First total synthesis of α-(2→3)/α-(2→6)-disialyl lactotetraosyl ceramide and disialyl Lewis A ganglioside as cancer-associated carbohydrate antigens
作者:Takayuki Ando、Hideharu Ishida、Makoto Kiso
DOI:10.1016/s0008-6215(02)00465-2
日期:2003.3
Abstract The first totalsynthesis of α-(2→3)/α-(2→6)-disialyl lactotetraosyl (DSLc 4 ) ceramide and α-(2→3)/α-(2→6)-disialyl Lewis A (DSLe a ) ganglioside as cancer-associated antigens is described. The suitably protected lactotriose (Lc 3 ) derivatives were successively glycosylated with sialic acid, sialyl-α-(2→3)- d -galactose and/or l -fucose donors in a regio- and stereo-selective manner, to
Synthesis of sialyl Lex ganglioside analogues sulfated at C-6 of either the galactose or N-acetylglucosamine residues, and at both of the galactose and N-acetylglucosamine residues: probes for clarifying the real carbohydrate ligand of L-selectin
Synthesis and biological activities of three sulfated sialyl Lex ganglioside analogues for clarifying the real carbohydrate ligand structure of L-selectin
O-benzoylation, removal of the benzylidene group affording 5, selective 6-O-levulinoylation, O-benzoylation, removal of the 2-(trimethylsilyl)ethyl group, and imidate formation, or via O-acetylation of 5, removal of the 2-trimethylsilyl)ethyl group, then imidate formation, gave the pentasaccharides 18-20. The glycosylation of the pentasaccharide acceptors (21-23) derived from 18-20 by removal of the 4-methoxybenzyl