NOVEL ACETOGENINS FROM THE LEAVES OF ANNONA-PURPUREA

The CH2Cl2 extract of the leaves of Annona purpurea L. (Annonaceae) showed strong brine shrimp toxicity and pronounced activity against larvae of the yellow-fever mosquito Aedes aegypti. Activity-directed fractionation of the extract by a combination of column chromatography on silica gel, gel filtration, and high-pressure liquid chromatography led to the isolation of acetogenins 1-6 as the main active principles. The structures of two novel acetogenins named purpureacin 1 (5) and purpureacin 2 (6) were elucidated by spectroscopic analysis (UV, EI- and DCI-MS, EI-MS of Me3Si derivatives, H-1- and C-13-NMR). The configuration of 5 and 6 was not established due to the limited sample amount. Compounds 3-6 also showed antifungal activity against Candida albicans, and 5 was slightly active against Bacillus subtilis.