Two new dammarane triterpene glycosides from the rhizomes of Panax notoginseng

Two new dammarane triterpene glycosides named notoginsenosides Rw 1 (1) and Rw 2 (2) were isolated from the rhizomes of Panax notoginseng, together with 20 known compounds including protopanaxadiol (3), protopanaxatriol (4), ginsenosides Rb1 (5), Rd (6), Re (7), Rg1 (8), Rg2 (9), 20-(S)-Rg3 (10), 20-(R)-Rg(3) (11), Rh1 (12), Rh4 (13), Rf (14), 20-O-glucopyranosyl Rf (15), notoginsenosides R1 (16), R2 (17), T5 (18), S (19), T (20), and Fa (21), and koryoginsenoside R1 (22). Based on FABMS, HRFABMS, IR, (1)H, 13C, and 2D-NMR (HSQC, HMBC, and COSY) spectral data, the structures of the new compounds were elucidated as 6-O-beta-d-xylopyranosyl-20-O-beta-d-xylopyranosyl-(1 --> 6)-beta-d-glucopyranosyldammar-24-ene-3beta,6alpha,12beta,20(S)tetraol (1) and 6-O-beta-d-xylopyranosyl-(1 --> 2)-beta-d-glucopyranosyldammar-22-ene-(trans)-3beta,6alpha,12beta,20(S), 25-pentaol (2). Compounds 3, 4, 13, and 22 were isolated from P. notoginseng for the first time.