Premium
Loss of α‐tocopherol upon exposure to nitric oxide or the sydnonimine SIN‐1
Author(s) -
de Groot Herbert,
Hegi Udo,
Sies Helmut
Publication year - 1993
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(93)81150-x
Subject(s) - chemistry , peroxynitrite , quinone , superoxide , tocopherol , nitric oxide , vitamin e , catalase , superoxide dismutase , antioxidant , radical , photochemistry , biochemistry , organic chemistry , enzyme
SIN‐1 which spontaneously decomposes to yield nitric oxide (NO . and Superoxide anion (O 2 .− radicals caused a loss of microsomal α‐tocopherol paralleled by the formation of α‐tocopheryl quinone. The loss was partially prevented by Superoxide dismutase but not by catalase. The SIN‐1‐induced loss of α‐tocopherol also occurred when tocopherol was dissolved in ethanol/potassium phosphate buffer (20/80, v/v). Likewise, addition of authentic NO . to α‐tocopherol dissolved in ethanol resulted in loss of the vitamin and quinone formation. These results suggest that NO . or its products such as peroxynitrite or nitrogen dioxide react with α‐tocopherol, the quinone derivative being a major oxidation product. Depletion of vitamin E by NO . may contribute to tissue injury, e.g. in neuronal tissues.