sodium-dodecyl-sulfate and benzophenone

Layered double hydroxides intercalated with dodecylsulfate or dodecylbenzenesulfonate were synthesized by co-precipitation under alkaline conditions. After characterization by PXRD, FTIR, and TGA/DTA, the ZnxAl/SUR compounds were reacted with neutral benzophenone, using different procedures. The products obtained from benzophenone adsolubilization were investigated by PXRD, FTIR, and DRUV-Vis spectroscopy before and after exposure to UV radiation. In general, the content of adsolubilized benzophenone was small and depended on the synthetic procedure. The best results were achieved under microwave irradiation, which furnished 9.09 wt% adsolubilized benzophenone. The products presented good adsorption in the full UV region, from UVC to UVA, and good stability to UV radiation. They did not cause skin irritation in tests conducted on rabbits, which makes them good candidates for the development of a new generation of sunscreens.

Topics: Animals; Benzenesulfonates; Benzophenones; Drug Evaluation, Preclinical; Rabbits; Sodium Dodecyl Sulfate; Spectroscopy, Fourier Transform Infrared; Sunscreening Agents; Surface-Active Agents; Ultraviolet Rays

Photoactivatable penetratin analogues bearing three different photoprobes, which do not disturb the membranotropic properties of the peptides, have been tested for their photo-cross-linking efficacy in glycerol and lipid media. In the case of glycerol, photo-cross-linking was observed, whereas in the case of SDS (used as a membrane model system), the dynamics of the SDS/penetratin assemblies and the photosensitizer properties of the probes prevented the cross-linking between the peptide and SDS. Bilayers of DMPG were partially photo-cross-linked by the penetratin analogues containing either a benzophenone or a trifluoromethylaryl-diazirine, whereas dithienyl ketone acted exclusively as a photosensitizer. The characterization by MALDI-TOF mass spectrometry of the photoadducts formed after irradiation required basic hydrolysis of DMPG for an efficient capture of the biotinylated peptide analogues with streptavidin-coated magnetic beads. MALDI-TOF analysis of the photoadducts between the photoactivatable penetratin and DMPG allowed an unambiguous identification of the covalent bond formed with the lipids. Altogether, we show herein that the efficacy of the lipid photo-cross-linking depends on the environment, the dynamics of the supramolecular assembly, and the physicochemical properties of the photoprobe.

Topics: Amino Acid Sequence; Benzophenones; Carrier Proteins; Cell-Penetrating Peptides; Cross-Linking Reagents; Diazomethane; Glycerol; Hydrophobic and Hydrophilic Interactions; Ketones; Lipid Bilayers; Mass Spectrometry; Phosphatidylglycerols; Phospholipids; Photochemical Processes; Sodium Dodecyl Sulfate; Thiophenes; Water

The influence of 60-Hz magnetic fields on free radical reactions can be quantitatively predicted from the knowledge of the effect of static fields on free radical behavior. Studies of radical reactions in micellar systems show that the behavior under a 60-Hz field is identical to that under a static field at any given point in time.

Topics: Benzophenones; Chemical Phenomena; Chemistry, Physical; Cyclohexanes; Cyclohexenes; Electromagnetic Fields; Free Radicals; Lasers; Magnetics; Micelles; Sodium Dodecyl Sulfate