity toward selectins, was also prepared from 2,2(bis-benzyloxymethyl)-1,3-bis(2-acetamido-2-deoxy-beta-D-glucopyranosyloxy)-propane, as well as both related divalent Lewis' molecules lacking the sialic acids, the rigid one and the flexible one. (C) 2003 Elsevier Science Ltd. All rights reserved.