Radiation Chemistry Studies on Chemotherapeutic Agents: Part I: Pulse Radiolysis of Adrenalin in Aqueous Solutions

Adrenalin has been studied as a model radiation protective agent by means of pulse radiolysis in aqueous solutions. The rate constants for the reactions of adrenalin with e–aq and OH were determined : k(e–aq+ adr—NH+2)= 7.5 × 108 dm3 mol–1 s–1, k(e–aq+ adr—NH)= 2.5 × 108 dm3 mol–1 s–1, and k(OH + adr)= 2.2 × 1010 dm3 mol–1 s–1(pH = 9.2). e–aq attacks the amino group by splitting off methylamine, whereas OH and O–aq lead to the formation of the corresponding adducts of the cyclohexadienyl type. OH radicals can also abstract an electron from an O– group at pH > 8.