Investigations of nicandrenone--a withanolide-like aromatic plant steroid from Nicandra physaloides.

On the basis of IR, UV, ORD, NMR and high resoluted mass spectral data as well as chemical transformations, evidence for structure 1 of the D-homo-aromatic plant steroid nicandrenone from Nicandra physaloides (Solanaceae) was given. The sterochemistry of both epoxy lactol functions in this compound was established using intramolecular hydrogen bonding investigations. Biogenetical aspects are discussed.