Constituents of Chenopodium pallidicaule (Canihua) seeds: Isolation and characterization of new triterpene saponins

Seven triterpenoid saponins were isolated from the seeds of Chenopodium pallidicaule (Chenopodiaceae). Of these compounds, four were identified as known saponins of oleanolic acid and phytolaccagenic acid. The other three compounds, named 1-3, are new saponins. The structures of these saponins were determined to be: (1) hederagenin 3-O-[alpha-L-arabinopyranosyl-(1-->3)-beta-D-glucuronopyranosyl]-28-O-beta-D-glucopyranoside; (2) phytolaccagenic acid 3-O-[beta-D-glucopyranosyl-(1-->4)-beta-D-glucopyranosyl]-28-O-beta-D-glucopyranoside; and (3) phytolaccagenic acid 3-0-[beta-D-glucopyranosyl-(1-->4)-beta-D-glucopyranosyl-(1-->4)-beta-D-glucopyranosyl]-28-O-beta-D-glucopyranoside. All structures were elucidated by chemical and spectroscopic methods.