Biological activities and metabolic profile of crude extracts from two Nigrospora sp. isolates

Secondary metabolites derived from microorganisms have attracted considerable attention due to their diverse bioactivities relevant to the pharmaceutical industry, including antimicrobial, antioxidant, and antitumor activities. However, fungal properties remain insufficiently explored due to their extensive biodiversity. Therefore, this study aimed to characterize the metabolite profile and to evaluate the antimicrobial, antitumoral, antioxidant, antihyperglycemic, and antilipidemic activities of two fungi belonging to the genus Nigrospora, isolated from slaughterhouse effluent and an endophyte of Myrciaria glazioviana. The fungi were grown in Potato Dextrose Broth (PDB) for 15 days at 28 °C. Ethyl acetate extracts of the fungal isolates were obtained and concentrated using a rotary evaporator. Subsequently, they were subjected to metabolomic profiling and to analyses of antimicrobial, antitumoral, and antioxidant activities using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS⁺) assays. UHPLC putatively annotated metabolites-MS/MS analysis. Both isolates showed significant results for all tested bioactivities. Among the evaluated fungi, the Nigrospora sp. Mg17 isolate stood out by exhibiting bactericidal activity against Staphylococcus aureus ATCC 25,923 and an IC₅₀ of 479.6 µg/mL against Streptococcus agalactiae ATCC 1381. Both extracts demonstrated notable antilipidemic potential, with enzymatic inhibition reaching up to 90% for Nigrospora sp. F4, as well as the antihyperglycemic activity of up to 51% (Mg17 extract). In the antioxidant analysis, the extract from the Nigrospora sp. Mg17 isolate demonstrated high efficiency, achieving 94% inhibition of the DPPH radical at 1 mg/mL. Therefore, the results reinforce the potential of bioprospecting microorganisms from diverse environments as a promising strategy for the discovery of new bioactive fungal metabolites with pharmacological and biotechnological applications, thereby contributing to the development of more sustainable alternatives.