Contributions to the chemistry of human hair: II. Lipid chemical aspects of permanently waved hair

The cell membrane complex (CMC) and the internal lipids of untreated and permanent waved hair were investigated. The permanent waving procedure results in a lower amount of the cell membrane fraction that could be isolated compared to untreated hair. There is no difference in the amino acid composition of the CMC fractions. The internal hair lipids were extracted from the CMC fraction with chloroform/methanol. For untreated human hair the cell membrane complex yields 57% of lipid material, whereas from the CMC of permanent wave hair only 35% of lipids could be extracted. The polar lipids and the fatty acids are the main components of the internal hair lipids. After a permanent waving treatment there is a distinct decrease in the polar lipid fraction which is higher at alkaline (pH 9) than at neutral pH (pH 7). The reduction treatment at pH 9.0 also causes a cleavage of the fatty acid fraction in the internal hair lipids.