Functional insights of a molecular complex pyrazolium 3,5-dinitrobenzoate:3,5-dinitrobenzoic acid on infectious agents and ctDNA - A comparative biological screening and complementary theoretical calculations

• Published in: Journal of photochemistry and photobiology. B, Biology Vol. 196; p. 111497
• Main Authors: Balachandar, S., Sethuram, M., Dhandapani, M.
• Format: Journal Article
• Language: English
• Published: Switzerland Elsevier B.V 01.07.2019; Elsevier BV
• Subjects: Acids; Antioxidants; Binding; Biological activity; Biological screening; Crystallization; Deoxyribonucleic acid; DNA; Electrostatic properties; Evaporation; Fluorimetry; Free radicals; Fukui functions calculation; Functional groups; Grooves; Hirshfeld surface analysis; Hydrogen bonding; Lewis acid; Mathematical analysis; Molecular docking; Molecular orbitals; Optimization; Organic chemistry; Scavenging; Screening; Spectral analysis; Spectrum analysis; Stability analysis; Surface analysis (chemical); Surface stability; XRD analysis; XRD analysis; Biological screening; Hirshfeld surface analysis; Molecular docking; Fukui functions calculation
• ISSN: 1011-1344; 1873-2682
• DOI: 10.1016/j.jphotobiol.2019.04.006

Systematic identification and quantification of active radical sites in a small molecule, pyrazolium 3,5-dinitrobenzoate:3,5-dinitrobenzoic acid as well as in the stable free radical (DPPH•) were carried out by Fukui functions calculation using DFT functional with B3LYP/6–311++G(d,p) level of basis set. Bioactive Lewis acid-base compound, pyrazolium 3,5-dinitrobenzoate:3,5-dinitrobenzoic acid (PDNB:DNBA) has been synthesized and crystallized by slow evaporation - solution method at 30 °C. Various functional groups and the structural arrangements were ascertained from spectral and XRD analyses, respectively. UV–vis spectral analysis was used to find out the stability of the anticipated drug for about 60 min using methanol as a solvent. Stabilization of the compound was linked to the presence of enormous N-H…O, O-H…O and C-H…O hydrogen bonding interactions identified through Hirshfeld surface analysis. Chemical stability and reactivity of the drug were validated from theoretical optimization and HOMO-LUMO analysis. Active nucleophilic, electrophilic and radical sites of PDNB:DNBA were also identified from molecular electrostatic potential analysis. Inhibition of growth of pathogens in screening experiments by the proposed drug attests its suitability in biological applications. Antioxidant activity of the compound, PDNB:DNBA, endorses its aptness for scavenging reactive radicals. Fluorimetry experiments confirm hyperchromism in DNA binding analysis proving groove mode of binding. Molecular docking explored the various modes of intermolecular interactions of the drug with microbes as well as DNA. [Display omitted] •SXRD confirms the molecular structure of PDNB:DNBA.•Stability analysis validated the chemical stability of the drug in ethanol.•Fukui functions calculation of both PDNB:DNBA and DPPH• unravelled the radical sites.•Hirshfeld surface analysis validates the hyperchromism through weak C…C interaction.•Biological screening of PDNB:DNBA is in good agreement with molecular docking study.