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International Journal of Environmental... Oct 2022In the present study, PbO electrodes, doped with different doses of Er (0%, 0.5%, 1%, 2%, and 4%), were fabricated and characterized. Surface morphology characterization...
In the present study, PbO electrodes, doped with different doses of Er (0%, 0.5%, 1%, 2%, and 4%), were fabricated and characterized. Surface morphology characterization by SEM-EDS and XRD showed that Er was successfully doped into the PbO catalyst layer and the particle size of Er-PbO was reduced significantly. Electrochemical oxidation of sulfamerazine (SMR) in the Er-PbO anode system obeyed te pseudo first-order kinetic model with the order of 2% Er-PbO > 4% Er-PbO > 1% Er-PbO > 0.5% Er-PbO > 0% PbO. For 2% Er-PbO, was 1.39 h, which was only 0.93 h for 0% PbO. Effects of different operational parameters on SMR degradation in 2% Er-PbO anode system were investigated, including the initial pH of the electrolyte and current density. Under the situation of an initial pH of 3, a current density of 30 mA·cm, a concentration of SMR 30 mg L, and 0.2 M NaSO used as supporting electrolyte, SMR was totally removed in 3 h, and COD mineralization efficiency was achieved 71.3% after 6 h electrolysis. Furthermore, the degradation pathway of SMR was proposed as combining the active sites identification by density functional calculation (DFT) and intermediates detection by LC-MS. Results showed that Er-PbO has great potential for antibiotic wastewater treatment in practical applications.
Topics: Sulfonamides; Sulfamerazine; Water Pollutants, Chemical; Oxides; Electrodes; Sulfanilamide; Oxidation-Reduction; Anti-Bacterial Agents; Titanium
PubMed: 36294088
DOI: 10.3390/ijerph192013503 -
Journal of the American Chemical Society Oct 2022Sulfoximines are increasingly incorporated in agrochemicals and pharmaceuticals, with the two enantiomers of chiral sulfoximines often having profoundly different...
Sulfoximines are increasingly incorporated in agrochemicals and pharmaceuticals, with the two enantiomers of chiral sulfoximines often having profoundly different binding interactions with biomolecules. Therefore, their application to drug discovery and development requires the challenging preparation of single enantiomers rather than racemic mixtures. Here, we report a general and fundamentally new asymmetric synthesis of sulfoximines. The first -alkylation of sulfenamides, which are readily accessible sulfur compounds with one carbon and one nitrogen substituent, represents the key step. A broad scope for -alkylation was achieved by rhodium-catalyzed coupling with diazo compounds under mild conditions. When a chiral rhodium catalyst was utilized with loadings as low as 0.1 mol %, the -alkylation products were obtained in high yields and with enantiomeric ratios up to 98:2 at the newly generated chiral sulfur center. The -alkylation products were efficiently converted to a variety of sulfoximines with complete retention of stereochemistry. The utility of this approach was further demonstrated by the asymmetric synthesis of a complex sulfoximine agrochemical.
Topics: Agrochemicals; Alkylation; Carbon; Catalysis; Molecular Structure; Nitrogen; Pharmaceutical Preparations; Rhodium; Stereoisomerism; Sulfamerazine; Sulfur
PubMed: 36154032
DOI: 10.1021/jacs.2c09158 -
Chemosphere Nov 2022Seeking effective methods to degrade organic pollutants has always been a hot research field. In this work, MoS/FeO catalyst was synthesized by hydrothermal method with...
Seeking effective methods to degrade organic pollutants has always been a hot research field. In this work, MoS/FeO catalyst was synthesized by hydrothermal method with MoS as carrier to construct an advanced oxidation system of electrochemical enhanced MoS/FeO-activated peroxymonosulfate (E/MoS/FeO/PMS). The materials were characterized by X-ray diffraction, transmission electron microscopy and X-ray photoelectron spectroscopy. The degradation efficiency of sulfamerazine (SM1) by E/MoS/FeO/PMS system was investigated and reaction mechanism was explored. The results showed that the removal rates of SM1 within 30 min were 31%, 20% and 89% with FeO, MoS and MoS/FeO as catalysts, respectively. The characterization results revealed that Fe(III) on the surface of FeO was reduced to Fe(II) and Mo(IV) was oxidized to Mo(VI) in the presence of MoS. The synergistic effect between FeO and MoS enhanced the PMS decomposition and improved the SM1 removal efficiency. Free radical quenching experiments showed that SO⋅, ·OH, O· and O were all involved in the degradation of SM1, and the effect of O was more significant than other active substances. Low concentrations of Cl and humic acid (HA) had no significant inhibitory effect on the degradation of SM1, while HCO had a significant inhibitory effect on the E/MoS/FeO/PMS system. In addition, catalyst cycling experiments showed that MoS/FeO maintained good stability before and after the catalytic reaction process.
