A new oligostilbene trimer, malaysianol F (
1), together with ten known stilbenes (
2–11), were successfully separated and purified from the acetone extract of the lianas of
Gnetum microcarpum. Malaysianol D (
2) was isolated for the first
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A new oligostilbene trimer, malaysianol F (
1), together with ten known stilbenes (
2–11), were successfully separated and purified from the acetone extract of the lianas of
Gnetum microcarpum. Malaysianol D (
2) was isolated for the first time in
Gnetum plants. The tanninless crude extract (52.5 g) was fractionated using a vacuum liquid chromatography (VLC) technique to give five major fractions. Fraction 2 (4.68 g), 3 (4.79 g) and 4 (9.29 g) were all subjected to further isolation and purification using VLC, column chromatography (CC) and repetitive radial chromatography (RC) techniques with the best solvent system to yield malaysianol F (
1) (6.2 mg), malaysianol D (
2) (62.5 mg), malaysianol E (
3) (2.4 mg), ε-viniferin (
4) (10 mg), resveratrol (
5) (6.5 mg), gnetol (
6) (3.5 mg), gnetucleistol C (
7) (12.2 mg), isorhapontigenin (
8) (8 mg), cuspidan B (
9) (3.2 mg), parvifolol D (
10) (4.8 mg) and gnetifolin M (
11) (2.5 mg). Their structures were determined on the basis of the analysis of spectral evidence by extensive NMR data analyses and comparison with the related published data. Several compounds were tested for anti-inflammatory activity. Their inhibitory effect on Prostaglandin E
2 (PGE
2) was tested using radioimmunoassay techniques. Compound
6 exhibited significant concentration-dependent inhibitory effects on PGE
2 production with IC
50 values of 1.84 µM comparable with the positive control, indomethacin (IC
50 1.29 µM).
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