New Acylated Secoiridoid Glucosides from Gentiana straminea (Gentianaceae)

Two new acylated secoiridoid glucosides. 4'-acetyl-6'-{[2-hydroxy-3-(1-beta-D-glucopyranosyloxy)]benzoyloxy}sweroside and 3',4'-diacetyl-6'-{[2-hydroxy-3-(1-beta-D-glucopyranosyloxy)]benzoyloxy}swertiamarin, named gentistraminosides A (1) and B (2), were isolated from the MeOH extract of Gentiana straminea MAXIM (Gentianaceae), together with twelve known ones, including eight iridoid and secoiridoid glucosides, macrophylloside A (3), loganic acid (4), secologanic acid (5), swertiamarin (6), gentiopicroside (7), loganic acid methyl ester (8), 6'-O-beta-D-glucopyranosyl gentiopicroside (9), and loganic acid 11-O-beta-D-glucopyranosyl ester (10), one flavone C-glucoside, isovitexin (11), one chromenecarboxylic acid glycosyl ester, macrophylloside D (12) and two triterpenoids, 1 alpha,2 alpha,3 beta,24-tetrahydroxyolean-12-en-28-oic acid (13), and 3 beta,6 alpha,24-trihydroxyolean-12-en-28-oic acid (14). Their structures were determined by means of detailed spectroscopic (NMR and MS) analysis.