Probing the scope of the sulfoxidation activity of vanadium bromoperoxidase from Ascophyllum nodosum

Abstract It has been shown previously that the vanadium bromoperoxidase from Ascophyllum nodosum mediates the production of ( R )-methyl phenyl sulfoxide with 91% enantiomeric excess from the corresponding sulfide in the presence of hydrogen peroxide. Investigation of the sulfoxidation activity of this enzyme shows that activating substituents at the para -position of the aromatic ring of methyl phenyl sulfide positively influence the selectivity of the reaction, whereas strongly electron-withdrawing groups cancel the catalyzed sulfoxidation reaction. The first evidence is presented that the vanadium bromoperoxidase catalyzes the sulfoxidation of racemic non-aromatic cyclic thioethers with high kinetic resolution.