Metal Organic Frameworks for Selective Degradation of Amoxicillin in Biomedical Wastes

The accumulation of antibiotics in wastewater has led to the development and spreading of antibiotic resistance in the environment. Amoxicillin (Amox), a beta-lactamic antibiotic, is one of the most frequently consumed antibiotics in the world. We have applied two metal-organic frameworks (MOFs) containing zinc(II) as platforms to degrade Amox. We have predicted the adsorption of this antibiotic via molecular docking calculations which have been further corroborated by means of Fourier transform infrared and UV-Vis spectroscopies, thermogravimetric analysis, X-ray diffraction and scanning microscopy measurements. We have subsequently performed mass spectrometry analysis of Amox@zeolitic imidazolate framework-8 (ZIF-8) and Amox@Zn(1,4-benzenedicarboxylate) (ZnBDC) to demonstrate the degradation of Amox upon contact with the Zn-containing frameworks. We propose a possible pathway for the degradation of Amox involving the cleavage of the four-membered β-lactam ring. These Zn-containing frameworks provide a biocompatible platform for the degradation in solution of Amox, which should also be suitable to degrade other β-lactam antibiotics.

废水中抗生素的蓄积已引发环境中抗生素耐药性的产生与扩散。阿莫西林（Amox）作为β-内酰胺类抗生素，是全球使用最为频繁的抗生素之一。本研究选取两种含锌(II)的金属有机框架（metal-organic frameworks, MOFs）作为降解平台，开展阿莫西林降解实验。通过分子对接计算预测了该抗生素的吸附行为，并借助傅里叶变换红外光谱、紫外-可见光谱、热重分析、X射线衍射以及扫描显微测试对计算结果进行了验证。随后，本研究对阿莫西林负载沸石咪唑酯骨架-8（Amox@ZIF-8）与阿莫西林负载对苯二甲酸锌（Amox@ZnBDC）进行质谱分析，以证实阿莫西林与含锌金属有机框架接触后发生降解。本研究提出了一条涉及四元β-内酰胺环断裂的阿莫西林降解潜在路径。此类含锌金属有机框架为阿莫西林在溶液中的降解提供了生物相容性载体平台，同时也适用于其他β-内酰胺类抗生素的降解。