Constituents of <i>Withania Somnifera</i> Dun. Part X The Structure of Withanolide D

Abstract

Abstract Withanolide D, the major component of the leaves of Withania somnifera chemotype II, is a steroidal lactone of the withanolide type, isomeric with withaferin A. It has been identified as 5, 6β‐epoxy‐4β, 20α‐dihydroxy‐1‐oxo‐(5β)witha‐2, 24‐dienolide. The structure has been elucidated by NMR measurements and by chemical degradation to 4β‐acetoxy‐5,6β‐epoxy (5β) pregnan‐1, 20‐dione.