New pregnane glycosides from Stelmatocrypton khasianum.

Four new pregnane glycosides, stelmatocryptonoside A, B, C, and D (1-4), were isolated from the stems of Stelmatocrypton khasianum. On the basis of chemical and spectral data, the structures of 1-4 were established as 3beta, 16alpha-dihydroxy-pregn-5-en-20-one-16-O-beta-D-glucopyranosyl-(1-->2)-[beta-D-glucopyranosyl-(1-->6)]-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranoside; 3beta, 20-dihydroxy-pregn-5-en-20-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl-(1-->2)-beta-D-digitalopyranoside; 3beta, 16alpha-dihydroxy-pregn-5-en-20-one-16-O-beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranoside; and 3beta, 16alpha-dihydroxy-pregn-5-en-20-one-16-O-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranoside. This is the first report of pregnane glycosides with sugar chains linked at C-16 of the aglycone.