http://nopr.niscpr.res.in/handle/123456789/60143 2026-10-10T06:22:06Z 2026-10-10T06:22:06Z Baameur, Lotfi Aggoun, Djouhra Messasma, Zakia Bouet, Gilles Guillanton, Georges Le Daran, Jean Claude Ourari, Ali http://nopr.niscpr.res.in/handle/123456789/60156 2022-07-26T10:56:08Z 2022-07-01T00:00:00Z

Title: Synthesis, crystal structure, quantum chemical calculations, electrochemistry and electro-catalytical properties as cytochrome P-450 model of tetradentate Mn(III)-Schiff base complex. Authors: Baameur, Lotfi; Aggoun, Djouhra; Messasma, Zakia; Bouet, Gilles; Guillanton, Georges Le; Daran, Jean Claude; Ourari, Ali Abstract: The tetradentate Schiff base ligand has been obtained from condensation with mixing ethylenediamine and 2 mmoles of 5-methoxy-2-hydroxybenzaldehyde in absolute ethanol H2L. To the ethanolic solution was added manganese(II)acetatetetrahydrated and lithium chloride (LiCl) to obtain the tetradentate manganese(III) Schiff base complex [Mn(III)(Cl)L]. Theprepared compounds have been characterized by several spectroscopic techniques such as elemental analyses, FT-IR, UV–vis., 1H NMR and HRMS. In this paper, the X-ray diffraction (XRD) and the computational studies (DFT) of the ligand(H2L) with its manganese(III)-Schiff base complex [Mn(III)(Cl)L] are described and confirmed the given molecularstructures. The crystallographic studies have been utilized toelucidate the kinetics, selectivity and stereochemistry of thetransferred oxygen atomsto the substrate molecules when the considered complex is used as catalyst accordingthecytochrome P450 model. In addition, the density functional theory (DFT) calculation with B3LYP/6-31G(d,p) level isperformed to obtain the optimized geometries and electronic properties of the prepared compounds. The global reactivityparameters have also been calculated using the energies of frontier molecular orbitals suggesting that the ligand H2L is morestable than its Mn(III) complex. This may be due to the presence of hydrogen bonds in the ligand and the weaker energies ofcoordination bonds in the complex. The electrochemical behaviour of Mn(III)(Cl)L has been studied by cyclic voltammetryin acetonitrile solutions at room temperature. The resulting cyclic voltammogram shows Mn(III)/Mn(II) couple at E1/2= -0.62V with glassy carbon (GC) electrode. This redox couple is involved in the electrocatalytic cycle where themanganese(III) cation is successively mono-electronated until the formation of superoxo intermediates and then the oxospecies, respectively. These oxo forms, generated in situ, transfer their oxygen atoms to the substrate giving the oxidizedproduct. So, the chemical and electrochemical reactions, implicated in this electrocatalytical process, obey to the biomimeticoxidation reactions as those of monooxygenase enzymes (Cytochrome P450). Page(s): 339-353

2022-07-01T00:00:00Z Birdeanu, Mihaela Epuran, Camelia Fratilescu, Ion Fagadar-Cosma, Eugenia http://nopr.niscpr.res.in/handle/123456789/60155 2022-07-26T10:50:54Z 2022-07-01T00:00:00Z

Title: Structured composites between MnTa2O6 and porphyrins: Influence of the number of carboxylic groups grafted on porphyrins on the capacity to inhibit corrosion of steel Authors: Birdeanu, Mihaela; Epuran, Camelia; Fratilescu, Ion; Fagadar-Cosma, Eugenia Abstract: New sandwich type materials based on MnTa2O6 and porphyrins mono- and tetra-substituted with –COOH groups, namely: (tetrakis-(4-carboxy-phenyl)-porphyrin and 5-(4-carboxy-phenyl)-10,15,20-tris-phenyl-porphyrin) have been synthesized and studied to assess the importance of its corrosion inhibition ability on with regard to its of steel the number of –COOH anchors. Morphological investigations on thin films have been carried out by atomic force microscopy. The inhibition of corrosion has been evaluated by open circuit potential measurements and potentiodynamic polarization technique with Tafel representation, after drop-casting deposition onto carbon steel in 0.1M HCl media. The inhibition efficiency of the novel sandwich-type materials based on pseudo-binary oxide MnTa2O6 and tetrakis-(4-carboxy-phenyl)-porphyrin or 5-(4-carboxy-phenyl)-10,15,20-tris-phenyl-porphyrin is in the range 76-86% for tetra substituted porphyrin and 84-95% for the mono-COOH substituted porphyrin. Page(s): 354-366

