Synthesis of galactose-containing analogues of (1-->6)-branched (1-->3)-glucohexaose and its lauryl glycoside.
Coupling of the trisaccharide acceptor either 2,4,6-tri-O-acetyl-beta-D-glucopyranosyl-(1-->3)-[2,3,4,6-tetra-O-benzoyl-beta-D-glucopyranosyl-(1-->6)]-5-O-acetyl-1,2-O-isopropylidene-alpha-D-glucofuranose (13) or lauryl 2,4,6-tri-O-acetyl-beta-D-glucopyranosyl-(1-->3)-[2,3,4,6-tetra-O-benzoyl-beta-D-glucopyranosyl-(1-->6)]-2,5-di-O-acetyl-alpha-D-glucopyranoside (15) with the trisaccharide donor 2,3,4,6-tetra-O-benzoyl-beta-D-glucopyranosyl-(1-->3)-[2,3,4,6-tetra-O-benzoyl-beta-D-glucopyranosyl-(1-->6)]-2,4-di-O-acetyl-alpha-D-galactopyranosyl trichloroacetimidate (12) gave alpha-linked hexasaccharides 14 and 16, respectively, while coupling of either 13 or 15 with trisaccharide donor 2,3,4,6-tetra-O-benzoyl-beta-D-galactopyranosyl-(1-->3)-[2,3,4,6-tetra-O-benzoyl-beta-D-galactopyranosyl-(1-->6)]-2,4-di-O-acetyl-alpha-D-galactopyranosyl trichloroacetimidate 17 did not afford any hexasaccarides. The analogues of the immunomodulator beta-D-Glcp-(1-->3)-[beta-D-Glcp-(1-->6)]-alpha-D-Glcp-(1-->3)-beta-D-Glcp-beta-(1-->3)-[beta-D-Glcp-(1-->6)]-beta-D-Glcp (1) was obtained by deprotection of 14 and 16.
Zhang
Guohua
G
Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, PO Box 2871, Beijing 100085, China.
Fu
Mingkun
M
Ning
Jun
J
D005690:Galactose / Q000031:analogs & derivatives* / Q000737:chemistry*; D006027:Glycosides / Q000138:chemical synthesis* / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D015394:Molecular Structure; D009844:Oligosaccharides / Q000138:chemical synthesis* / Q000737:chemistry; D013329:Structure-Activity Relationship
D006027:Glycosides; D009844:Oligosaccharides; D005690:Galactose