文摘
Four new carbohydrates were isolated from the acidic hydrolysis part of the ethyl acetate extract of Cynanchum otophyllum Schneid (Asclepiadaceae). Their structures were determined as methyl 2,6-dideoxy-3-O-methyl-β-d-arabino-hexopyranosyl-(1→4)-6-deoxy-3-O-methyl-β-d-ribo-hexopyranosyl-(1→4)-6-deoxy-3-O-methyl-α-l-ribo-hexopyranoside (1), methyl 6-deoxy-1,3-di-O-methyl-β-d-ribo-hexosyl-(1→4)-2,6-dideoxy-3-O-methyl-α-d-arabino-hexopyranoside (2), methyl 2,6-dideoxy-3-O-methyl-β-d-arabino-hexopyranosyl-(1→4)-6-deoxy-3-O-methyl-α-l-ribo-hexopyranoside (3), and 2,6-dideoxy-3-O-methyl-β-d-arabino-hexopyranosyl-(1→4)-2,6-dideoxy-3-O-methyl-α-d-arabino-hexopyranosyl-(1→4)-2,6-dideoxy-3-O-methyl-β-d-lyxo-hexopyranose (4), respectively, by spectral methods.