Electrochemical Determination Of Medicinal Molecules And Its Interactions With Protein

Protein is important bio-macromolecules in the life. Exploring the interaction mechanisms on protein with medicinal molecules at the biochemistry level is of current interest. Serum albumins are the most abundant proteins in plasma. As the major soluble protein of the circulatory system, they have many physiological functions. They can play an important role in drug disposition and efficacy. Many drugs or other bioactivity small molecules bind reversibly to albumin. Drugs first interact with serum albumin, can control the medicine reach the receptor site release, avoid drug rapid metabolism and pharmacological action. Based on the important meaning of interaction medicinal effect moleculars with protein.the paper investigates the electrochemical characters of carvedilol, amiodarone hydrochloride and salbutamol.the novel electroanalytical methods for them.moreover,the interactions of carvedilol, amiodarone hydrochloride and salbutamol with bovine serum albumin are them investigated by the electrochemistry and spectrum.The main contents were as follows:1. Carvedilol is used in the management of hypertension and angina pectoris and as an adjunct to standard therapy in symptomatic heart failure. A novel electrochemical method for determination of carvedilol (CAR) was develpoment using cyclic, linear sweep voltammetry at a carbon paste electrode (CPE). The interactions between CAR and bovine serum albumin (BSA) were investigated by linear sweep voltammetry, differential pulse voltammetry, UV absorption spectra and IR spectroscopy. Three irreversible oxidation peaks of CAR were observed at0.92V,1.18V and1.31V in pH4.0Britton-Robinson (B-R) buffer solution, respectively. The oxidation peak current at0.92V was linear with the concentration of CAR in the range from2.45×10-5tol.19×10-3mol/L and the RSD of CAR was4.8%. In the presence of BSA, The oxidation current of CAR was decreased and the decreasing value was linear with the BSA concentration in the range of2.92×10-7mol/L～1.09×10-5mol/L, with a detection limit of4.1X10-8 mol/L. The binding equilibrium constant and binding ratio were calculated as3.14X106L/mol and1:1. The results of UV absorption spectra showed that the UV absorption peak of BSA could red shift and the maximum absorption value was increased. The results of IR spectroscopy showed that CAR could interact with sulfur-containing and nitrogen-containing groups in BSA molecular.2. A simple and sensitive electrochemical method for the determination of amiodarone hydrochloride (Am) has been developed at multi-walled carbon nanotubes modified glass carbon electrode, and its interactions with BSA were investigated by electrochemical method and spectroscopy method. In pH5.0Britton-Robinson buffer solution, an irreversible oxidation peak of Am was observed on the MWNT-GCE at0.87V. Under optimized conditions, the current showed a linear dependence with concentration in the range between1.8×10-7mol/L and6.7×10-5mol/L. In the presence of BSA, The oxidation current of Am was decreased and the decreasing value was linear with the BSA concentration in the range of2.4×10-7mol/L～2.2×10-5mol/L, with a detection limit of9×10-8mol/L. The binding equilibrium constant and binding ratio was calculated as9.9×106L/mol and1:1. The results of UV absorption spectra showed that the UV absorption peak of BSA could red shift and the maximum absorption value was increased. The results of IR spectroscopy showed that Am could interact with sulfur-containing and nitrogen-containing groups in BSA molecular.3. A gold nanoparticles modified carbon paste electrode (CPE) was prepared. Electrochemical behaviors of salbutamol (Sal) on the modified electrode were investigated by cyclic voltammetric and square wave voltammetry. An irreversible oxidation peak was observed at gold nanoparticles modified CPE at0.60V (vs. SCE) and the electrochemical response of Sal was greatly enhanced compared with that of at bare CPE. A linear relationship between the anodic peak current and the Sal concentration was found. The peak current showed a RSD1.7%which indicated that the proposed method has high accuracy. The methods can be used for the determination of the drug in blood and urine with good results. In the presence of BSA, The oxidation current of Sal was decreased and the decreasing value was linear with the BSA concentration in the range of2.47×10-7mol/L～6.42×10-5mol/L, with a detection limit of8.23×10-8mol/L. The binding equilibrium constant and binding ratio were calculated as2.84X105L/mol and1:1. The results of UV absorption spectra showed that the UV absorption peak of BSA could red shift and the maximum absorption value was increased. The results of IR spectroscopy showed that Sal could interact with sulfur-containing and nitrogen-containing groups in BSA molecular.