Purification and structure elucidation of Penicillium chrysogenum derived antifungal compound with potential anti-Candida property: in silico and in vitro evidence.

Following preliminary bioactivity testing, the fungal strain identified as was cultured in a modified Czapec Yeast Broth medium (CYB) for the production of antifungal compounds. Several chromatographic techniques including HPLC were used to purify the fungal metabolites from the crude extract. The mass determination of the purified compound was performed using Water's LCMS system while the structure of the compound was elucidated using 400 and 500 Varian NMR machines. The chemical name of the purified compound is (2 R, 4S) -2, 4-dimethyl-4-((E)-2-((3S, 4S)-2, 4, 5-trihydroxy-3-methoxy-4-phenyl, 2, 3, 4-tetrahydroquinolin-6-yl) vinyl) cyclohexanone with the chemical formula CHNO and exact mass of 437.2. Molecular docking predicted compound docking score with dihydrofolate reductase enzyme and lanosterol 14α-demethylase enzyme as -8.1 kcal/mol and -9.8 kcal/mol respectively. Further, the compounds showed stable binding mode with the enzymes and reported robust binding energies. After insilico analysis, the compound with mass 437 was tested for its antifungal potential against two pathogenic yeast species (i.e. Candida albicans and Candida glaberata) using the agar tube diffusion method. Using sterile di-methyl sulfoxide (DMSO) the compound was prepared in four dose concentrations (100, 250, 500, 1000 µg mL) and mixed with autoclaved semisolid Potato Dextrose Agar (PDA) medium in screw-capped test tubes labelled with the corresponding dose concentration. The fungal strains were inoculated on this medium and linear growth inhibition of the fungal strains was calculated using fluconazole as the control drug. The results from experiments were encouraging as at concentrations of 500 and 1000 μg mL the compound inhibited the growth of by 17% and 38% while 19% and 41% inhibition were recorded against . The compound showed antifungal activity and against both the species and can act as a potent antifungal candidate in the future upon further investigation.Communicated by Ramaswamy H. Sarma.