Protoxylogranatin B, a Key Biosynthetic Intermediate from Xylocarpus granatum: Suggesting an Oxidative Cleavage Biogenetic Pathway to Limonoid

Abstract

Protoxylogranatin B, a new protolimonoid identified from the seeds of a Chinese mangrove, Xylocarpus granatum, was proposed as the key biosynthetic intermediate. Its structure was established on the basis of spectroscopic techniques, including 1 H- 1 H COSY, HSQC, HMBC and NOESY spectra. The finding of this compound suggested an