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Sulfamerazine (SMR) is a drug used as an antibacterial agent in the treatment of some pathologies, such as bronchitis, prostatitis and urinary tract infections. Although this drug was developed in 1945 and, due to its toxicity, was partially displaced by penicillin, due to the current problem of bacterial resistance, compounds such as SMR have regained validity. In this context, the thermodynamic study of SMR in cosolvent mixtures of acetonitrile (MeCN) + ethanol (EtOH) at nine temperatures (278.15–318.15 K) is presented. The solubility of SMR was determined by UV–Vis spectrophotometry, following the guidelines of the shake-flask method. The solubility process was endothermic in all cases; thus, the minimum solubility was reached in pure EtOH at 278.15 K, and the maximum solubility was reached in pure MeCN at 318.15 K. Both the solution process and the mixing process were entropy-driven. On the other hand, the solubility data were modeled by using the van't Hoff–Yalkowsky–Roseman model, obtaining an overall average relative deviation of 3.9%. In general terms, it can be concluded that the solution process of SMR in {MeCN (1) + EtOH (2)} mixtures is thermodependent, favored by the entropy of the solution and mixture; additionally, the van't Hoff–Yalkowsky–Roseman model allows very good approximations to be obtained and is a simple model that starts from only four experimental data. [ABSTRACT FROM AUTHOR]

Sulfamerazine (4-Amino-N-(4-methylpyrimidin-2-yl) benzenesulfonamide) is a polymorphic molecule crystallizing in three forms: Form I: Pn21a polymorph (with three entries in the Cambridge Structural Database CSD), Form II: Pbca polymorph (with two entries in the CSD) and Form III: P21/c polymorph with only one entry in the CSD). We have experimentally prepared a novel monoclinic P21/c polymorph (Form IV) of the sulfadrug and also obtained crystals of Form II (Pbca polymorph) by following a different synthesis procedure. Both crystals were structurally characterized by single-crystal X-ray diffraction XRD and geometrically optimized by density functional theory DFT. The five crystal structures (1), (3)–(6) of the four mentioned polymorphs were analyzed and discussed in terms of crystal packing, Hirshfeld surface analysis HSA of the intermolecular interactions, voids' distribution in the crystal packing, their related energies and the resulting underlying topologies. The energy and activity relations of the compounds were also investigated by DFT. [ABSTRACT FROM AUTHOR]

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This scientific study employs the Taylor dispersion technique for diffusion measurements to investigate the interaction between sulfamerazine (NaSMR) and macromolecular cyclodextrins (β-CD and HP-β-CD). The results reveal that the presence of β-CD influences the diffusion of the solution component, NaSMR, indicating a counterflow of this drug due to solute interaction. However, diffusion data indicate no inclusion of NaSMR within the sterically hindered HP-β-CD cavity. Additionally, toxicity tests were conducted, including pollen germination (Actinidia deliciosa) and growth curve assays in BY-2 cells. The pollen germination tests demonstrate a reduction in sulfamerazine toxicity, suggesting potential applications for this antimicrobial agent with diminished adverse effects. This comprehensive investigation contributes to a deeper understanding of sulfamerazine–cyclodextrin interactions and their implications for pharmaceutical and biological systems. [ABSTRACT FROM AUTHOR]

The current work was conducted to synthesize several novel anti-inflammatory quinazolines having sulfamerazine moieties as new 3CLpro, cPLA2, and sPLA2 inhibitors. The thioureido derivative 3 was formed when compound 2 was treated with sulfamerazine. Also, compound 3 was reacted with NH2-NH2 in ethanol to produce the N-aminoquinazoline derivative. Additionally, derivative 4 was reacted with 4-hydroxy-3-methoxybenzaldehyde, ethyl chloroacetate, and/or diethyl oxalate to produce quinazoline derivatives 5, 6, and 12, respectively. The results of the pharmacological study indicated that the synthesized 4–6 and 12 derivatives showed good 3CLpro, cPLA2, and sPLA2 inhibitory activity. The IC50 values of the target compounds 4–6, and 12 against the SARS-CoV-2 main protease were 2.012, 3.68, 1.18, and 5.47 µM, respectively, whereas those of baicalein and ivermectin were 1.72 and 42.39 µM, respectively. The IC50 values of the target compounds 4–6, and 12 against sPLA2 were 2.84, 2.73, 1.016, and 4.45 µM, respectively, whereas those of baicalein and ivermectin were 0.89 and 109.6 µM, respectively. The IC50 values of the target compounds 4–6, and 12 against cPLA2 were 1.44, 2.08, 0.5, and 2.39 µM, respectively, whereas those of baicalein and ivermectin were 3.88 and 138.0 µM, respectively. Also, incubation of lung cells with LPS plus derivatives 4–6, and 12 caused a significant decrease in levels of sPLA2, cPLA2, IL-8, TNF-α, and NO. The inhibitory activity of the synthesized compounds was more pronounced compared to baicalein and ivermectin. In contrast to ivermectin and baicalein, bioinformatics investigations were carried out to establish the possible binding interactions between the newly synthesized compounds 2–6 and 12 and the active site of 3CLpro. Docking simulations were utilized to identify the binding affinity and binding mode of compounds 2–6 and 12 with the active sites of 3CLpro, sPLA2, and cPLA2 enzymes. Our findings demonstrated that all compounds had outstanding binding affinities, especially with the key amino acids of the target enzymes. These findings imply that compound 6 is a potential lead for the development of more effective SARS-CoV-2 Mpro inhibitors and anti-COVID-19 quinazoline derivative-based drugs. Compound 6 was shown to have more antiviral activity than baicalein and against 3CLpro. Furthermore, the IC50 value of ivermectin against the SARS-CoV-2 main protease was revealed to be 42.39 µM, indicating that it has low effectiveness. [ABSTRACT FROM AUTHOR]

