LC-MS/MS and GC-MS Analysis-Based Novel Bioactive Compounds From Endophyte Acremonium sclerotigenum CBS 124.42...

Endophytes are microorganisms that reside inside the living tissues of leaves and possess antimicrobial, antioxidant, anticancer and anti-inflammatory activity etc. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) represents a powerful analytical platform for comprehensive metabolomic profiling of endophytic fungi, offering superior sensitivity, selectivity and structural elucidation capabilities compared to conventional methods. This study employed LC-MS/MS and GC-MS analyses to characterise bioactive compounds from the methanolic extract of endophytic fungus Acremonium sclerotigenum CBS 124.42 isolated from Stevia rebaudiana leaves. LC-MS/MS analysis identified nine major bioactive compounds, including flavonoid glycosides (928.4 m/z), rutin derivatives (1454.7 m/z), cyclic depsipeptides (1445.4 m/z), cyanidin-3-O-rutinoside (595.3 m/z), macrolactams (1394.2 m/z), proanthocyanins (1232.8 m/z), oligomeric imperatorin (676.8 m/z) and cyanidin-3-O-glucoside (1232.8 m/z). Stevioside was detected at 9.02 min with characteristic fragments at 317.9 m/z. GC-MS analysis revealed 18 distinct compounds, with benzene (azidomethyl) being most abundant (100% relative area), followed by hydrazine carbothioamide (71.3%) and benzyl(1,2,3-thiadiazol-4-yl) carbamate (43.22%). Significantly, this study reports the first identification of hydrazine carbothioamide and benzyl(1,2,3-thiadiazol-4-yl) carbamate from natural sources, compounds previously known only from chemical synthesis. These compounds demonstrated significant bioactivities including antioxidant (IC₅₀ = 28.1 ± 6.96 mg/g), antimicrobial (zone of inhibition: 10.3-23.6 mm) and anticancer properties, establishing A. sclerotigenum CBS 124.42 as a novel source of therapeutically relevant secondary metabolites.