PRENYLATED XANTHONOIDS FROM CALOPHYLLUM-APETALUM

Three new xanthonoids, apetalinones A-C, were isolated from the roots of Calophyllum apetalum, as well as the known compounds, calozeyloxant hone and zeyloxanthonone. The stem bark of this species yielded a new xanthonoid, apetalinone D, and another known xanthonoid, tomentonone. Five known xanthones (3,8-dihydroxy-1,2-dimethoxy-, 1,3-dihydroxy-2,5- dimethoxy-, 1,5-dihydroxy-, 1,3,5-trihydroxy-2-methoxy- and 1,3,5-trih ydroxyxanthone) and two flavonoids ((-)-epiafzelechin and (-)-epicatec hin) were also characterized as constituents in the stem wood. Among t hem, apetalinone A was a novel xanthone with 1,1-dimethylallyl ether m oiety, which indicated a new biosynthetic pathway including Claisen re arrangement and Diels-Alder reaction. (C) 1997 Elsevier Science Ltd.