Xylocarpins A−I, Limonoids from the Chinese Mangrove Plant <i>Xylocarpus granatum</i>

Abstract

Chemical examination of the fruits of the Chinese mangrove plant, Xylocarpus granatum, resulted in the isolation and characterization of nine new limonoids, named xylocarpins A-I (1-5, 7-10), along with nine known limonoids. Xylocarpins A-E were designated as polyoxyphragmalins, xylocarpin I was identified as a phragmalin orthoester, while xylocarpins F-H represented mexicanolides modified by ring oxidation and unusual 9,10-bond cleavage. The structure of xyloccensin U was revised to be 6-dehydroxyxylocarpin D on the basis of 2D spectroscopic data.