[Chemical constituents and biological activity of endophytic fungus Aspergillus versicolor from Aucuba japonica var. variegata].

The chemical constituents of the rice solid fermentation product of the endophytic fungus Aspergillus versicolor isolated from Aucuba japonica var. variegata were separated by various separation technologies such as silica gel column chromatography, gel column chromatography, reversed-phase silica gel column chromatography, and semi-preparative high performance liquid chromatography. The planar structures and stereochemistry of the isolated compounds were determined by high-resolution electrospray ionization mass spectrometry(HR-ESI-MS), nuclear magnetic resonance(NMR) spectroscopy, and quantum chemical calculations. A total of 21 compounds were isolated from the endophytic fungus A. versicolor and identified as(1S,2S,3S)-engyodontiumone G(1),(1S,2S,3R)-engyodontiumone F(2),(1S,2S)-AGI-B4(3), aspergillusone B(4), sydoxanthone C(5), fischexanthone(6), sydowinin A(7), 7-hydroxy-2-hydroxymethyl-5-methyl-4H-chromen-4-one(8), kojic acid monomethyl ether(9),(+)-sydowic acid(10),(-)-austrosene(11), monodictyphenone(12), gibellulins A(13), 3,7-dihydroxy-1,9-dimethyldibenzofuran(14), 4-(acetylamino) butyramide(15), emodin bianthrone B(16), emodin bianthrone A(17), flufunan(18), catechol(19), vanillin(20), and uracil(21). The absolute configurations of compounds 1-3 were determined through calculated electronic circular dichroism(ECD) for the first time. Compound 3 was the enantiomer of(1R,2R)-AGI-B4 and was reported for the first time. Biological activity screening results indicated that none of the tested compounds exhibited significant antifungal effects against the tested strains, nor did they demonstrate notable antitumor activity against the tested cancer cells.