New endiandric acid analogues from <i>Cryptocarya hainanensis</i>

This study presents the first phytochemical investigation on the ethanol extract from the leaves and twigs of <i>Cryptocarya hainanensis</i>, resulting in the isolation and characterisation of three previously undescribed endiandric acid analogues designated as cryptohainanins A - C (<b>1 </b>-<b> 3</b>). Structural elucidation was achieved through extensive spectroscopic analyses, including IR, HRESIMS, and NMR spectroscopy. Notably, this work reports the first occurrence of endiandric acid derivatives featuring new side-chain modifications within the genus <i>Cryptocarya</i>. These findings expand the known chemical diversity of <i>Cryptocarya</i> species and provide further biochemical evidence supporting the close phylogenetic relationship among three genera-<i>Beilschmiedia</i>, <i>Cryptocarya</i>, and <i>Endiandra</i>-within the Lauraceae family.