Protoxylocarpins F−H, Protolimonoids from Seed Kernels of Xylocarpus granatum

Three new protolimonoids, protoxylocarpins F−H (13), along with 11 known limonoids, were isolated from seed kernels of Xylocarpus granatum. Their structures were elucidated on the basis of extensive spectroscopic data analyses. All compounds isolated were evaluated for cytotoxic activity against five human tumor cell lines.