Antimicrobial potential of endophytic fungi from Astragalus chinensis.

ABSTRACT: The purpose of the present study was to discover antimicrobial endophytic fungi from Astragalus chinensis. Three fungal endophytes with antibacterial activity were isolated and determined as Chaetomium sp. HQ-1, Fusarium sp. HQ-7 and Fusarium sp. HQ-9 based on the neighbor-joining phylogenetic tree. Chaetomium sp. HQ-1 showed the best antibiotic potential and was thus selected for large-scale fermentation. Bioactivity-directed separation of ME fermentation of strain HQ-1 led to the discovery of three compounds, which were identified as differanisole A (1), 2,6-dichloro-4-propylphenol (2) and 4,5-dimethylresorcinol (3), from the HR-ESI-MS and NMR data analysis. All three compounds exhibited moderate antibacterial activity against Listeria monocytogenes, Staphylococcus aureus, and methicillin-resistant S. aureus, with MIC values ranging from 16 to 128 ?g/mL. Compounds 1 and 3 also displayed promising antifungal activity against Selerotium rolfsii with IC50 values of less than 16 and 32 ?g/mL, respectively, which were comparable to that of actidione (8 ?g/mL). The findings of the present study suggest that the endophytic fungi from A. chinensis have the potential to be used as bactericides and fungicides.

SUBMITTER: Liu P 

PROVIDER: S-EPMC6803603 | biostudies-literature | 2019 Nov

REPOSITORIES: biostudies-literature