Chemical Constituents from the Twigs of Calophyllum inophyllum Linn.

Abstract:

Eleven compounds were extracted from EtOH extract of the twigs of Calophyllum inophyllum. On the basis of spectroscopic data, their structures were identified as 6-hydroxy-2,3-dimethoxyxanthone (1), 1,3,7-trihydroxylxanthone (2), 1,3,7-trihydroxy-8-methoxyxanthone (3), 7-hydroxy-1,3-dimethoxyxanthone (4), pseudo taraxasterol (5), 1,3,6-trihydroxy-5,7-dimethoxyxanthone (6), 2-hydroxy-1-methoxy-xanthone (7), 2-hydroxy-1,8-dimethoxyxanthone (8), 1,3,5-trihydroxy-2-methoxyxanthone (9), 4-hydroxyxanthone (10), and 1,3,5-trihydroxyxanthone (11) . Compounds 6-8 were isolated from this plant for the first time, and compounds 2-5 from the genus Calophyllum for the first time. Compound 1 was a new natural product. Compound 9 showed inhibitory activities towards human gastric carcinoma (SGC-7901), with the IC₅₀ value of 1.8×10^-5 mol/L.