Singlet oxygen generation from phosphatidylcholine hydroperoxide in the presence of copper

Fusako Takayama, Toru Egashira, Yasumitsu Yamanaka

Research output: Contribution to journalArticlepeer-review

13 Citations (Scopus)


This study pursued whether singlet oxygen (1O2) is generated from phosphatidylcholine hydroperoxide (PCOOH), the oxidized modification product of a major constituent of biomembranes and serum lipoproteins. The 1O2 formation was detected, by utilizing the oxidation of 2,2,6,6-tetramethyl-4-piperidone (TMPD) by 1O2 to yield 2,2,6,6-tetramethyl-4-piperidone-1-oxyl (TEMPONE), which generates electron spin resonance (ESR) signals. The TEMPONE signal was detected in human plasma with addition of PCOOH by ESR determination after introducing copper(II). The TEMPONE formation was proportional to the amounts of PCOOH added according to moles of active oxygen. The TEMPONE signal intensity was weakened significantly in the presence of β-carotene and histidine in a concentration-dependent manner, but was not at all decreased by mannitol, Mn-superoxide dismutase and catalase. In addition, HPLC-chemiluminescence analysis demonstrated that incubation with the PCOOH/Cu(II) combination oxidized cholesterol, a relatively oxidation-resistant component, to the cholesterol hydroperoxide. These results reveal that 1O2 is generated from PCOOH in contact with copper(II). In conclusion, this in-vitro study provides directly the 1O2 formation in living organisms following the advancement of peroxidation of constitutive lipids.

Original languageEnglish
Pages (from-to)1807-1815
Number of pages9
JournalLife Sciences
Issue number15
Publication statusPublished - Mar 2 2001
Externally publishedYes


  • 2,2,6,6-Tetramethyl-4- piperidone-1-oxyl
  • 2,2,6,6-Tetramethyl-4-piperidone
  • Electron spin resonance
  • Lipid peroxidation
  • Phosphatidylcholine hydroperoxide
  • Reactive oxygen species
  • Singlet oxygen

ASJC Scopus subject areas

  • General Pharmacology, Toxicology and Pharmaceutics
  • General Biochemistry,Genetics and Molecular Biology


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