Goniotriocin and (2,4-cis- and -trans)-xylomaticinones, bioactive annonaceous acetogenins from Goniothalamus giganteus

Goniotricin (1) and a mixture of (2,4-cis and -trans)-xylomaticinones (2), new bioactive annonaceous acetogenins, were isolated from the bark of Gonio thalamus giganteus (Annonaceae) by activity-directed fractionation using th e brine shrimp lethality test. Compound 1 is the first nonadjacent ring-hyd roxylated bis-tetrahydrofuran (THF) acetogenin to be reported. Compound 2 i s the cis- and trans-ketolactone mixture of xylomaticin, a known compound w hose absolute stereochemistry has not been previously determined. The absol ute stereochemistry of 2 was determined by the advanced Mosher's ester meth od. Both 1 and 2 showed significant and selective cytotoxicities among the six tumor cell lines in our seven-day MTT human solid tumor panel. In the y ellow fever mosquito larvae microtiter assay, 1 was quite active, with an E D50 value of 3.5 mu g/mL.