Nature of the reaction of wool with alkali

Abstract

The course of the reaction of the cystine in wool with alkali has been reinvestigated. The earlier findings that one sulfur atom is split from each molecule of cystine a re confi rmed. Of the residual noncystine s ulfur in the alka li-tregted wool, mbre than 25 percent has bee n accounted for as lanthionine. No signifi cant amounts of s ulfhydryl groups are in the t reated wools. The res ults lead to the conclusion that the alkali cleavage of the dis ulfide group does not consist prim a rily in a hydrolytic rupture between the s ulfur atoms with the formation of a s ulfhydryl compound and a s ulfenic acid, as postulated earlier; rather, they are more consistent with a mechanism recently advanced by N icolet and Shinn, which involves a rupture between s ulfur and carbon to yield dehydroalanine and a -C H 2 -S-SH residue. An atom of s ulfur is then eliminated from the latter and the sulfhydryl group thus formed reacts with dehyclroalanine to form lantilionine.