Probing the binding interaction of zinc (II) Schiff bases with bovine serum albumin: A spectroscopic and molecular docking study

Abstract

Entrapping of potent Schiff base with biomimetic environment using fluorescence properties enables better understanding of their interaction for drug‐based application. A detailed photophysical study of zinc (II) Schiff bases, 2,6‐bis((E)‐((2‐(dimethylamino) ethyl)imino)methyl)‐4‐R‐phenol, where R = methyl/tertiary butyl/chloro is reported by utilizing bovine serum albumin (BSA) as the bio membrane. Steady state absorption and emission studies of Schiff base‐protein system have been found to get altered by change in the compartmental ligand. Alternation of polarity caused by such compartmental ligands is reported by comparing the fluorescence behavior of the probes in microheterogeneous environment in a mixture of dioxane and water of varying composition. Hildebrand equation accounts for negative binding constants among BSA with Schiff base with Cl (‐I) group as the compartmental ligand in contrast to the positive magnitudes with ligands exhibiting +I effect. Functionality of such compartmental ligands (intra interactions studied using Hirshfeld analyses) upon binding with the protein is also studied in terms of quenching and denaturation studies. Schiff base with Me is found to be the most favorable ligand that bound to BSA as corroborated from the binding, quenching, micropolarity, and docking studies. Molecular docking studies predict the affinity energies for suitable binding conformations to be ~ − 6 kcal mol−1 for BSA‐Schiff base (with Me ligand).

Supramolecular Arrangement and DFT analysis of Zinc(II) Schiff Bases: An Insight towards the Influence of Compartmental Ligands on Binding Interaction with Protein

“…The reactivity pattern of the system is analysed using FMO approach and substantiated with electrostatic potential maps. This has the background of predicting the crystal structures by DFT which agrees closely with the results obtained from X‐Ray diffraction data [12] . Therefore, the reported can enable a pre‐screening of the binding interaction of protein with the targeted Schiff base.…”

“…It can be mentioned that, the energy gap among HOMO and LUMO is least for the ligand with Cl group. In this connection, Sen Chowdhury et al [12] . have already reported the feasibility of such zinc(II) system to get interacted with bovine serum albumin (BSA) protein in terms of spectroscopic means.…”

“…[11] The representative structure of zinc(II) Schiff bases as tabulated in Table 1 are shown in Figure 1. Preliminary experiment (s) in terms of binding interaction of zinc(II) system with Cl-, Me and t Bu group with BSA has been reported by Sen Chowdhury et al [12] However, the reported study lacks the interaction analysis of Schiff base with protein. In order to get established as an API, the target system needs to have various interactions (associative or inhibitory) as per the type of protein.…”

“…It can be mentioned that, the energy gap among HOMO and LUMO is least for the ligand with Cl group. In this connection, Sen Chowdhury et al [12] have already reported the feasibility of such zinc(II) system to get interacted with bovine serum albumin (BSA) protein in terms of spectroscopic means. This research article intends to provide a deeper and broad aspect on the influence of four compartmental ligands on the molecular docking analysis of zinc(II) Schiff base with protein like.…”

“…Dasgupta et al [11] reported the synthesis of the four zinc(II) Schiff bases and employed as an effective nitro aromatic detector upon utilising their fluorescent behaviour. In continuation, Sen Chowdhury et al [12] reported the binding interaction among the neutral fluorophore of zinc(II) Schiff base having compartmental ligands, namely, tert-butyl ( t Bu), methyl, and chloride with BSA as the bio-membrane. The primary objective is to selectively screen and apply the zinc(II) system as an Active Pharmaceutical Ingredient (API).…”