A tirucallane and two pairs of tetranortriterpene 23-epimers from the Thai mangrove Xylocarpus moluccensis

A new tirucallane, 3β-hydroxy-3-decarbonyl-24-epi-piscidinol A (1), and two new pairs of tetranortriterpene 23-epimers, named thaimoluccepimers A (2) and B (3), were isolated from the seeds of a Thai mangrove, Xylocarpus moluccensis. The structures of these compounds were elucidated by HRESIMS and NMR spectroscopic analysis.