Some Novel Dinuclear phenylboronates of biologically potent β‐enaminoesters: Synthesis,Spectroscopic characterization,antimicrobial activity and their antiandrogenic effect

Organoboron derivatives of biologically potent β‐enamino esters of the type [Where R = CH₃(1a), C₂H₅ (1b), C₃H₇(1c) and C (CH₃)₃ (1d)] have been prepared by the reactions of β‐enamino esters and Phenyl boronic acid [PhB (OH)₂] in 1:2 molar ratio in refluxing tetrahydrofuran (THF). All these derivatives have been characterized by physico‐chemical properties, elemental analyses and molecular weight measurements. The structures of these compounds have been proposed on the basis of IR, ¹H, ¹³C, ¹¹B NMR spectral data and GC‐mass spectrometry. Phenyl boronic acid, β‐enamino esters and their respective phenylboronates derivatives have been screened for the antibmicrobial activities against pathogenic bacteria (B. subtilis and E. coli) and fungi (A. niger and P. peniculosum) to access their growth inhibiting potential. In addition to this, antiandrogenic effect of Ligand, L^aH₂ and its boron derivative (1a) has also been tested in male albino rats.     

Kinetics and mechanism of the oxidation of some α‐hydroxy acids by 2,2′‐bipyridinium chlorochromate

The oxidation of glycolic, lactic, malic, and a few substituted mandelic acids by 2,2′‐bipyridinium chlorochromate (BPCC) in dimethylsulphoxide leads to the formation of corresponding oxoacids. The reaction is first order each in BPCC and the hydroxy acids. The reaction is catalyzed by the hydrogen ions. The hydrogen ion dependence has the form: k_obs = a + b [H⁺]. The oxidation of α‐deuteriomandelic acid exhibited a substantial primary kinetic isotope effect (k_H/k_d = 5.29 at 303 K). Oxidation of p‐methylmandelic acid was studied in 19 different organic solvents. The solvent effect has been analyzed by using Kamlet's and Swain's multiparametric equations. A mechanism involving a hydride ion transfer via a chromate ester is proposed. © 2002 Wiley Periodicals, Inc. Int J Chem Kinet 34: 248–254, 2002     

Unusual synthesis of azines and their oxidative degradation to carboxylic acid using iodobenzene diacetate

Reaction of 3-hydrazonobutan-2-one oxime with aromatic aldehydes resulted in the formation of 1,2-bis(arylidene)hydrazine commonly referred as azine as an unexpected product, instead of expected product 3-(aryl)methylenehydrazonobutan-2-one oxime, which were subsequently oxidized to corresponding aromatic acids with an ecofriendly oxidizing agent iodobenzene diacetate. Azines and carboxylic acids were characterized by IR and NMR (¹H, ¹³C, HMBC, and HMQC) studies.     

Red-emitting β-diketonate Eu(III) Complexes With Substituted 1,10-phenanthroline Derivatives: Optoelectronic and Spectroscopic Analysis

Journal of Fluorescence - A series of europium diketonate complexes with 1-phenyl-1,3-butanedione (PBD) and 1,10-phenanthroline derivatives were synthesized and explored spectroscopically....     

Optoelectronic and biological quantification of semi-conducting,crimson europium chelates with fluorinated β-keto acid and N-donor ancillary ligands

Research on Chemical Intermediates - Five luminescent ternary and one binary Europium(III) complexes were synthesised with β-keto acid as primary ligand and neocuproine(neo),...     

