Esters of 5-carboxyl-5-methyl-1-pyrroline N-oxide: A family of spin traps for superoxide

Pei Tsai, Kazuhiro Ichikawa, Colin Mailer, Sovitj Pou, Howard J. Halpern, Bruce H. Robinson, Robert Nielsen, Gerald M. Rosen

    Research output: Contribution to journalArticle

    66 Citations (Scopus)

    Abstract

    Apparent rate constants, at acidic pH and neutral pH for the reaction of a family of ester-containing 5-carboxyl-5-methyl-1-pyrroline N-oxides with superoxide (O2.-) were estimated, using ferricytochrome c as a competitive inhibitor. It was of interest to note that the rate constants were similar among the different nitrones and not that significantly different from that found for 5-(diethoxyphosphoryl)-5-dimethyl-1-pyrroline N-oxide. At acidic pH, the rate constant for spin trapping O2.- 3-fold greater than that at physiological pH. Subsequent experiments determined the half-life of aminoxyls, derived from the reaction of these nitrones with O2.-. The EPR spectra were modeled by using a global analysis method. The results clearly demonstrated that EPR spectra of all the aminoxyls were inconsistent with a model that included a single γ-hydrogen splitting. A better interpretation modeled them as two diastereomers with identical nitrogen splittings and slightly different β-hydrogen splittings. Detailed line width analyses slightly favored an equal line width-unequal population ratio for the two diastereomers.

    Original languageEnglish
    Pages (from-to)7811-7817
    Number of pages7
    JournalJournal of Organic Chemistry
    Volume68
    Issue number20
    DOIs
    Publication statusPublished - Oct 3 2003

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    Superoxides
    Oxides
    Rate constants
    Esters
    Linewidth
    Paramagnetic resonance
    Hydrogen
    Cytochromes c
    Nitrogen
    pyrroline
    Experiments
    nitrones

    All Science Journal Classification (ASJC) codes

    • Organic Chemistry

    Cite this

    Tsai, P., Ichikawa, K., Mailer, C., Pou, S., Halpern, H. J., Robinson, B. H., ... Rosen, G. M. (2003). Esters of 5-carboxyl-5-methyl-1-pyrroline N-oxide: A family of spin traps for superoxide. Journal of Organic Chemistry, 68(20), 7811-7817. https://doi.org/10.1021/jo0350413

    Esters of 5-carboxyl-5-methyl-1-pyrroline N-oxide : A family of spin traps for superoxide. / Tsai, Pei; Ichikawa, Kazuhiro; Mailer, Colin; Pou, Sovitj; Halpern, Howard J.; Robinson, Bruce H.; Nielsen, Robert; Rosen, Gerald M.

    In: Journal of Organic Chemistry, Vol. 68, No. 20, 03.10.2003, p. 7811-7817.

    Research output: Contribution to journalArticle

    Tsai, P, Ichikawa, K, Mailer, C, Pou, S, Halpern, HJ, Robinson, BH, Nielsen, R & Rosen, GM 2003, 'Esters of 5-carboxyl-5-methyl-1-pyrroline N-oxide: A family of spin traps for superoxide', Journal of Organic Chemistry, vol. 68, no. 20, pp. 7811-7817. https://doi.org/10.1021/jo0350413
    Tsai P, Ichikawa K, Mailer C, Pou S, Halpern HJ, Robinson BH et al. Esters of 5-carboxyl-5-methyl-1-pyrroline N-oxide: A family of spin traps for superoxide. Journal of Organic Chemistry. 2003 Oct 3;68(20):7811-7817. https://doi.org/10.1021/jo0350413
    Tsai, Pei ; Ichikawa, Kazuhiro ; Mailer, Colin ; Pou, Sovitj ; Halpern, Howard J. ; Robinson, Bruce H. ; Nielsen, Robert ; Rosen, Gerald M. / Esters of 5-carboxyl-5-methyl-1-pyrroline N-oxide : A family of spin traps for superoxide. In: Journal of Organic Chemistry. 2003 ; Vol. 68, No. 20. pp. 7811-7817.
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