Steroidal saponins from the rhizomes of Hosta sieboldii and their cytostatic activity on HL-60 cells.

A total of eighteen steroidal saponins were isolated from the rhizomes of Hosta sieboldii, one of which appeared to be the first isolation from a plant source and six to be new compounds. The structures of the new saponins were determined by spectral data and a few chemical transformations to be (25R)-2 alpha, 3 beta-dihydroxy-5 alpha-spirostan-12-one (manogenin) 3-O-¿O-beta-D-glucopyranosyl-(1-->2)-O-beta-D-glucopyranosyl -(1-->4)-beta-D-galactopyranoside¿, (25R)-2 alpha,3 beta-dihydroxy-5 alpha-spirost-9-en-12-one (9,11-dehydromanogenin) 3-O-¿O-beta-D-glucopyranosyl-(1-->2)-O-beta-D- glucopyranosyl-(1-->4)-beta-D-galactopyranoside¿, 9,11-dehydromanogenin 3-O-¿O-beta-D-glucopyranosyl-(1-->2)-O-[O-alpha-L- rhamnopyranosyl-(1-->4)-beta-D-xylopyranosyl-(1-->3)]-O-beta-D- glucopyranosyl-(1-->4)-beta-D-galactopyranoside¿, (25R)-2 alpha,3 beta-dihydroxy-26-beta-D-glucopyranosyloxy-22-methoxy-5 alpha-furostan-12-one 3-O-¿O-beta-D-glucopyranosyl-(1-->2)-O-[beta-D-xylopyranosyl-(1-->3)]-O- beta-D-glucopyranosyl-(1-->4)-beta-D-galactopyranoside¿, (25R)-2 alpha, 3 beta-dihydroxy-26-beta-D-glucopyranosyloxy-22-methoxy-5 alpha-furost-9-en-12-one 3-O-¿O-beta-D-glucopyranosyl-(1-->2)-O-[beta-D-xylopyranosyl-(1-->3)]-O- beta-D-glucopyranosyl-(1-->4)-beta-D-galactopyranoside¿ and (25R)-5 alpha-spirostan-2 alpha,3 beta,12 beta-triol 3-O-¿O-alpha-L- rhamnopyranosyl-(1-->2)-beta-D-galactopyranoside¿, respectively. Cytostatic activity of the isolated saponins on leukaemia HL-60 cells was examined.