Topics: Environmental Pollutants; Ferric Compounds; Ferrous Compounds; Free Radicals; Humic Substances; Molybdenum; Peroxides; Sulfamerazine
PubMed: 36030935
DOI: 10.1016/j.chemosphere.2022.136198 -
Ecotoxicology and Environmental Safety Sep 2022Sulfonamide antibiotics (SAs) are widely used in medicine, animal husbandry and aquaculture, and excessive intake of SAs may pose potential toxicity to organisms. The...
Sulfonamide antibiotics (SAs) are widely used in medicine, animal husbandry and aquaculture, and excessive intake of SAs may pose potential toxicity to organisms. The toxicological mechanisms of two classical SAs, sulfamerazine (SMR) and sulfamethoxazole (SMT), were investigated by molecular docking, DFT and multi-spectroscopic techniques using HSA and BSA as model proteins. The quenching of HSA/BSA endogenous fluorescence by SMR was higher than that by SMT due to the stronger binding effect of the pyrimidine ring on HSA/BSA compared to the oxazole ring, and that result was consistent with that predicted by DFT calculations. Thermodynamic parameters show that the binding of SAs to HSA/BSA is an exothermic process that proceeds spontaneously (ΔG < 0). Marker competition experiments illustrate that the binding site of SMR/SMT on serum albumin is located in subdomain IIIA. The combination of SAs and HSA/BSA is mainly realized by hydrogen bond and hydrophobic interaction, and the concept is also supported by molecular modeling. The reduced α-helix content of HSA/BSA induced by SMR/SMT indicates a greater stretching of the protein α-helix structure of the SMR/SMT-HSA/BSA. The results could provide useful toxicological information on the hazards of SAs in response to growing concern that SAs may pose a toxic threat to organisms.
Topics: Animals; Anti-Bacterial Agents; Binding Sites; Circular Dichroism; Density Functional Theory; Molecular Docking Simulation; Protein Binding; Serum Albumin, Bovine; Spectrometry, Fluorescence; Sulfanilamide; Sulfonamides; Thermodynamics
PubMed: 35987082
DOI: 10.1016/j.ecoenv.2022.113979 -
Analytica Chimica Acta Aug 2022A novel strategy utilizing the quartz crystal microbalance (QCM) was developed for the in situ discrimination of polymorphic nucleation (form-I and form-II) and phase...
A novel strategy utilizing the quartz crystal microbalance (QCM) was developed for the in situ discrimination of polymorphic nucleation (form-I and form-II) and phase transformation of sulfamerazine (SMZ) in cooling crystallization. According to Ostwald's rule of stages, metastable form-I of SMZ is first nucleated and then shifted to stable form-II by solution-mediated phase transformation. Through surface modification with the self-assembled monolayer technique of a functional group, QCM distinctively detects the formation of the two polymorphs. The results indicated that -NH (among the several functional groups tested) selectively accommodated stable form-II on the QCM sensor's surface and completely prevented the adsorption of metastable form-I on the surface. Therefore, the-NH-terminated QCM detected the formation of form-I only using the solution viscosity variation on the surface. However, it monitored the nucleation and growth of form-II via the solid mass change on the surface during the phase transformation of form-I to form-II. This strategy suggests a new and precise solution for in situ discrimination of SMZ polymorphs and their phase transformation.
Topics: Crystallization; Quartz; Quartz Crystal Microbalance Techniques; Sulfamerazine
PubMed: 35934408
DOI: 10.1016/j.aca.2022.340137 -
Waste Management (New York, N.Y.) Aug 2022Antibiotics and antibiotic resistance genes (ARGs) in sewage sludge can cause high ecotoxicological risks in the environment and public health concerns. The aims of this...
