Photolysis of the Photosensitizers Bithionol and Fentichlor
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.
KeywordsHydroxyl Glutathione Cysteine Adduct Dermatitis
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