Two new pentacyclic triterpenoids from the stems of Manihot esculenta

In recent years, we have been engaged in a program to discover secondary metabolites with fascinating structural features and significant biological activities from Euphorbiaceae family. Two new pentacyclic triterpenoids, maesculentins A (1) and B (2), were isolated from the stems of Manihot esculenta Crantz, together with eleven known ones. The structures of two new triterpenoids (1-2) were elucidated by extensive spectroscopic techniques including NMR spectroscopy and mass spectrometry. Compounds 1 and 2 were cis-trans isomers, which showed moderate cytotoxicity activity against HGC-27 tumour cell line. (C) 2015 Phytochemical Society of Europe. Published by Elsevier B.V. All rights reserved.