Complete assignments of 1H and 13C NMR data for two 3β,8β-epoxymexicanolides from the fruit of a Chinese mangrove Xylocarpus granatum

Three 3 beta,8 beta-epoxymexicanolides, including xyloccensin K, 6-acetoxycedrodorin and a new one named xyloccensin W, were isolated from the fruit of a Chinese mangrove Xylocarpus granatum. Their structures were determined by spectroscopic analyses. The first complete assignment of H-1 and C-13 NMR data for xyloccensin W was achieved by means of 2D NMR techniques, including H-1-H-1 COSY, HSQC, HMBC and NOESY spectra. In addition, the confusion of H-1 and C-13 NMR data previously reported for xyloccensin K was clarified. Copyright (c) 2005 John Wiley & Sons, Ltd.