Cleavage of Integral Surface Lipids of Wool by Aminolysis

摘要

A complex mixture of lipids is obtained upon treatment of wool with anhydrous alkylamines, with the major class being identified as N-alkylfatty 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-methyleicosanoic acid derivative to be 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. They also support the hypothesis that the proteins within the cuticle cell membrane are acylated with fatty acids through a thioester linkage.