Identification of two new phenathrenones and a saponin as antiprotozoal constituents of Drypetes gerrardii

摘要: In an in vitro screen of 206 extracts from South African plants, the CH2Cl2/MeOH (1:1) stem extract Drypetes gerrardii Hutch. var (Putranjivaceae) inhibited Plasmodium falciparum and Leishmania donovani (IC50s 0.50 7.31 μg/ml, respectively). addition, leaves showed activity against Trypanosoma brucei rhodesiense (IC50 12.1 μg/ml). The active constituents were tracked by HPLC-based profiling, isolated preparative semi-preparative RP-HPLC chromatography. Their structures established HRESIMS, 1D 2D NMR (1H, 13C, COSY, HMBC, HSQC, NOESY). From extract, a new phenanthrenone derivative, drypetenone D (1), heterodimer, E (2), isolated. Compound 1 potent P. 0.9 μM) with selectivity index (SI) 71, as calculated cytotoxicity data for L-6 cells. These qualified vivo assessment berghei mouse model, but compound turned out to be inactive. 2 also exhibited good antiplasmodial 2.0 (SI 31). leaf saponin putranoside A (3) was identified. 3 weak trypanocidal activity, IC50 18.0 μM, SI 4.