Synthesis of multivalent lactose derivatives by 1,3-dipolar cycloadditions: selective galectin-1 inhibition
摘要:
Acetylene derivatives of phenylalanine, phenethylamine and the multifunctional unnatural amino acids, phenyl-bis-alanine and phenyl-tris-alanine, were synthesized and functionalized with 2-azidoethyl beta-D-galactopyranosyl-(1 -> 4)-beta-D-glucopyranoside via regioselective copper(I)-mediated 1,3-dipolar cycloaddition to give a panel of mono-, di- and trivalent lactoside derivatives. Evaluation of the compounds as inhibitors against the tumour- and inflammation-related galectin-1, -3, 4N, 4C, -4, -7, -8N and -9N revealed a divalent compound with a K-d value as low as 3.2 mu M for galectin-1, which corresponded to a relative potency of 30 per lactose unit as compared to the natural disaccharide ligand lactose. This divalent compound had at least one order of magnitude higher affinity for galectin-1 than for any of the other galectins investigated. (c) 2006 Elsevier Ltd. All rights reserved.
Amino Acids and Peptides; XLIII1. Dehydroamino Acids; XVIII2. Synthesis of Dehydroamino Acids and Amino Acids fromN-Acyl-2-(dialkyloxyphosphinyl)-glycin Esters; II
The preparation of alkyl diamino dicarboxylic acids with high optical purity (100% ee, >98.5% de) and high yields based on asymmetric catalytic hydrogenation is described. The required prochiral precursors are prepared from dialdehydes and Z-, Boc-, and acetyl-protected phosphonoglycines. Aqueous solutions of glyoxal, succinic dialdehyde, and glutaric dialdehyde were used to prepare the diunsaturated