Oxidative coupling reaction with FeCl₃?6H₂O as oxidant and acid-catalyzed dimerization of natural gnetol in methanol afforded two new gnetol dimers and one new phenyl naphthalene derivative: 4-[1-(2,6-dihydroxyphenyl)-2-(3,5- dihydroxyphenyl)ethyl]-2-[(1E)-2-(3,5-dihydroxyphenyl)ethenyl]-1,3-benzenediol (1), 2-[1-(2,6-dihydroxyphenyl)-2-(3,5-di- hydroxyphenyl)ethyl]-5-[(1E)-2-(2,6-dihydroxyphenyl)ethenyl]-1,3-benzenediol (2) and 4-(6,8-dimethoxyl-2-naphthalenyl)- 1,3-benzenediol (3). Their structures were elucidated on the basis of spectral analysis, and their possible formation mechanisms were discussed. 1 and 2 were new linear stilbene dimers synthesized for the first time. Pharmacological tests showed 1, 2 and 3 to exhibit potent anti-oxidation activity with IC₅₀ values of 6.29?10^-9, 4.19?10^-6, and 2.96?10^-5 mol稬^-1, respectively, and 2 was shown to have potent anti-inflammatory activity.

Key words: gnetol dimer, oxidative coupling reaction, bioactivity