N. Deighton et al., IDENTIFICATION BY EPR SPECTROSCOPY OF CARVACROL AND THYMOL AS THE MAJOR SOURCES OF FREE-RADICALS IN THE OXIDATION OF PLANT ESSENTIAL OILS, Journal of the Science of Food and Agriculture, 63(2), 1993, pp. 221-225
The formation of stable free radicals upon reaction of the essential o
ils of 10 plant species with ultraviolet radiation and the superoxide
radical anion, O2-, has been investigated by electron paramagnetic res
onance (EPR) spectroscopy. Only the oils from oregano, summer savory a
nd thyme produced EPR spectra and the results can be accounted for in
terms of free radicals produced by the closely related phenolics, carv
acrol and thymol. These observations are interpreted in terms of the k
nown antioxidant properties of these molecules.