ANTIMICROBIAL, ANTIOXIDANT, GC-MS ANALYSIS AND MOLECULAR DOCKING ANALYSIS OF BIOACTIVE COMPOUNDS OF ENDOPHYTE ASPERGILLUS FLAVUS FROM ARGEMONE MEXICANA

Abstract

Studies of potent antibiotics from plant endophytes have become a new interest among researchers. Plant derived antibiotics are costly, laborious, time-consuming and require extensive area of land. Endophytes can be used as an alternative source of antibiotics. Endophytes are microbes (bacteria and fungi) that live inside healthy plant tissues and do not show any antagonistic symptoms. They produce a variety of secondary metabolites having various commercial properties, medicinal, environmental, and agronomic purposes. In present work, endophytic fungi Aspergillus flavus associated with Argemone mexicana, was tested for its antimicrobial activity. The secondary metabolites of A. flavus were extracted using ethyl acetate solvent and tested for their antibacterial potential against certain Gram-negative bacteria, Salmonella typhimurium, Klebsiella pneumoniae, Vibrio cholerae, Escherichia coli, and Gram-positive bacteria Staphylococcus aureus using Agar well diffusion assay. Thin layer chromatographic bands were also checked further to know the bioactive spot. Gas chromatography- mass spectroscopy (GC-MS) was used to identify the bioactive compounds in TLC fraction and eighteen bioactive compounds were identified. Molecular docking and MM-GBSA were performed for the bioactive compounds with the respective proteins of the S. aureus (5JG0, 5JQ6, 1T2W, 3WYI, 3TFP, 3G7B, and 3WQU) and E. coli (1AJ0, 1GG4, 1 AJ6, 5ZHE and 7D6G) by using Schrodinger Maestro. In silico analysis suggested that Methyl (3-oxo-2-pentylcyclopentyl) acetate (MOPA) and 13-Hexyloxacyclotridec-10-en-2-one (HCT) exhibited the best binding affinity with most of the receptors. Pharmacokinetics and physicochemical analysis also showed that HCT and MOPA are the best drug candidate for the S. aureus and E. coli.