A 6-fluoroquinolone (norfloxacin) and the naphthyridine analogue enoxacin give the corresponding 6-hydroxy derivatives by irradiation in water at pH 7.2 and, with lower efficiency, at pH 4.5 and 10. At pH 1 no defluorination takes place and the piperazinyl side chain is degraded. The 6,8-difluoro derivative lomefloxacin is defluorinated selectively from position 8 over the entire pH range considered (pH 1 to 10). The intermediate cation in position 8 does not add water and rather undergoes insertion into the β-CH bond of the neighboring N-ethyl group. The cation adds chloride, however. The structure–photoreactivity relationship for fluoroquinolones and the relation with the known phototoxicity of these compounds are commented upon.
一种 6-
氟喹诺酮(
诺氟沙星)和
萘啶类似物
依诺沙星在 pH 值为 7.2 的
水中经辐照可产生相应的 6-羟基衍
生物,在 pH 值为 4.5 和 10 的
水中则效率较低。在 pH 值为 1 时,不会发生脱
氟反应,
哌嗪侧链会发生降解。在整个 pH 值范围内(pH 值 1 至 10),6,8-二
氟衍
生物洛美沙星可选择性地从第 8 位脱
氟。位于第 8 位的中间阳离子不会加
水,而是插入邻近 N-乙基的 β-CH 键。不过,该阳离子加入了
氯。本文对
氟喹诺
酮类化合物的结构-光反应关系以及与已知光毒性的关系进行了评论。