Chemical investigation of the ethyl acetate extract from the fruits of Derris indica has led to the isolation of a new furanoflavonoid derivative, 4'-hydroxypinnatin (1), and five known compounds. Pinnatin (2) showed strong cytotoxicity against cholangiocarcinoma (KKU-100) and human hepatoma (HepG2) cell lines with IC50 values of 6.0 ± 2.7 and 9.0 ± 4.1 μg/ml, respectively, and showed maximal cell killing effect of about 88-90%. Flavone 5 exhibited the most cytotoxicity against KKU-100 but it showed moderate efficacy (Emax = 50.7%).
Keywords: Derris indica; HepG2; KKU-100; cholangiocarcinoma; furanoflavone.