infrared spectroscopy, including deuterated free fatty acids. Inversion of the C-3 configuration in CerNS and CerNdS increased phase transition temperatures, had no significant effects on lamellar phases, but also decreased the proportion of orthorhombic packing and decreased lipid mixing in the model membranes. These changes in membrane organization resulted in membrane permeabilities that ranged from unchanged
Synthesis of 6-hydroxyceramide using ruthenium-catalyzed hydrosilylation–protodesilylation. Unexpected formation of a long periodicity lamellar phase in skin lipid membranes
The synthesis of a ceramide with a 6-hydroxysphingosine base, a unique component of the human epidermal barrier, is reported. The key step involves a mild and selective trans-reduction of a triple bond using [Cp*Ru(CH3CN)3]PF6-catalyzed hydrosilylation followed by protodesilylation. The oxidation of sphingosine-based ceramide to 6-hydroxyceramide is also described. X-Ray powder diffraction on the model