The current challenges of the pharmaceutical industry regarding the environmental impact caused by its waste have led to the design and development of more efficient industrial processes. In this context, solubility studies are at the core of different processes, such as formulation, preformulation, synthesis, purification, recrystallization, quantification, and quality control. This research evaluates the solubility of sulfamerazine (SMR) in acetonitrile + 1-propanol cosolvent mixtures at nine temperature levels with UV/vis spectrophotometry using the vial-shake method. According to the analysis of the solid phase in equilibrium using differential scanning calorimetry, there were no polymorphic changes. The minimal solubility of SMR was reached in 1-propanol at 278.15 K, and the maximal solubility in acetonitrile at 313.15 K. In all cases, the process was endothermic and dependent on the cosolvent composition, and the solution enthalpy drove the solution process. The solubility data were well correlated with the van't Hoff, Yalkowsky–Roseman–van't Hoff, Apelblat, Buchowski–Ksiazczak λh, Yaws, NRTL, Wilson, and modified Wilson models, with the YR model being one of the most attractive because it presented an excellent prediction percentage from four sets of experimental data. The solution process of SMR in acetonitrile + 1-propanol cosolvent mixtures depends on the affinity of SMR for acetonitrile and temperature increase. [ABSTRACT FROM AUTHOR]

• This article is the successful synthesis of a novel crystalline molecular salt formed between gatifloxacin (GAT) and sulfanilamide derivative sulfamerazine (SMZ), designated as GAT-SMZ. • This innovative complex aims to enhance the physicochemical properties of GAT while improving its antibacterial efficacy. • Single-crystal X-ray diffraction studies revealed that the incorporation of SMZ into the GAT lattice significantly alters the zwitterionic structure of GAT, leading to the formation of a stable tetrameric arrangement between GAT and SMZ molecules. • Pharmaceutical evaluations demonstrated that the resulting molecular salt exhibits notable improvements in solubility and permeability compared to the parent drug, gatifloxacin. • Remarkably, these enhanced physicochemical properties translate into superior in vitro antibacterial activity, characterized by larger inhibition zones and reduced minimum inhibitory concentration (MIC) values. A molecular salt combined with the fluoroquinolone antibacterial gatifloxacin (GAT) and the sulfonamides antibacterial sulfamerazine (SMZ) is designed and synthesized successfully, which is the first report of the dual-drug cocrystallization of gatifloxacin. The precise structure of the acquired molecule salt GAT-SMZ has been characterized via single crystal X-ray diffraction and other techniques. Single crystal diffraction analysis displays that due to the transfer of protons from SMZ to GAT, the molecular salt of GAT-SMZ is formed, and the supramolecular network is dominated by charge-assisted one-dimensional hydrogen bond chain and two-dimensional accumulation layer in the crystal. Such structural feature endows molecular salt with superior physicochemical properties, including enhanced solubility and permeability. More importantly, the superior pharmaceutical performances of the dual-drug salt resulted in enhanced antibacterial activity against the tested strains. These observations are strongly supported by theoretical studies based on Hirshfeld surface and molecular docking analyses. Thus, this contribution not only highlights the validity of combining theory with experiment to drive the problem of physicochemical properties of drugs through co-crystallization methods, but also fills in the previous studies gatifloxacin dual-drug salt synergistic antibacterial research blank. [ABSTRACT FROM AUTHOR]

Parkinson's disease (PD) is the second most prevalent neurodegenerative disorder. The presence of Lewy bodies, primarily consisting of amyloid aggregates of the protein α-synuclein (α-Syn), is a common feature seen in dopaminergic neurons in (PD) patients. In the present study, we screened 2320 FDA-approved drugs and found 3 lead molecules, sulfamerazine, lathosterol, and tamoxifen, that reproducibly inhibited α-Syn fibrillation. Dose-response studies showed that sulfamerazine and lathosterol are relatively more potent than tamoxifen in inhibiting α-Syn aggregation. Among the lead compounds, sulfamerazine showed a significant reduction in α-Syn aggregation and associated toxicity in Caenorhabditis elegans model of PD. Sulfamerazine also reduced the accumulation of α-Syn aggregates in neuronal SH-SY5Y cells. Microscale thermophoresis confirmed the binding of sulfamerazine to α-Syn. NMR studies corroborated the binding of sulfamerazine with α-Syn and show that upon interaction, α-Syn is sequestered into large soluble dispersed assemblies, which is similar to as seen in transmission electron microscopy. We conclude that sulfamerazine and its derivatives hold promise as therapeutic agents against Parkinson's disease.

