New insights into the aquatic photochemistry of fluoroquinolone antibiotics: Direct photodegradation, hydroxyl-radical oxidation, and antibacterial activity changes
New insights into the aquatic photochemistry of fluoroquinolone antibiotics: Direct photodegradation, hydroxyl-radical oxidation, and antibacterial activity changes
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氟喹诺酮类抗生素水生光化学的新见解：直接光降解、羟基自由基氧化和抗菌活性变化
DOI：
10.1016/j.scitotenv.2015.04.099
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发表时间：
2015-09-15
影响因子：
9.8
通讯作者：
Yao, Ziwei
中科院分区：
文献类型：
--
作者：
Ge, Linke;Na, Guangshui;Yao, Ziwei
氟喹诺酮类抗生素（FQs）在地表沃茨中的普遍存在和光反应性促使人们对其水溶液光化学行为有新的认识。研究了环丙沙星、达氟沙星、左氟沙星、沙拉芬、二氟沙星和恩诺沙星6种氟喹诺酮类药物的光化学反应。提出了计算它们在阳光照射的表面沃茨中的太阳直接光降解半衰期（t（d，E））和羟基自由基氧化半衰期（t（中心点OH，E））的方法。在北纬45度，td，E值范围为0.56分钟至28.8分钟，而t（中心点OH，E）的范围为3.24小时至33.6小时，这表明大多数氟喹诺酮往往经历快速直接光解，而不是羟基自由基氧化在表面沃茨。然而，左氧氟沙星和沙拉芬的案例研究表明，羟基自由基氧化诱导危险的光氯化，并导致多重降解途径，如哌嗪羟基化和清除。利用大肠杆菌进一步研究了FQs在不同沃茨中光降解所引起的抗菌活性变化，发现活性变化依赖于主要的光降解途径和产物。具有完整FQ核的初级中间体保留了显著的抗菌活性。这些结果对于评估氟喹诺酮在地表沃茨中的归宿和风险具有重要意义。(C)2015 Elsevier B.V.版权所有。
The ubiquity and photoreactivity of fluoroquinolone antibiotics (FQs) in surface waters urge new insights into their aqueous photochemical behavior. This study concerns the photochemistry of 6 FQs: ciprofloxacin, danofloxacin, levofloxacin, sarafloxacin, difloxacin and enrofloxacin. Methods were developed to calculate their solar direct photodegradation half-lives (t(d,E)) and hydroxyl-radical oxidation half-lives (t(center dot OH,E)) in sunlit surface waters. The td, E values range from 0.56 min to 28.8 min at 45 degrees N latitude, whereas t(center dot OH,E) ranges from 3.24 h to 33.6 h, suggesting that most FQs tend to undergo fast direct photolysis rather than hydroxyl-radical oxidation in surface waters. However, a case study for levofloxacin and sarafloxacin indicated that the hydroxyl-radical oxidation induced risky photochlorination and resulted inmulti-degradation pathways, such as piperazinyl hydroxylation and clearage. Changes in the antibacterial activity of FQs caused by photodegradation in various waters were further examined using Escherichia coli, and it was found that the activity evolution depended on primary photodegradation pathways and products. Primary intermediates with intact FQ nuclei retained significant antibacterial activity. These results are important for assessing the fate and risk of FQs in surface waters. (C) 2015 Elsevier B.V. All rights reserved.