A New Antifeedant Withanolide from Jaborosa lanigera.

The withanolides are a group of natural C28steroidal lactones built on an intact or arranged ergostane framework that occurs mainly in plants of certain genera of Solanaceae. The first member of this group of compounds, withaferin A, was isolated from the well-known Indian medicinal plant, Withania somnifera [1] and its structure was fully elucidated by Lavie and coworkers in 1965 [2]. The withanolides exhibit a variety of biological activities as antifeedant, immunosuppressive and cancer chemoprevention activity [3]. Jaborosa Miers is a South American genus belonging to the Solanaceae family that comprises about 23 species, 11 of which are almost exclusively distributed in Argentina [4]. Previous studies on populations of J. laciniata, J. magellanica, J. leucothrica and