A number of Calophyllum (Clusiaceae) species have been investigated but only a few have been extensively studied.
Phytochemical studies on the Calophyllum species have revealed plants from this genus to be rich in secondary metabolites
such as xanthones, coumarins, flavonoids and triterpenoids. The study on chemical constituents of the stem bark of
Calophyllum teysmannii and Calophyllum lowii has resulted in the isolation and characterization of four xanthone derivatives,
named ananixanthone (1), thwaitesixanthone (2), fuscaxanthone C (3) and caloxanthone L (4). Several triterpenoids and
steroids, friedelan-3-one, stigmasterol, sitosterol and glutanone were also successfully isolated from these plants. The structures
of these minor components were established by means of spectroscopic analysis including nuclear magnetic resonance (NMR-
1D, 2D), UV, IR and mass spectrometry. The crude extracts of Calophyllum lowii were tested against DPPH free radical
scavenging agent. However only methanol extracts gave strong antioxidant activity.