Synthesis of oligosaccharide derivatives related to those from sanqi, a Chinese herbal medicine from Panax notoginseng Original Research Article

Oligosaccharide derivatives from sanqi, a Chinese herbal medicine derived from Panax notoginseng, methyl β-d-galactopyranosyl-(1→3)-[α-l-arabinofuranosyl-(1→6)]-α-d-galactopyranoside, diosgenyl β-d-galactopyranosyl-(1→3)-[α-l-arabinofuranosyl-(1→6)]-α-d-galactopyranoside, and methyl β-d-galactopyranosyl-(1→3)-[α-l-arabinofuranosyl-(1→6)]-α-d-galactopyranosyl-(1→4)-β-d-galactopyranosyl-(1→3)-[α-l-arabinofuranosyl-(1→6)]-α-d-galactopyranoside, were synthesized under standard glycosylation conditions. An unexpected α-(1→4) linkage was formed predominantly in the presence of neighboring participation group during regioselective synthesis of hexasaccharide via 3+3 strategy.