pH Effects on the Spectroscopic and Photochemical Behavior of Enoxacin: A Steady-State and Time-Resolved Study
作者:S. Sortino、G. De Guidi、S. Giuffrida、S. Monti、A. Velardita
DOI:10.1562/0031-8655(1998)067<0167:peotsa>2.3.co;2
日期:——
The spectroscopic and photochemical behavior of Enoxacin (ENX), 1-ethyl-6-fluoro-1,4-dihydro-4-oxo-7-(1-piperazinyl)- 1,8-naphthyridine-3-carboxylic acid, has been investigated in aqueous solutions between pH 3.5 and pH 12. The absorption and emission properties of ENX are strongly affected by pH. The fluorescence quantum yield, 4 x 10(-3) at pH 3.5, increases by a factor of two on going to neutral
依诺沙星(ENX)1-乙基-6-氟-1,4-二氢-4-氧代-7-(1-哌嗪基)-1,8-萘啶-3-羧酸的光谱和光化学行为在pH 3.5至pH 12的水溶液中进行了研究。ENX的吸收和发射性能受pH强烈影响。在pH值为3.5时,荧光量子产率为4 x 10(-3),在达到中性pH值时增加了两倍,而在碱性pH值下观察到了强烈的降低。光降解量子产率也取决于pH,在中性条件下最大(约0.04)。纳秒级的快速光解实验证实,吸收瞬变的产率在中性pH值下最大,而在酸性和碱性pH值下降低到零。这些结果表明,羧基的解离和哌嗪基残基的质子化都是形成ENX的光化学活性形式的关键步骤。有人提出,由于两性离子的三重态伴随碳正离子的形成,CF键的杂合裂解会导致F的损失。还提出了将该中间体发展为最终产品的途径。