Withanolides with Phytotoxic Activity from Jaborosa caulescens var. caulescens and J. caulescens var. bipinnatifida.

VIVIANA E. NICOTRA; ROBERTO R. GIL; JUAN C. OBERTI; GERARDO BURTON

JOURNAL OF NATURAL PRODUCTS

American Chemical Society and the American Society of Pharmacognosy-Washington.DC.

Lugar: Washington DC; Año: 2007 vol. 70 p. 808 - 812

0163-3864

Seven new withanolides (1-7) were isolated from the aerial parts of Jaborosa caulescens var. caulescens and Jaborosa caulescens var. bipinnatifida. Three of the new compounds are related to jaborosalactones R, S, and T with a δ-lactone side chain and a hemiketal (or ketal) ring formed between a 21-hydroxyl and a 12-ketone (1-3). Compounds 4-7 are trechonolide-type withanolides with a γ-lactone side chain and a hemiketal (or ketal) ring formed between a 22-hydroxyl and a 12-ketone. Compounds 4 and 5 also contain a hydroxyl group at C-21. Compounds 1, 2, and 7 showed selectivephytotoxicity toward monocotyledonous and dicotyledonous species.