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 thalictroides) roots and rhizomes. Their structures were established by spectral (1H NMR, 13C NMR, 2D-NMR, and APCI-MS) techniques and chemical reactions as hederagenin 3-O-α-L-arabinopyranoside (1); caulophyllogenin 3-O-α-L-arabinopyranoside (2); hederagenin 3-O-β-D-glucopyranosyl(1→2)-α-L-arabinopyranoside (3); 3-O-α-L-arabinopyranosyl-hederagenin 28-O-α-L-rhamnopyranosyl(1→4)-β-D-glucopyranosyl(1→6)- β-D-glucopyranoside (4); 3-O-α-L-arabinopyranosyl- caulophyllogenin 28-O-α-L-rhamnopyranosyl-(1→4)-β-D-glucopyranosyl(1→6)- β-D-glucopyranoside (5); 3-O-β-D-glucopyranosyl-(1→2)-α-L-arabinopyranosyl echinocystic acid 28-O-α-L-rhamnopyranosyl-(1→4)-β-D-glucopyranosyl(1→6)- β-D-glucopyranoside (6); 3-O-β-D-glucopyranosyl-(1→2)-α-L-arabinopyranosyl-hederagenin 28-O-α-L-rhamnopyranosyl-(1→4)-β-D-glucopyranosyl(1→6)- β-D-glucopyranoside (7). All seven compounds were identified in this species for the first time.