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O. V. Oommen ¹, P. Sreejith ¹, R. S. Beyo ¹, L. Divya ¹, A. S. Vijayasree ¹, M. Manju ¹

Affiliations
1 Department of Zoology, University of Kerala, Kariavattom, Thiruvananthapuram-695 581, Kerala, IN

Abstract

Our studies describe the effect of T₃ on the regulation of mitochondrial metabolism, lipid peroxidation and antioxidant enzyme homeostasis in a fresh water teleost, Anabas testudineus. These experiments suggest the possibility that certain of the clinical and biochemical manifestations of T₃ can be attributed to a direct effect of T₃ on mitochondria. Thyroid hormone enhances mitochondrial ATP production rate in the highly oxidative tissue such as liver. These in vitro and in vivo studies substantiate and confirm the earlier reported T₃-induced oxidative metabolism in lower vertebrates. These induced oxidative metabolisms create oxidative stress in tissues. This confirms that T₃ has an immediate response in in vivo and in vitro system on energy adjustment in the fish, A. testudineus. Tri-iodothyronine is also capable of combating the oxidative stress by activating the antioxidant system to remove the ROS. Tri-iodothyronine appears to have a dual role, as a stimulator of oxidative process and as a regulator of antioxidant enzyme activity. This establishes another example for the multi-functional role of T₃ in lower vertebrates also. However, the precise mechanism of action remains to be understood. The protein expression study revealed that T₃ administration in fish creates hypermetaolic state. This hypermetabolic state creates oxidative stress in fish. To maintain the homeostasis of the fish, physiology the main antioxidant CuZn SOD is directly altered. Due to augmented SOD utilization, expression of CuZn SOD is diminished in fish liver and brain. These findings conclude that thyroid hormone effectively maintains physiological status of fresh water fish. It is obvious that thyroid hormones have an over all effect on metabolism in responsive tissue and that their effect is a direct one. Theses studies establish multi-functional role of T₃ in lower vertebrates.

Keywords

Anabas testudineus, Free Radicals, Mitochondrial Respiration, Superoxide Dismutase, Thyroid Hormone, Tri-Iodothyronine.

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M. Manju ¹, B. S. Shankara ¹, T. N. Padmini ¹, M. K. Veeraiah ²

Affiliations
1 Sri Krishna Institute of Technology, Bangalore, Karnataka, IN
2 Sri Siddhartha Institute of Technology, Tumkur, Karnataka, IN

Abstract

The phase behavior of Poly Ethylene Glycol (PEG) with Methyl Methacrylate and 2-Ethoxy Ethylmethacrylate (MMA/EOEMA) copolymer was investigated using viscometric, FT-IR, DSC thermal analysis and surface morphology studies. The studies were carried out at various blend compositions with chloroform as common solvent. From the viscosity data based on sign convention involved in the criterion, the values of μ and α for PEG with copolymer blends system was computed and found to be partially positive indicating it is partially phase separation for all blends composition. The phase separations of the blends were also supported by DSC thermal analysis method. The properties of specific, intermolecular and hydrogen bonding interactions of PEG with copolymer blends are studied by spectroscopic techniques such as FT-IR and the obtained results were further confirmed by surface morphology studies. The phase separation behaviour of the copolymers with PEG blend is clearly visible from the Scanning Electron Microscopy patterns. 

Keywords

MMA/EOEMA Copolymer, PEG, Blends Miscibility, Compatibility, Phase Behavior.

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T. N. Padmini ¹, M. Manju ¹, B. C. Sateesh ²

Affiliations
1 Department of Chemistry, Sri Krishna Institute of Technology, Bangalore, Karnataka, IN
2 Department of Chemistry, Shri Pillappa College of Engineering, Bangalore, Karnataka, IN

Abstract

The kinetic studies on oxidation of Ethyl-2-(methylthio) pyrimidine 5-carboxylate by potassium dichromate in aqueous perchloric acid medium was studied at 26 ± 0.1^oC. The reaction shows first order dependence in both Ethyl-2-(methylthio) pyrimidine 5-carboxylate and potassium dichromate which supports the derived rate law and fractional order dependence in perchloric acid. The effect of temperature on the rate of reaction has also been studied and the activation parameters have been evaluated. The reaction constants involved in the mechanism were computed. The stoichiometry of the reaction was found to be 3:2 and the oxidation products were identified as 2-methyl sulfanyl-pyrimidine-5-carboxylic acid and acetaldehyde.

Keywords

Oxidation, Kinetics, Mechanism, Ethyl-2-(Methylthio) Pyrimidine 5-Carboxylate, Potassium Dichromate.

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