5,5-dimethyl-1-pyrroline-N-oxide alone enhances the spontaneous superoxide generation by primaquine
| Autor: | Yoshinori Saigusa, Kohji Ichimori, Hiroe Nakazawa, László Prónai |
|---|---|
| Rok vydání: | 1991 |
| Předmět: |
Reducing agent
Biophysics Primaquine Photochemistry Biochemistry Adduct law.invention Cyclic N-Oxides Superoxide dismutase chemistry.chemical_compound Superoxides law Molecular Biology Chemiluminescence Spin trapping Autoxidation biology Chemistry Dimethyl sulfoxide Superoxide Electron Spin Resonance Spectroscopy Imidazoles Spectrophotometry Pyrazines Luminescent Measurements biology.protein Spin Labels |
| Zdroj: | Archives of Biochemistry and Biophysics. 288:276-281 |
| ISSN: | 0003-9861 |
| DOI: | 10.1016/0003-9861(91)90195-o |
| Popis: | Primaquine (PQ), a well-known antimalarial drug, has been reported to generate superoxide (O2−) in the presence of reducing agents such as NADPH. In the present study, chemiluminescence was detected by adding only PQ to aqueous 2-methyl-6-[p-methoxyphenyl]-3,7-dihydroimidazo-[1,2-α]pyrazin-3-one (MCLA), which is a specific chemiluminescent probe for O2−, and was quenched by superoxide dismutase (SOD), indicating that PQ alone can generate O2− in aerobic conditions. Furthermore, 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) enhanced the O2− generation by PQ. Superoxide spin adduct, DMPO-OOH, was also detected by ESR both in aqueous solutions and in dimethyl sulfoxide with DMPO. The level of O2− generation showed a linear correlation with the DMPO concentration, and SOD competitively inhibited the DMPO-OOH formation. The results suggested that in aerobic conditions PQ is autoxidized to 5-hydroxy-PQ, which generates O2−, and DMPO accelerates the autoxidation process by trapping O2−. DMPO or M4PO alone enhances the spontaneous O2− generation by PQ, therefore cautious evaluation is necessary in all studies using the ESR/spin trapping technique to elucidate the mechanism of PQ-related radical generation. |
| Databáze: | OpenAIRE |
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