Adsorption and transformation of tetracycline antibiotics with aluminum oxide
Adsorption and transformation of tetracycline antibiotics with aluminum oxide
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DOI：
10.1016/j.chemosphere.2010.03.020
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发表时间：
2010-05-01
期刊：
影响因子：
8.8
通讯作者：
Huang, Ching-Hua
中科院分区：
文献类型：
--
作者：
Chen, Wan-Ru;Huang, Ching-Hua
四环素类抗生素(TCs)，包括四环素(TTC)、金霉素(CTC)和土霉素(OTC)，对氧化铝(Al2O3)有强烈吸附作用，表面相互作用促进TCs的结构转变。后一种现象以前并未得到广泛认识。通常，TC 对 Al2O3 的快速吸附发生在前 3 小时内（[TC] = 40 μM，[Al2O3]=1.78 g L-1，pH = 5，T=22 摄氏度），随后母体化合物连续一级衰减（k(obs) = 15 +/- 1.0、18 +/- 1.0 和 6.2 +/- 0.9 x 10(-3) h(-1) 分别用于 TTC、CTC 和 OTC）和产品形成。 TC 的转化反应速率与 Al2O3 表面的吸附密切相关。在中性 pH 值左右的条件下，吸附和转化发生率最高。产品评价表明，Al2O3 促进 TIC 脱水生成脱水四环素 (AHTTC)、TIC 差向异构化以及 Al-TTC 复合物的形成。 Al2O3 主要促进 CTC 向 iso-CTC 的转化。表面结合的Al(+III)作为路易斯酸位点促进TC的上述转化。 AHTTC 的形成因其较高的细胞毒性而受到特别关注。这项研究的结果表明，氧化铝可能会通过吸附和转化影响水生环境中TC抗生素的命运。 (C) 2010 Elsevier Ltd. 保留所有权利。
Tetracycline antibiotics (TCs) including tetracycline (TTC), chlorotetracycline (CTC) and oxytetracycline (OTC) adsorb strongly to aluminum oxide (Al2O3), and the surface interaction promotes structural transformation of TCs. The latter phenomenon was not widely recognized previously. Typically, rapid adsorption of TCs to Al2O3 occurs in the first 3 h ([TC] = 40 mu M, [Al2O3]=1.78 g L-1, pH = 5, and T=22 degrees C), followed by continuous first-order decay of the parent compound (k(obs) = 15 +/- 1.0, 18 +/- 1.0 and 6.2 +/- 0.9 x 10(-3) h(-1) for TTC, CTC and OTC, respectively) and product formation. The transformation reaction rate of TCs strongly correlates with adsorption to Al2O3 surfaces. Both adsorption and transformation occur at the highest rate at around neutral pH conditions. Product evaluation indicates that Al2O3 promotes dehydration of TIC to yield anhydrotetracycline (AHTTC), epimerization of TIC, and formation of Al-TTC complexes. Al2O3 promotes predominantly the transformation of CTC to iso-CTC. The surface-bound Al(+III) acts as a Lewis acid site to promote the above transformation of TCs. Formation of AHTTC is of special concern because of its higher cytotoxicity. Results of this study indicate that aluminum oxide will likely affect the fate of TC antibiotics in the aquatic environment via both adsorption and transformation. (C) 2010 Elsevier Ltd. All rights reserved.