Novel bioactive styryl-lactones: goniofufurone, goniopypyrone, and 8-acetylgoniotriol from Goniothalamus giganteus(annonaceae). X-Ray molecular structure of goniofufurone and of goniopypyrone

Abstract

By use of brine shrimp lethality for activity-directed fractionation, three novel styryl-lactones which are cytotoxic to human tumour cells, goniofufurone, goniopypyrone, and 8-acetylgoniotriol, have been isolated from ethanolic extracts of the stem bark of Goniothalamus giganteus Hook, f., Thomas (Annonaceae). The structures were elucidated by IR, mass, ¹H NMR, ¹³C NMR, and 2D NMR (¹H–¹H COSY, and ¹H–¹³C HETCOR) spectra. The structures of goniofufurone and goniopypyrone, which represent unusual natural skeletons, were confirmed by X-ray crystallographic analysis, to help establish the relative configurations. Goniopypyrone was the most bioactive, showing nonselective ED₅₀ values of ∼6.7 × 10^–1µg/ml in each of our three human tumour cell lines.