title: Proxyl nitroxide of lithocholic acid: a potential spin probe for model membranes.
abstract: A new steroidal proxyl (2,2,5,5-tetramethylpyrrolidine-N-oxyl) nitroxide (SPN), with the proxyl nitroxide moiety in the pendant side chain of the steroid, has been synthesized. Its localization in lipid bilayers was ascertained with the help of 1H NMR and 31P NMR experiments. The effects of the nitroxide group in SPN incorporated into the bilayer on 13C relaxation times are interpreted qualitatively in terms of localization of the nitroxide group within the bilayer structure. The nitroxide SPN was used to monitor changes in membrane fluidity and permeability induced by local anaesthetics, mepivacaine and xylocaine and the antikeratinizing agent, azelaic acid. The results conclusively proved the applicability of the new steroidal proxyl nitroxide (SPN) as a potential spin probe for spin labeling studies.
authors.affiliation: Department of Chemistry, Indian Institute of Technology, Bombay.
authors.forename: S
authors.initials: S
authors.lastname: Banerjee
authors.forename: G K
authors.initials: GK
authors.lastname: Trivedi
authors.forename: S
authors.initials: S
authors.lastname: Srivastava
authors.forename: R S
authors.initials: RS
authors.lastname: Phadke
mesh_terms: D003497:Cyclic N-Oxides / Q000138:chemical synthesis* / Q000737:chemistry; D003998:Dicarboxylic Acids / Q000494:pharmacology; D004578:Electron Spin Resonance Spectroscopy; D008012:Lidocaine / Q000494:pharmacology; D008051:Lipid Bilayers / Q000737:chemistry; D008095:Lithocholic Acid / Q000031:analogs & derivatives* / Q000138:chemical synthesis* / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008560:Membrane Fluidity / Q000187:drug effects; D008567:Membranes, Artificial; D008619:Mepivacaine / Q000494:pharmacology; D015394:Molecular Structure; D010539:Permeability / Q000187:drug effects; D013113:Spin Labels / Q000138:chemical synthesis*
chemical_list: D003497:Cyclic N-Oxides; D003998:Dicarboxylic Acids; D008051:Lipid Bilayers; D008567:Membranes, Artificial; D013113:Spin Labels; C012517:proxyl nitroxide; D008095:Lithocholic Acid; D008012:Lidocaine; D008619:Mepivacaine; C010038:azelaic acid