Gymnascella thermotolerans-GTE-21, an Endophytic Fungus in Euphorbia geniculata as a Versatile Producer of Bioactive Metabolites.

The thermophilic fungus Gymnascella thermotolerans GTE-21 produces a significant amount of both volatile and nonvolatile compounds with potent antifungal and anticancer properties. Gas chromatography-mass spectrometry (GC-MS) was utilized to identify 14 volatile organic compounds (VOCs) released by G. thermotolerans. The most predominant compound identified was diisooctyl phthalate, constituting 71.99% of the total VOCs, followed by phenol, 2-methoxy-4-(2-propenyl) at 7.12%. The GTE-21's VOCs demonstrated significant antifungal growth inhibition activity of 42.5% against Fusarium solani and 39.03% against Alternaria alternata. Additionally, GTE-21's crude extract exhibited substantial antibacterial effects, evidenced by inhibition zones of 1.5 cm against S. epidermidis, 1.4 cm against C. ciferrii, and 1.3 cm against S. aureus. The CHR2RClR2R:MeOH (1:1) fraction was more effective against human pathogens, producing the largest zones of inhibition of 1.1 and 1.03 cm against S. epidermidis and C. ciferrii, respectively. The evaluation of GTE-21's antifungal activity using the Evans blue assay showed that fungal spores treated with GTE-21's crude extract exhibited 96.2% inhibition at a concentration of 25 mg/ml. Similarly, the fractions CH2Cl2:MeOH (1:1) and CH2Cl2:MeOH (9:1) demonstrated spore inhibition rates of 96.3% and 94.3%, respectively. The EtOAc crude extract demonstrated pronounced cytotoxic effects against the SKOV-3 and MDA-MB-231 cancer cell lines. For SKOV-3, cell viability decreased to 3.40% and 0.47% at concentrations of 50 and 100 μL, respectively. In the case of MDA-MB-231, cell viability was reduced to 0.19% at both 50 and 100 μL concentrations. [ABSTRACT FROM AUTHOR]