Xanthone constituents of the fruits of Garcinia mangostana with anticomplement activity.

Phytochemical investigation of a chloroform-soluble fraction of the freeze-dried fruits of Garcinia mangostana (Clusiaceace) with anticomplement activity in the classical pathway led to the identification of five known xanthones. The structures of these compounds were confirmed by interpretation of NMR and MS spectroscopic data. Of the isolates obtained, 1-isomangostin and garcinone E were found to be active constituents in the anticomplement assay used.