Glandulosides A-D, triterpene saponins from Acanthophyllum glandulosum

Four novel triterpenoid saponins, glandulosides A (1), B (2), C (3), and D (4), together with two known saponins (5 and 6) have been isolated from the roots of Acanthophyllum glandulosum. Their structures were elucidated using a combination of homo- and heteronuclear 2D NMR techniques (COSY, TOCSY, NOESY, HSQC, and HMBC) and by FABMS. The new compounds were characterized as 23-O-β-D-galactopyranosylgypsogenic acid-28-O-β-D-glucopyranosyl- (1→3)-[β-D-galactopyranosyl-(1→6)]-β-D-galactopyranoside (1), 3-O-β-D-galactopyranosyl-(1→2)-[β-D-xylopyranosyl-(1→3) ]-β-D-glucuronopyranosylgyp-sogenin-28-O-β-D-xylopyranosyl-(1→3) -β-D-xylopyranosyl-(1→4)-α-L-rhamnopyranosyl-(1→2) -3-O-acetyl-β-D-fucopyranoside (2), 3-O-β-D-galactopyranosyl- (1→2)-[β-D-xylopyranosyl-(1→3)]-β-D-glucuronopyranosyl- gypsogenin-28-O-β-D-xylopyranosyl-(1→3)-β-D-xylopyranosyl-(1-4) -α-L-rhamnopyranosyl-(1→2)-3,4-di-O-acetyl-β-D-fucopyranoside (3), and 3-O-β-D-galactopyranosyl-(1→2)-[β-D-xylopyranosyl- (1→3)]-β-D-glucuronopyrano-sylgypsogenin-28-O-β-D-xylopyranosyl- (1→3)-β-D-xylopyranosyl-(1→4)-α-L-rhamnopyranosyl- (1→2)-[3-O-acetyl-β-D-quinovopyranosyl-(1→4)]-β-D- fucopyranoside (4).