Evaluation and chemical characterization of bioactive secondary metabolites from endophytic fungi associated with the ethnomedicinal plant Bergenia ciliata

Abstract

The objective of this work was to assess the bioactive potential of endophytic fungi, Colletotrichum brevisporum (JPSK3), Pestalotiopsis microspora (JPSK19), and Guignardia mangiferae (JPSK25), from Bergenia ciliata. The antibacterial effects were determined by the well diffusion technique against human pathogens (Staphylococcus aureus, Escherichia coli, Bacillus cereus, and Salmonella typhi) and they showed good activities. In the antioxidant assay, the fungal extract P. microspora shows higher free radical scavenging effects in 2,2-diphenyl-1-picrylhydrazyl (82.48%), hydrogen peroxide (84.91%), superoxide (78.85%), and reducing power absorbance of 0.125 at a dosage of 125 g/mL than other two fungi. The fungal extract was also subjected to phenol and flavonoid quantifications. The fungus P. microspora shows the highest phenol (89.56 0.03 mg of GAE/g of extract) and flavonoid (51.52 0.69 mg of quercetin equivalents/g of extract), respectively. The chemical composition of abundant biologically active compounds was determined by gas chromatography-mass spectrophotometry (GC-MS). Furthermore, it was confirmed through spectral and analytical analysis (thin layer chromatography, ultraviolet, Fourier transform infrared spectroscopy, high-performance liquid chromatography, GC-MS, and nuclear magnetic spectroscopy). In P. microspora, the compound phenol, p-tert-butyl (C10H14O), was confirmed for the first time. This fungal compound could be a potential alternative medicine in the future. This is the first work on endophytic fungal studies of ethnomedicinal plant Bergenia ciliata.