Radioprotection

Although methyl mercaptan (CH3SH) is of little biological interest in terms of its radioprotective properties, a wealth of experimental information is available and can be used in testing a novel theoretical model to be employed in the subsequent study of cysteamine, an experimentally known radioprotective compound. Among those properties is the ionization energy of the thiol. 

In the investigation of species resulting from the indirect effect, calculations of the electron affinities and ionization potentials of the hydrogen and hydroxyl adduct DNA base radicals allow for further understanding of possible electron transfer processes. In conjunction with experimental observations, our ab initio results provide us with a complete list of redox properties for the DNA radical intermediates and predict that only a fraction of the base adduct radicals can be reduced via electron transfer from thiols, while DNA sugar radicals will be reduced. 

Recent work shows that density functional theory (DFT) employing the Becke three parameter exchange functional B3-LYP [165] is superior to MP2 ab 

Becker and M.D. Sevilla, in Advances in Radiation Biology, eds. J.T. Lett H. Adler, 121-180, Academic Press, New-York, 1993. 

Chatterjee, in Radiation Chemistry Principles and Applications.VCH, New York, 1987. 

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Various other properties intestinal antiseptic (932, 933), fungicide (934, 935), insecticide (895. 898), coccidiostatic activity (936), car-cinolytic activity (937), radioprotective activity (938), antimutagenic activity (939, 940). 

The ability of various selenium heterocycles to check the loss of orthophosphate caused by irradiation of ATP has been studied by Brucker and Bulka (92). They found that only 2-amino-4,5-dimethyiselenazole shows radioprotective properties, while other 2-aminoselenazoles, selenosemicarbazides, and acetone selenosemicar-bazones possess no such activity but are in addition very sensitive to radiation (93). 

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