Hypochlorite-mediated degradation and detoxification of sulfathiazole in aqueous solution and soil slurry.

Although various activated sodium hypochlorite (NaClO) systems were proven to be promising strategies for recalcitrant organics treatment, the direct interaction between NaClO and pollutants without explicit activation is quite limited. In this work, a revolutionary approach to degrade sulfathiazole (STZ) in aqueous and soil slurry by single NaClO without any activator was proposed. The results demonstrated that 100% and 94.11% of STZ could be degraded by 0.025 mM and 5 mM NaClO in water and soil slurry, respectively. The elimination of STZ was shown to involve superoxide anion (O2•-), chlorine oxygen radical (ClO•), and hydroxyl radical (•OH), according to quenching experiments and the analysis of electron paramagnetic resonance. The addition of Cl-, HCO3-, SO42-, and humic acid (HA) marginally impeded the decomposition of STZ, while NO3-, Fe3+, and Mn2+ facilitated the process. The NaClO process exhibited significant removal effectiveness at a neutral initial pH. Moreover, the NaClO facilitated application in various soil samples and water matrices, and the procedure was also successful in effectively eliminating a range of sulfonamides. The suggested NaClO degradation mechanism of STZ was based on the observed intermediates, and the majority of the products exhibited lower ecotoxicity than STZ. Besides, the experiment results by using X-ray diffraction (XRD) and a fourier transform infrared spectrometer (FTIR) indicated the negligible effects on the composition and structure of soil by the treatment of NaClO. Simultaneously, the experimental results also illustrated that the bioavailability of heavy metals and the physiochemical characteristics of the soil before and after the remediation did not change to a significant extent. Following the remediation of NaClO, the phytotoxicity tests showed reduced toxicity to wheat and cucumber seeds. As a result, treating soil and water contaminated with STZ by using NaClO was a reasonably practical and eco-friendly method.

Bioactive Co(II), Ni(II), and Cu(II) Complexes Containing a Tridentate Sulfathiazole-Based (ONN) Schiff Base.

New Co(II), Ni(II), and Cu(II) complexes were synthesized with the Schiff base ligand obtained by the condensation of sulfathiazole with salicylaldehyde. Their characterization was performed by elemental analysis, molar conductance, spectroscopic techniques (IR, diffuse reflectance and UV-Vis-NIR), magnetic moments, thermal analysis, and calorimetry (thermogravimetry/derivative thermogravimetry/differential scanning calorimetry), while their morphological and crystal systems were explained on the basis of powder X-ray diffraction results. The IR data indicated that the Schiff base ligand is tridentate coordinated to the metallic ion with two N atoms from azomethine group and thiazole ring and one O atom from phenolic group. The composition of the complexes was found to be of the [ML2]∙nH2O (M = Co, n = 1.5 (1); M = Ni, n = 1 (2); M = Cu, n = 4.5 (3)) type, having an octahedral geometry for the Co(II) and Ni(II) complexes and a tetragonally distorted octahedral geometry for the Cu(II) complex. The presence of lattice water molecules was confirmed by thermal analysis. XRD analysis evidenced the polycrystalline nature of the powders, with a monoclinic structure. The unit cell volume of the complexes was found to increase in the order of (2) < (1) < (3). SEM evidenced hard agglomerates with micrometric-range sizes for all the investigated samples (ligand and complexes). EDS analysis showed that the N:S and N:M atomic ratios were close to the theoretical ones (1.5 and 6.0, respectively). The geometric and electronic structures of the Schiff base ligand 4-((2-hydroxybenzylidene) amino)-N-(thiazol-2-yl) benzenesulfonamide (HL) was computationally investigated by the density functional theory (DFT) method. The predictive molecular properties of the chemical reactivity of the HL and Cu(II) complex were determined by a DFT calculation. The Schiff base and its metal complexes were tested against some bacterial strains (Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Bacillus subtilis). The results indicated that the antibacterial activity of all metal complexes is better than that of the Schiff base.

Ultrasensitive determination of sulfathiazole using a molecularly imprinted electrochemical sensor with CuS microflowers as an electron transfer probe and Au@COF for signal amplification.

