Bioactivity of a radical scavenger bis(pyrazolium p-toluenesulphonate) on ctDNA and certain microbes: a combined experimental and theoretical analysis.

A small organic molecule, bis(pyrazolium p-toluenesulphonate) (BPPTS), was crystallized, characterized and used to scavenge free radicals in biological systems. SXRD and spectroscopic analyses were used to confirm the structure of BPPTS. Methanolic and ethanolic solutions of BPPTS were used to assess the stability of the proposed drug using the UV-vis spectrophotometric technique. Optimization of the molecular structure was carried out by DFT with B3LYP/6-311++G(d,p) level of basis set. MEP and Fukui functions that elaborate theoretically the predominant electrophilic, nucleophilic and radical sites in BPPTS were correlated with experimental biological screening. BPPTS exhibits strong activity against Bacillus subtilis and Escherichia coli, comparable with all other analyzed pathogens. The free radical scavenging activity of BPPTS was assessed by both experimental studies and theoretical calculations. The binding sites of DPPH, which can bind to BPPTS, were also predicted by Fukui functions. DNA binding of BPPTS in UV-vis studies revealed the groove mode of binding due to the occurrence of hyperchromism. The phenomenon of hyperchromism was established by the Hirshfeld surface analysis of BPPTS, which confirmed the presence of π···π interactions (2.4%). Molecular docking established a positive correlation between experimental bio-screening reports and simulated data. ADMET properties were also calculated.

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.

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.

Target prediction and antioxidant analysis on isoflavones of demethyltexasin: a DFT study.

Glycosylated flavonoids are often found in supplementary food sources and are structurally more active than aglycones, as the glycosyl unit offers better solubility, stability, and functionality. The most common glycosyl units present in most secondary metabolites are glucoside and rhamnoside attached to flavonoid moiety. In the present work, 4'-O-glycosylated (4'-O-glucoside and 4'-O-rhamnoside) demethyltexasin, a soy isoflavone bearing a chromen nucleus, is investigated through a green route aided by density functional theory. Antioxidant activity is computed via three different antioxidant mechanisms, in which hydrogen atom abstraction is facilitated effectively in both gas and solvent phases. The 6-OH site (A-ring) in both isoflavone demethyltexasin glucoside (DMTG) and isoflavone demethyltexasin rhamnoside (DMTR) acted as better radical scavenging sites. Charge localization in B-ring is well altered by the glycosyl and rhamnosyl groups attached. Target prediction analysis supports DMTG with good binding ability with the selected homosapien class targets. The results depict that even though the flavonoid possessing rhamnosyl unit induces charge delocalization at the 4'-O position, it offers resistance toward antioxidant activity when compared to glycosyl moeity. Graphical abstract The contour representation of antioxidants demethyltexasin 4'-O- glucoside (DMTG) and demethyltexasin 4'-O- rhamnoside (DMTR) against reactive oxygen species(ROS).

Ligand based pharmacophoric modelling and docking of bioactive pyrazolium 3-nitrophthalate (P3NP) on Bacillus subtilis, Aspergillus fumigatus and Aspergillus niger - Computational and Hirshfeld surface analysis.

Biologically active Lewis acid-base compound, pyrazolium 3-nitro phthalate (P3NP) has been synthesized and crystallized by slow evaporation - solution method at 30°C. Spectral and single crystal X-Ray diffraction (XRD) were used to characterize the compound. The stability of the P3NP was confirmed by UV-Visible spectral analysis. P3NP crystallizes in monoclinic P21/C space group with cell parameters, a=13.009 (3) Å, b=12.584 (3) Å, c=7.529 (18) Å and ß=93.052 (4)(o) with Z=4. Crystal packing was stabilized by N(+)H⋯O(-), OH⋯O and CH⋯O intermolecular hydrogen bonds. The nature of anion - cation interactions and crystal packing from various types of intermolecular contacts and their importance were explored using the Hirshfeld surface analysis. The structure was optimized by Density Functional Theory at B3LYP level with 6-311++G(d,p) basis set and the vibrational frequencies were theoretically calculated. Band gap between Highest Occupied Molecular Orbital (HOMO) and Lowest Unoccupied Molecular Orbital (LUMO) and Electrostatic potential (ESP) were calculated. Antimicrobial activities of P3NP with targets were clinically tested and were found to exhibit antibacterial activity against gram positive and antifungal activity against pathogens with Minimum Inhibitory Concentration (MIC). Ligand based pharmacophore modelling was used to understand the potential of P3NP ligand to bind with selected target proteins. iGEM Dock was used to predict the modes of interactions of the ligand with target proteins of the microbes predicted from pharmacophore. PreADMET predicts no absorption of ligand in Human Intestinal Absorption (HIA).

