水中氟喹诺酮类抗生素光降解过程中抑菌活性的变化  

Changes in antibacterial activity of fluoroquinolone antibiotics due to photodegradation

作　　者：任红蕾[1,2] 张蓬[2] 李凯[2,3] 葛林科[2] 那广水[2] 姜华[1] 

机构地区：[1]辽宁师范大学生命科学学院,大连116029 [2]国家海洋环境监测中心,国家海洋局近岸海域生态环境重点实验室,大连116023 [3]大连海洋大学海洋科技与环境学院,大连116023

出　　处：《环境化学》2014年第5期753-759,共7页Environmental Chemistry

基　　金：国家自然科学基金(21007013,41106079);国家海洋局青年海洋科学基金(2012501);近岸海域生态环境重点实验室开放基金(201007)资助

摘　　要：本文采用体外抑菌实验,以大肠杆菌(Escherichia coli)为受试菌种,比较研究了模拟日光(λ>290 nm)照射下,恩诺沙星、环丙沙星、二氟沙星、沙拉沙星等4种不同氟喹诺酮类抗生素(FQs)在纯水、淡水、海水中光降解过程抑菌活性的变化及作用机制.发现恩诺沙星和二氟沙星在光解初始阶段(0—t1/2),光解溶液的抑菌活性没有出现显著降低的趋势(P>0.05),这是因为其光转化分别生成了抑菌活性更大的产物环丙沙星和沙拉沙星,且这两种产物在0—t1/2不断积累.区别于前两种FQs,环丙沙星和沙拉沙星光降解过程中抑菌活性呈明显降低趋势(P<0.01),表明其产物的抑菌活性相对于母体化合物可以忽略.纯水、淡水和海水中同种FQ光解过程中表现出相似的抑菌活性变化规律.Photodegradation is an important transformation pathway for fluoroquinolone antibiotics （FQs） in surface waters, so it is of great significance to investigate their antibacterial activity ecological risk due to photodegradation. In the present study, antibacterial activity changes and the corresponding mechanisms of four FQs （ enrofloxacin, ciprofloxacin, difloxacin and sarafloxacin ） due to their simulated solar （λ〉290 nm） photodegradation in various waters were examined by in vitro antibacterial experiments using Escherichia coli （ E. coli） as the test species. It was found that the antibacterial activity of the photolysis solutions of enrofloxacin and difloxacin did not change significantly （P〉0.05） in the initial photodegradation period （0-t1/2）, which was attributed to the formation and accumulation of degradation intermediates （ e. g. ciprofloxacin and sarafloxacin, respectively ） that were also antibacterial to E. coli. However, the antibacterial activity of ciprofloxacin and sarafloxacin solutions decreased obviously （ P〈0. 01 ） during photodegradation, suggesting that their photolytic products exhibited less antibacterial activity relative to the parent compounds. Evolution of antibacterial activity of the individual FQ photolytic solutions was similar in pure water, fresh water and sea water. These results are of importance toward the goal of assessing the phototransformation risk of FQs in surface waters. Especially for some FQs, such as enrofloxacin＆amp;nbsp;and difloxacin, their risk needs to be particularly concerned.

关 键 词：氟喹诺酮类抗生素 光降解 抑菌活性 光化学转化风险 水环境 

分 类 号：X131[环境科学与工程—环境科学] X172