Polyphenol oxidase activities by cobalt (II) complex with Benzopyran Derivatives, Synthetic, Characterization, Kinetics Study and Molecular Modeling Studies

Document Type : Original Article


Chemistry Department, Faculty of Science & Arts Al-Mukhwah, Al-Baha University, Al-Baha, Saudi Arabia


The Cobalt complex of 2-Amino-4-(2-chloro-5-nitrophenyl)-5,6,7,8-tetrahydro-7,7-dimethyl-5-oxo- 4H-chromene-3-carbonitrile)( CNB) was synthesized. The organic ligand CNB was previously synthesized using an environment friendly method using microwave irradiation. The cobalt complex cobalt (II)-CNB was characterized by different tools such as IR, electronic spectroscopy, elemental analysis, Thermal analysis and mass spectroscopy. The mode of metal binding shows that the cobalt binds with the ligand through the nitrogen atoms of the amino and cyanide groups. The cobalt complex cobalt (II)-CNB has been used in the homogenous oxidation of polyphenol 1, 2, 3-trihydroxybenzene in presence of a green oxidant H2O2 as biomimetic metalloenzymes. Kinetic parameters were calculate kcat 1.0971×10-5S-1, KM1.412 ×10-2 M, Vmax 7.68×10-4MS−1 and catalytic efficiency 7.769×10-7 .The oxidation reaction is inhibited by competitive inhibition by kojic acid with IC50 = 200 μM and molecular modeling studies geometrical optimization ,(HOMOs) ,(LUMOs and electrostatic potentials (ESP).


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