Covalent organic frameworks (COFs) featuring long-range ordered pore size and large specific surface area have been recognized as a fantastic platform for contaminant removal. However, the influence of nanopore size on their adsorption behavior has not been well understood. Herein, three stable β-ketoenamine COFs, i.e., TpPa-1, TpBD, and TpTph, with the same type of linkage but diverse nanopore size were successfully obtained by a salt-mediated crystallization strategy. Their adsorption behavior and interaction mechanisms toward sulfamerazine (SMR) in aqueous solution were studied by adsorption experiments and density functional theory (DFT) calculations. The adsorption kinetics of SMR over COFs followed the order TpPa-1 < TpBD < TpTph, which is consistent with the changing trend of nanopore size, suggesting that a large nanopore is beneficial in boosting mass transfer. However, the maximum adsorption capacities followed the order TpPa-1 (82.9 mg/g) < TpTph (150 mg/g) < TpBD (188 mg/g). Referring to the data of specific surface area and nanopore size of COFs, it can be inferred that the specific surface area of COFs plays a less important role, and pore characteristics might be the dominant factor affecting the adsorption behavior of SMR. Furthermore, DFT results confirmed that SMR can be loaded into the channels of TpPa-1, TpBD, and TpTph due to its small molecule size, and the adsorption interactions are dominated by C–H···π and H-bonding. The different adsorption performance of SMR on TpPa-1, TpBD, and TpTph stems from their different number of adsorption sites and binding energies. These findings demonstrated the feasibility of adjusting the adsorption capacity of COFs by regulating the nanopore sizes, providing possible solutions for tailor-made COFs with superior adsorption performance. [ABSTRACT FROM AUTHOR]

[Display omitted] • In situ construction of NM88(DB) 0.85 /COF-OMe via modifying NM88 with DB and COF-OMe. • Electron-donating effect facilitated the interfacial contact of NM88(DB) 0.85 /COF-OMe. • NM88(DB) 0.85 /COF-OMe possessed high absorption utilization of visible light. • Enhanced Electronic effect accelerated Fe(III)/Fe(II) cycle of NM88(DB) 0.85 /COF-OMe. • NM88(DB) 0.85 /COF-OMe possessed 15.1 and 17.3 times degradation kinetics of NM88 and COF-OMe. 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 2 -MIL-88B(Fe) (NM88) was modified with 3,5-diaminobenzoic acid (DB) and TPB-DMTP-COF (COF-OMe) to in situ construct NM88(DB) 0.85 /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) 0.85 /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 2 – by trapping experiments, and a possible mechanism of the degradation system followed Z-scheme charge transfer. [ABSTRACT FROM AUTHOR]

Ozone, UV/ozone, ozone/persulfate (PS) and UV/ozone/PS systems were used to mineralize sulfonamides. Sulfadiazine (SDZ), sulfamerazine (SMR) and sulfamethazine (SMZ) were the target compounds. The novel contribution of this study is its determination of the effects of PS addition, sulfonamide structure, pH and salinity on sulfonamide mineralization in ozone-based systems. The mineralization rate of sulfonamides satisfied pseudo-first-order kinetics. The SMZ mineralization rate constant in ozone, UV/ozone, ozone/PS and UV/ozone/PS systems at pH 5 were 0.0058; 0.0101; 0.0069 and 0.0802 min−1, respectively, and those at pH 7 were 0.0075; 0.0116; 0.0083 and 0.0873 min−1, respectively. The increase in the number of methyl substituents in the heterocyclic group of SMZ and the corresponding increase in the steric hindrance of radical addition, reduced mineralization rates below those of SMR and SDZ. The addition of PS promoted sulfonamide mineralization in the ozone-based systems; conversely, salinity inhibited sulfonamide mineralization. HIGHLIGHTS Ozone, UV/ozone, ozone/PS and UV/ozone/PS systems were investigated.; The mineralization constants of SDZ, SMR and SMZ were compared.; The effects of pH, salinity and PS addition on mineralization were determined.; SMZ was most refractory and UV/ozone/PS was most effective.;

