Two New Triterpenoid Saponins from <i>Akebia quinata</i> (Thunb.) Decne.

Abstract

Abstract Two new triterpenoid saponins, hederagenin 3‐O‐α‐ L ‐arabinopyranosyl‐(1→2)‐α‐ L ‐arabinopyranoside named akeboside L a (compound 1), oleanolic acid 3‐O‐α‐ L ‐arabinopyranosyl‐(1→2)‐(β‐ D ‐glucopyranoside named akeboside L b (compound 2), along with five known saponins, oleanolic acid 3‐O‐α‐ L ‐rhamnopyranosyl‐(1→2)‐ot‐ L ‐arabinopyranoside (compound 3), hederagenin 3‐O‐α‐ L ‐rhamnopyranosyl‐(1→2)‐α‐ L ‐arabinopyranoside (compound 4), oleanolic acid 3‐O‐β‐ D ‐xylopyranosyl‐(1→3)‐α‐ L ‐rhamnopyranosyl‐(1→2)‐α‐ L ‐arabinopyranoside (compound 5), 3‐O‐α‐ L ‐rhamnopyranosyl‐(1→2)‐α‐ L ‐arabinopyranosyl oleanolic acid 28‐O‐α‐ L ‐rhamnopyranosyl‐(1→4)‐α‐ D ‐glucopyranosyl‐(1→6)‐(β‐ D ‐glucopyranoside (compound 6), 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 (compound 7) were isolated from the n ‐butanol part of the 80% ethanol extracts of the dried stems of Akebia quinata (Thunb.) Decne. Compound 5 was isolated from plants of genus Akebia for the first time. The structures were elucidated on the basis of physicochemical properties and spectral data.