Structure elucidation and anti-Klebsiella activity with in silico ADME prediction and molecular docking of the bioactive metabolite from Aspergillus sp. 3MAG

Abstract

Abstract Marine environments are considered an interesting source of new active ingredients. The discovery and subsequent clinical introduction of antibiotics is one of the most important game-changers in the history of medicine. So, A pure compound of Dibutyl phthalate ester was extracted from a marine-derived fungus of Aspergillussp. 3MAG isolated from soft coral collected from the Red Sea. The suppression of Klebsiella pneumoniae strain 3MAG by Dibutyl phthalate ester was an intriguing finding in our investigation measured by minimum inhibitory concentration (MIC) of value 40 µg/ml and minimum bactericidal concentration (MBC) of value 200 µg/ml. The kinetic time killer curve showed that the bacterial cells die within 4 hours. The transmission electron microscope technique detected Klebsiella pneumoniae strain 3MAG cellular damage after being exposed to Dibutyl phthalate ester instead of its typical cell shape. Bacterial and fungal strains were molecularly identified. The fractionation and purification of the Dibutyl phthalate ester compound were achieved using silica gel column G254 and preparative thin-layer chromatography (TLC). Spectrum data such as UV spectroscopy, LC-mass, and nuclear magnetic resonance (NMR) aided in the structure elucidation of Dibutyl phthalate. The ADME-related physicochemical properties of the obtained compound were predicted using SwissADME web tools and the ProToxii webserver was used to estimate in silico toxicity. While by using inslico molecular docking, Dibutyl phthalate ester interacted with OMPA (7RJJ) through hydrophobic contact with THR475, GLU480, GLN485 and LEU486, Cation-pi interaction with GLU480 and Hydrogen bond with ASN484, THR475 and LEU486 which may lead to disruption of the Klebsiella pneumoniae outer membrane.