Cytotoxic and Anti-HIV-1 Caged Xanthones from the Resin and Fruits of Garcinia hanburyi

Three new caged xanthones, 7-methoxydesoxymorellin (1), 2-isoprenylforbesione (2) and 8,8a-epoxymorellic acid (3), together with nine known caged xanthones were isolated from the EtOAc extracts of resin and fruits of Garcinia hanburyi. The structures were determined by spectroscopic methods. Most of the isolated compounds showed significant cytotoxicities against a panel of mammalian cancer cell lines. Compound 3, together with the known compounds desoxymorellin, morellic acid, gambogic acid, hanburin, forbesione and dihydroisomorellin, exhibited anti-HIV-1 activity in the reverse transcriptase (RT) assay while the known compounds desoxygambogenin and dihydroisomorellin were found moderately active in the syncytium assay. This work represents the first report on the anti-HIV-1 activities of caged xanthones.