To date, there is still very little knowledge about the combined effects of typical biosurfactants and solution pH values on iron oxide colloid-mediated transport of sulfamerazine (SMZ, a typical sulfonamide antibiotic) in saturated porous media. Herein, the influences of rhamnolipid (a common biosurfactant in the environment) on SMZ mobility in the absence or presence of ferrihydrite (a model iron oxide) colloids in saturated quartz sand were explored. Generally, the rhamnolipid suppressed the transport of SMZ without ferrihydrite colloids owing to the bridging effect of this biosurfactant (i.e., rhamnolipid served as a bridging agent between SMZ and sand). Moreover, ferrihydrite colloids also inhibited SMZ mobility due to the deposition of colloid-associated SMZ. Surprisingly, the presence of rhamnolipid significantly influenced ferrihydrite colloid-mediated transport of SMZ, and this effect was highly dependent on the solution pH. Concretely, rhamnolipid enhanced the inhibitory effects of ferrihydrite colloids on SMZ transport at pH 5.0 because of the increased SMZ retention on the deposited colloids via the bridging effect of biosurfactant. At pH 7.0, the transport-inhibition effects of colloids were weakened by adding rhamnolipid, which was due to the colloid-associated SMZ transport and the promoting electrostatic repulsion between the free SMZ and sand/ the deposited colloids. Surprisingly, ferrihydrite colloids facilitated SMZ transport in the addition of rhamnolipid at pH 9.0. This phenomenon stemmed from the enhanced free SMZ mobility, the colloid-assisted mobility of SMZ, and the competitive deposition between SMZ– species and negatively charged colloids. Moreover, the two-site non-equilibrium model was performed to help interpret the controlling mechanisms for the synergistic effects of rhamnolipid and solution pH on colloid-mediated transport of SMZ. The outcomes of this study offer valuable knowledge about the functions of widespread biosurfactants in the environmental consequences of antibiotics in subsurface systems with iron oxide colloids. [Display omitted] • Rhamnolipid inhibits sulfamerazine transport due to the bridging effect • Additional sites offered by ferrihydrite colloids suppress sulfamerazine mobility • The presence of rhamnolipid enhances the inhibitory effects of colloids at pH 5.0 • The inhibitory effects of colloids are weakened by adding rhamnolipid at pH 7.0 • Colloids enhance sulfamerazine mobility in the presence of rhamnolipid at pH 9.0 [ABSTRACT FROM AUTHOR]

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 (QbD) tool for the development of HME ASDs. [ABSTRACT FROM AUTHOR]

Ag/g-C3N4 was synthesized by a photo-reduction method in the presence of g-C3N4 as the photocatacytic material and polyvinylpyrrolidone as an inhibitor. The degradation effect and mechanism of sulfamerazine by Ag/g-C3N4 was studied in the presence of visible lightir irradiation. The results indicated that sulfamerazine could be effectively degraded by Ag/g-C3N4. The degradation rate of sulfamerazine was 97. 3% after being irradiated for 30 min. Photogenerated hole and ·O2 - were the main active species, which could regrade sulfamerazine by the cleavage of S--N bond, the hydroxylation of the benzene ring, the nitration of amino and the carboxylation of methyl. [ABSTRACT FROM AUTHOR]

Introduction: Experimental Solubilities of sulfamerazine (SMR) and sulfamethazine (SMT) in some (methanol + water), (ethanol + water) and (1-propanol + water) cosolvent mixtures were collected from the literature at five temperatures from 293.15 to 313.15 K. Methodology: The results were analyzed with the van't Hoff, Apelblat modified, Buchowski-Ksiazaczak h, van't Hoff-Yaws model, twoparameter Weibull function model. It was determined that the models that best describe the solubility of these sulfonamides in (alcohol + water) mixtures were the van't Hoff and Apelblat models, obtaining correlation indices greater than 0.99 in all cases. Results: The results obtained with the Modified Apelblat equation presents a high correlation index for the solubility of SMR and SMT in cosolvent mixtures, followed by the van't Hoff-Yaws model that presents a high fit of the estimated data with respect to the theoretical ones. According to the two-parameter Weibull function model, the solubility of SMR and SMT in the co-solvent mixtures shows important deviations from ideality, which is consistent with the literature. The results are discussed in terms of the solute-solvent interactions that occur in this system. [ABSTRACT FROM AUTHOR]

In this study, novel photo‐stimulated molecularly imprinted polymers based on magnetic mesoporous carrier surface were developed for selective identification and intelligent separation of sulfamerazine in complex samples. The photosensitive monomer of the molecularly imprinted polymers was azobenzene derivative 5‐[(4‐(methacryloyloxy)phenyl) diazenyl] isophthalic acid with stimulus reaction mechanisms, which has photoisomerization between trans and cis for N=N bonds. Further, the properties of the photo‐stimulated molecularly imprinted polymers were further evaluated through several sets of adsorption experiments. It illustrated that the maximum adsorption amount is 0.45 mmol/L. By ultraviolet spectrophotometry, the material reaches typical characteristic peaks of photo sensitivity, and the cycle time is 16 min. Three adsorption and desorption processes were repeated, the adsorption rate reached 34.4%. Overall, the photo‐stimulated molecularly imprinted polymers can enrich and separate determine sulfamerazine with high selectivity, which have good recovery for real samples. [ABSTRACT FROM AUTHOR]

