Chem. Pharm. Bull. 54(7) 1053—1057 (2006)

nents, we investigated the chemical constituents of Gnetum cleistostachyum C. Y. CHENG (Gnetaceae). One new stilbenolignan named gnetucleistol F (1), four known stilbenolignans, gnetofuran A (2), lehmbachol D (3), gnetifolin F (4) and gnetumontanin C (5), together with shegansu B (6), gnetupendin B, gnetol and daucosterol were isolated from this plant. In order to confirm the structures and obtain enough samples for pharmacological test, a biomimetically synthetic route for the stilbenolignans was designed and compounds 1, 2, 3 and 4 were synthesized successfully by oxidative coupling reaction. On the basis of the biogenetic pathway, their possible mechanisms were discussed. Pharmacological tests for 1, 2, 3, 4 and 5 indicated that 1—5 showed moderate antiinflammatory activities, and compound 1 also showed potent anti-oxidant activity.