Two new stilbenes, gnetucleistol D (1) (2-methoxyoxyresveratrol), gnetucleistol E (2) (3-methoxy-isorhapontigenin) , together with four known stilbenes rhapontigenin (3) , isorhapontigenin (4) , 4- methoxyresveratrol (5) and pinosylvin (6) were isolated from Gnetum cleistostachyum C. Y. Cheng (Gnetaceae), and their structures have been determined on the basis of spectral evidences, including EI-MS, UV, IR, 1H NMR, 13C NMR and NOE respectively.

Key words: G. cleistostachyum C. Y. Cheng, STILBENE P, CHEMICAL COMPOSITION, ETHANOL, UV, 1HNMR, IR, C13NMR