SYNTHESIS, CHARACTERIZATION, QUANTITATIVE STRUCTURE-ACTIVITY RELATIONSHIP, DOCKING, ANTIBACTERIAL ACTIVITY, AND BRINE SHRIMP LETHAL STUDIES ON L-PHENYLALANINE SCHIFF BASES

ABSTRACTObjective: Aim of this work is to synthesize and characterization of the hydroxyl group the hydroxyl group substituted L-phenylalanine Schiff basesto compare their predicted quantitative structure-activity relationship (QSAR) and molecular docking against Escherichia coli protein ZipA (1s1j)outcomes with the antibacterial activity and brine shrimp lethal assay (BSLA) results.Methods: The Schiff bases of L-Phenylalanine were synthesized by the simple condensation reaction using methanol, water in 2:1 ratio at reflux andwere characterized by spectral techniques. QSAR parameters of the Schiff bases were predicted using java-based online and offline tools. Moleculardocking carried through online mcule server and CLC Drug Discovery Workbench 3. Antibacterial activity and toxicity studies were conducted usingbroth dilution and brine shrimp lethal assay methods, respectively.Results: The Schiff bases fulfilled the QSAR drug-likeness parameters and showed the docking score between −6.8 and −6.0 Kcal/mol which arehigher than amoxilicillin and gentamicin like standard drugs. They also possess good inhibition for urinary tract infection causing E. coli bacteria,and minimum inhibitory concentrations (MIC) exists between 3.25 and 5.25 μg/ml. The brine shrimp lethal concentration for 50% mortality [LC50])between 58.73 and 135.6 μg/ml.Conclusion: Para, meta and 2,4 hydroxyl substituted Schiff bases exhibited good inhibition against Gram-negative E. coli bacteria at low concentrationand the MIC exists below the LC50 value. The Schiff base showed high drug score, high docking score, and low toxicity than other Schiff base. Dockingscore, high inhibition, low clogP, low MICKeywords: L-phenylalanine, Schiff base, Quantitative structure-activity relationship, Docking, Antibacterial, Lethal concentration for 50% mortality

Cobalt(III), nickel(II) and ruthenium(II) complexes of 1,10-phenanthroline family of ligands: DNA binding and photocleavage studies

DNA binding and photocleavage characteristics of a series of mixed-ligand complexes of the type [M(phen)2LL]n+ (where M = Co(III), Ni(II) or Ru(II), LL = 1,10-phenanthroline (phen), phenanthroline-dione (phen-dione) or dipyridophenazine (dppz) andn = 3 or 2) have been investigated in detail. Various physico-chemical and biochemical techniques including UV/Visible, fluorescence and viscometric titration, thermal denaturation, and differential pulse voltammetry have been employed to probe the details of DNA binding by these complexes; intrinsic binding constants (Kb) have been estimated under a similar set of experimental conditions. Analysis of the results suggests that intercalative ability of the coordinated ligands varies as dppz>phen>phen-dione in this series of complexes. While the Co(II) and Ru(II) complexes investigated in this study effect photocleavage of the supercoiled pBR 322 DNA, the corresponding Ni(II) complexes are found to be inactive under similar experimental conditions. Results of detailed investigations carried out inquiring into the mechanistic aspects of DNA photocleavage by [Co(phen)2(dppz)]3+ have also been reported

An exploration of fractal-based prognostic model and comparative analysis for second wave of COVID-19 diffusion

