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A new tetradentate binucleating ligand [H2L] has been synthesized by condensation between 3, 3′-diaminobenzidine and o-hydroxyacetophenone in the molar ratio 1:4. The reaction of the ligand with metal chelation leads to bimolecular complexes of the general formula [M2(L)]. The ligand and metal complexes have been characterized by elemental analysis, UV, IR,…1H NMR, 13C NMR, conductivity measurements and magnetic studies. In conductivity experiments, all metal chelates showed to be non-electrolytic in nature. The bonding sites are the nitrogen atoms of the azomethine and the oxygen atoms of the phenolic groups. The anti-microbial activities were screened against one Gram-positive bacterium (Streptococcus pyogenes) and one Gram-negative bacterium (Klebsella pneumoniae). The anti-fungal activity was screened against Asperigillus flavus. All complexes showed significant anti-bacterial and anti-fungal activities. The DNA binding studies were performed by electronic spectroscopy, cyclic voltammetry studies and viscosity measurements. The cleavage studies of these complexes are investigated by gel electrophoresis method in the presence of peroxide. All complexes cleaved efficiently and the complex interacts with DNA through an intercalating way.

Polymer electrolyte membranes comprising of poly (ethyl methacrylate)/ poly (vinyl chloride), propylene carbonate (PC) as plasticizer and LiClO4 as salt were prepared by solvent casting technique. XRD, FTIR and SEM studies have been made to investigate the structural, complexation and variation in film morphology of the polymer electrolyte. The maximum ionic conductivity value 3.454x10-3 S/cm has been observed for PVC (5)-PEMA (20)-PC (67) - LiClO4 (8 wt %) system at 303K using ac impedance spectroscopic technique. Also, the TG/DTA studies showed the thermal stability of the film.

Age related impairments in behavioral functions following lead (Pb) exposure have been linked to changes in neurotransmitter levels in brain regions. In the present study, we have evaluated the protective effect of a mixture of essential elements containing calcium, zinc and iron against Pb-induced long-term effects on aminergic system and behavior of rats. Rats were lactationally exposed to Pb (0.2%) or Pb acetate together with nutrient metal mixture (0.02% Ca, Zn and Fe) in drinking water of the mother from postnatal day (PND) 1 to PND 21. Increases in synaptosomal dopamine, epinephrine, norepinephrine and serotonin levels and decrease in mitochondrial monoamine oxidase (MAO) in cortex, cerebellum, and hippocampus regions were observed following Pb exposure in different age groups (PND 45, 4, 12 and 18 months) of rats. The alterations were greater in hippocampus than cortex and cerebellum. Total locomotor activity, exploratory and open field behaviors were also altered following Pb exposure. However, the alterations were maximum in PND 45 coinciding with greater blood Pb levels observed in PND 45. These data suggest that, Pb exposure induced age dependent alterations in motor behavior and synaptosomal aminergic system were significantly reversed with the supplementation of nutrient metal mixture suggesting therapeutic nature of essential metal supplements against Pb-induced toxicity., (Copyright © 2013 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.)

Fish inhabiting polluted estuaries are highly exposed to severe stress characterized by an oxidant-antioxidant imbalance. The aim of the study was to explore the use of stress parameters such as adenosine triphosphate/adenosine diphosphate (ATP/ADP) ratio, mitochondrial membrane potential (∆ψm) and total protein expression patterns as biomarkers against oxidant exposures in hepatocytes of Mugil cephalus living in either a contaminated (Test; Ennore) or uncontaminated (Control; Kovalam) estuary. Earlier, the pollutant stress impact was determined through light and electron microscopy studies. The ATP/ADP ratio was measured using high performance liquid chromatography; ∆ψm by fluorescent probe 5, 5', 6, 6'-tetrachloro-1, 1', 3, 3'-tetraethyl benzimidazolcarbocyanine iodide (JC-1) dye and total protein expression patterns by protein profiling. The preponderance of stress impact was confirmed through microscopy studies that featured cytological alterations, disturbances in the surface morphology and in the cell organelles at the ultrastructural levels. Hepatocytes of test fish demonstrated a decrease in ATP and an increase in ADP and thereby alteration in ATP/ADP ratio (p<0.05; 20.75%). A significant disturbance (p<0.05; 26.57%) in ∆ψm with a ratio of J-aggregates/JC-1 monomer of 1 was observed for test fish hepatocytes compared to control group with a J-aggregates/JC-1 monomer ratio of 1.5. Quantitative assessment of protein expression levels also revealed enhanced induction of both low and high molecular weight proteins in test fish hepatocytes. The findings highlight the use of these parameters as the highly sensitive biomarkers in response to contaminant exposure compared to the routinely used antioxidant and oxidant stress parameters in biomonitoring programs. Among the measured parameters, the determination of ∆ψm may be suggested as a novel candidate as a biomarker because of its greater specificity and rapid quantitative risk assessment of pollutant exposures., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Exposure to heavy metals and organic pollutants in natural water bodies can have detrimental effects on fish health. A combination of biochemical and energy studies were used to observe the changes in fish liver mitochondria in response to environmental pollutant induced nitrative stress in natural field conditions. The fish samples Mugil cephalus were collected from polluted (Ennore) and unpolluted (Kovalam) estuaries for a period of two years. The results revealed elevated nitrite (NO2-) and nitrate (NO3-) levels, increased nitric oxide (NO) synthesis and 3-nitrotyrosine expression, decreased respiratory chain enzyme activities and ATP/ADP ratio, reduced mitochondrial superoxide dismutase (MnSOD), glutathione peroxidase (Gpx) levels, diminished thiol status that leads to alterations in the mitochondrial function and elevated mitochondrial heat shock protein 70 (mtHSP70) expression (30%) to a significant extent in fish from the polluted estuary than in the unpolluted estuary. The overexpression of HSP70 under stress may aid mitochondrial survival by protecting against nitrative stress induced damage. The results also reveal the percentage increase in fish liver mitochondrial HSP70 in response to cumulative effect of environmental pollutants.