Sulfanilamide Research Articles

Electrochemical Detection of Sulfanilamide at MWCNT Coated Conducting Polymer Modified Electrode

Oxidation of sulfanilamide (SN) at the Glassy Carbon Electrode (GCE) modified with a thin layer of electropolymerized Eriochrome Black-T (EBT) and multi walled carbon nanotubes (MWCNT) was investigated voltammetrically. The performance of layer by layer modified composite electrode was compared with bare GCE, p(EBT)/GCE, and MWCNT/GCE using cyclic voltammetry (CV), differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS). An enhanced current response and lower peak potential were observed for SN oxidation at the layered composite electrode compared to rest of the electrodes. Hence, it was employed for analytical determination of SN after optimization of experimental parameters. Under optimized condition, the oxidation peak current increased linearly with concentration of SN over the range of 2 Χ10-8 to 5 Χ 10-6 M. The limit of detection was calculated to be 1.2 Χ 10-8 M. The electrode showed good selectivity, repeatability and reproducibility. It was also successfully applied for the determination of SN present in spiked human serum and ground water samples. Figure 1

Preparation and application of epitope magnetic molecularly imprinted polymers for enrichment of sulfonamide antibiotics in water

Sulfonamides, which are widely used synthetic antibiotics, are hydrophilic and stable. They can easily migrate into the environment and aquatic animals, and increase the risk of cancer, drug resistance, and allergic symptoms if consumed by humans. Here, we developed an epitope magnetic imprinting approach to enrich multiple sulfonamide antibiotics from a water sample. Epitope magnetic molecularly imprinted polymers (EMMIPs) were prepared by free-radical polymerization using vinyl-functioned Fe3 O4 as a core, sulfanilamide (SA) as a dummy template, methacrylic acid as a functional monomer, and ethylene glycol dimethacrylate as a cross-linker. The performance of the EMMIPs was first evaluated by rebinding SA, and then an adsorption experiment was conducted to assess the extraction of multiple sulfonamide antibiotics containing the SA group. The binding experiments showed that the EMMIPs reached adsorption equilibrium in only 5min with adsorption of SA at 2040μg/g, compared with just 462μg/g for the epitope magnetic non-imprinted polymers. EMMIPs were combined with HPLC for the detection of six sulfonamide antibiotics in surface water samples. The recoveries ranged from 79.3 to 92.4% and the relative standard deviations from 0.9 to 7.3%.

Synthesis of Schiff Bases of Benzaldehyde and Salicylaldehyde as Anti-inflammatory Agents

Three Schiff bases from Benzaldehyde and Salicylaldehyde have been synthesized (A, 1and 2) and two of them (1and 2) have been tested for anti-inflammatory activity. The p-aminobenzene sulfonamide has been synthesized from acetanilide through the addition of excess chlorosulfonic acid then concentrated ammonia solution; Schiff base of this derivative (2) exhibited good level of activity against egg-white induced edema in rat hind paw, while the other tested derivative exhibited no activity.
 Key words: Schiff bases, sulfonamide derivatives, salicylaldehyde

A sensitive method for the determination of Sulfonamides in seawater samples by Solid Phase Extraction and UV–Visible spectrophotometry

The authors have developed a sensitive spectrophotometric method for determination of sulfonamide derivatives such as sulfanilamide (SAA), sulfadiazine (SDZ), sulfacetamide (SCT) sulfamethoxazole (SMX), sulfamerazine (SMR), sulfadimethoxine (SDX), sulfamethiazole (SMT) and Sulfathiazole (STZ). This method is based on the Bratton-Marshall reaction, which involves the diazotization of sulfonamides with sodium nitrite under acidic conditions, followed by coupling with N-(1-naphtyl) ethylenediamine dihydrochloride (NED) to form a pink colored compound. Therefore, the Bratton-Marshall method was modified by optimizing the reaction conditions, which allows us to determine a low concentration range of sulfonamides compared to the reported methods. The limits of detection and quantification obtained were 0.019–0.05 and 0.06–0.16μgmL−1, respectively. In comparison with other reported methods using different coupling agents, the proposed method was found to be the most simple and sensitive for sulfonamides determination. In this paper, the modified method was successfully employed for the determination of sulfonamides in drinking water, seawater and pharmaceutical and veterinary formulations.The purpose of this work is to optimize and develop a simple method for extraction and concentration of sulfonamides present as residues in seawater and their quantification with the recommended spectrophotometric method. Solid phase extraction (SPE) of sulfonamides from seawater samples was evaluated using Oasis HLB cartridges (3mL, 540mg). The recovery efficiency was investigated in the sulfonamides concentration range comprised between 0.19 and 126ngmL−1. The ease of use of this extraction method makes it very useful for routine laboratory work.

