RESUMEN
The objective of this study was to evaluate the antioxidant activity, determine and quantify the phenolic compounds and other compounds, and evaluate the cellular cytotoxicity of mycelium extracts of two new Basidiomycete mushrooms strains isolated in Brazil and identified as Lepista sordida GMA-05 and Trametes hirsuta GMA-01. Higher amounts of proteins, free amino acids, total and reducing carbohydrates, and phenolic compounds as chlorogenic, ferulic, caffeic, and gallic acids were found in extracts of T. hirsuta and L. sordida. Protocatechuic acid was found only in aqueous extracts of L. sordida. The TLC of the extracts showed the predominance of glucose and smaller amounts of xylose. It was observed through UPLC-MS higher amounts of phenolic compounds. The aqueous extract from T. hirsuta had the most noteworthy results in the antioxidant assays, especially the ABTS test. The cytotoxic activity was evaluated using two different cell lineages and showed higher toxicity for L. sordida in macrophages J774-A1. However, in Vero cells, it was 12.6-fold less toxic when compared to T. hirsuta. Thus, both mushrooms show potential as functional foods or additives, presenting phenolic content, antioxidant activity, and low cytotoxic activity in the tested cells.