The peroxynitrite photocatalytic degradation system was considered a green, convenient, and efficient water treatment process, but not satisfying against some antibiotics, e.g. sulfonamides (SAs). To improve the photocatalytic degradation efficiency of SAs, sulfur was introduced to a magnetic Fe-MOF (Fe-metal organic framework) Prussian blue analog to achieve a heteroatomic material CuFeO@S, which was applied in heterogeneous visible light photo-assisted catalytic process with persulfate (PS) as an oxidant. The characterization results of CuFeO@S by XRD and XPS confirmed the presence of Fe 3 O 4 (for magnetic separation), Cu+ (for activation of PS) and S2− (for narrowing the energy band and prolonging the lifetime of photo-generated electronics). Through systematic optimization of reaction conditions in CuFeO@S + PS + hv system, efficient degradation of four tested SAs was achieved in 30 min (removal rate of 97–100% for the tested 4 SAs). Moreover, the material could be magnetically recycled and reused for over 7 cycles with a removal rate of >90% for sulfamerazine. Furthermore, the removal rate of sulfamerazine in pond water reached 99% at a mineralization rate of about 34% (decrease in total organic matter), demonstrating its potential in the treatment of antibiotic-containing wastewater. [Display omitted] • Sulfur was incorporated into a magnetic Prussian blue analog to improve the photo-catalytic efficiency. •Removal rates of over 99% against sulfonamides were achieved in a photo-assisted persulfate oxidation system. •The residual material after the reaction could be recycled for reuse with a magnet. [ABSTRACT FROM AUTHOR]

[Display omitted] • Novel magnetic biochars (Fe-BCs) was produced by a dry process. • Fe-BCs had higher BET surface areas and better magnetic separability. • Adsorption process was highly dependent on the initial pH. • Density functional theory (DFT) calculation proved the significance of Fe-O in the adsorption process. Sulfonamides antibiotics are representatives of new pollutants which are difficult to be biodegraded. In this study, bagasse-derived magnetic material (Fe-BCs) prepared by a totally dry process were used for the removal of sulfamethoxazole (SMZ) and sulfamerazine (SMR) from aqueous solution. Various characterization techniques revealed abundant porous structures and various functional groups as well as the graphite-like heterogeneous structure of Fe-BCs. Langmuir isotherm model demonstrated that the maximum adsorption amounts of SMZ and SMR on Fe-BC-800 with surface area of 535.9 m2 g−1 were 414.2 and 386.3 mg/g at 20 °C, respectively. The interaction between sulfonamides antibiotics and magnetic biochar was analyzed by adsorption isotherm, adsorption kinetics and density functional theory (DFT), and the possible adsorption mechanism was proposed. DFT calculation confirmed that Fe-O played an important role in the adsorption process of SMZ and SMR on the Fe-BCs. The adsorption mechanism of SMZ and SMR on the Fe-BCs included electrostatic, Lewis acid-base, pore filling, π-π EDA, conventional hydrogen bond and negative charge assisted H-bond interactions. This study could provide valuable information for the removal of antibiotic pollutants from water by biomass-based functional materials. [ABSTRACT FROM AUTHOR]

A molecularly imprinted monolith was prepared and evaluated for the special selective separation of sulfamerazine (SMR) by capillary electrochromatography (CEC). The single-step in situ polymerization method was applied through thermally immobilized vinyl groups of itaconic acid and a derivatization capillary column using SMR as the template. The monolith with optimal selectivity and permeability was performed at 45°C for 7 h according to the molar ratios of 1 : 4 : 10 (template/functional monomer/cross-linker). Under the optimized separation conditions of 75% acetonitrile in 20 mM phosphate buffer with pH 5.0, 15 kV applied voltage and 20°C column temperature, the imprinted monolith showed strong recognition ability for SMR and high column performance. Finally, the molecularly imprinted monolith coupled with the CEC method was successfully developed for the quantification of SMR in aquatic products, which was properly validated by a good linear relationship, recoveries and limit of detection. The coupling technique of the molecularly imprinted technology and CEC achieved pre-treatment enrichment and separation analysis in only one miniaturized chromatographic column.

The heavy use of sulfonamide antibiotics leads to significant detection in water, and the existence of "fake persistence" seriously affects the ecological health. In this work, the Fe2+/ persulfate (PS) catalytic oxidation approach was used to remove sulfamerazine (SMI). Results showed that SMI could be effectively removed in the Fe24/PS system and the removal rate of over 90% was achieved. The pH value in Fe27PS system would rapidly decrease to 3 with the beginning of reaction in the initial pH range of 3.0-9.0. The inorganic anions HCO-3 and NO-3 in water had significant inhibitory effect on the SMI degradation process, while NO-2 had obvious promotion effect. The free radical validation results suggested that both SO-4 and HO played important roles in the oxidation process. Based on the chemical stoichiometric matrix method, the independent reaction formulas for the SMI degradation process were developed and a possible degradation path of SMI was also proposed. In addition, both the theoretical calculation and experimental results indicated that the degradation process of SMI was consistent with the first-order kinetics. [ABSTRACT FROM AUTHOR]