Photocatalytic Degradation of Antibacterial Sulfanilamide from Aqueous Solution Using TiO<sub>2 </sub>Nanocatalyst

Photocatalytic degradation of sulfanilamide (SNM) as a kind of pollutant agent through titanium dioxide nano particles (TiO2) under UV irradiation was evaluated. The effect of different parameters, such as TiO2 and SNM concentrations, amount of pH, inorganic salt and type of light source on the reaction rate was investigated. The results show that SNM was completely removed from the solution after 60 min under UV irradiation. Furthermore, kinetic studied were performed at 25°C over different ranges of SNM concentrations from 100 to 300 ppm, TiO2 concentrations from 0.05 to 1 gL-1 and pH of suspensions from 3 to 11. In this range of concentration of materials, a Langmuir–Hinshelwood kinetic model can describe the process. An overall pseudo-first order kinetic constant was calculated for sulfanilamide conversion. The optimum TiO2 loading, which provides enough surface area for reaction without irradiation loss due to scattering of UV light, was found to be 0.1gL-1, and SNM concentration was100 ppm. Higher degradation efficiency of SNM was observed at pH=9. Finally, the results of this work proved that photocatalysis of SNM is a promising technology to reduce persistent substances even if they are present in low concentrations.

Mixture toxicity of six sulfonamides and their two transformation products to green algae Scenedesmus vacuolatus and duckweed Lemna minor

Since humans and ecosystems are continually exposed to a very complex and permanently changing mixture of chemicals, there is increasing concern in the general public about the potential adverse effects they may cause. Among all “emerging pollutants”, pharmaceuticals in particular have raised great environmental concern. For these reasons the aim of our study was to evaluate the mixture toxicity of six antimicrobial sulfonamides (SAs) and their two most commonly identified degradation products – sulfanilic acid (SNA) and sulfanilamide (SN) - to limnic green algae Scenedesmus vacuolatus and duckweed Lemna minor. The ecotoxicological data for the single toxicity of SNA and SN towards selected organisms are presented. The concept of Concentration Addition (CA) was applied to estimate the effects, and less than additive effects were observed. In general terms, it seems sufficiently precautionary for the aquatic environment to consider the toxicity of a sulfonamide mixture as additive. The Concentration Addition model proves to be a reasonable worst-case estimation. Such a comparative study on the mixture toxicity of sulfonamides and their transformation products has been presented for the first time.

Molecular Dynamics of Amorphous Sulfamethazine With Structurally Related Sulfonamide Impurities Evaluated Using Thermal Analysis

In this study, the effects of structurally related organic impurities on the molecular dynamics of amorphous sulfamethazine were evaluated using thermal analysis. Sulfanilamide (SNA), sulfamerazine (SMR), and sulfadimethoxine were used as virtual impurities of sulfamethazine. The amorphous state was prepared in situ in differential scanning calorimetry by quenching the melted physical mixtures of sulfamethazine and each impurity compound in the differential scanning calorimetry pan. In the following heating process, the glass transition temperatures (Tg) of each were measured. The fragility parameters were estimated from the width of Tg. The Tg of amorphous sulfamethazine with those impurities changed in accordance with the manner set forth in the Gordon-Taylor equation. The fragility parameter slightly increased when a small amount of SNA or SMR was incorporated. Moreover, the probability of a measurement in which crystallization of sulfamethazine was observed above its Tg, increased at a low-concentration range of SNA, SMR, or sulfadimethoxine. It was considered that the existence of a small amount of impurity would induce heterogeneity in the molecular density of the amorphous state, which would be associated with the local fluctuation. It was suggested that the change in the molecular dynamics would be related to the probability of crystallization of sulfamethazine.

