%0 Journal Article
%T Characterization of Cr-Curcumin Complex by Differential Pulse Voltammetry and UV-Vis Spectrophotometry
%A Maurice O. Iwunze
%J ISRN Analytical Chemistry
%D 2014
%R 10.1155/2014/372576
%X Differential Pulse Voltammetry (DPV) and UV-Vis techniques were used in characterizing the complexation of chromium with curcumin. It was observed that chromium complexed with curcumin in a 1£¿:£¿3 ratio. The experimental values that were used to calculate this ratio were independently determined by the two techniques used. The values obtained from each technique agree with each other reasonably well, within limits of experimental error. The stability constant or formation constant, , of the complex, , was determined using the Lingane equation and Gibb¡¯s free energy of formation was calculated as £¿58.18£¿kJ. 1. Introduction The trivalent chromium which was used in this work is known to possess numerous health benefits, which include its enhancement of insulin action in regulating blood sugar level¡ªcritical factor in diabetic patients, weight loss, regulation of blood pressure, and cholesterol control [1¨C7]. In its use in weight loss, chromium picolinate, Cr(Pc)3, is generally used [8¨C11], although it has been seriously criticized about its effectiveness [12]. However, Cr(Pc)3 has been used to augment the chromium intake through dietary products [9]. On the other hand, curcumin, a phytochemical, has been known to exhibit many beneficial health effects including its anticarcinogenic [13¨C15] and antioxidative [16¨C21] activities. The internet is replete with enormous information and advertisement about using these chemicals as supplements for a better life. It is therefore anticipated that a complex formed by this mineral, Cr, and the phytochemical, curcumin, should have greater beneficial health effect. The physicochemical and stability study of this complex should therefore be a good candidate to study and characterize. This is the theme of this work. 2. Experimental 2.1. Chemicals Certified chromic nitrate was obtained from Fisher Scientific. 98% pure curcumin and 98% pure tetramethylammonium bromide (used as supporting electrolyte), were obtained from Acros Organics. Analytical reagent grade of DMSO was obtained from Aldrich Chemicals. 2.2. Instruments Electrochemical. All electrochemical experiments were conducted using a three-electrode system comprising of the working electrode (1.0£¿mm diameter) Glassy Carbon Electrode (GCE), obtained from Cypress Systems, a wound platinum wire as the counter electrode, and a commercial calomel electrode as the reference electrode which was obtained from Fisher Scientific. The reaction was carried out in a 1-compartment electrochemical cell. A computer-controlled electrochemical analyzer system supplied by Cypress
%U http://www.hindawi.com/journals/isrn.analytical.chemistry/2014/372576/