In this work, a molecularly imprinted sensor employing copper sulfide (CuS) as a novel signal probe was successfully developed for ultrasensitive and selective determination of sulfathiazole (STZ). The reduction signals of Cu2+ produced in the process of electron transfer of CuS containing large amounts of Cu2+ are easy to be captured, which provide high electrochemical signals. Moreover, gold nanoparticles@covalent organic framework with excellent conductivity was introduced on the electrode surface for signal amplification and facilitating electron transfer processes of CuS. Under optimized testing conditions, the proposed sensor offered a linear DPV response to STZ over a very wide concentration range (1.0 × 10-4 to 1.0 × 10-11 mol L-1), with a limit of detection of 4.3 × 10-12 mol L-1. Fodder and mutton samples spiked with STZ were analyzed using this sensor, and the satisfactory recoveries ranging from 83.0% to 107.2% were obtained. In addition, the proposed sensor was used to determine the concentration of STZ in chicken liver and pork liver, with quantification results being near identical to those determined by high-performance liquid chromatography.

Synthesis, characterization, biological evaluation, and in silico studies of novel 1,3-diaryltriazene-substituted sulfathiazole derivatives.

In the present study, a series of eleven novel 1,3-diaryltriazene-substituted sulfathiazole moieties (ST1-11) was synthesized by the reaction of diazonium salt of sulfathiazole with substituted aromatic amines and their chemical structures were characterized by Fourier transform infrared, 1 H-NMR (nuclear magnetic resonance), 13 C-NMR, and high-resolution mass spectroscopy methods. These synthesized novel derivatives were found to be effective inhibitor molecules for α-glycosidase (α-GLY), human carbonic anhydrase (hCA), and acetylcholinesterase (AChE), with KI values in the range of 426.84 ± 58.42-708.61 ± 122.67 nM for α-GLY, 450.37 ± 50.35-1,094.34 ± 111.37 nM for hCA I, 504.37 ± 57.22-1,205.36 ± 195.47 nM for hCA II, and 68.28 ± 10.26-193.74 ± 19.75 nM for AChE. Among the synthesized novel compounds, several lead compounds were investigated against the tested metabolic enzymes. More specifically, ST11 (4-[3-(perfluorophenyl)triaz-1-en-1-yl]-N-(thiazol-2-yl)benzenesulfonamide) showed a highly efficient inhibition profile against hCA I, hCA II, and AChE, with KI values of 450.37 ± 50.35, 504.37 ± 57.22, and 68.28 ± 10.26 nM, respectively. Due to its significant biological inhibitory potency, this derivative may be considered as an interesting lead compound against these enzymes.

Photodegradation of tetracycline and sulfathiazole individually and in mixtures.

Antibiotics in environment can be of concern as they can enter the food chain posing risks to ecosystems and human health. Photodegradation has been considered as a promising way of naturally degrading antibiotics in environment. Antibiotics are usually present in mixtures in environment; however, previous studies focused on individual compounds. Therefore, this study investigated the effect of UV irradiation on the degradation of tetracycline (TC) and sulfathiazole (STH) in individual solutions and mixtures. Under dark conditions, the initial masses of TC and STH were reduced by about 35% and 26%, respectively, over a 35 d-reaction period. With UV irradiation TC and STH were completely removed within 14 d and 35 d, respectively, regardless of the initial concentrations. Both the TC and STH removals were faster (i.e., 2-4 times) when they were in mixtures. This may be partly attributed to the byproducts such as sulfate that can promote indirect photolysis and partly to the enhanced hydrolysis due to changes in the solution pH. Overall, this study suggests that when photodegradation is used to remove antibiotics in water, the removal kinetics of antibiotics individually and in mixtures can be considered to develop more efficient treatment technologies.

Comment on "Photodegradation of sulfathiazole under simulated sunlight: Kinetics, photo-induced structural rearrangement, and antimicrobial activities of photoproducts" by Niu et al. [Water Research 124 2017 576-583].

Recent efforts have employed antimicrobial susceptibility assays to describe the residual antimicrobial activity of antibiotics and their transformation products in a variety of environmental processes. Some authors have evaluated the results of these assays using the minimum inhibitory concentration (MIC); however, this approach has fundamental weaknesses. To highlight best practices, this comment describes the advantages of using dose-response curves to calculate the half maximal inhibitory concentration (IC50) and the potential impacts of growth media on the antimicrobial activity of sulfonamide antibiotics.

Synthesis, characterization and biological studies of a cobalt(III) complex of sulfathiazole.

