Oleyl oleate is a monounsaturated wax ester formed by the condensation of oleic acid (C18:1 cis-9) with oleyl alcohol (C18:1 cis-9). It represents a prototypical simple lipid within the wax ester category, alongside compounds such as cetyl palmitate and stearyl stearate.
Chemical Structure
Oleyl oleate has the molecular formula C36H68O2 and a molecular weight of 532.92 g/mol. Its structural arrangement, characterized by cis double bonds at the Δ9 positions, includes 32 rotatable bonds, no hydrogen bond donors, and a topological polar surface area (TPSA) of 26.3 Ų. The molecule is extremely lipophilic (XLogP3 15.5), with kinked unsaturated chains that prevent tight packing compared with saturated homologs.
Physical Properties
At room temperature, oleyl oleate is a pale yellow, low-viscosity liquid. It has a predicted melting point of approximately 11–15°C, a boiling point near 597°C, and a density around 0.85 g/cm³. The compound exhibits very low water solubility (log10WS −13.46) but is miscible with organic solvents such as chloroform and ethanol, as well as with vegetable oils. Its double unsaturations contribute to the formation of fluid lipid films with a refractive index of approximately 1.45.
Biosynthesis and Sources
Oleyl oleate occurs naturally in human sebum, where it accounts for roughly 2–5% of wax esters and is synthesized through sebaceous acyltransferase activity. Commercial production is typically achieved by esterification of oleic acid and oleyl alcohol under catalytic conditions, often using palm or olive-derived feedstocks, yielding products with purity exceeding 95%.
