Bioactivity Screening and GC–MS Profiling of Endophytic Fungi From the Medicinal Plant Munronia pinnata

Abstract

Endophytic fungi inhabiting medicinal plants represent a largely untapped reservoir of biologically active compounds with potential therapeutic value. This study reports the isolation of endophytic fungi associated with the medicinal plant Munronia pinnata , followed by morphological and molecular characterization, secondary metabolite extraction, evaluation of anti‐microbial and anti‐oxidant properties, and metabolite profiling by GC–MS. A total of 18 endophytic fungi were isolated, including Colletotrichum , Aspergillus , Diaporthe , and Fusarium . Colletotrichum plurivorum and Aspergillus aculeatinus were identified by multi‐locus phylogeny and exhibited broad‐spectrum anti‐microbial activity, with zones of inhibition ranging from 17 ± 1 to 42 ± 2 mm in the agar plug diffusion assay against Staphylococcus aureus (ATCC 25923), Bacillus cereus (ATCC 11778), and Escherichia coli (ATCC 25922). The ethyl acetate extracts of C. plurivorum and A. aculeatinus showed zones of inhibition of 15 ± 1 to 23 ± 1 mm in the agar disc diffusion assay, with minimum inhibitory concentrations ranging from 31.5 to 125 µg/mL against the same set of pathogens. The ethyl acetate extract of A. aculeatinus exhibited potent anti‐oxidant activity in both the ferric reducing anti‐oxidant power and 2,2′‐azino‐bis(3‐ethylbenzothiazoline‐6‐sulfonic acid) radical cation scavenging (IC 50 value of 15.6 ± 0.3 µg/mL) assays. GC–MS analysis of the ethyl acetate extract revealed 12 compounds from C. plurivorum and 16 from A. aculeatinus , likely contributing to the observed bioactivities. These compounds include fatty acids, phenolics, terpenoids, anthraquinones, and a rare naphthalene derivative. The results highlight the potential of endophytes as untapped reservoirs of novel therapeutic agents for the development of innovative and sustainable products in the pharmaceutical industry.

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