Characterization of the triterpene saponins of the roots and rhizomes of blue cohosh (Caulophyllum thalictroides)

Seven triterpene saponins were isolated from n-butanol fractions of blue cohosh (Caulophyllum halictroides) roots and rhizomes. Their structures were established by spectral (H-1 NMR, C-13 NMR, 2D-NMR, and APCI-MS) techniques and chemical reactions as hederagenin 3-O-alpha -L-arabinopyranoside (1); caulophyllogenin 3-O-alpha -L-arabinopyranoside (2); hederagenin 3-O-beta -D-glucopyranosyl (1 -->2)-alpha -L-arabinopyranoside (3); 3-O-alpha -L-arabinopyranosyl-hederagenin 28-O-alpha -L-rhamnopyranosyl(1 -->4)-beta -D-glucopyranosyl(1 -->6)-beta -D-glucopyranoside (4); 3-O-alpha -L-arabinopyranosyl- caulophyllogenin 28-O-alpha -L-rhamnopyranosyl-(1 -->4)-beta -D-glucopyranosyl(1 -->6)-beta -D-glucopyranoside (5); 3-O-beta -D-glucopyranosyl(1 -->2)-alpha -L-arabinopyranosyl-echinocystic acid 28-O-alpha -L-rhamnopyranosyl-(1 -->4)-beta -D-glucopyranosyl(1 -->6)-beta -D-glucopyranoside (6); 3-O-beta -D-glucopyranosyl-(1 -->2)-alpha -L-arabinopyranosyl-hederagenin 28-O-alpha -L-rhamnopyranosyl-(1 -->4)-beta -D-glucopyranosyl(1 -->6)-beta -D-glucopyranoside (7). All seven compounds were identified in this species for the first time.