Triterpenes from the stem bark of Mitragyna diversifolia and their cytotoxic activity

AIM:To study the chemical constituents and bioactivity of the stem bark of Mitragyna diversifolia.METHOD:Compounds were isolated by various chromatographic methods.Their structures were elucidated on the basis of spectroscopic techniques(IR,UV,MS,and NMR),and they were evaluated for their cytotoxic activities by the MTT method.RESULTS:Eight triterpenes were isolated and identified as 3,6,19-trihydroxy-urs-12-en-28-oic acid(1),3,6,19-trihydroxy-urs-12-en-28-oic acid(2),3-oxo-6-19-dihydroxy-urs-12-en-28-oic acid(3),3,6,19-trihydroxy-urs-12-en-24,28-dioic acid 24-methyl ester(4),3,6,19,24-tetrahydroxy-urs-12-en-28-oic acid(5),rotundic acid(6),23-nor-24-exomethylene-3,6,19-trihydroxy-urs-12-en-28-oic acid(7),and pololic acid(8),respectively.All of the isolates were tested against two human tumor cell lines,MCF-7(breast) and HT-29(colon).CONCLUSION:Compound 1 was a new triterpene.Compounds 5-7 exhibited potent inhibitory effects on the growth of MCF-7 and HT-29 cells,and the others showed no cytotoxicity.