A great number of antimicrobials belonging to fluoroquinolones and sulfonamides families are used in the livestock industries. These compounds are not completely absorbed, by reaching agricultural soils and whereas maintaining their pharmacological activity. Due to this, a theoretical and electrochemical study of two pharmaceuticals that belong to sulfonamides and fluoroquinolones family, such as sulfamerazine (SRZ) and norfloxacin (NOR), respectively, are carried out in order to understand their behavior in aqueous solutions for future adsorption studies in soil organic matter. In this work, the electro – oxidation reaction of these two pharmaceuticals is studied at pH 7.0 by using a glassy carbon as working electrode and cyclic voltammetry as technique. Additionally, kinetic studies are done with the aim of determining the control of the reaction, the rate determining step and the number of transferred electrons in the whole process. Parallel to this, computational studies are done in order to support to the electrochemical results here achieved. On the other hand, the analytical parameters for the electrochemical method are obtained, which presents a highly linear equation for both pharmaceuticals. The method has a limit of detection of 38.1 and 29.6 μmoL/L and limit of quantification of 115.4 and 89.5 μmoL/L for NOR and SRZ, respectively. For accuracy, an error of 1.96% and 4.55% was obtained with respect to the analysis of a standard of 200 μmoL/L of SRZ and NOR, respectively. Image 1 • Electrochemical response for veterinary antimicrobials revealed relation with acidity of functional groups. • At lower pH, higher positive overpotentials are required which is related to the lability of the structural properties. • The oxidation process of these antimicrobials correspond to irreversible processes controlled by diffusion. • For both antimicrobials, the rate determining step corresponds to an electrochemical step (electron transfer). • As analytical method, good accuracy and precision were observed, then it can be applied to detect/quantify these antimicrobials. [ABSTRACT FROM AUTHOR]

To develop an efficient and reusable heterogeneous Fenton-like catalyst is a great challenge for its application in practical water treatment. Effective oxygen vacancy (OVs)-promoted Fe 2 O 3 -CeO 2 catalyst was prepared by a sol-gel method, and applied in the heterogeneous Fenton-like reaction of the sulfamerazine (SMR) degradation. The Fe 2 O 3 -CeO 2 catalyst showed good activity and stability, and total SMR conversion was achieved in the Fenton-like reaction after 75 min at pH 3.0 and 45 °C under O 2 atmosphere. Moreover, the SMR removal was significantly enhanced under O 2 atmosphere. The surface-bounded OH radicals played a dominant role for the SMR degradation. The Fe 2 O 3 -CeO 2 catalyst remarkably promoted the generation of OH in the Fenton-like reaction under O 2 atmosphere, mostly because abundant OVs on the catalyst surface not only accelerated electron transfer to promote the H 2 O 2 decomposition, but also oxygen molecules, adsorbed on OVs, formed O 2 −/HO 2 and promoted the Fe2+/Fe3+ redox cycle. Image 1 • The Fe 2 O 3 -CeO 2 catalyst exhibited good activity and stability in the Fenton-like SMR degradation. • The activity of the Fe 2 O 3 -CeO 2 catalyst was enhanced under O 2 atmosphere. • OVs on the Fe 2 O 3 -CeO 2 catalyst improved the generation of OH radicals. • Surface-bounded OH played a critical role in the Fenton-like system. • The reaction mechanism over the OVs-promoted Fe 2 O 3 -CeO 2 catalyst was proposed. [ABSTRACT FROM AUTHOR]

