Dynamics and partitioning of spin-labeled stearates into the lipid domain of stratum corneum

Effects of terpenes on fluidity and lipid extraction in phospholipid membranes

“…As in other studies [20,21], the magnetic parameters were determined based on a global analysis of all the spectra obtained in this work. Once the parameters were determined, all of the spectra were simulated using the same input parameters for the magnetic tensors g and A: g xx (1) = 2.0080; g yy (1) = 2.0060; g zz (1) = 2.0017; A xx (1) = 6.9; A yy (1) = 6.0; A zz (1) = 32.0; g xx (2) = 2.0082; g yy (2) = 2.0062; g zz (2) = 2.0027; A xx (2) = 5.7; A yy (2) = 5.6; and A zz (2) = 31.2, in which the numbers (1) and (2) indicate the first and second spectral component, respectively.…”

Electron paramagnetic resonance (EPR) spectral components of spin-labeled lipids in saturated phospholipid bilayers: effect of cholesterol

“…6 In previous studies, two-component EPR spectra of several spin labels in membranes of stratum corneum, the upper skin layer, were examined using the fitting program NLLS to monitor the dynamic and fraction of probe in each component. [8][9][10] The presence of the terpenes L-menthol and 1,8-cineole, two potent skin permeation enhancers, in stratum corneum at 1% (w/w) or DPPC vesicles at a terpene:lipid molar ratio of 0.7:1 drastically increased the lipid fluidity, especially by transferring the spin probes from a more to a less motionally restricted spectral component in the membranes. 9,10 More recently, EPR spectra of spin labels in membrane were simulated using two-component models to study effects of the anti antileishmanial drug miltefosine in stratum corneum intercellular membranes 11 and trypanocidal action of elatol 12 as well as the toxicity of terpenes in cultured fibroblasts.…”

Molecular Dynamics and Partitioning of Di‐tert‐butyl Nitroxide in Stratum Corneum Membranes: Effect of Terpenes

“…Electron paramagnetic resonance (EPR) of spin labels has been employed to obtain information on the molecular dynamics of SC membranes [6][7][8][9][10][11][12] and SC proteins [13][14][15][16] in the intact tissue. The EPR spectra of spinlabeled stearic acids in SC membranes were able to distinguish two main environments for the probe distribution into the membranes.…”

“…The EPR spectra of spinlabeled stearic acids in SC membranes were able to distinguish two main environments for the probe distribution into the membranes. In a previous study [9], the origin of these two spectral components was interpreted based on the ability of spin labels to participate in intermolecular hydrogen bonding within the membrane. The more motionally restricted component was assigned to a class of spin probe hydrogen bonded to the polar head groups (more rigid structure) and the more mobilized component was attributed to the spin labels temporarily non-hydrogen-bonded to the polar interface and more deeply inserted in the hydrophobic core.…”