2022-07-01T00:00:00Z Moohambihai, P Nagashri, K http://nopr.niscpr.res.in/handle/123456789/60154 2022-07-26T10:45:48Z 2022-07-01T00:00:00Z

Title: In vitro evaluations of antimicrobial, cytotoxicity, DNA binding, cholinesterase studies of copper complexes with phenyl-selanyl ligands Authors: Moohambihai, P; Nagashri, K Abstract: Copper (II) complexes (3a-i) with (16E)-N-(2-phenylquinolin-4(1H)-ylidine)-2-(phenylselanyl)pyridine-3-amine ligands have been synthesized. They have been characterised by various spectroscopic studies. In-vitro cytotoxic potential has been determined, with significant cytotoxicity against MCF-7 cell line. The copper complexes interact with the calf thymus, (CT-DNA), according to absorption spectra and viscosity measurements. In addition, the copper complexes have been tested for their antimicrobial activity against three Gram-negative bacteria; Proteus vulgaris, Klebsiella pneumoniae, and Shigella flexneri, three Gram-positive bacteria; Staphylococcus aureus, Staphylococcus epidermidis, and Bacillus subtilis, and three fungi; Aspergillus fumigatus, Aspergillus clavatus and Candida albicans. The ligand's acetylcholinesterase (AChE) inhibiting function has been investigated in order to determine the ligand's efficacy in the treatment of neurodegenerative disorders. When compared to standard Rivastigmine and Galantamine, the synthesised ligand 2c show selective inhibition (AChE and BuChE) with IC50 values of 0.19 and 3.03 μM. The egg albumin method is used to test the anti-inflammatory efficiency and α-glucosidase inhibitory activities of copper chelates are tested. Page(s): 367-379

2022-07-01T00:00:00Z Shah, Jinesh B Valaki, Janak B http://nopr.niscpr.res.in/handle/123456789/60153 2022-07-26T10:42:08Z 2022-07-01T00:00:00Z

Title: Characterization of Bio-oil, Bio-char, and Pyro-gas derived from cotton stalk slow pyrolysis - as sustainable energy sources Authors: Shah, Jinesh B; Valaki, Janak B Abstract: The untapped energy present in this cotton stalk residue is one of the major environmental threats due to its field burning. In this research paper, slow pyrolysis process has been performed on cotton stalk having particle size 0.85 mm at 300°C, 400°C, and 500°C, at 10°C/min heating rate and 1-hour residence time. The process produced bio-oil, bio-char and pyro-gas. Physiochemical properties, GC-MS analysis, stability analysis and miscibility analysis of bio-oil have been carried out to ensure its feasibility as energy source. To ensure suitability of bio-char as soil nutrient and energy sources, its elemental analysis, metal element analysis and microscopic examination have been performed. Pyro-gas is characterized to find its suitability as energy source for heating purpose during pyrolysis process by recirculating. The maximum yield for bio-oil and Pyro-gas is 36.60 wt.% and 25.25 wt.%, respectively at 500°C, while maximum yield for char is 58.54 wt. % at 300°C. Result of physiochemical properties of bio-oil reveals remarkable variation as compare to diesel whereas GC-MS analysis found bio-oil as complex mixture. 0.02349 cst/hr. aging rate of bio-oil shows good stability at room temperature. Physiochemical properties of bio-oil vary with pure diesel causes phase separation of bio-oil and diesel during blending. Bio-oil - diesel Stabilized emulsion has been achieved by addition of 6 wt. % of n-butanol as co-solvent. Characterization and microscopic examination of bio-char favours usage of char as soil nutrient and energy substitute. The Pyro-gas analysis confirms its suitability as energy substitute during entire process, as it contains a substantial amount of carbon dioxide and methane. Page(s): 380-389

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