Chemical Constituents from the Twigs of Calophyllum inophyllum Linn.
红厚壳枝条的化学成分

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.