• Two Ag(I) complexes with sulfa compounds – sulfapyridine and sulfamerizine are described. • The Ag(I)sulfa complexes showed MIC 90 lower than the market drug against M. tuberculosis – silversulfadiazine (7.80 mg L−1). Sulfonamides (sulfas) are a specific class of organic compounds that possesses antibacterial, anti-inflammatory, antiviral and antitumor activities. This class of molecules is also used in the synthesis of silver(I) complexes, which usually present significant biological activity as antimicrobial agents. In this context, the present work describes the synthesis, structural characterization and antibacterial assays of two silver(I) complexes with the sulfa drugs sulfapyridine (SPY) and sulfamerazine (SM). Chemical analyses and high-resolution mass spectrometric studies led to 1:1 metal/ligand compositions, suggesting the minimal formulas C 11 H 10 N 3 O 2 SAg·2H 2 O for AgSPY and C 11 H 11 N 4 O 2 SAg·2H 2 O for AgSM. Spectroscopic techniques such as 1H, 13C and {1H–15N} nuclear magnetic resonance (NMR), and also infrared measurements (IR) suggest the coordination of the ligands to silver(I) ions by the nitrogen atom of the SO 2 N moiety for both complexes. Crystal structures of AgSPY and AgSM were solved and refined by X-ray powder diffraction studies, where dimeric structures with Ag(I) ions bridging between two ligand molecules by the usual eight membered ring [AgNCN] 2 and strong argentophilic interactions were observed. Minimum Inhibitory Concentration (MIC 90) assays showed the promising activities of the free sulfonamides and the respective complexes against Mycobacterium tuberculosis H37Rv. MIC 90 values, in µmol L–1, were 2.47, 3.60, 1.33 and 1.61 for SPY, AgSPY, SM and AgSM, respectively. The obtained MIC 90 values were lower than those found for silver sulfadiazine and silver nitrate in the same experimental conditions. Two Ag(I) complexes with sulfa compounds – sulfapyridine and sulfamerizine are described. The Ag(I)sulfa complexes showed MIC 90 lower than the market drug against M. tuberculosis – SilverSulfadiazine (7.80 mg L−1). [Display omitted] [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • A novel 3D electrochemical sensor with selective recognition of SMR was successfully developed. • Highly conductive NH 2 -MWCNT@COF and MoS 2 nanosheets were employed to enhance the sensor signal. • The strategy offers a framework for rational development of electrochemical sensing platforms for more analytes. Abstract A novel three dimensional electrochemical sensor with signal amplification and selective recognition of sulfamerazine (SMR) was successfully constructed. First, highly conductive amino-functionalized carbon nanotubes@covalent organic frameworks (NH 2 -MWCNT@COF) and molybdenum disulfide (MoS 2) nanosheets were employed to modify the glassy carbon electrode (GCE) by simple physical deposition, in order to enhance the SMR response signal. Then, molecularly imprinted polymer (MIP) membrane was anchored on the surface of this modified GCE by electrochemical polymerization to achieve selective recognition for SMR. The electrochemical performance of the assembled electrochemical sensor was systematically investigated with differential pulse voltammetry and cyclic voltammetry. This obtained sensor displayed excellent selectivity for SMR and good reproducibility. Under optimal conditions, the sensor offered a wide current response for SMR from 3.0 × 10−7 to 2.0 × 10−4 mol L−1, with a limit of detection of 1.1 × 10−7 mol L−1. Furthermore, this developed sensor was successfully applied for the determination of SMR in pork and chicken samples with recoveries of 86.0%–102.0%, and results correlated well with those obtained by high-performance liquid chromatography. [ABSTRACT FROM AUTHOR]

Abstract Understanding the dynamics of veterinary antibiotic and related antibiotic resistance genes (ARGs) during swine manure composting is crucial in assessing the environmental risk of antibiotics, which could effectively reduce their impact in natural environments. This study investigated the dissipation of oxytetracycline (OTC), sulfamerazine (SM1) and ciprofloxacin (CIP) as well as the behaviour of their corresponding ARGs during swine manure composting. These antibiotics were added at two concentration levels and two different methods of addition (single/mixture). The results indicated that the removal efficiency of antibiotics by composting were ≥85%, except for the single-SM1 treatment. The tetracycline resistance genes (TRGs) encoding ribosomal protection proteins (RPP) and efflux pump (EFP) and fluoroquinolone resistance genes (FRGs) could be effectively removed after 42 days. On the contrary, the TRGs encoding enzymatic inactivation (EI) and sulfonamide resistance genes (SRGs) were enriched up to 31-fold (sul 2 in single-low-SM1). Statistical analyses indicated that the behaviour of these class antibiotics and ARGs were controlled by microbial activity and significantly influenced by environmental factors (mainly C/N, moisture and pH) throughout the composting process. Graphical abstract Image 1 Highlights • The addition of antibiotics did not retard the composting process of swine manure. • The removal efficiencies of OTC and CIP were higher than SM1 in swine manure composting. • The TRGs encoding both RPP and EFP and FRGs could be effectively removed in swine manure composting. • Dissipation behaviours of antibiotics and related ARGs were significantly associated with the composting conditions. [ABSTRACT FROM AUTHOR]

Four thermoresponsive silica-poly(N-isopropylacrylamide-co-butyl methacrylate) materials were prepared by grafting (N-isopropylacrylamide-co-butyl methacrylate) at different ratios on multimodal porous silica via surface-initiated atom transfer radical polymerization. The thermoresponsive materials were employed as the adsorbent for the rapid determination of sulfamerazine in river water by solid-phase extraction. The properties of silica-poly(N-isopropylacrylamide-co-butyl methacrylate) were characterized by scanning electron microscopy and Fourier transform infrared spectroscopy. Static adsorption measurements showed that the silica-poly(N-isopropylacrylamide-co-butyl methacrylate)3 material had the highest adsorption characteristics (8.72 mg g−1) at 35°C. The solid-phase extraction conditions were optimized, including the elution solvent and its volume used. The thermoresponsive silica-poly(N-isopropylacrylamide-co-butyl methacrylate)3 material provided satisfactory results for solid-phase extraction, with a recovery of 90.06%, allowing the rapid purification of sulfamerazine in river water. [ABSTRACT FROM AUTHOR]

