Dammarane saponins from Zizyphus lotus

Four dammarane-type saponins were isolated by means of centrifugal partition chromatography from the root bark of Zizyphus lotus. Their structures were elucidated using a combination of 1D and 2D H-1 and C-13 NMR spectra and mass spectroscopy. One of these glycosides is the known jujuboside A. The others are three new dammarane saponins, identified as 3-O-beta-D-glucopyranosyl(1-->6)-beta-D-glucopyranosyl (1-->3)-[alpha-L-rhamnopyranosyl(1-->2)]-alpha-L- arabinopyranosyl jujubogenin = jujuboside C, 3-O-alpha-L-rhamnopyranosyl(1-->2)-[beta-D-glucopyranosyl (1-->3)]-beta-D-galactopyranosyl lotogenin - lotoside I, and 3-O-alpha-L-rhamnopyranosyl(1-->2)-[beta-glucopyranosyl (1-->3)]-beta-D-glucopyranosyl lotogenin - lotoside II. Lotogenin is a new dammarane derivative identified as (15R, 16R, 20R,22R)-16 beta,22-epoxydammar-24-ene-3 beta,15 alpha, 16 alpha,20 beta-tetraol. Copyright (C) 1997 Elsevier Science Ltd.