Oropheayunnol, an unusual 22,23-epoxy apotirucallane triterpenoid from Orophea yunnanensis.
A new apotirucallane-type triterpenoid with an unusual 22,23-epoxy group in the side chain, 22,23-epoxy-apotirucalla-14-ene-3alpha,7alpha,24alpha,25-tetraol (1), was isolated from the leaves and twigs of Orophea yunnanensis. The structure of 1 was established on the basis of HRESIMS, 1D, and 2D NMR spectroscopic methods. This is the first phytochemical study of Orophea yunnanensis, and the biogenetic origin of 1 was postulated. Compound 1 exhibited weak cytotoxicity in vitro against the growth of CNE1 nasopharyngeal carcinoma cell line with an IC50 value of 9.7 microg/mL.