Jignasu P. Mehta

Synthesis and biological screening of 1,2,4-triazole derivatives

A series of 2-((arylamino)methyl)-5-(3-methoxyphenyl)-1-phenyl-1H-1,2,4-triazole-3-thione derivatives have been synthesized and characterized by FT-IR, NMR, mass spectral and elemental analysis. Compounds (MM4a-m) have been evaluated for their in vitro antibacterial activity against selected gram-positive and gram-negative bacteria and in vitro antifungal activity against fungal pathogens by using broth dilution method. The compounds have been screened for antitubercular activity against Mycobacterium tuberculosis H37Rv strain by using L J Slope method. Of all the compounds, MM4d, MM4e, MM4j and MM4k show good antibacterial activity and MM4a, MM4d, MM4e and MM4j compounds have been found to possess good antitubercular activity.

Pr（III） and Nd（III） Absorption Spectroscopic Probe to Investigate Interaction with Lysozyme （HEW）

Abstract Pr(III) and Nd(III) can be utilized as absorption spectroscopic probes to investigate the interaction of biomolecules like Lysozyme (HEW) with Ca (II) in-vitro; the most abundant metal ion in the human body system. The spectroscopic techniques involving comparative absorption, absorption difference, and quantitative intensity analysis using 4f-4f transitions are utilized for changes in the inner sphere coordination pattern of Pr(III) and Nd(III) in solution as well as in solid state. The present study deals with an important biomolecule in human metabolism, that is, Lysozyme (HEW). The absorption spectral parameters such as the oscillator strength (P), the Judd-Ofelt (Tλ) intensity parameters, and the Slater-Condon inter electronic parameters are calculated using chi square methods. The obtained results are used to determine the probable geometry of the complex in the solution, the nature of the bond between Pr(III)/Nd(III) with lysozyme, and the inner sphere coordination environment of f-f transitions. The results obtained from various experimental conditions are utilized to investigate the coordination changes in the Pr(III)/Nd(III) complexes caused by different coordinating sites of lysozyme, normalized bite, denticity, the solvent nature, the coordination number, the nature of bond and other parameters to mimic the interaction of the Ca(II) ion with such biomolecule.

Eu（III） Indirect Probe to Investigate Interaction of DOPA （3, 4, Di-Hydroxyphenylalanine） and Dopamine （3, 4-Dihydroxy Phenyl Ethyl Amine） Using Electrochemical Methods

Abstract Eu (III) can be utilized as an indirect electrochemical probe to investigate the interaction of bio-molecules such as DOPA and Dopamine with Ca (II) in vitro. The interaction of DOPA and Dopamine with Eu(III)-Eu(II) redox pair was investigated by electrochemical techniques. Both the neurotransmitters are structurally related and undergo interaction with Eu (III). Eu (III) coordinates with DOPA and Dopamine through five-member chelate rings via carboxylic oxygen and amino nitrogen. The electrode kinetic parameters viz, transfer coefficient (αna), diffusion coefficient (D), forward heterogeneous rate constant (kofh) were evaluated for Eu(III)-DOPA/Eu(III)-Dopamine. The results obtained were used to investigate the nature of interaction of Eu (III) with multi-donor biomolecules. The possible mechanism was also proposed.

An efficient synthesis, characterization, and antimicrobial screening of tetrahydropyrimidine derivatives

Several new substituted 1,2,3,4-tetrahydropyrimidine derivatives 2a–h have been synthesized by the modified Biginelli and Hantzsch reactions and compounds were characterized by spectral techniques. All compounds were evaluated for their in vitro antimicrobial activity against different strains of Gram-negative (E. coli and P. aeruginosa) and Gram-positive (S. aureus and S. pyogenus) bacteria and selected fungi C. albicans, A. niger, and A. clavatus using serial Broth dilution method (Mueller–Hinton broth dilution method). Compound 2e was found active against both Gram-negative and -positive bacterial strains used for present study, while compound 2b was good active against Gram-negative and S. pyogenus bacterial strains. Compounds 2a–h were not that much significant against (C. albicans, A. niger, and A. clavatus) selected fungal strains.