This paper describes the application of poly (ethylene glycol dimethacrylate-N-methacryloyl-L-tryptophane methyl ester) [p(EGDMA-MATrp)] microspheres as an affinity sorbent for the SPE (solid phase extraction) cleanup of sulfamerazine (SMR) from food samples of animal origin before high performance liquid chromatography (HPLC) analysis. The microspheres were prepared by suspension polymerization of ethylene glycol dimethacrylate (EGDMA) and N-methacryloyl-L-tryptophane methyl ester (MATrp) as a crosslinker and a monomer, respectively. Various parameters affecting the SPE cleanup efficiency of the p(EGDMA-MATrp) microspheres (contact time, pH, initial SMR concentration, ionic strength etc.) were optimized. Under the optimized conditions, maximum adsorption capacity was found to be 8.55 ± 0.44 mg/g sorbent at pH 5.0. 90% of the adsorbed SMR was desorbed by using ACN:MeOH (5:5) mixture as a desorption agent. Applicability of the microspheres for the SPE cleanup of SMR residues in the food samples such as egg and milk with HPLC was also determined. It was demonstrated that the prepared p(EGDMA-MATrp) microspheres could be repeatedly applied for SPE cleanup of sulfamerazine before chromatographic analysis. Also, the recoveries of SMR in milk and egg samples were reasonably satisfactory and in the range of 71 to 90%. [ABSTRACT FROM AUTHOR]

Understanding antibiotic adsorption in livestock manures is crucial to assess the fate and risk of antibiotics in the environment. In this study, three quantitative models developed with swine manure-water distribution coefficients (Lg K d ) for oxytetracycline (OTC), ciprofloxacin (CIP) and sulfamerazine (SM1) in swine manures. Physicochemical parameters ( n = 12) of the swine manure were used as independent variables using partial least-squares (PLSs) analysis. The cumulative cross-validated regression coefficients ( Q 2 cum ) values, standard deviations ( SD s) and external validation coefficient ( Q 2 ext ) ranged from 0.761 to 0.868, 0.027 to 0.064, and 0.743 to 0.827 for the three models; as such, internal and external predictability of the models were strong. The pH, soluble organic carbon (SOC) and nitrogen (SON), and Ca were important explanatory variables for the OTC-Model, pH, SOC, and SON for the CIP-model, and pH, total organic nitrogen (TON), and SOC for the SM1-model. The high VIPs (variable importance in the projections) of pH (1.178–1.396), SOC (0.968–1.034), and SON (0.822 and 0.865) established these physicochemical parameters as likely being dominant (associatively) in affecting transport of antibiotics in swine manures. [ABSTRACT FROM AUTHOR]

The analytical potential of X-ray small-angle scattering (SAXS) combined with simultaneous wide-angle diffraction (WAXS) has been explored on the example of three active pharmaceutical ingredients, (desvenlofaxine, simvastatin, and sulfamerazine, resp.) with the aim of identifying quantitative parameters obtained from SAXS that allow to describe the nano-structural characteristics of different amorphous forms and to monitor the processes of amorphisation and ageing. Cryo-milling, co-milling with polymer, melting and melt-quenching have been used for amorphisation of initially crystalline powders. In parallel to SAXS, the WAXS patterns have been obtained to fingerprint the crystalline state. The SAXS results demonstrate strong, systematic nanostructure variations in amorphous samples obtained by different milling conditions, or by melt-quenching. It has been found that the mean-square density fluctuation, directly obtained from the SAXS invariant, is a sensitive and robust parameter to characterize the degree of nano-heterogeneity, which is related to entropy and hence thermodynamic stability. The SAXS curves also allow estimates of amorphous domain sizes of different density. The propensity to recrystallize or to remain amorphous, respectively, upon ageing has been found to depend on the existence of domains in the starting amorphous materials. [ABSTRACT FROM AUTHOR]

In this study, high performance internally cross-linked monovalent selective anion exchange membranes were prepared via a one-pot approach by simply adding different amounts of sulfamerazine (SF) to partially-quaternized chloromethylated polysulfone (QPSF). The composition and structure of the prepared membranes were studied by Fourier transform infrared spectroscopy (FT-IR), Scanning electron microscope (SEM) and Atomic force microscopy (AFM). The monovalent anion selectivity was evaluated by electrodialysis using a Cl - /SO 4 2- system. The experimental results show that all QPSF-SF-x membranes exhibit excellent monovalent anion selectivity ( P SO 4 2 − Cl −  = 3.98–15.90) at an average pH level of 6.0 because of the presence of sulfamerazine, which can change the compactness and electronegativity of the QPSF membranes. Especially, the optimized QPSF-SF-0.09 membrane had a permselectivity of 24.55 at pH 10.0 and showed an excellent permselectivity in alkaline condition. Based on an overall consideration of the facile synthesis procedure and the excellent monovalent ion selectivity of the resulting membranes, this process is expected to inspire the further investigation of monovalent anion selective membranes. [ABSTRACT FROM AUTHOR]