Nor-lignans and steroidal saponins from Asparagus gobicus.

From the roots of Asparagus gobicus, four new nor-lignans, 3'-methoxynyasin, iso-agatharesinol, gobicusins A, B and one new steroidal saponin, 3-O-[beta-D-xylopyranosyl(1-4)-beta-D-glucopyranosyl(1-2)-beta-D-glucopyranosyl]-(25S)-5beta-spirostan-3beta-ol (11) were isolated, together with twelve known compounds. The structures of the new compounds were established by spectroscopic methods including 2D-NMR techniques (1H-1H COSY, HMBC, HMQC) and chemical transformations. Nyasol (5) and 11 exhibited remarkable in vitro cytotoxic activity against cultured HO-8910 (human ovarian carcinoma) and Bel-7402 (human hepatoma) cells with IC50 vales of 30.6 and 29.4 microM, 5.2 and 5.2 microM, respectively.