The coronavirus disease 2019 (COVID-19) pandemic has fatalized 216 countries across the world and has claimed the lives of millions of people globally. Researches are being carried out worldwide by scientists to understand the nature of this catastrophic virus and find a potential vaccine for it. The most possible efforts have been taken to present this paper as a form of contribution to the understanding of this lethal virus in the first and second wave. This paper presents a unique technique for the methodical comparison of disastrous virus dissemination in two waves amid five most infested countries and the death rate of the virus in order to attain a clear view on the behaviour of the spread of the disease. For this study, the data set of the number of deaths per day and the number of infected cases per day of the most affected countries, the USA, Brazil, Russia, India, and the UK, have been considered in the first and second waves. The correlation fractal dimension has been estimated for the prescribed data sets of COVID-19, and the rate of death has been compared based on the correlation fractal dimension estimate curve. The statistical tool, analysis of variance, has also been used to support the performance of the proposed method. Further, the prediction of the daily death rate has been demonstrated through the autoregressive moving average model. In addition, this study also emphasis a feasible reconstruction of the death rate based on the fractal interpolation function. Subsequently, the normal probability plot is portrayed for the original data and the predicted data, derived through the fractal interpolation function to estimate the accuracy of the prediction. Finally, this paper neatly summarized with the comparison and prediction of epidemic curve of the first and second waves of COVID-19 pandemic to visualize the transmission rate in the both times

Antimicrobial activity and corrosion inhibition property of Schiff bases derived from Imidazole

311-318Schiff base ligands such as methyl 4-[(2-butyl-4-chloro-5-formyl-1H-imidazol-1-yl)methyl]benzoate thiosemicarbazone (L1) and 2-butyl-4-chloro-5-formylimidazole 2,4-dinitrophenylhydrzone (L2) are designed and synthesized via the reaction between methyl 4-[(2-butyl-4-chloro-5-formyl-1H-imidazol-1-yl)methyl]benzoate & thiosemicarbazide for L1and 2-butyl-4-chloro-5-formylimidazole & 2,4-dinitrophenylhydrazine for L2.Schiff bases are characterized by FT-IR, UV-visible, mass spectrometry,1H and 13C-NMR spectral studies. These ligands are individually tested for their antimicrobial activities for both gram positive and gram negative to examine their inhibition potential by well diffusion method. The corrosion inhibition property of all the three ligands L1, L2 & L3 on mild steel in 0.5 N HCl solution has been investigated at different concentrations and different temperatures by weight loss method. The biological activity of L2 has shown better activity against gram negative bacteria such as E-coli, Klebsiella pneumonia, Acinetobacter baumannii, Pseudomonas aeruginosa and gram positive bacteria Staphylococcus aureus when compared to standard ligand L3. All the three ligands exhibit good corrosion inhibition property on mild steel in 0.5N HCl solution even at 0.1% concentration level and the rate of corrosion of mild steel is increased with increase of temperature of corrosion medium

Effect of Divalent Metal Dopant on the Structural and optical Properties of Tio 2 Quantum Dots

Abstract: In search of efficient materials for photo anode for DSSC, we made an attempt to prepare pure and transition metal (Zn 2+ , Cd 2+ and Ni 2+ ) doped Tio 2 simple microwave irradiated solvothermal method. The samples were characterized by structural and optical measurements. The particle size increased as the addition of dopant in the host TiO 2 lattices was increased in accordance with the crystallite size obtained by XRD analysis.UV-Vis spectral measurement suggests that addition of dopants in the host TiO 2 lattices helping to tune the optical band gap energy.The presence of small amount of dopants (5 mole % of Zn 2+ , Cd 2+ and Ni 2+ ) greatly affects the PL intensity of thehost TiO 2 nanocrystals. The doped nanocrystals(TiO 2 :Zn 2+ , TiO 2 :Cd 2+ and TiO 2 :Ni 2+ ) leads to strong enhancement in photoluminescence yield compared to pure TiO 2 and consequently to new useful materials for photonic applications

Oxidation of methionine by N-chloroacet-amide- Catalytic effect of formaldehyde

275-277Oxidation of -methionine(Met) by N-chloroacetamide (NCA) in buffered medium (pH ~ 7) in the presence and absence of formaldehyde is first order each in [NCAland [Met] and first order in [HCHO] when present. The observed rate constant shows a complex dependence on [H+]. The catalytic behaviour of HCHO could be explained by the fact that the rehybridization of sulphur atom from tetrahedral to trigonal bipyramidal structure is influenced by HCHO. The derived rate laws are consistent with the observed kinetics