Volume-7 ~ Issue-9 ~ September-2014

Abstract: Citrus samples of three different fruits, sweet orange (Citrus sinensis) lime (Citrus aurantifolia) and lemon (Citrus lemon) were picked fresh from the trees at intervals of seven days, from September to November at different locations in Kurgwi, washed and kept in the refrigerator at 4oC pending analysis. Two stages of fruit development, Ripe and Unripe, were considered during sampling. The bark of these fruits were peeled off with sterile knife and sliced into half, then manually compressed into a 250cm3 beaker and filtered off with glass wool in to a 100cm3 beaker to remove the pulps which could block pipette jets. The Standard Methods of the Association of Official Analytical Chemists, AOAC methods, 939.13 and 966.18 were used for the determination of ascorbic acid in the fruit juice. Results of these determinations showed that sweet orange (Citrus sinensis) lemon (Citrus lemon) and lime (Citrus aurantifolia) have concentration range of 50.23mg/100mL – 56. 26mg/100mL, 51.33 mg/100mL – 53.47 mg/100mL and 34.12mg/100mL – 35.62mg/100mL, respectively. The unripe species of all the fruits tend to have higher ascorbic acid content as shown in the results obtained, with sweet orange and lemon having almost twice the level of ascorbic acid than lime. Patients with diabetes, stroke, heart diseases and cancer etc could take more of sweet orange and lemon, which have higher levels of ascorbic acid than lime as revealed by this research.

Keywords: Ascorbic acid, Lemon, Lime, Sweet Orange.

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Abstract: Inthiswork,differentmorphologiesofzincoxide(ZnO)nanostructureshavebeenfabricatedbya simpleandrapid dip coating method.Inthis method ZnO nanostructuresare deposited from sol-gel of zinc acetateusing dip coating onto Porous Anodic Alumina Membrane (PAAM).Afterthermalannealinginoxygenat600°Cfor30 min,the ZnO nanoparticles are uniformly agglomerated into, almost, 1D nanorods array. When the starting precursor is zinc nitrate and the annealing was carried out for 10 h at the same conditions, the ZnO nanoparticles are uniformly agglomerated into, almost, nanoseeds (nanocolloidal particles).

Keywords: PAA membrane; ZnO; nanostructures; dip coating; SEM; EDX.

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Abstract: Electrochemical method is a simple one to prepare poly o-methoxy phenol-pyrrole P(o-MP-co-pyrrole). Effects of different reaction parameters such as temperature, monomer and acid concentrations on the growth of the copolymer are studied by using cyclic voltammetry. The kinetic studies indicate that the orders of the reaction are 2.3and 1.1 for monomer and acid concentrations, respectively. The apparent activation energy is calculated to be 27 kJ/mol. In addition, the fabricated copolymer is characterized and investigated by 1H-NMR, TGA, IR-UV spectroscopy, XRD, SEM and elemental analysis. Moreover, the mechanism of the reaction is proposed and discussed by using Fineman-Ross method.

Keyword: Copolymer, pyrrole, orho cresol, cyclic voltammetry

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Abstract: The Coumarine heterocyclic ring is common feature of various bioactive compounds such as calanolides, lipid-lowering agents. The Chemists all over the globe are motivated not only for the environmentally benign synthesis of new products but also to develop green synthesis for existing chemicals. Coumarins, the most important classes of fluorescent molecules constitute important structural features present in a number of bioactive natural products. Recent studies have been revealed that coumarin and the derivatives exhibit several other medicinal applications such as anti-coagulants, antifungal, insecticidal, hypnoticsphytoalexins, HIV protease & inhibitors. Coumarins act as in intermediate for the synthesis of various biologically active molecule such as coumarones, and fluorocoumarins . Thus the synthesis of coumarins is of continuing interest.Potassium dihydrogen phosphate a commercially available environmentally benign catalyst non-toxic widely used for the synthesis of the substituted coumarin .The scope of this catalyst has not been fully explored, but can be used as buffer, neutralizing agent. Owing to the numerous advantages associated with cheap and non-hazardous catalyst, and also realizing g the importance of coumarin herein we would like to focus the eco –friendly method for his synthesis of derivatives of coumarin using cheaper and commercially available acid catalysts Potassium dihydrogen phosphate and also by the Knoevenagel condensation under microwave irradiation.

Key words: Potassium dihydrogen phosphate , microwave irradiation, anti-microbial

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