The emergence of old and new antibiotic resistance created in the last decades revealed a substantial medical need for new classes of antimicrobial agents. The antimicrobial activity of sulfa drugs is often enhanced by complexation with metal ions, which is in concordance with the well-known importance of metal ions in biological systems. Besides, sulfonamides and its derivatives constitute an important class of drugs, with several types of pharmacological agents possessing antibacterial, anti-carbonic anhydrase, diuretic, hypoglycemic, antithyroid, antiviral and anticancer activities, among others. The purpose of this work has been the obtainment, characterization and determination of biological properties (antibacterial, antifungal, mutagenicity and phytotoxicity) of a new Co(III)-sulfathiazole complex: Costz, besides of its interaction with bovine serum albumin (BSA). The reaction between sodium sulfathiazole (Nastz) and cobalt(II) chloride in the presence of H2O2 leads to a brown solid, [CoIII(stz)2OH(H2O)3], (Costz). The structure of this compound has been examined by means of elemental analyses, FT-IR, 1H NMR, UV-Visible spectrometric methods and thermal studies. The Co(III) ion, which exhibits a distorted octahedral environment, could coordinate with the N thiazolic atom of sulfathiazolate. The complex quenched partially the native fluorescence of bovine serum albumin (BSA), suggesting a specific interaction with the protein. The Costz complex showed, in vitro, a moderate antifungal activity against Aspergillus fumigatus and A. flavus. As antibacterial, Costz displayed, in vitro, enhanced activity respective to the ligand against Pseudomonas aeruginosa. Costz did not show mutagenic properties with the Ames test. In the Allium cepa test the complex showed cytotoxic properties but not genotoxic ones. These results may be auspicious, however, further biological studies are needed to consider the complex Costz as a possible drug in the future.

An unexpected reactivity during periodate oxidation of chitosan and the affinity of its 2, 3-di-aldehyde toward sulfa drugs.

In an attempt to determine the reactivity during the periodate oxidation of the vicinal amino sugar, chitosan was oxidized by KIO4 in a neutral medium. The reactivity was unexpectedly found to be low. The formation of di-aldehyde chitosan (DACT) might cause the low reactivity of chitosan oxidation. Therefore, density functional theory (DFT) calculations were carried out, which revealed that the greater stability of the cyclic amino iodate intermediate might retard the ring opening to form DACT. Furthermore, the affinity of the formation of two novel Schiff bases from the interaction of delivered DACT with two sulfa drugs [sulfanilamide and sulfathiazole] was also investigated using aldehyde content estimation. DACT and Schiff's bases were characterized by FT-IR spectroscopy, X-ray diffraction, and DTA analysis. The X-ray diffraction plane (110) of DACT at the high angle side was expanded more by sulfathiazole than sulfanilamide, indicating that sulfathiazole reacted effectively with DACT. The lowest interaction of DACT with sulfa drugs could be ascribed to the lowest aldehyde content and the intramolecular hemiacetal formation that hinders the Schiff's base condensation.

Photodegradation of sulfathiazole under simulated sunlight: Kinetics, photo-induced structural rearrangement, and antimicrobial activities of photoproducts.

Photolysis is a core natural process impacting the fate of some sulfonamide antibiotics in sunlit waters. In this study, sunlight-induced phototransformation of sulfathiazole was investigated. A photolytic quantum yield of 0.079 was obtained in buffered water (pH = 8.0). Different natural organic matter isolates inhibited the photolysis of sulfathiazole by light screening effect. A kinetic model was developed to predict the photodegradation rate of sulfathiazole using the light screening correction factor of the water matrix in the wavelength range of 300-350 nm. An isomeric photoproduct of sulfathiazole with a longer retention time was observed on liquid chromatography. Based on its MS/MS spectra and absorption characteristics, the isomer was postulated as 2-imino-3-(p-aminobenzenesulfinyl-oxy)-thiazole. A reaction mechanism for the photo-cleavage and photo-induced structural rearrangement was proposed. The formation mechanism of the isomer was supported by photochemical experiments spiking synthetic 2-aminothiazole; while the formation kinetics were treated with a partly-diffusion-controlled model. The three identified products showed significantly enhanced photo-stability. Antimicrobial assay of irradiated sulfathiazole solutions with Escherichia coli indicated little antimicrobial potency ascribed to photoproducts. This study demonstrates the efficacy of sunlight in rapidly degrading sulfathiazole at a predictable rate, leading to photoproducts of low antimicrobial potency. The mass spectrometry and mechanistic work described here are new insights into the photochemistry of sulfonamides.

Evaluation of sulfathiazole degradation by persulfate in Milli-Q water and in effluent of a sewage treatment plant.

