Temperature Effects on the Formation of Free Radicals in the Amino Acids

Publisher Website
Google Scholar
Abstract
Influence of temperature on free radicals formed by gamma irradiation in the amino acids has been investigated by means of electron spin reasonance. The free radicals observed at room temperature in the amino acids are not the same as those found when the sample is irradiated at the temperature of liquid nitrogen, 77[degree]K. When the sample is irradiated at the lower temperature and allowed to warm to room temperature, the radical obtained is usually the same as that produced by irradiation at room temperature. Although we cannot identify specifically the primary free radicals produced by irradiation at 77[degree]K, we can make some general deductions about them. The hyperfine structure is not usually spread out as much, nor is it as resolvable, as at room temperature. When the hyperfine structure is resolved, it usually consists of fewer components than does the corresponding pattern at room temperature. At 77[degree]K there is more often evidence for more than one kind of free radical than at room temperature. These characteristic differences between free radicals produced at 77[degree]K and those produced at room temperature would seem to result from the greater compactness and rigidity of structure at the lower temperature, which would tend to prevent both the escape of atom groups and the reorientation or rearrangement of parts of the damaged molecule to form the most stable free radical.

This publication has 0 references indexed in Scilit: