Cytotoxic labdane diterpenoids isolated from the hexane fraction of the croton stipuliformis stem bark

Abstract

The composition of the cytotoxic hexane fraction of the Croton stipuliformis bark was studied by means of a gas chromatography coupled to a mass spectrometry; sesquiterpenes and sterols were characterized as the main constituents. Along with these compounds, three labdane and seco-labdane diterpenoids, 8(17),12E,14-labdatrien-18-oic acid [3], 12E-3,4-seco-labda-4(18),8(17),12,14-tetraen-3-oic acid [2], and its methyl ester [1] were isolated from this fraction through preparative HPLC, and their structures were elucidated by HR-FABMS, 1D and 2D NMR analyses. Additionally, the cytotoxic activity of these three compounds against human tumor cell lines HEp-2, HT-29, MKN-45, MCF-7, and HeLa was assessed. The three compounds showed a non-specific and moderate cytotoxicity against the above- mentioned cell lines.