New oleanane saponins in Chenopodium quinoa

Six triterpenoid saponins were isolated from the seeds of Chenopodium quino a (Chenopodiaceae). Their structures were as follows: phytolaccagenic acid 3-O-[(alpha -L-arabinopyranosyl-(1 " -->3 ')-beta -D-glucuronopyranosyl]-28 -O-beta -D-glucopyranoside (1); spergulagenic acid 3-O-[beta -D-glucopyrano syl-(1 -->2)-beta -D-glucopyranosyl-(1 -->3)-alpha -L-arabinopyranosyl-28-O -beta -D-glucopyranoside (2); hederagenin 3-O-[beta -D-glueopyranosyl-(1 -- >3)-alpha -L-arabinopyranosyll-28-O-beta -D-glucopyranoside (3); phytolacca genic acid 3-O-[beta -D-glueopyranosyl-(1 -->4)-beta -D-glucopyranosyl-(1 - ->4)-beta -D-glucopyranosyl]-28-O-beta -D-glucopyranoside (4); hederagenin 3-O-[beta -D-glucopyranosyl-(1 -->4)-beta -D-glucopyranosyl-(1 -->4)-beta - D-glucopyranosyl]-28-O-beta -D-glucopyranoside (5); and spergulagenic acid 3-O-[alpha -L-arabinopyranosyl-(1 " --> -3 ")-beta -D-glucuronopyranosyl]-2 8-O-beta -D-glucopyranoside (6). Saponins 5 and 6 are new. The structures w ere characterized on the basis of hydrolysis and spectral evidence, includi ng IR, UV, optical rotations, 1D- and 2D-NMR (HMQC and HMBC), ESIMS, and FA BMS analyses.