Chloroperoxidase-catalyzed oxidation of methionine derivatives

Treatment of N-methoxycarbonyl C-carboxylate ester derivatives of L- and D-methionine and L-ethionine by chloroperoxidase–hydrogen peroxide resulted in oxidation at sulfur to produce the (RS) sulfoxide in moderate to high diastereomeric excess. The (RS) sulfoxide of methionine was also obtained in moderate to high diastereomeric excess from (±)SO-N-methoxycarbonyl-L-methionine methyl ester sulfoxide by ester hydrolysis using α-chymotrypsin, Aspergillus sp. protease or subtilisin Carlsberg. Key words: amino acid oxidation, biocatalysis, biotransformation, chloroperoxidase, enzyme catalysis, lipase, sulfoxidation.