Transformation of tetracyclines induced by Fe(III)-bearing smectite clays under anoxic dark conditions

Chen, Ning; Huang, Meiying; Liu, Cun; Fang, Guodong; Liu, Guangxia; Sun, Zhaoyue; Zhou, Dongmei; Gao, Juan; Gu, Cheng

doi:10.1016/j.watres.2019.114997

Cited by 30 publications

(8 citation statements)

References 57 publications

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“…When we employed three types of smectites (saponite, montmorillonite, and nontronite) with different Fe contents, a relatively high Glc consumption was achieved in proportion to the Fe content in the clay minerals (Figure S6). − Although the Fe species in the structure participate in the dehydrogenation of Glc, the reaction proceeds even without Fe. The Lewis acidic site (an electron acceptor) has been suggested to correspond to the Al 3+ substituted by Si 4+ in the SiO 4 tetrahedral sheet of saponite (isomorphic substitution) .…”

Section: Resultsmentioning

confidence: 99%

Acceleration of the Dehydrogenation of d-Glucose to 2-Keto-d-gluconate in Aqueous Amino Acid via Hydrated Stacked Clay Nanosheets

et al. 2022

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The assembly of discrete active species to form periodical nanostructures is essential in realizing low-cost artificial enzymes that mimic natural enzymatic functions in extraordinary bio(chemo)selective reactions. In this study, we developed artificial bifunctional glucose/gluconic acid dehydrogenase from naturally abundant resources: L-aspartic acid (Asp) and montmorillonite (a subgroup of smectite natural clay minerals). β-D-Glucose (Glc) was dehydrogenated to 2-keto-D-gluconate (2-KGA) at 25 and 30 °C in an aqueous acidic solution (pH = 3, 4, and 5). The reaction involved sequential steps that yielded D-gluconic acid (GA) as an intermediate. The second step of the dehydrogenation (GA to 2-KGA) occurred at a higher rate than the first (Glc to GA), which is comparable to the natural process. A negatively charged carboxylate in Asp was required for the dehydrogenation, which donates an electron pair (COO: − ) to the hydroxyl group bonded to the C(1)-position of Glc. The acidic sites in clay served as coenzymatic sites (electron acceptor), promoting the Glc dehydrogenation as the Glc reduced by Asp approached the clay coenzymatic sites. The active coenzymatic structures were developed in 48 h (induction period) through the rearrangement of the adsorbed Asp and Glc molecules on montmorillonite in water (intermediate structure). The spontaneous assembling of the intermediate structures facilitated the one-pot dehydrogenation of Glc to 2-KGA via periodic "hydrated stacked layers" comprising clay nanosheets, Asp, and Glc. The facile synthetic route proposed here is inexpensive and would be beneficial without using both GDH and GADH enzymes bound to a cell membrane.

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Section: Resultsmentioning

confidence: 99%

Acceleration of the Dehydrogenation of d-Glucose to 2-Keto-d-gluconate in Aqueous Amino Acid via Hydrated Stacked Clay Nanosheets

et al. 2022

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“…To test the hypothesis that there is an underlying molecular-level mechanism explaining the pH-dependent Cu II -mediated oxidation of OTC, this study attempted to link pH-dependent speciation of Cu II –OTC complexes with the charge transfer rate k trans derived from the kinetics model of Cu I evolution. Previous studies have identified O3, N4, and O10 atoms of TCs as redox-active donor atoms which could be partially attacked by various electrophilic oxidant. ,,, Quite interestingly, preferentially coordinated tricarbonyl group (O3) at varying pH and additional coordinated dimethylamino group (N4) only at pH 8.5, which were identified by spectral analysis and corresponded with two kinds of site models, also participated into the complexation of Cu II –OTC, suggesting that O3 and N4 atoms as two Cu II -binding sites may be also the redox-active sites as the Cu II -mediated oxidation of OTC. To prove the above hypothesis, the correlation between the concentration of speciation of Cu II –OTC complexes and the charge transfer rate k trans at varying pH conditions were established (Figure ), which indicated that C [Cu II –H 2 L 0 ] at pH 3.0, C [Cu II –HL – ] at pH 5.0, and C [Cu II –L 2– ] at pH 8.5 performed a good linear correlation with k trans ,1 at corresponding pH and k trans ,2 at pH 8.5, i.e., C [speciation of Cu II –O3] was directly proportion to k trans ,1 but C [speciation of Cu II –N4] was inversely proportion to k trans ,2 .…”

Section: Resultsmentioning

confidence: 99%

“…Figure shows that the coordination modes between TCs and metals are various due to the differences in the binding sites of TCs and the properties of the metal ions. In studying their effects on abiotic transformations of antibiotics, − redox-active transition metal ions have attracted researchers extensive interest and attention, especially for Fe III /Fe II and Cu II . Huang’s research group ,, conducted a systematic study on the Cu II -catalyzed transformation of organic pollutants, indicating that Cu II ion could play catalyzed oxidative or hydrolytic roles depending on different functional groups of Cu II -binding complexes and oxygen could reoxidize Cu I back to Cu II to enhance rapid degradation of TCs and β-lactam antibiotics .…”

Section: Introductionmentioning

confidence: 99%

Insights into pH-Dependent Cu^II-Mediated Transformation of Oxytetracycline: Evidence from Cu^I Formation Kinetics

Liu

Zhang

Chen

et al. 2022

ACS Earth Space Chem.

