Granatumins A-G, limonoids from the seeds of a Krishna mangrove, Xylocarpus granatum

Seven new limonoids (1-7), named granatumins A-G, were isolated from seeds of an Indian mangrove (Xylocarpus granatum) collected from the wetlands of Krishna estuary, Andhra Pradesh. The known compounds khayasin T, tigloylseneganolide A, 6-deoxyswietenine, swietemahonolide, febrifugin A, gedunin, xylogranatinin, phaseic acid, (2R,3R)-3,4',5,7-tetrahydroxyflavanone, and (E)-4-hydroxycinnamic acid were also isolated. The structures were established on the basis of spectroscopic data. Granatumins A and B are mexicanolides with endo-conjugated Delta(8,30) and Delta(14,15) double bonds, and granatumins F and G are polyhydroxylated phragmalins found previously in plants of the Meliaceae. Khayasin T exhibited moderate insecticidal activity against fifth instar larvae of Brontispa longissima (Gestro) at a concentration of 20 mg/L.