Antibiotics and antibiotic resistance genes (ARGs) in sewage sludge can cause high ecotoxicological risks in the environment and public health concerns. The aims of this study were to establish enzymatic integrated in-situ advanced anaerobic digestion (AAD) by adding cellulase and papain as well as the two enzymes combined with zero valent iron (ZVI) directly into the anaerobic digesters to explore the removal of antibiotics and ARGs under the mesophilic condition (35 °C). The methane production potential during in-situ AAD was effectively improved. Papain and cellulase at 30 mg/gTSS were most effective in improving antibiotic removal. The removal of sulfamerazine (SMZ) and sulfadiazine (SMR) could reach 89.10 % and 71.75 %. Combined enzymes with ZVI also enhanced the removal of all target antibiotics, especially roxithromycin (ROX), SMZ and SMR most significantly. Except for sul1, tetA and tetB, the removal of ARGs by papain reached 6.33 %-82.15 %. The addition of cellulase effectively improved tetA removal. The combination of biological enzymes further enhanced the removal of qnrS and ermX. The tetG, tetB, sul3, ermX, ermT, qnrS, and aac(6')-IB-CR by combined enzymes with ZVI could even not be detected after digestion. Addition of papain, cellulase, and ZVI caused variations in the dominant bacteria. All target antibiotics presented significant positive correlations with the genera norank_f__Bacteroidetes_vadinHA17, norank_f__norank_o__SJA-15, norank_f__norank_o__Aminicenantales. Redundancy analysis showed archaea Methanosaeta and Candidatus_ Methanoacidiosum genera greatly contributed to antibiotics removal with the combination of enzymes and ZVI. Co-occurrence network analysis indicated the removal of ARGs was mainly based on the changes of existence of host bacteria.
Topics: Anaerobiosis; Anti-Bacterial Agents; Bacteria; Cellulases; Drug Resistance, Microbial; Genes, Bacterial; Iron; Papain; Sewage
PubMed: 35926402
DOI: 10.1016/j.wasman.2022.07.020 -
Chirality Sep 2022Although the power of chiral sulfinamide reagents in synthetic chemistry has long been recognized, methods for their synthesis are still auxiliary-based approaches which...
Although the power of chiral sulfinamide reagents in synthetic chemistry has long been recognized, methods for their synthesis are still auxiliary-based approaches which possess the disadvantages of poor atom economy and limited substrate universality. Due to the weak nucleophilicity of amides, it is more difficult to prepare chiral N-acylsulfinamides by traditional methods. Herein, we describe an example of catalytic asymmetric synthesis of N-acyl sulfinamides. In this work, N-acyl sulfenamides act as useful substrates, because of the indispensable N-H bond, which could form an efficient hydrogen bond with chiral phosphoric acid. H O (35%) was used as the terminal oxidant for preparation of sulfinamides in high yields and enantioselectivities, which could be easily derivatized to sulfoxides without loss of the enantioselectivity.
Topics: Amides; Catalysis; Stereoisomerism; Sulfamerazine
PubMed: 35681267
DOI: 10.1002/chir.23478 -
Journal of Colloid and Interface Science Oct 2022In the photo-Fenton reactions, fast recombination of photoinduced electrons and holes in Fe-based metal-organic frameworks (Fe-MOFs) slows Fe(III)/Fe(II) cycle, which...
In the photo-Fenton reactions, fast recombination of photoinduced electrons and holes in Fe-based metal-organic frameworks (Fe-MOFs) slows Fe(III)/Fe(II) cycle, which remains big challenge that significantly retards the overall process. Herein, NH-MIL-88B(Fe) (NM88) was modified with 3,5-diaminobenzoic acid (DB) and TPB-DMTP-COF (COF-OMe) to in situ construct NM88(DB)/COF-OMe composite that could strongly harvest the visible light for photo-Fenton degradation of sulfamerazine (SMR). With the addition of DB, electron-donating effect of NM88 was strengthened, which then promoted amino groups to react with aldehyde groups (Schiff-base), and thus highly facilitated the interfacial contact between NM88 and COF-OMe. Such modifications increased the degradation rate constants for NM88(DB)/COF-OMe to 15.1 and 17.3 times that of NM88 and COF-OMe respectively with good reusability. Moreover, the catalyst exhibited 32-170 times higher degradation kinetics in comparison to other reported catalysts. Results showed that due to the Schiff-base reaction between NM88(DB) and COF-OMe, electron density on Fe(III) was decreased; and the photogenerated electrons of COF-OMe moved to NM88(DB) to reduce Fe(III), thus resulting in the generation of highly active Fe(II) and ·OH species. Furthermore, the main reactive species were determined to be ·OH and ·O by trapping experiments, and a possible mechanism of the degradation system followed Z-scheme charge transfer.
