Characterization of secondary metabolites of an endophytic fungus from Curcuma wenyujin.

Endophytic fungi are ubiquitous in the plant kingdom and they produce a variety of secondary metabolites to protect plant communities and to show some potential for human use. However, secondary metabolites produced by endophytic fungi in the medicinal plant Curcuma wenyujin are sparsely explored and characterized. The aim of this study was to characterize the secondary metabolites of an active endophytic fungus. M7226, the mutant counterpart of endophytic fungus EZG0807 previously isolated from the root of C. wenyujin, was as a target strain. After fermentation, the secondary metabolites were purified using a series of purification methods including thin layer chromatography, column chromatography with silica, ODS-C18, Sephadex LH-20, and macroporous resin, and were analyzed using multiple pieces of data (UV, IR, MS, and NMR). Five compounds were isolated and identified as curcumin, cinnamic acid, 1,4-dihydroxyanthraquinone, gibberellic acid, and kaempferol. Interestingly, curcumin, one of the main active ingredients of C. wenyujin, was isolated as a secondary metabolite from a fungal endophyte for the first time.