Polar solvation molecular dynamics, quantum reactivity (ELF, HOMO–LUMO, NBO) studies, spectroscopy (FT-IR, UV), and the antibiotic potential of carbazide derivative via in-silico molecular docking

Abstract

Recently, the treatment of bacterial infection has been very worrisome as a decline in antibiotic sensitivity is hitting a majority of the world population. Among many bacterial infection’s causing agents, Enterococcus species and Mycoplasma pneumonia are highly threatening because of their resistance to powerful antibiotics such as vancomycin, erythromycin, and azithromycin. Herein, effect of polar (DMSO, EtOH, MeOH, H2O) solvation on the quantum chemical parameters, molecular structure, spectroscopy, and the antimicrobial potential of p-phenylenediamine-thiosemicarbazide-formaldehyde (PTSF) terpolymer is presented within the framework of density functional theory (DFT), solvation molecular dynamics, and molecular docking approach. Herein, ethanol was keenly observed with the most insightful properties across all analyses specifically by its high energy gap (4.6344 eV) which accounted for the stability of compound. The molecular docking revealed the binding affinities for PSTF with respect to the best docking modes are −4.6 kcal/mol with LYS 288 and bond distance of 2.82 Å for 5V2M and −5.1 kcal/mol with ASN 770 at 2.27 Å, GLU 767 at 2.61 Å, ARG 777 at 3.69 Å, GLU 775 at 2.57 Å, and ALA 763 at 2.86 Å for 6rj1. From the result obtained, the studied compound has higher binding affinity at the active site of 6RJ1 than that of 5V2M. This suggests that PSTF has greater efficacy for inhibiting the growth of M. pneumoniae than vancomycin resistant Enterococcus faecalis. Hence, further in vitro and in vivo studies should delve into the more exploration of the reported ligand.