Molecular characterization and phenolic acids analysis of an endophytic fungus with high antioxidant activity

Abstract:

[Objective] An endophytic fungus SG17 was isolated from the root of Myricaria laxiflora before flooding. In order to explore the antioxidant capacity and the possible material foundation, bio-identification, antioxidant confirmation and phenolic acids analysis were conducted here. [Methods] The internal transcribed spacer (ITS) of nrDNA was sequenced, and a total antioxidant kit was used to measure the capacity with the positive control of Vitamin C. Furthermore, High performance liquid chromatography (HPLC) and thin layer chromatography (TLC) were applied to analyze the natural phenolic compounds from the fermentation broth. [Results] The antioxidant capacity of SG17 was extraordinarily high, and the extract of the fermentation liquid was 31.86% as high as the same content of vitamin C. ITS sequence and BLAST analysis indicated that SG17 would be Aspergillus fumigates, and this conclusion was further proved by morphological characterization. The contents of phenolic acids were rich in the fermentation broth, in which gallic acid could be detected by HPLC, and a compound with the same UV spectrum as chlorogenic acid was found both by HPLC and TLC. [Conclusion] The endophyte SG17, an Aspergillus fumigatus, had much higher antioxidant activity than reported before, and could be explored as a potential antioxidant resource in the future.

Key words:Endophytic fungi, Antioxidant, Molecular identification, Phenolic acids, High performance liquid chromatography, Thin layer chromatography