Pulse radiolysis study on gatifloxacin——A fluoroquinolone antibiotic  

作　　者：LI HaiXia LIU YanCheng TANG RuiZhi ZHANG Peng FU HaiYing YAO SiDe WANG WenFeng 

机构地区：[1]Shanghai Institute of Applied Physics,Chinese Academy of Sciences,Shanghai 201800,China [2]Graduate University of Chinese Academy of Sciences,Beijing 100049,China

出　　处：《Science China Chemistry》2012年第7期1358-1363,共6页中国科学（化学英文版）

基　　金：supported by the National Natural Science Foundation of China (21173252)

摘　　要：The reactions between gatifloxacin(GFX) and various one-electron oxidants,such as ˙OH,N3˙,Br2˙ˉ,and SO4˙ˉ,have been studied by pulse radiolysis techniques.The GFX radical anion formed in the reaction of GFX with eaqˉ could either be protonated or deprotonated,and the absorption of GFX radical anion was located at 390 nm.The transient species produced by the reaction of GFX with ˙OH radical shows a broad band in the 380?600 nm region with a shoulder,while the oxidation by N3˙,SO4˙ˉ,and Br2˙ˉ results in an absorption band with λmax = 370 nm.At neutral condition(pH 7),the rate constants of GFX reacting with ˙OH,N3˙,Br2˙ˉ,SO4˙ˉ and eaqˉ are estimated to be 1.0 × 1010,3.1 × 109,2.8 × 109,3.0 × 109,and 1.8 × 1010 dm3 mol?1 s?1,respectively.From the pH dependence on the formation of electron adducts and on the rate constant of GFX with eaqˉ,the pKa of GFX radical anion is estimated to be 5.5 and 9.3.The reactions between gatifloxacin （GFX） and various one-electron oxidants, such as OH, N3, Br2-, and SO4-, have been studied by pulse radiolysis techniques. The GFX radical anion formed in the reaction of GFX with eaq- could either be protonated or deprotonated, and the absorption of GFX radical anion was located at 390 nm. The transient species produced by the reaction of GFX with ＂OH radical shows a broad band in the 380-600 nm region with a shoulder, while the oxidation by N3, SO4-, and Br2- results in an absorption band with ,λmax= 370 nm. At neutral condition （pH 7）, the rate constants of GFX reacting with OH, N3, Br2-, SO4- and eaq- are estimated to be 1.0 × 10^10, 3.1 × 10^9, 2.8 × 10^9, 3.0 × 10^9, and 1.8 × 10^10 dm3 mol-1 s-1, respectively. From the pH dependence on the formation of electron adducts and on the rate constant of GFX with eaq-, the pKa of GFX radical anion is estimated to be 5.5 and 9.3.

关 键 词：GATIFLOXACIN pulse radiolysis radical anion radical cation 

分 类 号：TQ460.6[化学工程—制药化工] X788.03[环境科学与工程—环境工程]