New linear pyranoxanthones from Calophyllum apetalum
The investigation of chemical constituents in stem bark and root of Calophyllum apetalum (Guttiferae) led to isolate sixteen xanthones and two coumarin derivatives. Among them, two linear pyranoxanthones [caloxanthones I (1) and J (2)] from the stem bark, and two xanthones [caloxanthone K (1 0) and 1,3,6,8-trihydroxy-2-methoxyxanthone (1 2)] from the root were new ones. The respective structures were determined by the spectral analysis.