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As animal feed additives, both veterinary tetracycline antibiotics (TCs) and heavy metals, such as CuII ions, often coexisted in aquaculture wastewater and could cotransport as CuII–TCs complexes into groundwater. Previous study emphasized the oxidative role of CuII on the transformation of TCs in the presence of oxygen and the excess CuII, but the transformation of TCs with limited CuII in dark and anoxic groundwater remained unclear. Hence, this study systematically investigated the CuII-mediated transformation of oxytetracycline (OTC), as the most widely used veterinary TCs, under limited CuII and anoxic conditions. The results indicated that OTC degradation was significantly pH-dependent in relation with the speciation of CuII–OTC complexes at pH 3–8.5, and the presence of humic acid (1–10 mg/L) or CaII (10–50 times of CuII) did not change the transformation rate of OTC with CuII significantly. Linking OTC degradation kinetics and CuI formation kinetics, the oxidative role of CuII could be quantitatively evaluated to 6.99–20.2% at varying pH and CuII/OTC ratios from 1:1 to 4:1. A redox site model was built to describe the kinetics of CuI formation, which indicated that CuII-mediated oxidative transformation of OTC is subject to nonidentical specific CuII-binding sites at varying pH. This study is among the first to focus on the CuI formation kinetics to further evaluate the oxidative role of CuII in the catalyzed transformation of TCs, which provides novel insights into the natural attenuation of CuII–TCs complexes as an overlooked class of emerging contaminants in anoxic groundwater.

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“…It has been reported that some antibiotic molecules can complex with surface Fe(III) of iron minerals and that electron transfer within the complex induces the reduction of Fe(III) and the degradation of antibiotics. 28,29 It was presumed that TCs can play the same role as these organic molecules, promoting the generation of ROS and contributing to the oxidation of coexisting As(III). A recent study reported that TTC induced the reductive dissolution of ferrihydrite (Fe(II) release) and led to the release and oxidation of As(III) adsorbed by ferrihydrite in both aerobic and anaerobic conditions.…”

Section: Introductionmentioning

confidence: 99%

The Oxidation and Immobilization of As(III) by Colloidal Ferric Hydroxide in the Concomitant Pollution of Oxytetracycline

Tong

Wang

et al. 2023

ACS EST Eng.

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The concomitant pollution of arsenic and antibiotics has commonly occurred in the environments recently, the behaviors of which may be different from single existence. Colloidal ferric hydroxide (CFH) is ubiquitous, existing in surface waters, seawaters, sediments, and paddy soils. In this study, the interaction between oxytetracycline (OTC) and CFH facilitated OTC degradation and reduced Fe(III) to Fe(II). In oxic conditions, the reactions between dissolved oxygen (DO) and Fe(II) generated reactive oxygen species (ROS). • OH and O 2•− were the main free radicals through electron paramagnetic resonance (EPR) measurement, and 8.1 ± 0.5 μM • OH was detected after 48 h of reaction. Quenching experiments indicated that • OH had dominated the oxidation of As(III). Furthermore, ferric arsenate formed after the oxidation of As(III) to As(V), which greatly decreased As(III) risks in the environment. The transformation of As(III) was also observed with other iron oxides or different antibiotics. The results of this study proved the facilitation of residual antibiotics in the redox process of iron oxides and transformation of co-existing pollutants, which extended our understanding on the roles of organic pollutants in combined contamination.

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Transformation of tetracyclines induced by Fe(III)-bearing smectite clays under anoxic dark conditions

Cited by 30 publications

References 57 publications

Acceleration of the Dehydrogenation of d-Glucose to 2-Keto-d-gluconate in Aqueous Amino Acid via Hydrated Stacked Clay Nanosheets

Acceleration of the Dehydrogenation of d-Glucose to 2-Keto-d-gluconate in Aqueous Amino Acid via Hydrated Stacked Clay Nanosheets

Insights into pH-Dependent Cu^II-Mediated Transformation of Oxytetracycline: Evidence from Cu^I Formation Kinetics

The Oxidation and Immobilization of As(III) by Colloidal Ferric Hydroxide in the Concomitant Pollution of Oxytetracycline

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Transformation of tetracyclines induced by Fe(III)-bearing smectite clays under anoxic dark conditions

Cited by 30 publications

References 57 publications

Acceleration of the Dehydrogenation of d-Glucose to 2-Keto-d-gluconate in Aqueous Amino Acid via Hydrated Stacked Clay Nanosheets

Acceleration of the Dehydrogenation of d-Glucose to 2-Keto-d-gluconate in Aqueous Amino Acid via Hydrated Stacked Clay Nanosheets

Insights into pH-Dependent CuII-Mediated Transformation of Oxytetracycline: Evidence from CuI Formation Kinetics

The Oxidation and Immobilization of As(III) by Colloidal Ferric Hydroxide in the Concomitant Pollution of Oxytetracycline

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Insights into pH-Dependent Cu^II-Mediated Transformation of Oxytetracycline: Evidence from Cu^I Formation Kinetics