Jordan University of Science and Technology

Bioactive withanolides from Withania obtusifolia


Authors:  Feras Q. Alali, Chiraz Soumia M. Amrine, Tamam El-Elimat, Ahmad Alkofahi, Khaled Tawaha, Mohammad Gharaibah, Steven M. Swanson, Joseph O. Falkinham III, Marisa Cabeza, Araceli Sánchez, Mario Figueroa, and Nicholas H. Oberlies 

Abstract:  
Seven withanolides were isolated from the leaves of Withania obtusifolia. Of these, one was new [obtusifonolide (1)], five were new to the species [sitoindoside IX (2), 6?-chloro-5?-hydroxy withaferin A (3), isowithanone (4), 2,3-dihydro-3-ethoxywithaferin A (5), and daturataturin A (6)], and one was reported previously from W. obtusifolia [withaferin A (7)]. The structures were elucidated using a set of spectroscopic and spectrometric techniques. Compounds (1?7) were evaluated for cytotoxicity against a human cancer cell panel and for antimicrobial activity in an array of bacteria and fungi. Compound 7 showed cytotoxic activity against the MDA-MB-435 (human melanoma) and SW-620 (human colon cancer) cell lines with IC50 values of 1.7 and 0.3 ?M, respectively. The in vitro activity of 7 on 17?-hydroxysteroid dehydrogenase and 5?-reductase was also investigated.