Bioactive metabolites from an endophytic fungus of Aspergillus species isolated from seeds of Gloriosa superba Linn.

Abstract

A fungal isolate out of 22 endophytic fungi, isolated from the different parts of medicinal plant Gloriosa superba, was subjected to bioassay guided fractionation. This fractionation resulted in the isolation of a novel bioactive metabolite along with three other known compounds. The structures of compounds were assessed on the basis of their spectroscopic analysis. Isolated compounds were also assayed for their biological potential. Compounds, in comparison to standard antimicrobial agents, were tested for their antimicrobial activity against five human pathogenic bacteria: Staphylococcus aureus (MTCC 96), Bacillus subtilis (MTCC 2451), Escherichia coli (MTCC 82), Pseudomonas aeruginosa (MTCC 2642), and Salmonella typhimurium (MTCC 1251), and three pathogenic fungal strains: Saccharomyces cerevisiae (MTCC 172), Candida albicans (MTCC 3018), and Cryptococcus gastricus (MTCC 1715). The compounds were also evaluated for their anticancer potential against six cancer cell lines, viz., A-549, HEP-2, MCF-7, OVCAR-5, THP-1, and CVI-1. Compound 4 which is isolated for first time from any endophytic fungi, exhibited significant antimicrobial and cytotoxic activity. All the fungal strains were considerably inhibited by the compound. Leukemic cancer cell line THP-1 and Breast cancer cell line: MCF-7 were significantly inhibited by 2 and 4. Compound 4 inhibited these cell lines with IC50 30 μg/mL and 50 μg/mL, respectively, and was found to possess potency comparable to standard anticancer agents Mitomycin-c and 5-FU. Compound 4 also inhibited Lung cancer cell line—A-549 and CV-1.