Previous studies on Calopyllum species have resulted in isolation of secondary metabolites such as xanthone and coumarins.
However, phytochemistry investigations on Calophyllum benjaminum and Calophyllum javanicum have never been reported.
Our recent study on the chemical constituents of the stem bark of both Calophyllum benjaminum and Calophyllum javanicum
have yielded three xanthones. These were identified as fuscaxanthone C (1), β-mangostin (2), thwaitesixanthone (3), and
dombakinaxanthone (4) together with four triterpenes known as friedelin, β-sitosterol, γ-sitosterol and stigmasterol. The
hexane, chloroform, ethyl acetate and methanol extracts of Calophyllum benjaminum were tested for antioxidant properties by
DPPH free radical scavenging test. Only the methanol extract shows significant antioxidant activity.