The presence of antibiotics and their metabolites in natural waters has raised some concern among scientists around the world because it can lead to bacterial resistance and other unknown consequences to mankind and wildlife. Persulfate (PS)-driven oxidation is a new technology that has been used successfully to remediate contaminated sites, but its use to treat wastewater, especially sewage treatment plant (STP) effluent, is still scarce. This paper describes the effect of several persulfate activation methods for degrading sulfathiazole (STZ) in Milli-Q water and in STP effluent. Some parameters, such as pH, persulfate concentration, presence of Mn2+, Zn2+, Cu2+, Fe2+, and Fe3+, as well as copper and iron organic complexes, were studied in STZ degradation. Raising the pH from 5 to 9, as well as the persulfate concentration, resulted in increased STZ degradation. Among the transition metals evaluated, only Fe2+ and Cu2+ were able to activate persulfate molecules. Copper was a better activator than iron since its effect lasts longer. Citrate was the best ligand evaluated increasing Fe(II) activation capacity at pH 7. Hydroxylamine addition to Fe(II) on persulfate system extended the Fe(II) effect. The presence of bicarbonate or humic acid did not affect PS-driven degradation of STZ. Finally, the degradation of STZ in STP effluent promoted by PS-driven oxidation (25 °C) was as fast as in Milli-Q water, proving to be successful.

Simultaneous Differential Scanning Calorimetry-Synchrotron X-ray Powder Diffraction: A Powerful Technique for Physical Form Characterization in Pharmaceutical Materials.

We report a powerful new technique: hyphenating synchrotron X-ray powder diffraction (XRD) with differential scanning calorimetry (DSC). This is achieved with a simple modification to a standard laboratory DSC instrument, in contrast to previous reports which have involved extensive and complex modifications to a DSC to mount it in the synchrotron beam. The high-energy X-rays of the synchrotron permit the recording of powder diffraction patterns in as little as 2 s, meaning that thermally induced phase changes can be accurately quantified and additional insight on the nature of phase transitions obtained. Such detailed knowledge cannot be gained from existing laboratory XRD instruments, since much longer collection times are required. We demonstrate the power of our approach with two model systems, glutaric acid and sulfathiazole, both of which show enantiotropic polymorphism. The phase transformations between the low and high temperature polymorphs are revealed to be direct solid-solid processes, and sequential refinement against the diffraction patterns obtained permits phase fractions at each temperature to be calculated and unit cell parameters to be accurately quantified as a function of temperature. The combination of XRD and DSC has further allowed us to identify mixtures of phases which appeared phase-pure by DSC.

A Drug-Drug Salt Hydrate of Norfloxacin and Sulfathiazole: Enhancement of in Vitro Biological Properties via Improved Physicochemical Properties.

A new multicomponent solid consisting of an antibacterial (norfloxacin) and an antimicrobial (sulfathiazole) was made and characterized with single crystal X-ray diffraction, PXRD, FTIR, and DSC. The title salt shows enhanced solubility in different pH buffers and improved diffusion as well as release and inhibition of bacterial and fungal species relative to the parent drugs. The enhanced in vitro biological properties of the drug-drug salt hydrate may be attributed to the higher extent of its supersaturation with respect to the individual components, which leads to higher diffusion rates.

Novel prodrugs with a spontaneous cleavable guanidine moiety.

Water-soluble prodrug strategy is a practical alternative for improving the drug bioavailability of sparingly-soluble drugs with reduced drug efficacy. Many water-soluble prodrugs of sparingly-soluble drugs, such as the phosphate ester of a drug, have been reported. Recently, we described a novel water-soluble prodrug based on O-N intramolecular acyl migration. However, these prodrug approaches require a hydroxy group in the structure of their drugs, and other prodrug approaches are often restricted by the structure of the parent drugs. To develop prodrugs with no restriction in the structure, we focused on a decomposition reaction of arginine methyl ester. This reaction proceeds at room temperature under neutral conditions, and we applied this reaction to the prodrug strategy for drugs with an amino group. We designed and synthesized novel prodrugs of representative sparingly soluble drugs phenytoin and sulfathiazole. Phenytoin and sulfathiazole were obtained as stable salt that were converted to parent drugs under physiological conditions. Phenytoin prodrug 3 showed a short half-life (t1/2) of 13min, whereas sulfathiazole prodrug 7 had a moderate t1/2 of 40min. Prodrugs 3 and 7 appear to be suitable for use as an injectable formulation and orally administered drug, respectively.

