Two New Benzoquinone Derivatives from Vietnamese Knema globularia Stems

The chemical investigation of the stems of Knema globularia led to the isolation of two new benzoquinones derivatives, embenones A and B (1 and 2), along with three known compounds (3–5). The structures of the isolated compounds were determined using spectroscopic techniques, including HRESIMS, 1D and 2D NMR, in conjunction with comparison to existing literature data. Compounds 1 and 2 represent new carbon skeletons in nature. Furthermore, all isolated compounds were evaluated for their α‐glucosidase inhibitory activity, with compounds 1–3 exhibiting superior potency relative to the positive control (acarbose, IC50 331 μM). Their IC50 values ranged from 1.40 to 96.1 μM.