Solid Tumor Inhibitory and other Constituents of Casimiroa tetrameria

AimTo isolate and characterize solid tumor inhibitory and other constituents from a bioactive extract of Casimiroa tetrameria ((Rutaceae).MethodsA crude extract of C. tetrameria obtained from the US National Cancer Institute Natural Product Repository and found to exhibit selective toxicity to solid tumor cells was subjected bioactivity-guided fractionation involving solvent-solvent partitioning, gel filtration, and chromatography. The structures of all isolated compounds were elucidated by spectroscopic analysis (NMR and MS) and/or by comparison with the reported data. Compounds 1 and 4–9 were evaluated for their solid tumor selective cytotoxicity.ResultsNine metabolites, including a new furanocoumarin, 5-methoxy-8-(4′-acetoxy-3′-methylbut-2-enyloxy)-psoralen (1), and the previously known compounds 2–9 were encountered. Of these the flavonoid zapotin (6), and N-benzoyltyramide derivatives 7 and 8 were found to be the active constituents.ConclusionZapotin (6) is the most potent constituent of C. tetrameria with solid tumor selectivity.