Growth, spectral, dielectric and antimicrobial studies on 4-piperidinium carboxylamide picrate crystals.

Single crystal of 4-piperidinium carboxylamide picrate was grown by slow evaporation solution growth technique at ambient temperature. The average dimensions of grown crystal were 0.7×0.3×0.2 cm(3). The solubility of the compound was analyzed using methanol and acetone. Optical property of the compound was ascertained by UV-visible absorption spectral study. The sharp and well defined Bragg peaks observed in the powder X-ray diffraction pattern confirm its crystallinity. The different kinds of protons and carbons in the compound were confirmed by (1)H and (13)C NMR spectral analyses. The presence of various functional groups in the compound was assigned through polarized Raman spectral study. The mechanical property of the crystal was measured by Vicker's microhardness test and the compound was found to be soft material. The dielectric constant and dielectric loss of the crystal decrease with increase in frequency. The antibacterial and antifungal activities of the crystal were studied by disc diffusion method and found that the compound shows good inhibition efficiency against various bacteria and fungi species.

Structure and spectral properties of L-histidinium dipicrate dihydrate.

Non-linear optical active L-histidinium dipicrate dihydrate (LHDD) single crystals were grown by slow evaporation method. The Fourier transform FT-IR, FT-Raman, (1)H and (13)C NMR spectra of the crystal have been recorded and analysed. The spectral analyses confirm the formation of the compound and the stoichiometry. The geometry and spectral characteristics were examined using the density functional theory (DFT) method, B3LYP with 6-31G(d,p) basis set. The first-order hyperpolarisability, energies of frontier molecular orbitals and the Mulliken population analysis were also calculated. The HOMO-LUMO energy gap value 2.73 eV indicates the charge transfer from picrate to histidinium through the hydrogen bond. The second-order NLO properties of the molecule are studied by Kurtz-Perry powder technique. SHG efficiency of the compound is nearly 2.5 times greater than KDP. Theoretical calculations indicate hyperpolarisability of LHDD is 39 times greater than urea. The results show that the title molecule can be used for opto-electronic applications.

N (2)-(4-Meth-oxy-salicyl-idene)arginine hemihydrate.

The title compound, C14H20N4O4·0.5H2O [systematic name: (2S)-5-{[amino-(iminium-yl)meth-yl]amino}-2-{[(1Z)-4-meth-oxy-2-oxido-benzyl-idene]aza-nium-yl}penta-noate hemihydrate], has been synthesized by the reaction of l-arginine and 4-meth-oxy-salicyl-aldehyde and crystallizes with two independent substituted l-arginine mol-ecules and one water mol-ecule of solvation in the asymmetric unit. Each mol-ecule exists as a zwitterion and adopts a Z configuration about the central C=N. The mol-ecular conformation is stabilized by strong intra-molecular N-H⋯O hydrogen bonds that generate S(6) and S(10) ring motifs. Inter-molecular N-H⋯O and O-H⋯O hydrogen bonds involving also the water mol-ecule and weak inter-molecular C-H⋯Owater inter-actions link the mol-ecules into an infinite one-dimensional ribbon structure extending along the b axis. The known (2S) absolute configuration for l-arginine was invoked. Weak intermolecular C-H⋯π interactions are also present.

l-Histidinium dipicrate dihydrate.

In the title mol-ecular salt, C6H11N3O2 (2+)·2C6H2N3O7 (-)·2H2O, the histidine mol-ecule exists as a histidinium dication, being protonated at the N atom of the imidazole ring. The charges are balanced by two picrate anions and the compound crystallizes as a dihydrate. In the crystal, the components are linked via N-H⋯O and O-H⋯O hydrogen bonds and weak C-H⋯O inter-actions, forming a three-dimensional supermolecular structure.