Withasteroids of Physalis. IV. 28-hydrowithaphysanolide. 13C NMR spectrum of 14-alpha-hydroxywithasteroids

A new withasteroid has been isolated fromPhysalis viscosa L. — 28-hydroxywithaphysanolide, with mp 234°C, composition C28H38O8. The13C NMR spectra of a number of withasteroids have been investigated. For 28-hydroxywithaphysanolide we propose the structure 4β,14α,17β,20R,28-pentahydroxy-l-oxo-22R-witha-2,5,24-trienolide. The corresponding corrections have been made in the structural formulas of withaphysanolide and physalactone.