Cleavage of Integral Surface Lipids of Wool by Aminolysis

Abstract

A complex mixture of lipids is obtained upon treatment of wool with anhydrous alkylamines, with the major class being identified as N-alkylfalty amides (0.60 mg/g of extracted wool). Analysis of the lipids released by isopropylamine treatment shows that the major fatty amide is N-isopropyl-18-methyleicosanamide, which comprises 61% by weight of the total fatty amides released. Fatty acid hydroxamates (RCONHOH) are formed upon treatment of wool with anhydrous hydroxylamine. The alkyl hydroxamates (0.55 mg/g of extracted wool) are analyzed by HPLC, which again shows the 18-methyleieosanoic acid derivative to he the dominant species (71% by weight of the total fatty acid hydroxamates). These results indicate that the covalently bound fatty acids on the surface of wool may be readily cleaved by aminolysis with anhydrous alkylamines. I hey also support the hypothesis that the proteins within the cuticle cell membrane are acylated with fatty acids through a thioester linkage.