OBJECTIVETo investigate the chemical constituents of an endophytic fungus, Nodulisporium sp. A4, from the medicinal plant Aquilaria sinensis and search for antitumor natural products.

METHODThe fungus was cultured in liquid medium and extracted with EtOAc. The compounds were isolated by various chromatographic methods (silica gel, reverse silica gel, Sephadex-LH20, preparative TLC and so on) and recrystallization. Structural elucidation was conducted by extensive analysis of spectroscopic data as well as by comparison with literature reports. The antitumor activity of isolated compounds was tested by MTT method in vitro.

RESULTSeven compounds were isolated and identified from the broth culture, their structures were determined to be 5-methyl-2-vinyltetrahydrofuran-3-ol (1), 6-methyl-2-(5-methyl-5-vinyltetrahydrofuran-2-yl) hept-5-en-2-ol (2), 6alpha-hydroxycyclonerolidol (3), rel-(1S,4S, 5R,7R,10R)-10-desmethyl-1-methyl-11-eudesmene (4), tyrosol (5), 8-methoxynaphthalen-1-ol (6), and 1,8-dimethoxynaphthalene (7). Three compounds were isolated and identified from the mycelia as ergosterol (8), ergosterol peroxide (9), and cerevisterol (10). The in vitro pharmalogical evaluation results displayed that compounds 3 and 4 showed 89.1%, 44.2% and 82.3%, 79.8% inhibition against tumor cell lines SF268 and NCI-H460 at 100 mg x L(-1), respectively.

CONCLUSIONCompound 1 was a new natural product, compounds 2, 3, 7 and 10 were reported from the genus Nodulisporium sp. for the first time. Compounds 3 and 4 exhibited weak inhibitory effects on the proliferation of tumor cell lines SF268 and NCI-H460.