Radiolysis of aqueous adenine (vitamin B4) and 8-hydroxyadenine

The radiolysis of adenine (vitamin B4) was studied in aqueous solution (pH∼7.4) saturated either with argon (operating radicals: 44% e−aq, 46% OH, 10% H) or with air (46% OH, 54% O2−) and with N2O (90% OH, 10% H), respectively. The obtained initial Gi-values are: 0.88, 1.16 and 1.45. As main radiolytic product was determined 8-hydroxyadenine (8-HOA), whose yield depends on the OH concentration in the reacting media. Hence, under the same experimental conditions the Gi-values are in media saturated with argon: 0.1, in air: 0.15 and in N2O: 0.29. In aerated solution also a mixture of aldehydes as well as of carboxylic acids were formed, but they were not identified.8-HOA is of some biological interest; therefore, its radiolysis was also investigated under the same conditions. The determined Gi(-8HOA)-values were in airfree solution negligible, in aerated solutions: 3.1 and in the presence of N2O: 4.0. For explanation of the product formation some probable reaction mechanisms were given.