Xylocarpanoids A and B, unique C28 skeleton limonoids from Xylocarpus granatum

One novel tetranortriterpenoid derivative, xylocarponoid A, representing the first example of C28 skeleton limonoid, was isolated from the seeds of the Chinese mangrove, Xylocarpus granatum. Its C-1′-epimer, xylocarponoid B, was formed in CDCl3. Their structures were elucidated by extensive spectroscopic analysis. A plausible biosynthetic pathway of xylocarponoid A was proposed.

One novel tetranortriterpenoid derivative, xylocarponoid A, representing the first example of C28 skeleton limonoid, was isolated from the seeds of the Chinese mangrove, Xylocarpus granatum. Its C-1′-epimer, xylocarponoid B, was formed in CDCl3. The structures were elucidated by extensive spectroscopic analysis. A plausible biosynthetic pathway of xylocarponoid A via intramolecular aldol reaction is also discussed.