Topics: Electronics; Ferric Compounds; Ferrous Compounds; Sulfamerazine
PubMed: 35660881
DOI: 10.1016/j.jcis.2022.05.142 -
Pharmaceutics May 2022Several literature publications have described the potential application of active pharmaceutical ingredient (API)-polymer phase diagrams to identify appropriate...
Several literature publications have described the potential application of active pharmaceutical ingredient (API)-polymer phase diagrams to identify appropriate temperature ranges for processing amorphous solid dispersion (ASD) formulations via the hot-melt extrusion (HME) technique. However, systematic investigations and reliable applications of the phase diagram as a risk assessment tool for HME are non-existent. Accordingly, within AbbVie, an HME risk classification system (HCS) based on API-polymer phase diagrams has been developed as a material-sparing tool for the early risk assessment of especially high melting temperature APIs, which are typically considered unsuitable for HME. The essence of the HCS is to provide an API risk categorization framework for the development of ASDs via the HME process. The proposed classification system is based on the recognition that the manufacture of crystal-free ASD using the HME process fundamentally depends on the ability of the melt temperature to reach the API's thermodynamic solubility temperature or above. Furthermore, we explored the API-polymer phase diagram as a simple tool for process design space selection pertaining to API or polymer thermal degradation regions and glass transition temperature-related dissolution kinetics limitations. Application of the HCS was demonstrated via HME experiments with two high melting temperature APIs, sulfamerazine and telmisartan, with the polymers Copovidone and Soluplus. Analysis of the resulting ASDs in terms of the residual crystallinity and degradation showed excellent agreement with the preassigned HCS class. Within AbbVie, the HCS concept has been successfully applied to more than 60 different APIs over the last 8 years as a robust validated risk assessment and quality-by-design (QD) tool for the development of HME ASDs.
PubMed: 35631630
DOI: 10.3390/pharmaceutics14051044 -
Environmental Research Sep 2022Heteroatom-doped carbon materials can effectively activate HO into •OH during the metal-free electro-Fenton (EF) process. However, information on bifunctional...
Heteroatom-doped carbon materials can effectively activate HO into •OH during the metal-free electro-Fenton (EF) process. However, information on bifunctional catalysts for the simultaneous generation and activation of HO is scarce. In this study, O- and F-doped porous carbon cathode materials (PPCs) were prepared by the direct carbonization of polyvinylidene fluoride (PVDF) for sulfamerazine (SMR) removal in a metal-free EF process. The porous structure and chemical composition of the PPCs were regulated by the carbonization temperature. PPC-6 (carbonized at 600 °C) exhibited optimal electrocatalytic performance in terms of electrochemical HO generation and activation owing to its high specific surface area, mesoporous structure, and optimum fractions of doped O and F. Excellent performance of the 2e oxygen reduction reaction was found with an HO selectivity of 93.5% and an average electron transfer number of 2.13. An HO accumulative concentration of 103.9 mg/L and an SMR removal efficiency of 90.1% were achieved during the metal-free EF process. PPC-6 was able to stably remove SMR over five consecutive cycles, retaining 92.6% of its original performance. Quantitative structure-activity relationship analysis revealed that doped oxygen functional groups contributed substantially to HO generation, and semi-ionic C-F bonds with high electronegativity were the cause of the activation of HO to •OH. These findings suggest that the PVDF-derived carbonaceous catalysts are feasible and desirable for metal-free EF processes.
Topics: Carbon; Fluorocarbon Polymers; Hydrogen Peroxide; Metals; Oxidation-Reduction; Oxygen; Polyvinyls; Porosity; Sulfamerazine; Water Pollutants, Chemical
PubMed: 35613635
DOI: 10.1016/j.envres.2022.113508