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Rama Prabha M.,Avinashilingam University For Women | Vasantha K.,Government of Tamilnadu
Journal of Applied Pharmaceutical Science | Year: 2011

Oxidative stress has been implicated with the pathology of many diseases such as inflammatory conditions, cancer, diabetes and aging. In view of that an attempt was made to evaluate free radical scavenging activity, cytotoxic activity and polyphenolic content of methanolic extract of Calotropis procera flowers.Free radical scavenging activity was estimated using in vitro models like 1,1,-diphenyl-2- picryl hydrazyl (DPPH), hydroxyl radical, hydrogen peroxide radical, reducing power and ferric thiocyanate method. Cytotoxicity was analysed following MTT assay using Hep2 and Vero cell lines and polyphenols were estimated using standard methods. Two way ANOVA was used for statistical analyses. The methanol extract of C. procera at 500 μg/ml showed better scavenging activity in ferric thiocyanade method (83.63 %) with the lowest IC50 of 100 μg/ml followed by hydrogen peroxide, hydroxyl radical scavenging and least activity was found to be present in DPPH assay (50.82 %). The extract had 100 % cytotoxicity on Hep2 cell lines. Flavonoids were found in greater amount than phenols and found to be had higher correlation with antioxidant activities. It was suggested that the flowers of C. procera possess in vitro antioxidant, cytotoxic activities and thus having much therapeutic value because of their polyphenolic content. Source

Rajalakshmi R.,Avinashilingam University For Women
E-Journal of Chemistry | Year: 2012

Corrosion control methods, especially the use of inhibitors, have gained monumental importance in the present scenario of expunging corrosion and the quest for eco-friendly reasons continues. To arrive at an inexpensive non-toxic, eco-friendly inhibitor formulations the present study on the use of Staminate Flower extract of Cocos Nucifera has been carried out by the classical weight loss measurements and electrochemical polarization measurements. The acid extract could bring out a maximum of 97.3% inhibition of mild steel corrosion in 1M HCl. Thermodynamic parameters of the corrosion process were calculated from temperature study. The adsorptive behaviour of Staminate Flower extract in acid solution may be approximated both by Langmuir and Temkin type isotherms. The results obtained by Tafel, Linear polarization resistance, and impedance spectroscopy have been correlated with the classical weight loss measurements. Values of Tafel constant ba and bc confirmed that the Staminate Flower extract acts like mixed type inhibitor. Examination of the surface of the metal in the presence of the inhibitor confirmed the deposition of inhibitor on the metal surface. The Staminate Flower extract in HCl medium efficiently inhibits the corrosion and proved to be zero cost inhibitor, eco-friendly, non-toxic, and highly economical. Source

Geethanjali S.,Avinashilingam University For Women | Subash A.,Avinashilingam University For Women
Enzyme Research | Year: 2013

The purified fish visceral protease enzyme was immobilized by using various concentrations of sodium alginate and calcium chloride to optimize the best concentration for the formation of the beads. Then it was characterized by assaying the optimal pH, temperature, storage stability and reusability. The results on immobilization with sodium alginate and calcium chloride showed that a combination of 2% sodium alginate and 0.3 M calcium chloride weas found to be the optimum concentration for the formation of spherical and stable beads, this gave a maximal entrapped activity of 48.31%, and there was no change in the optimum pH 8.0 and temperature 40°C of protease before and after entrapment. The results on stability and reusability indicated that it was stable at 4°C retaining 100% residual activity after 5 days of storage and 67% loss of activity after ten days of storage and it retained 100% residual activity on the first reuse, 75% residual activity on the second reuse, 25% residual activity on the third use and complete loss in the activity on the fourth reuse. © 2013 S. Geethanjali and Anitha Subash. Source

Leelavathi S.,Avinashilingam University For Women | Rajalakshmi R.,Avinashilingam University For Women
Journal of Materials and Environmental Science | Year: 2013

There is a growing trend to utilize plant extracts and pharmaceutical compounds as corrosion inhibitors. the inhibitive performance of extract of dodonaea viscosa leaves (DLVE) on the corrosion of mild steel in 1M HCL and 0.5m H2SO4 were studied using mass loss and electro chemical measurements. characterization of DLVE wascarried out using gc-ms and ft-ir spectroscopy. results confirmed that the extract of dodonaea viscosa leaves (DVLE) acts as an effective corrosion inhibitor in theacid environment. the inhibition efficiency increased with increase in concentration of the inhibitor and decreased with temperature. thermodynamic parameters revealed that the inhibition is through spontaneous adsorption of inhibitors onto the metal surface. potentiodynamic polarization and electrochemical impedance studies confirmed that the system follows mixed mode of inhibition. adsorbed film of inhibitor at metal /solution interface has been confirmed using reflectance fourier transform infrared spectroscopy. surface analysis by uv, ftir and sem confirmed the formation of protective layer on the mild steel (MS) surface. efforts were also taken to propose a suitable mechanism for the inhibition. Source

Ali Fathima Sabirneeza A.,Avinashilingam University For Women | Subhashini S.,Avinashilingam University For Women
Journal of Applied Polymer Science | Year: 2013

A novel water-soluble conducting polymer composite, poly(vinyl alcohol-histidine) was synthesized from aqueous solution by free radical condensation using persulfate. The composite was characterized using UV-Visible, Fourier transform infrared, scanning electron microscopy, thermogravimetric analysis (TG/DTG), and differential scanning calorimetry techniques while its AC conductance was measured by LCZ analyzer. The inhibitive action of the composite on the corrosion behavior of mild steel in 1M HCl was studied by conventional weight loss method, potentiodynamic polarization studies (Tafel), linear polarization studies, and electrochemical impedance spectroscopy. The effects of inhibitor concentrations, exposure time, and temperature have been investigated. The corrosion rate, inhibition efficiency (IE), and other parameters have been evaluated for different inhibitor concentrations. The composite provided more than 95% IE at an optimum concentration of 0.6% by weight. The results showed the composite as an effective mixed type inhibitor. The adsorption of this inhibitor obeyed Temkin adsorption isotherm. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 Copyright © 2012 Wiley Periodicals, Inc. Source

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