Acemosin- a cytotoxic 20-norsteroid from Asparagus racemosus.

A novel cytotoxic 20-norsteroid with twenty-six carbon atoms named acemosin (1) was isolated and structural characterized together with two known compounds, asparacosin A (2) and stigmasterol (3) from the roots of Asparagus racemosus. Their structures were elucidated by a combination of 2D NMR, HR-MS and X-ray crystallographic analyses. Acemosin (1) possesses an unprecedented carbon skeleton, where the methyl group at C-20 is absent. Acemosin shows moderate cytotoxicity against HepG2 cancer cell line with its IC50 value of 87.3 µg/mL.

Stemofurans X-Y from the roots of Stemona species from Laos.

Two new phenylbenzofuran-type stilbenoids named stemofurans X and Y (1, 2) were isolated from the roots of Stemona pierrei and S. tuberosa, respectively, together with ten known compounds. These compounds were stemanthrenes B-C (3, 4), (+)-syringaresinol (5), maistemonine (6), isomaistemonine (7) and sesamin (8) from S. pierrei, and stemophenanthrenes A-C (9-11) and isopinosylvin A (12) from S. tuberosa. Stemofurans X-Y (1, 2) showed moderate cytotoxicity against the four cancer cell lines KB (human epidermal carcinoma), MCF7 (human breast carcinoma), SK-LU-1 (human lung carcinoma), and Hep-G2 (hepatocellular carcinoma).

Three new phenanthrenes, a new stilbenoid isolated from the roots of Stemona tuberosa Lour. and their cytotoxicity.

Three new phenanthrenes, stemophenanthrenes A-C (1-3), along with one new stilbenoid, isopinosylvin A (4) and a known compound methyl ferulate (5), were isolated and identified from the roots of Stemona tuberosa Lour. plants, collected in Attapu province (Laos). Their structures were elucidated by spectroscopic analysis (FT-ICR-MS, IR, UV, 1D and 2D NMR). These compounds show moderate cytotoxic activity against four cancer cell lines, KB (a human epidermal carcinoma), MCF7 (human breast carcinoma), SK-LU-1 (human lung carcinoma) and HepG2 (hepatocellular carcinoma).