Bioactive saponins and glycosides. VIII. Notoginseng (1): new dammarane-type triterpene oligoglycosides, notoginsenosides-A, -B, -C, and -D, from the dried root of Panax notoginseng (Burk.) F.H. Chen.

Abstract

The glycosidic fraction from the dried roots of Panax notoginseng (Burk.) F.H. Chen was found to show protective effect on liver injury induced by D-galactosamine and lipopolysaccharide. From the glycosidic fraction with hepatoprotective effect, nine new dammarane-type triterpene oligoglycosides, notoginsenosides-A, -B, -C, -D, -E, -G, -H, -I, and -J and an acetylenic fatty acid glycoside, notoginsenic acid beta-sophoroside, were isolated together with fourteen known dammarane-type triterpene oligoglycosides. The structures of notoginsenosides-A, -B, -C and -D were determined on the basis of chemical and physicochemical evidence, which included the chemical correlation with ginsenoside-Rb1 using photosensitized oxygenation, as follows: notoginsenoside A; 3-O-[beta-D-glucopyranosyl (1-->2)-beta-D-glucopyranosyl]-20-O-[beta-D-glucopyranosyl (1-->6)-beta-D-glucopyranosyl] 3 beta, 12 beta,20(S),25-tetrahydroxydammar -23-ene; B; 3-O-[beta-D-glucopyranosyl (1-->2)-beta-D-glucopyranosyl]-20-O-[beta-D-glucopyranosyl (1-->6)-beta-D- glucopyranosyl] 3 beta, 12 beta,20(S)-trihydroxydammar-25-en-24-one, C; 3-O-[beta-D-glucopyranosyl (1-->2)-beta-D-glucopyranosyl]-20-O-[beta-D -glucopyranosyl (1-->6)-beta-D-glucopyranosyl] 3 beta,12 beta,20(S)- trihydroxy-24 zeta-hydroperoxydammar-25-ene, and D; 3-O-[beta-D-xylopyranosyl (1-->2)-beta-D-glucopyranosyl (1-->2)-beta-D-glucopyranosyl]-20-O-[beta-D-xylopyranosyl (1-->6)-beta-D-glucopyranosyl (1-->6)-beta-D-glucopyranosyl]20(S)-protopanaxadiol, respectively.