Immobilization and Kinetics of Catalase on Calcium Carbonate Nanoparticles Attached Epoxy Support

A novel hybrid epoxy/nano CaCO₃ composite matrix for catalase immobilization was prepared by polymerizing epoxy resin in the presence of CaCO₃ nanoparticles. The hybrid support was characterized using scanning electron microscopy and Fourier transform infrared spectroscopy. Catalase was successfully immobilized onto epoxy/nano CaCO₃ support with a conjugation yield of 0.67?±?0.01 mg/cm² and 92.63?±?0.80 % retention of activity. Optimum pH and optimum temperature of free and immobilized catalases were found to be 7.0 and 35 °C. The value of K _m for H₂O₂ was higher for immobilized enzyme (31.42 mM) than native enzyme (27.73 mM). A decrease in V _max value from 1,500 to 421.10 μmol (min mg protein)^?1 was observed after immobilization. Thermal and storage stabilities of catalase improved immensely after immobilization. Immobilized enzyme retained three times than the activity of free enzyme when kept at 75 °C for 1 h and the half-life of enzyme increased five times when stored in phosphate buffer (0.01 M, pH 7.0) at 5 °C. The enzyme could be reused 30 times without any significant loss of its initial activity. Desorption of catalase from the hybrid support was minimum at pH 7.0.     

On generalized measures of entropy and dependence

Various authors have studied extensions of Shannon’s entropy but their inferential properties and applications in applied sciences have not invited proper attention from researchers. In the present paper we explore the motivation and implication of using various classes of the generalized entropies and conditional entropies. We evaluate β-class and (α, β)-class entropies for multivariate normal density function. We also obtain the measures of dependence in terms of the classes of generalized entropies.      

One- and two-dimensional NMR studies of methyl acrylate/vinyl acetate/N-vinyl carbazole terpolymers

Terpolymers of methyl acrylate/vinyl acetate/N-vinyl carbazole (M/A/C) with different compositions were synthesized by solution polymerization using AIBN as an initiator. Composition of terpolymers was determined from quantitative ¹³C{¹H} NMR spectrum. Two-dimensional heteronuclear single quantum correlation (HSQC) and total correlated spectroscopy (TOCSY) were used to assign the methylene and methine carbon resonances by analyzing two and three bond order couplings. Various resonance signals were assigned to different compositional and configurational sequences with the help of one- and two-dimensional NMR spectra. Three and four bond order coupling between carbonyl carbon and other neighboring protons have been investigated with the help of 2D heteronuclear multiple bond correlation (HMBC) spectra. The complex and overlapped ¹H NMR spectrum of terpolymer was analyzed completely with the help of 2D HSQC and TOCSY spectra.     

Investigation of optimum pulse shape for 112 Gbps DP-DQPSK in DWDM transmission

This paper reports the simulative analyses to investigate the impact of different pulse shapes on DP-DQPSK modulation for high-spectral efficient DWDM transmission at 112 Gbps per channel. In the simulation model we have considered three different pulse shapes viz. NRZ, 50% duty cycle RZ (RZ50) and 67% duty cycle RZ (RZ67) in symbol-aligned and symbol-interleaved format. The analysis has been carried out for various linear and nonlinear system impairments where the pulse is subjected to degradation under the influence of amplified spontaneous emission (ASE) noise, group velocity dispersion (GVD), cross-phase modulation (XPM) and polarization mode dispersion (PMD) and thus, limiting the system performance. Results show that the RZ50 pulse shape for DP-DQPSK with symbol interleaving shows the maximum tolerance for the various system degradations in long haul DWDM transmission. Even the system based on the NRZ pulse shape can gain significant improvement from the symbol-interleaving.     

518—π-acid effect on electrode behaviour of ternary complexes in solution: Complex formation between copper(II)-1,10-phenanthroline complex and ligands containing oxygen and/or nitrogen donor atoms as secondary ligands. part II

The study of mixed-ligand complexes [Cu_x(phen)_yL_z] (where phen stands for 1,10-phenanthroline and L for aliphatic acids, aromatic acids, amino acids and phenols in the ratio of 1 : 1 : 1 and 1 : 2 : 1) has been made at three different temperatures, namely 30, 35 and 40°C. It is observed that all the complexes follow a partictiar reaction mechanism with temperature, and the half-wave potential shifts towards the more positive side with rise of temperature, indicating easier reduction. Besides the formal rate constant, the activation energy of diffusion, E_D, has been calculated for each system. The effect of activation energy and the energy of rearrangement of electronic configuration of the depolarizer has been discussed against availability of the redox orbital for the electroreduction process.