RESUMO
Objective According to the folk application, the chemical constituents of the seeds of Caesalpinia decapetala were studied. Methods Silica gel and Sephadex LH-20 column chromatography techniques were used as pretreatments for ethanol extract of the seeds of C. decapetala, and then semi-preparative HPLC technique was used. Structures were identified by NMR and MS spectra. Results Five cassane-type diterpenes were isolated from the chloroform extract of C. decapetala. According to NMR and MS spectra data, the isolated compounds were identified as caesalmin F1 (1), α-caesalpin (2), caesalmin F (3), caesalmin C (4), and caesalmin E (5). Conclusion Compound 1 is a new compound, and compounds 1, 4 and 5 are isolated for the first time from C. decapetala. Compounds 1, 4 and 5 show moderate anti-tumor activity against HeLa cells with IC50 values of 64.3, 42.9, and 81.2 μmol/L, respectively.