Photolysis of the Photosensitizers Bithionol and Fentichlor

  • A. S. W. Li
  • C. F. Chignell
Conference paper
Part of the NATO ASI Series book series (volume 15)


Antiseptic preparations containing bithionol (BT, 2,2′-thiobis(4,6-dichlorophenol)) and fentichlor (FT, 2,2′-thiobis(4-chlorophenol)) have been reported to cause contact photoallergy1,2, a delayed hypersensitivity response involving the photochemical covalent binding of the photoallergen to skin proteins3. Although it has been previously suggested that free-radicals are involved in photoallergy, there are relatively few studies concerning the free-radical photochemistry of BT and FT. In this report we present a detailed description of the photochemical pathways of these two compounds as studied by electron spin resonance (ESR) spectroscopy. Short-lived photoproducts were studied by reaction with spin-trapping agents to form relatively stable nitroxides (spin adducts) which can be detected by conventional ESR.


Electron Spin Resonance Electron Spin Resonance Spectrum Aryl Radical Spin Adduct Electron Spin Resonance Signal Intensity 
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    Li ASW, Chignell CF (1987) Spectroscopic studies of cutaneous photo-sensitizing agents - X V. PH dependence of the photochemistry of photo- allergens bithionol and fentichlor: An electron spin resonance study of the free radical photoproducts, submitted.Google Scholar
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Copyright information

© Springer- Verlag Berlin Heidelberg 1988

Authors and Affiliations

  • A. S. W. Li
    • 1
  • C. F. Chignell
    • 1
  1. 1.Laboratory of Molecular BiophysicsNational Institute of Environmental Health SciencesUSA

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