LEONTICINS A-C, 3 OCTASACCHARIDE SAPONINS FROM LEONTICE-KIANGNANENSIS

Three octasaccharide saponins, leonticins A, B, and C (1-3), were isol ated from the tubers of Leontice kiangnanensis. Their structures were elucidated by a combination of chemical degradation and spectral metho ds including negative FABMS and NMR measurements as 3-O-beta-D ranosyl (1-->2)-alpha-L-arabinopyranosylhederagenin eta-D-glucopyranosyl(1-->6 )-beta-D-glucopyranoside (1), yranosyl(1-->2)]-alpha-L-arabinopyranosy loleanolic acid eta-D-glucopyranosyl(1-->6)-beta-D-glucopyranoside (2) , and 3-O-[beta-D-xylopyranosyl( anosyl(1-->2)]-alpha-L-arabinopyranos ylechinoystic acid eta-D-glucopyranosyl(1-->6)-beta-D-glucopyranoside (3), respectively. The complete assignments of the proton and carbon r esonances for 1-3 were achieved based on extensive 2D NMR analysis (DQ F-COSY, TOCSY, ROESY, HSQC, and HMBC).