An absorption spectral study of Nd (III) with glutathione (reduced), GSH in aqueous and aquated organic solvent in presence and absence of Zn (II)

Abstract The coordination chemistry of glutathione (reduced) GSH is of great importance as it acts as an excellent model system for the binding of metal ions. The GSH complexation with metal ions is involved in the toxicology of different metal ions. Its coordination behaviour for soft metal ions and hard metal ions is found different because of the structure of GSH and its different potential binding sites. We have studied two chemically dissimilar metal ions viz. Nd (III) being hard metal ion, which will prefer hard donor sites like carboxylic groups, and Zn (II) the soft metal ion more suited to peptide—NH and sulfhydryl groups. The absorption difference and comparative absorption spectroscopy involving 4 f –4 f transitions of the heterobimetallic complexation of GSH with Nd (III) and Zn (II) has been explored in aqueous and aquated organic solvents. The changes in the oscillator strengths of different 4 f –4 f bands and Judd–Ofelt intensity ( T λ ) parameters determined experimentally is being used to investigate the complexation of GSH. The in vivo intracellular complexation of GSH with Ca (II) in presence of Zn (II) ion has been mimicked through Nd (III)–GSH–Zn (II) absorption spectral studies in vitro.

Enhanced catalytic oxidation of monoterpenes by zeolite-Y entrapped iron complex: spectral studies and mechanistic vision

Abstract[Fe(L)2(H2O)2]–Y complex (where, L = (Z)-2-((4-hydroxybenzylidene)-amino)benzoic acid) has been synthesized by Flexible Ligand (FL) method and characterized by chemical analysis (CHN, ICP-OES, TGA, AAS), diffraction method (XRD), absorption spectroscopy (FTIR, UV–Vis), BET and SEM techniques. To investigate the catalytic performance (activity, stability, and reusability), [Fe(L)2(H2O)2]–Y was employed as heterogeneous catalyst in the liquid phase oxidation of α-pinene and limonene with H2O2 oxidant. [Fe(L)2(H2O)2]–Y catalyzed the oxidation of α-pinene via free radical formation as confirmed by in-situ IR and DR UV–Vis spectroscopy. [Fe(L)2(H2O)2]–Y showed conversion of α-pinene (67%) and limonene (79%) with better TONs, which is far better performance than neat iron complex.

Determination of phenolic acids and a flavonoid in Eleusine coracana (L.) by semi-preparative HPLC photo diode array detector

Semi preparative HPLC procedure is proposed for the determination of six phenolic acids and one flavonoid in Eleusine coracana (L.) with gradient elution and photodiode array detection. The influence of composition of the mobile phase concentration of the mix modifier and temperature on the separation of gallic acid, p-hydroxybenzoic, vanillic, caffeic, ferulic, and cinnamic acids and quercetin for 90 min is studied. The procedure was applied for the separation of phenolic compounds in methanolic extracts of Eleusine coracana (L.). The lower limits of quantification of phenolic compounds and the flavonoid are 0.050–0.150 μg/mL.

Electroanalytical tools to investigate the divalent state of Eu(III) and Nd(III) ions in non-aqueous medium

Abstract The divalent state of Ln(III) ions has attracted much interest because of their ability to serve isomorphously in many biological system of divalent Ca(II) ion. Therefore, present paper deals with the study of divalent state of Eu(III) and Nd(III) ions in nonaqueous medium. In present study, cyclic voltammetry and chronopotentiometry were utilized to establish the divalent state of Eu(III) and Nd(III) ions. The cyclic voltammetric technique showed two-step reduction process at cathode for both Ln(III) ions under specified experimental conditions and chronopotentiometric method also showed two different transition times (τ). Looking to the shape of cyclic voltammogram we calculated heterogeneous forward rate constant ( K 0 fh , cm/s) and diffusion coefficient ( D , cm 2 /s) for both ions, which suggested that sweep rate had great effect on the shape of cyclic voltammogram of Eu(III) and Nd(III) ions. The result of chronopotentiometry also suggested that stable divalent states of Eu(III) and Nd(III) ions existed with chronopotentiogram with two distinct transition times. The diffusion coefficients ( D , cm 2 /s) were calculated from Sand equation. The diffusion coefficients of both techniques were compared and the results suggested that the system at electrode surface was changing from being reversible to irreversible.

Evaluation of Phenolic Content and Antioxidant Capacity of Eleusine coracana (L.)

The aim of this study is to evaluate the content of phenolics: total seven phenolic acids and one flavonoid were separated from the species of Eleusine coracana (L.). The separated phenolics were characterized by various spectral techniques. The antioxidant capacity of all phenolics was determined by rancimat study of sunflower oil using control and standard drugs like Glipizide and Metformin. The stability period of sunflower oil was found to increase from 0.89 hr to 1.04 hr in presence of eight extracted ingredients of Eleusine coracana (L.), which was compared with result of neat sunflower oil.