The Study on the Constituents of Clematis and Akebia sp. III. The Study on the structures of Akebosides isolated from the Stem of Akebia quinata DECNE.

Abstract

The structures of three akebosides St_h, St_j, St_k were elucidated and the structures of five akebosides St_b, St_e, St_d, St_e, St_r were also suggested. Four (St_e, St_f, St_j, St_k) of them are newly isolated saponins. The chemical structures of akebosides St_k (I), St_j (VIII), St_h (XIII) were established to be 3-O-α-L-rhamnopyranosyl-(1→6)-β-D-glucopyranosyl-(1→2)-α-L-arabinopyranosyl hederagenin 28-O-α-L-rhamnopyranosyl-(1→4)-β-D-glucopyranosyl-(1→6)-β-D-glucopyranoside, 3-O-α-L-rhamnopyranosyl-(1→6)-β-D-glucopyranosyl-(1→2)-α-L-arabinopyranosyl oleanolic acid 28-O-α-L-rhamnopyranosyl-(1→4)-β-D-glucopyranosyl-(1→6)-β-D-glucopyranoside, and 3-O-α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranosyl hederagenin 28-O-α-L-rhamnopyranosyl-(1→4)-β-D-glucopyranosyl-(1→6)-β-D-glucopyranoside, respectively. Furthermore, saponins of seed, leaf, stem, and root of A. quinata were compared.