ABSTRACT
Objective: To study the chemical constituents and the cytotoxic activity of curcumins from the rhizome of Curcuma phaeocaulis. Methods: The 95% ethanol extract from the rhizome of C. phaeocaulis was extracted with petroleum ether, ethyl acetate, and n-butanol. The separation and purification of ethyl acetate fraction was carried out by silica gel column, sephadex LH-20 column, reversed-phase medium pressure chromatography, preparative thin-layer chromatography, and semi-preparative high performance liquid chromatography. The structures of the isolated components were identified by modern spectroscopy techniques. The isolated compounds were screened for cytotoxic activity by MTT assay. Results: Four curcuminoids were isolated from the ethyl acetate extract of the rhizome of C. phaeocaulis, and identified as 1,7-bis (4-hydroxyphenyl)-1E,6E-heptadien-3-one (1), 1,7-bis (4-hydroxyphenyl)-1,4,6-heptatrien-3-one (2), 1,7-bis (4-hydroxyphenyl)-4E,6E-heptadien-3-one (3), and (1R,5S,6S)-1,5-epoxy-6- hydroxy-1,7-bis (3-methoxy-4-hydroxy-phenyl)-heptane (4). MTT experiments showed that compounds 1-3 inhibited HGC-27 cells proliferation, and only compound 2 inhibited MDA-MB-231 cells proliferation. Compounds 2 and 3 also showed strong toxic effects on human normal liver cells. Conclusion: Four curcuminoids were isolated from C. phaeocaulis. Compound 1 was a new compound named curcumin P. Compounds 1-3 had a certain inhibitory effect on the proliferation of HGC-27 cells. Notably, compound 1 selectively inhibited the proliferation of HGC-27 cells and showed no obvious toxic effects on L-02 cells.