Caesalpins A-H, Bioactive Cassane-Type Diterpenes from the Seeds of Caesalpinia minax

Eight new cassane-type diterpenes, caesalpins A-H (1-8), were isolated from the ethyl acetate extract of Caesalpinia minax. Compound 1 displayed significant antiproliferative activity against HepG-2 (IC50 4.7 mu M) and MCF-7 (IC50 2.1 mu M) cells, and compounds 2 and 4 exhibited selective cytotoxic activities against MCF-7 (IC50 7.9 mu M) and AGS (IC50 6.5 mu M) cells.