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.

A new ent-clerodane diterpene from the aerial parts of Baccharis gaudichaudiana.

A new ent-clerodane diterpene, named bacchariol (1) was isolated from the aerial parts of Baccharis gaudichaudiana DC. (Compositae), together with known ent-clerodane diterpenes (2, 3), eight known flavonoids (4-11) and 3, 5-dicaffeoylquinic acid (12). Their structures were determined by spectroscopic analyses. Flavonoids (7, 8, 11) and 12 showed moderate scavenging activities toward 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radicals.