Cucurbitacins From Bryonia Verrucosa. Isomerization of 2-Hydroxy-3-Keto-Cucurbitacins

Abstract
Three new cucurbitacins as well as thirteen known ones were isolated from the fruits of Bryonia verrucosa. the new compounds were characterized by chemical and spectral methods. an effective and simple method to isomerize 2-hydroxy-3-keto-cucurbitacins in acid media is described.