Metal-based biologically active azoles and ß-lactams derived from sulfa drugs.

Metal complexes of Schiff bases derived from sulfamethoxazole (SMZ) and sulfathiazole (STZ), converted to their ß-lactam derivatives have been synthesized and experimentally characterized by elemental analysis, spectral (IR, (1)H NMR, (13)C NMR, and EI-mass), molar conductance measurements and thermal analysis techniques. The structural and electronic properties of the studied molecules were investigated theoretically by performing density functional theory (DFT) to access reliable results to the experimental values. The spectral and thermal analysis reveals that the Schiff bases act as bidentate ligands via the coordination of azomethine nitrogen to metal ions as well as the proton displacement from the phenolic group through the metal ions; therefore, Cu complexes can attain the square planner arrangement and Zn complexes have a distorted tetrahedral structure. The thermogravimetric (TG/DTG) analyses confirm high stability for all complexes followed by thermal decomposition in different steps. In addition, the antibacterial activities of synthesized compounds have been screened in vitro against various pathogenic bacterial species. Inspection of the results revealed that all newly synthesized complexes individually exhibit varying degrees of inhibitory effects on the growth of the tested bacterial species, therefore, they may be considered as drug candidates for bacterial pathogens. The free Schiff base ligands (1-2) exhibited a broad spectrum antibacterial activity against Gram negative Escherichia coli, Pseudomonas aeruginosa, and Proteus spp., and Gram positive Staphylococcus aureus bacterial strains. The results also indicated that the ß-lactam derivatives (3-4) have high antibacterial activities on Gram positive bacteria as well as the metal complexes (5-8), particularly Zn complexes, have a significant activity against all Gram negative bacterial strains. It has been shown that the metal complexes have significantly higher activity than corresponding ligands due to chelation process which reduces the polarity of metal ion by coordinating with ligands.

Chlorination and oxidation of sulfonamides by free chlorine: Identification and behaviour of reaction products by UPLC-MS/MS.

Sulfonamides (SAs) are one class of the most widely used antibiotics around the world and have been frequently detected in municipal wastewater and surface water in recent years. Their transformation in waste water treatment plants (WWTP) and in water treatment plants (WTP), as well as, their fate and transport in the aquatic environment are of concern. The reaction of six sulfonamides (sulfamethoxazole, sulfapyridine, sulfamethazine, sulfamerazine, sulfathiazole and sulfadiazine) with free chlorine was investigated at a laboratory scale in order to identify the main chlorination by-products. A previously validated method, liquid chromatography/mass spectrometry, was used to analyse SAs and their chlorination by-products. At room temperature, pH 6-7, reaction times of up to 2 h and an initial concentration of 2 mg/L of free chlorine, the majority of SAs suffered degradation of around 65%, with the exception of sulfamethoxazole and sulfathiazole (20%). The main reaction of SAs with free chlorine occurred in the first minute.

Preparation of alginate-chitosan fibers with potential biomedical applications.

The preparation of alginate-chitosan fibers, through wet spinning technique, as well as the study of their properties as a function of chitosan's molecular weight and retention time in the coagulation bath, is presented and discussed in this work. Scanning electron microscopy (SEM) revealed that the fibers presented irregular and rough surfaces, with a grooved and heavily striated morphology distributed throughout the structure. Dynamic mechanical analysis (DMA) showed that, with the exception of elongation at break, the incorporation of chitosan into the fibers improved their tensile properties. The in vitro release profile of sulfathiazole as a function of chitosan's molecular weight indicated that the fibers are viable carriers of drugs. Kinetic models showed that the release of the model drug is first-order, and the release mechanism is governed by the Korsmeyer-Peppas model. Likewise, fibers loaded with sulfathiazole showed excellent inhibition of Escherichia coli growth after an incubation time of 24h at 37 °C.

Structural characterization of new Schiff bases of sulfamethoxazole and sulfathiazole, their antibacterial activity and docking computation with DHPS protein structure.

