5,9,11-Trihydroxy-2,2-dimethyl-3-(2-methylbut-3-en-2-yl)pyrano[2,3-a]xanthen-12(2H)-one from the Stem Bark of Calophyllum tetrapterum Miq.

A new pyranoxanthone namely 5,9,11-trihydroxy-2,2-dimethyl-3-(2-methylbut-3-en-2-yl)pyrano[2,3-a]xanthen-12(2H)-one (1) was isolated from the stem bark of Calophyllum tetrapterum Miq. The structure of compound 1 was determined by means of spectroscopic methods including UV, IR, HRESIMS, 1D and 2D NMR