Bioactivity screening of endophytic fungus eutypa linearis isolated from coleus amboinicus (Lour.)

Coleus amboinicus (Lour.) is a medicinal plant containing various bioactive compounds. Endophytes are microorganisms living inside the intracellular tissue of plants and are known as the source of bioactive compounds. In order to explore the potential of endophytes in producing novel bioactive compounds, this study focused on isolating endophytic fungi from the leaves of C.amboinicus, characterizing, and screening their metabolite bioactivity during submerged culture fermentation. Isolation of endophytic fungi from the leaves segment of C.amboinicus was conducted in PDA media and fungus identification was carried out by analyzing its morphology and through molecular examination. The production of metabolites was examined using thin-layer chromatography and gas chromatography. Identification of the endophytic fungus showed 98.84 similarity with Eutypa linearis. This species was fermented by submersion in PDB medium for 14 days under dark and exposed to light conditions. The fermentation broth was extracted using ethyl acetate. The results showed that exposure to light influenced metabolite production. The ethyl acetate extract exhibited antioxidant and cytotoxic activities. Antioxidant activity of this extract as examined by DPPH assay showed IC50 of 105.31±2.11µg/mL. Cytotoxic activity against the Hela cell line was known to be the best compared with other cell lines (IC50 302.28±10.30 µg/mL) although it was found to be nonselective (SI<3). The extract contained five major compounds namely benzenemethanol, 4-nitro-(CAS) p-nitrobenzyl alcohol; 2-pentadecanone (CAS) pentadecan-2-one; (1R*,6S*,10R*)-5,5-dimethyl-11,12-dioxatricyclo8.2.1.0(1,6) tridecan-10-ol; 9,12-cctadecadienoic acid (Z,Z)-, methyl ester (CAS) methyl linoleate; and 3-furanacetic acid, 4-hexyl-2,5-dihydro-2,5-dioxo- (CAS) 2-carboxymethyl-3-N-hexyl-maleic anhydride. Copyright © 2020 THE AUTHOR(S).