Triterpenoid saponins from Hedyotis nudicaulis

Three new triterpenoid saponins, nudicaucins A, B and C and a known saponin guaiacin D have been isolated from the n-butanol extract of Hedyotis nudicaulis. The structures of nudicaucins A, B and C were elucidated to be beta-D-glucopyranosyl 3-O-[beta-D-galactopyranosyl(1 --> 3)alpha-L-arabinopyranosyl]-30-norolean-12,20(29)-dien-28-oate, beta-D-glucopyranosyl 3-O-[beta-D-galactopyranosyl( 1 --> 3)alpha-L-arabinopyranosyl]oleanoate and beta-D-glucopyranosyl 3-O-[alpha-L-rhamnopyranosyl( 1 --> 2)alpha-L-arabinopyranosyl(3 --> 1)beta-D-glucopyranosyl]oleanoate, respectively, on the basis of NMR spectroscopic analysis and comparison of the spectral data with those of known saponins. (C) 1998 Published by Elsevier Science Ltd. All rights reserved.