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

It has been shown previously that the vanadium bromoperoxidase from Ascophy llum nodosum mediates the production of (R)-methyl phenyl sulfoxide with 91 % enantiomeric excess from the corresponding sulfide in the presence of hyd rogen peroxide. Investigation of the sulfoxidation activity of this enzyme shows that activating substituents at the para-position of the aromatic rin g of methyl phenyl sulfide positively influence the selectivity of the reac tion, whereas strongly electron-withdrawing groups cancel the catalyzed sul foxidation reaction. The first evidence is presented that the vanadium brom operoxidase catalyzes the sulfoxidation of racemic non-aromatic cyclic thio ethers with high kinetic resolution. (C) 1999 Elsevier Science Ltd. All rig hts reserved.