Objective To investigate the biphenyl compounds in the ethyl acetate-soluble fraction of the twigs of Garcinia yunnanensis. Methods Based on the UV spectral characteristics absorption of biphenyl derivatives, targeted separation and purification were performed using various chromatography techniques, including silica gel column chromatography, Sephadex LH-20 gel column and semi-preparative HPLC. The structures of the isolated compounds were elucidated by means of physicochemical properties and spectral data of the monomer compounds, in combination with relevant literature. The anti-inflammatory activity of the new compound was evaluated by measuring its inhibition effect of nitric oxide (NO) production. Results Eight bipheny derivatives were obtained from the ethyl acetate fraction of G. yunnanensis, elucidated as (R)-5-(4-hydroxyphenyl)-2-(2-hydroxypropan-2-yl)-2,3-dihydrobenzofuran-7-ol (1 ), garcibiphenyl C (2 ), cylindrobiphenyl B (3 ), multibiphenyl C (4 ), doitungbiphenyls B (5 ), multiflorabiphenyl B (6 ), honokiol (7 ), and magnolol (8 ). Conclusion Compound 1 is a new compound named yunnabiphenyl A, while compounds 2 —8 were reported from this plant for the first time. Compound 1 showed moderate anti-inflammatory activity, with a median inhibition concentration (IC₅₀) value of 21.5 μmol/L.

Garcinia yunnanensis H. H. Hu  /  biphenyl  /  anti-inflammatory  /  yunnabiphenyl A  /  honokiol  /  magnolol  /  garcibiphenyl C