Abstract
From the aerial part of Clematis tibetana, two new hederagenin 3, 28-O-bisdesmosides called clematibetosides A and C, and a new gypsogenin 3, 28-O-bisdesmoside called clematibetoside B, have been isolated together with ten known saponins. The structures of the new saponins have been elucidated based on chemical and spectral evidence as follows: clematibetoside A, 3-O-(2-O-caffeoyl)-β-D-glucopyranosyl-(1→4)-β-D-glucopyranosyl-(1→4)-β-D-ribopyranosyl-(1→3)-α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranosyl hederagenin 28-O-α-L-rhamnopyranosyl-(1→4)-β-D-glucopyranosyl-(1→6)-β-D-glucopyranoside; clematibetoside B, 3-O-α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranosyl gypsogenin 28-O-α-L-rhamnopyranosyl-(1→4)-β-D-glucopyranosyl-(1→6)-β-D-glucopyranoside; clematibetoside C, 3-O-β-D-ribopyranosyl hederagenin 28-O-α-L-rhamnopyranosyl-(1→4)-β-D-glucopyranosyl-(1→6)-β-D-glucopyranoside.
