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A new acetogenin has been isolated from the ethyl acetate extract of leaves and twigs of G. sawtehii(Annonaceae). The structure of compound 1was identified as sawtehtetronenin on the basis of spectral evidence (UV, IR, MS and 1H, and 13C NMR) and by comparison with related compounds. Sawtehtetronenin was found to be cytotoxic to human hepatocellular carcinoma HepG2 and breast cancer MDA-MB231 cells with IC50values of 79.3+11.9 μM and 108.1+1.5 μM, respectively. Compound 1was less toxic to both cell lines when compared with camptothecin, a chemotherapeutic drug.

Chromatographic separation of the ethyl acetate extract of roots of Polyalthia cerasoideshas led to the isolation of the new compound, 6,8-dihydroxy-7-methoxy-1-methyl-azafluorenone. This compound exhibited potent cytotoxic activities with IC50values in the range of 2.64-3.58 μg.mL−1for A549, GLC4 and GLC4/Adr cells, but was not recognized by ABCC1/MRP1 protein. The compound also showed very strong inhibition of M. tuberculosisusing a broth microdilution method, with an MIC value of 0.78 μg.mL−1, which was equal to that of ofloxacin, one of the four antibiotic drugs used as a positive control.