Influence of the glucosylated β-cyclodextrin inclusion on sulfur trioxide spin-adduct stabilizations and spin-trapping rate processes for DMPO-type spin traps

Yoshimi Sueishi, Atsushi Miyata, Daisuke Yoshioka, Masato Kamibayashi, Yashige Kotake

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

The effect of CD-inclusion on spin-trapping rates and spin-adduct decay rates for sulfur trioxide radical anion (SO3-•) was investigated. SO3-• radical was produced with UV photolysis of sodium sulfite in basic aqueous solution, and spin-trapped with various spin traps, i.e., PBN (α-phenyl-N-t-butylnitrone), DMPO (5,5-dimethyl pyrroline-1-oxide), and three other phosphoryl DMPO-type spin traps. A modified β-CD, 6-O-α-d-glucosyl-β-cyclodextrin (G-β-CD) having better inclusion properties than β-CD, was employed. Upon adding excess G-β-CD, decay rates of SO3-• radical adducts significantly decreased in most spin traps. Half-lives of SO3-• radical adducts of phosphoryl spin traps were one to two orders of magnitude longer than that of PBN or DMPO, and the G-β-CD addition further extended the half-life time. The spin traps containing phosphoryl-group all showed higher SO3-• trapping rates than those of PBN and DMPO, but two phosphoryl spin traps achieved slower trapping rates by G-β-CD addition. In addition, the structures of CD-inclusion complexes of spin traps were established by means of 1D and 2D NMR measurements. Based on the results, the influences of inclusion on the spin-trapping rate processes and spin-adduct stabilizations were discussed. We conclude that substituents in DMPO-type spin traps may be modified to provide best spin-trapping capabilities in the presence or absence of CD.

Original languageEnglish
Pages (from-to)357-364
Number of pages8
JournalJournal of Inclusion Phenomena and Macrocyclic Chemistry
Volume66
Issue number3
DOIs
Publication statusPublished - 2010

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Keywords

  • Cyclodextrin
  • ESR
  • Inclusion complex
  • NMR
  • Spin trap

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Food Science
  • Chemistry(all)

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