New Schiff bases (1, 2) of substituted salicylaldehydes and sulfamethoxazole (SMX)/sulfathiazole (STZ) are synthesized and characterized by elemental analysis and spectroscopic data. Single crystal X-ray structure of one of the compounds (E)-4-((3,5-dichloro-2-hydroxybenzylidene)amino)-N-(5-methylisoxazol-3-yl)benzenesulfonamide (1c) has been determined. Antimicrobial activities of the Schiff bases and parent sulfonamides (SMX, STZ) have been examined against several Gram-positive and Gram-negative bacteria and sulfonamide resistant pathogens; the lowest MIC is observed for (E)-4-((3,5-dichloro-2-hydroxybenzylidene)amino)-N-(thiazol-2-yl)benzene sulfonamide (2c) (8.0 µg mL(-1)) and (E)-4-((3,5-dichloro-2-hydroxybenzylidene)amino)-N-(5-methylisoxazol-3-yl)benzene sulfonamide (1c) (16.0 µg mL(-1)) against sulfonamide resistant pathogens. DFT optimized structures of the Schiff bases have been used to carry out molecular docking studies with DHPS (dihydropteroate synthase) protein structure (downloaded from Protein Data Bank) using Discovery Studio 3.5 to find the most preferred binding mode of the ligand inside the protein cavity. The theoretical data have been well correlated with the experimental results. Cell viability assay and ADMET studies predict that 1c and 2c have good drug like characters.

Physicochemical characterization of novel Schiff bases derived from developed bacterial cellulose 2,3-dialdehyde.

The synthesis of two novel Schiff's bases (cellulose-2,3-bis-[(4-methylene-amino)-benzene-sulfonamide] (5) & cellulose-2,3-bis-[(4-methylene-amino)-N-(thiazol-2-yl)-benzenesulfonamide] (6) via condensation reactions of periodate oxidized developed bacterial cellulose ODBC (2) with sulfa drugs [sulfanilamide (3) & sulfathiazole (4)] was reported. The physicochemical characterization of the condensation products was performed using FTIR, (1)H NMR, (13)C NMR spectral analyses, X-ray diffraction and DTA. The ODBC exhibited the highest degree of oxidation based on the aldehyde group number percentage (82.9%), which confirms the highest reactivity of developed bacterial cellulose [DBC (1)]. The X-ray diffractograms indicated an increase in the interplanar distance of the cellulose Schiff base (6) compared to ODBC (2) due to sulfathiazole (4) inclusion between ODBC (2) sheets corresponding to the 1 1 0 plane. In addition, the aldehyde content of Schiff base (6) was (20.8%) much lower than that of Schiff base (5) (41.5%). These results confirmed the high affinity of sulfathiazole (4) to the ODBC (2) chain, and the substantial changes in the original properties of ODBC were due to these chemical modifications rather than the sulfanilamide (3).

Photodegradation of sulfonamide antimicrobial compounds (sulfadiazine, sulfamethizole, sulfamethoxazole and sulfathiazole) in various UV/oxidant systems.

This study used Na2S2O8, NaBrO8 and H2O2to degrade sulfadiazine (SDZ), sulfamethizole (SFZ), sulfamethoxazole (SMX) and sulfathiazole (STZ) under ultraviolet (UV) irradiation. The initial concentration of sulfonamide and oxidant in all experiments was 20 mg/L and 5 mM, respectively. The degradation rate for sulfonamides satisfies pseudo-first-order kinetics in all UV/oxidant systems. The highest degradation rate for SDZ, SFZ, SMX and STZ was in the UV/Na2S2O8, UV/NaBrO3, UV/Na2S2O8 and UV/H2O2 system, respectively. In the UV/Na2S2O8 system, the photodegradation rate of SDZ, SFZ, SMX and STZ was 0.0245 min⁻¹, 0.0096 min⁻¹, 0.0283 min⁻¹ and 0.0141 min⁻¹, respectively; moreover, for the total organic carbon removal rate for SDZ, SFZ, SMX and STZ it was 0.0057 min⁻¹, 0.0081 min⁻¹, 0.0130 min⁻¹ and 0.0106 min⁻¹, respectively. Experimental results indicate that the ability of oxidants to degrade sulfonamide varied with pollutant type. Moreover, UV/Na2S2O8 had the highest mineralization rate for all tested sulfonamides.

[SAR of benzoyl sulfathiazole derivatives as PTP1B inhibitors].

Protein tyrosine phosphatase (PTP) 1B is a potential target for the treatment of diabetes and obesity. We have previously identified the benzoyl sulfathiazole derivative II as a non-competitive PTP1B inhibitor with in vivo insulin sensitizing effects. Preliminary SAR study on this compound series has been carried out herein, and thirteen new compounds have been designed and synthesized. Among them, compound 10 exhibited potent inhibition against human recombinant PTP1B with the IC50 value of 3.97 micromol x L(-1), and is comparable to that of compound II.