2014 年 35 巻 1 号 p. 23-29
The most important and principal function of the skin is to provide a protective interface between human body and external environment. Ceramides exist as main components of intercellular lipids of stratum corneum, and play an essential role of a barrier function of the skin. It is well known that natural ceramides are optically active, and consist of (2S, 3R)-configuration (D-erythro configuration) at the sphingosine moiety. Thus, the optically active (2S, 3R)-ceramides have been developed based on the strategy of asymmetric synthesis. In order to embody the function of the ceramides in various cosmetic products, effective and stable novel formula of the ceramides have been devised with consideration of lamellar structure of natural intercellular lipids. As a consequence of studies especially focused on stereochemistry, compositions containing the optically active ceramides showed significant recovering effect of water-holding capacity and barrier function of the skin. The following article reviews recent developments in the functional properties of the optically active ceramides as well as various formulating techniques of these materials.