Evaluation of DNA Binding, Radicals Scavenging and Antimicrobial Studies of Newly Synthesized N-Substituted Naphthalimides: Spectroscopic and Molecular Docking Investigations

Abstract

In this study, we investigated a new series of naphthalimide based Schiff base compounds as potential DNA binding, antioxidant and antimicrobial agents. The structural characterization of synthesized compounds was carried out with the aid of elemental analysis and spectroscopic techniques (UV-vis., IR, (1)H and (13)C NMR). The DNA binding properties of target compounds against Ct-DNA (calf thymus) have been investigated in detail by numerous biophysical techniques (UV-vis, fluorescence, ethidium bromide displacement assay, Time resolved fluorescence, viscosity, cyclic voltammetry and circular dichorism) and the evidences have suggested that the test compounds could interact with DNA via intercalative binding. The extent of DNA binding (Kb) of these compounds follow the order of 3b (3.33 × 10(4) M(-1)) > 3a (2.25 × 10(4) M(-1)) > 3c (2 × 10(4) M(-1)), suggesting that compound 3b binds more strongly to Ct- DNA than the compounds 3a and 3c. Molecular docking results further support intercalative binding of test compounds with DNA. The binding energies of docked compounds (3a-3c) were found to be -8.20 to -8.69 kcal/ mol, suggesting greater binding affinity to Ct-DNA. The synthesized compounds displayed potential antimicrobial activities against Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae and Salmonella typhimurium. Compound 3c has emerged as most active against all the four tested bacterial strains with MIC value in the range of 0.031-0.062 mg/mL. In the mutagenicity studies, all the test compounds were found to be non-mutagenic both in the presence and absence of metabolic activation. Furthermore, the antioxidant activity experiments show that these compounds exhibited potential scavenging activities against DPPH and H2O2 radicals.

RETRACTED: Synthesis and studies of selective chemosensor for naked-eye detection of anions and cations based on a new Schiff-base derivative

“…To assess the solvatochromic effect, the electronic absorption spectra of L (4⤬10 −5 mol.L − 1 ) in some organic solvents with different polarities were recorded at room temperature. As expected, the influence of solvents on the prepared dyes and/or changes in the hydrogen bonding strength in polar solvents [46,47]. The resulting values are summarized in Table 1.…”

“…1. It has been proved that the electron transitions of azo-azomethine compounds depend strongly on the nature of the media [46]. To assess the solvatochromic effect, the electronic absorption spectra of L (4⤬10 −5 mol.L − 1 ) in some organic solvents with different polarities were recorded at room temperature.…”

“…The ionochromic behavior of Schiff bases and the interaction with a wide range of metal ions have been well documented [44]. Schiff bases containing salicyaldimine based ligands can be used in the development of cost-effective chemosensors because they show significant color changes of the solution and maxima of the absorption bond when they interact with anions and cations [45][46]. Recently, we reported aneasy and applicable method for the preparation [47] and use of low cost chemosensors based on Schiff bases for the selective detection of some toxic metal ions and anions [48,49].…”

Experimental and molecular docking investigation on DNA interaction of N‐substituted phthalimides: antibacterial, antioxidant and hemolytic activities

“…As part of our research work, aimed at designing and developing biologically active cyclic imides, herein we describe the antibacterial and DNA‐binding studies of some novel N ‐substituted phthalimide derivatives. These newly synthesized compounds have been screened for their scavenging capacity against DPPH and hydrogen peroxide free radicals and the results were compared with ascorbic acid as a synthetic antioxidant.…”

5-[Substituted]-1, 3, 4-thiadiazol-2-amines: Synthesis, Spectral Characterization, and Evaluation of their DNA interactions

“…The effects were, however, only moderate 45 Table 2. Fluorimetric spectral data with addition of CT-DNA to compounds, 1-7 The fluorescence quenching of DNA-bound EB can be described by the linear Stern-Volmer equation 46 in which the synthesized compounds were the quenchers: F0 and F represent the fluorescence intensities in the absence and presence of quencher, respectively; KSVis a linear Stern-Volmer quenching constant; [Q] is the concentration of quencher and is the average fluorescence lifetime of the quencher (10 -8 s). A plot of F 0 /F versus [Q] gave a slope to intercept which is equal to KSV.…”