Decomposition of an aqueous solution of [11C]Ro 15-4513: implication of hydrated electrons in the radiolysis of [11C]Ro 15-4513.

An aqueous solution of [(11)C]Ro 15-4513 underwent decomposition to give a few radioactive degradation products. The major degradation product corresponded to that of authentic Ro 15-4513 with (60)Co radiolysis, which showed a molecular weight of 301 (M+H). The structure of this degradation product was estimated to have an amine group instead of an azido group on Ro 15-4513. Radiolysis of Ro 15-4513 was not suppressed by the addition of selective hydroxyl radical scavenger (MeOH, HCOO(-)), in contrast, it was suppressed effectively in the presence of a selective hydrated electron scavenger (NaNO(3)), suggesting that hydrated electrons would play an important role in the radiolysis of [(11)C]Ro 15-4513.