<i>Aspergillus versicolor</i> Strain PSFNRO‐2: A Novel Producer of 1,2,3‐Thiadiazol and Pyridinium Salt Derivative Bioactive Compounds From an Endophyte of <i>Stevia rebaudiana</i> (Bertoni) Bertoni

Endophytes contain many bioactive compounds. The methanolic extract of Aspergillus versicolor strain PSFNRO-2 was extracted using ethyl acetate solvent, and the endophyte was isolated from the Stevia rebaudiana (Bertoni) Bertoni plant, which was discussed previously. The extract was tested for different assays and zone formation (enzyme production). The culture conditions were 4 days at pH 6.5 and a temperature of 28°C. The maximum formation zone was for lipase (48.6 ± 2.51 mm), then protease (53.6 ± 3.78 mm) and amylase (11.3 ± 1.52 mm). The different enzyme activity for amylase (18.6 ± 0.1 U/mL), lipase (15.4 ± 0.09 U/mL) and protease was (18.7 ± 0.15 U/mL). Gas chromatography-mass spectrometry (GC-MS) analysis reveals the prominent presence of silanediol dimethyl, which has a 100% area of abundance; sec-butyl N-[bis(dimethylamino)methylidene]-P-methyl phosphonamidite has 49.91%; hexadecanoic acid, methyl ester has 23.35%; phenol, 2,5-bis(1,1-dimethylethyl) has 20.87%; oxime, methoxy-phenol has 17.88%; N-difluorophosphoxy-O-trimethylsilylhydroxylamine has 15.18%; n-hexadecanoic acid has 14.01%; and 13-octadecanoic acid, methyl ester has 8.87% area, respectively. n-Dodecylpyridinium chloride is chemically synthesized, and its pyridinium salts have antibacterial and antiseptic properties. Benzyl (1,2,3-thiadiazol-4-y) carbamate has the role of an antimicrobial, antifungal and anticancer activity. sec-Butyl N-[bis(dimethylamino)methylidene]-P-methyl phosphonamidite was a chemical reagent commonly synthesizing modified oligonucleotide. These bioactive compounds were not naturally sourced but found in the endophyte A. versicolor strain PSFNRO-2, which can be studied for the pharmaceutical industry and medicinal chemistry, offering a novel and sustainable source for pharmaceutical and therapeutic applications.