Conversion of alpha-amino acids and peptides to nitriles and aldehydes by bromoperoxidase

Pure bromoperoxidase from the marine alga, Penicillus capitatus, converts alpha-amino acids and peptides to the corresponding decarboxylated nitriles and aldehydes in the presence of hydrogen peroxide and bromide ion. Thus, both valine and valylvaline are converted to isobutyronitrile and isobutyraldehyde while alanine is converted to acetonitrile and acetaldehyde. The reaction is nonstereospecific and can be catalyzed by bromoperoxidases obtained from different sources. Bromoperoxidase catalyzes the conversion of methoxytyrosine to p-methoxyphenylacetonitrile. This reaction is consistent with the involvement of bromoperoxidase in the formation of aeroplysinin-1, a brominated aromatic nitrile antibiotic produced by a marine sponge.