Synthesis, X-ray crystallography, spectroscopic characterization and spectroscopic/electrochemical evidence of formation of phenoxy free radical in active center analogs of galactose oxidase – [Cu(Salgly)H2O] and [Cu(Salphenylalanine)H2O]

The formation of phenolate free radical is the factor of high turnover for catalytic activity of galactose oxidase (GO) compared to that by inorganic complexes. A new active center analog of GO, [Cu(II)(Salphenylalanine)H2O] have been synthesized and its single crystal X-ray analysis was done. In aqueous surfactant micellar solution chemical oxidation as well as electrochemical oxidation of structural models of galactose oxidase – [Cu(II)Salgly·H2O] and [Cu(II)(Salphenylalanine)·H2O], have been found to generate free radical originating at the phenolate group. Formation of the free radical have been proved by electron paramagnetic resonance spectroscopy, electronic spectroscopy and electrochemistry.

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► Active center analogs of galactose oxidase synthesised and characterized.
► Phenolate free radical generated chemically and electrochemically.
► Free radical formation proved by UV/Vis, EPR and CV.