Dolabellane diterpenes from Cleome droserifolia

Abstract

Three diterpenoid dolabellane esters were isolated from Cleome droserifolia. The chemical structures of the isolated compounds were determined by spectral as well as chemical methods. These dolabellanes (I, II and III) are ester derivatives of 3-hydroxy-3-methyl glutaric acid (3-HMGA). Compounds I and II have the second (3HMGA) carboxyl function free, while compound III is the methyl ester of compound I. This is the first report of the isolation of this class of compounds from the genus Cleome and is the first report of the isolation of compound III from a natural source. In addition, eight flavone derivatives were isolated.