Synthesis and Spin-Trapping Behavior of 5-ChEPMPO, a Cholesteryl Ester Analogue of the Spin Trap DEPMPO

• Published in: Journal of organic chemistry Vol. 70; no. 25; pp. 10426 - 10433
• Main Authors: Hardy, Micaël, Ouari, Olivier, Charles, Laurence, Finet, Jean-Pierre, Iacazio, Gilles, Monnier, Valérie, Rockenbauer, Antal, Tordo, Paul
• Format: Journal Article
• Language: English
• Published: WASHINGTON American Chemical Society 09.12.2005; Amer Chemical Soc
• Subjects: Alicyclic compounds, terpenoids, prostaglandins, steroids; Chemistry; Chemistry, Organic; Cholesterol - analogs & derivatives; Cholesterol - chemical synthesis; Cholesterol - chemistry; Cholesterol Esters - chemical synthesis; Electron Spin Resonance Spectroscopy; Exact sciences and technology; Linoleic Acids; Lipid Peroxides; Mass Spectrometry; Organic chemistry; Physical Sciences; Preparations and properties; Pyrroles - chemical synthesis; Pyrroles - chemistry; Science & Technology; Spin Labels - chemical synthesis; Spin Trapping; Steroids; N-OXIDE; OXYGEN; IN-VITRO; SUPEROXIDE; NITRONE; PEROXYL RADICALS; ESR; BETA-CYCLODEXTRIN; LIPID RADICALS; INCLUSION COMPLEX; Ester; Chemical synthesis; Spin trapping; EPR spectrometry
• ISSN: 0022-3263; 1520-6904
• DOI: 10.1021/jo0517390

5-(Cholesteryloxyethoxyphosphoryl)-5-methylpyrroline N-oxide (5-ChEPMPO), a DEPMPO analogue bearing a cholesterol group on the phosphorus atom, has been prepared and used to trap peroxyl-, alkoxyl-, thiyl-, and carbon-centered radicals in organic solvent. The important steric hindrance in 5-ChEPMPO does not affect the properties of 5-ChEPMPO in comparison to DEPMPO for the spin trapping of an enantiopure linoleic acid hydroperoxide. The 5-ChEPMPO−OOL spin adduct was observed by ESR and confirmed by ESI-MS/MS experiments. The relaxation terms of the 5-ChEPMPO−lipid peroxyl spin adduct were compared with those of other peroxyl spin adducts, and it was shown that the cholesteryl group has only a weak influence on the exchange rate between adduct conformers.