Zhao Cen, Arroyo-Mora Luis E, DeCaprio Anthony P, Dionysiou Dionysios D, O'Shea Kevin E, Sharma Virender K
Department of Chemistry and Biochemistry, Florida International University, Miami, FL 33199, USA.
Department of Forensic and Investigative Science, West Virginia University, 1600 University Avenue. Morgantown West Virginia 26505.
Water Res. 2023 Apr 15;233:119773. doi: 10.1016/j.watres.2023.119773. Epub 2023 Feb 23.
The presence of cylindrospermopsin (CYN), a potent cyanotoxin, in drinking water sources poses a tremendous risk to humans and the environment. Detailed kinetic studies herein demonstrate ferrate(VI) (FeO, Fe(VI)) mediated oxidation of CYN and the model compound 6-hydroxymethyl uracil (6-HOMU) lead to their effective degradation under neutral and alkaline solution pH. A transformation product analysis indicated oxidation of the uracil ring, which has functionality critical to the toxicity of CYN. The oxidative cleavage of the C5=C6 double bond resulted in fragmentation of the uracil ring. Amide hydrolysis is a contributing pathway leading to the fragmentation of the uracil ring. Under extended treatment, hydrolysis, and extensive oxidation lead to complete destruction of the uracil ring skeleton, resulting in the generation of a variety of products including nontoxic cylindrospermopsic acid. The ELISA biological activity of the CYN product mixtures produced during Fe(VI) treatment parallels the concentration of CYN. These results suggest the products do not possess ELISA biological activity at the concentrations produced during treatment. The Fe(VI) mediated degradation was also effective in the presence of humic acid and unaffected by the presence of common inorganic ions under our experimental conditions. The Fe(VI) remediation of CYN and uracil based toxins appears a promising drinking water treatment process.
饮用水源中存在的强效蓝藻毒素柱孢藻毒素（CYN）对人类和环境构成了巨大风险。本文详细的动力学研究表明，高铁酸盐（VI）（FeO，Fe（VI））介导的CYN和模型化合物6 - 羟甲基尿嘧啶（6 - HOMU）的氧化导致它们在中性和碱性溶液pH条件下有效降解。转化产物分析表明尿嘧啶环发生了氧化，这对CYN的毒性至关重要。C5 = C6双键的氧化裂解导致尿嘧啶环断裂。酰胺水解是导致尿嘧啶环断裂的一个促成途径。在延长处理下，水解和广泛氧化导致尿嘧啶环骨架完全破坏，产生包括无毒柱孢藻毒素酸在内的多种产物。Fe（VI）处理过程中产生的CYN产物混合物的ELISA生物活性与CYN浓度平行。这些结果表明，在处理过程中产生的浓度下，产物不具有ELISA生物活性。在我们的实验条件下，Fe（VI）介导的降解在腐殖酸存在下也有效，并且不受常见无机离子存在的影响。Fe（VI）对CYN和基于尿嘧啶的毒素的修复似乎是一种有前景的饮用水处理工艺。
