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.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► 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.