Some Chemical Reactions Involved in the Alkaline Yellowing of Wool

Abstract

An investigation of the products formed during the treatment of a number of amino acids and proteins with alkali has provided evidence for the similarity of some reactions between free and protein-bound amino acids. Based on this similarity, the behavior of free amino acids and other model compounds has been interpreted to account for the yellowing of proteins. Yellowing in both cases has been attributed to an initial β-elimination reaction involving the amino acids cystine, cysteine, serine or threonine to form dehydro-alanyl residues, which then either rearrange or react further to form colored compounds.