New biphenyl derivatives from Garcinia yunnanensis

Six previously undescribed biphenyl derivatives, named as 10-hydroxyl-multiflorabiphenyl B (1), 11-hydroxyl-multiflorabiphenyl B (2), yunnabiphenyl A (3), 8-O-phenylacetoxyl- yunnabiphenyl A (4), 8-O-β-d-glucopyranosyl-yunnabiphenyl A (5), 8-O-acetyl-yunnabiphenyl A (6), together with one known analogue multiflorabiphenyl B (7), were isolated from the twigs of Garcinia yunnanensis. Their structures were elucidated by comprehensive analysis of HRESI-MS, NMR spectroscopy, and comparison with literature data. Compounds 3-6 represent the first reported natural biphenyl derivatives featuring a 2‑oxygenated ethyl substituent, which serve as chemotaxonomic markers for this species. Additionally, all six new compounds were evaluated for their ability to inhibit LPS-induced nitric oxide (NO) release in BV2 microglial cells, demonstrating moderate anti-inflammatory activity.