Phylogenetic diversity and antioxidant activity of selected fungi from ethno-medicinal plants and soil

Abstract

Endophytic fungi are proli c generators of bioactive metabolites with natural antioxidant properties that have a range of potential uses. In the present work, the antioxidant activity and phylogenetic diversity of endophytic fungi obtained from semi-arid terrestrial plants and the fungi obtained from the mangrove soil samples is investigated. The fungal isolates were identi ed by employing morphological features and phylogenetic characterization by internal transcribed spacer (ITS) sequences. Six taxonomic orders of Ascomycota associated with nine genera were identi ed, these being Diaporthales, Eurotiales, Hypocreales, Onygenales, Pleosporales and Xylariales. The antioxidant activity methanolic extracts of the fungal isolates were determined using modi ed 2,2'-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3ethylbenzothiazoline-6-sulphonicacid) (ABTS) methods. Among the fungal isolates, Aspergillus sp. AREF023 and Fusarium sp. AREF014, obtained from different parts of Datura metel, displayed the highest level of radical inhibition (80.76% and 70.62% respectively). GC/-MS analysis of the active isolates con rmed the presence of known antioxidant phenolic compounds, including 2-tert-Butyl-5-hydroxymethyl-5methyl-[1,3]dioxolan-4-one and Phenol, 2,5-bis(1,1-dimethylethyl), in the their crude extracts. Our ndings suggest that fungal isolates from D. metel can be a sustainable resource for natural antioxidants.