Comparative Antibacterial Analysis of the Anthraquinone Compounds Based on the AIM Theory and Molecular Docking Analysis
Abstract Hydroxyanthraquinones and anthraquinone glucoside derivatives are always considered as the active antibacterial components. In the present text, a comprehensive comparison and analysis of these compounds were performed for their structure characteristics and antibacterial effect by applying quantum chemical calculations, atoms in molecules theory and molecular docking procedure. The molecular geometric configuration, electrostatic potential, the frontier orbital energies and topological properties were analyzed. Once glucose ring is introduced into the hydroxyanthraquinone rings, almost all of the positive molecular potentials are distributed among the hydroxyl hydrogen atoms of the glucose rings. The anthraquinone glucoside compounds have generally higher intermolecular binding energies than the corresponding aglycones due to the strong interaction between the glucose rings and the surrounding amino acids. Once glucoside ring is introduced into the emodin, low electron density ρ(r) and positive Laplacian value of the O-H bond are the evidences of the highly polarized and covalently decreased bonding interactions. The type of carboxyl, hydroxyl, hydroxylmethyl groups on phenyl ring and the substituent glucose rings are important to the interactions with the topoisomerase type II enzyme DNA gyrase B.