SYNTHESIS AND ANTI-INFLAMMATORY ACTIVITY OF SOME NEW PYRAZOLO[3,4-d] PYRIMIDINES

5-Amino-3-methyl-1-phenyl-1 H -pyrazole-4-carbonitrile ( 5 ) was reacted with chloroacetyl chloride under fusion condition to afford two compounds, which identified as 6-chloromethylpyrazolo[3,4- d ]pyrimdine ( 3 ) and 4-amino-5-chloropyrazolo[3,4- b ]pyridine ( 7 ) ln different ratios. Treatment of compound ( 3 ) with aromatic amines, gave the arylaminomethyl derivatives ( 8a-c ). Compound ( 3 ) was reacted with sodium azide, phosphorous oxychloride, sulphanilamide to give new derivatives ( 9, 10, and 14 ). The 4-chloro derivative ( 11 ) underwent nucleophilic substitution using some reagent such as P 2 S 5 , sodium azide and hydrazine hydrate to furnish novel pyrazolo[3,4- d ]pyrimidines ( 12, 13, 15, 16, 17 ). All synthesized compounds were characterized using elemental analysis and spectral techniques. The anti-inflammatory activity of all the newly synthesized compounds was evaluated using the carrageenan induced paw oedema test in rats using indomethacin as the reference drug.

Investigation of sulfonamides inhibition of carbonic anhydrase enzyme using multiphotometric and electrochemical techniques.

Two approaches for sulfonamides (SA's) determination, based on carbonic anhydrase enzyme inhibition have been investigated in this work. In the first method, nine different SA's have been screened using simultaneous multiphotometric measurement in multiwell plates. The sulfanilamide (SAD) showed significant inhibition compared to other sulfonamides. The carbonic anhydrase (CA) kinetic interactions reveal noncompetitive binding of SAD. Interferences from other inhibitors with enzyme were studied and the results showed very good selectivity toward SAD. In the second approach, an electrochemical enzyme inhibition biosensor, based on CA entrapped in a carbon paste electrode using carbon black nanoparticles and solid paraffin, was successfully applied to SAD measurements. Results from the quantitative analysis of SAD are discussed in terms of detection limit, linear range and sensitivity using multiphotometric and biosensor-based methods The biosensor developed was successfully applied to the determination of SAD at submicromolar levels and it is recommended for application for in situ analysis.

Drug resistance of wound-isolated pseudomonas aeruginosa and its correlation with use of antibiotics in children

Objective To discuss drug resistance of wound-isolated pseudomonas aeruginosa and its correlation with use of antibiotics in children, for guiding the clinical use of antibiotics. Methods One hundred and forty wounded children admitted from January 2009 and December 2013 were collected in the study. There were 97 males and 43 females, aged (5.4±2.6)years. All were victims of road traffic accidents. Distribution of bacteria isolated from the wound and drug resistance of pseudomonas aeruginosa were detected. Twenty-seven children with pseudomonas aeruginosa infection were divided into imipenem-resistant group (n=7) and non-imipenem resistant group (n=20). Drug resistance and application intensity of antibiotics were compared between the two groups. Results A total of 64 pathogens were isolated from the wound culture. Top five bacteria detected were acinetobacter baumannii, pseudomonas aeruginosa, enterobacter cloacae, escherichia coli and staphylococcus epidermidis. Pseudomonas aeruginosa showed resistance to β-lactam antibiotics, tetracyclines, chloram-phenicol and sulfanilamide. Drug resistance of piperacillin tazobactam (64.7%), meropenem (100%), ceftazidime (64.7%) and piperacillin (76.5%) in imipenem-resistant group were all 40% higher than that in non-imipenem resistant group (P 0.05). There was no significant difference in total application intensity of antibiotics between the groups (P>0.05). Conclusions Wound-isolated pseudomonas aeruginosa in children is multidrug resistant. Thus bacterial monitoring in children with traumatic wounds should be strengthened and antibiotics should be selected rationally to reduce the production of multidrug resistance of pseudomonas aeruginosa. Key words: Pseudomonas aeruginosa; Anti-bacterial agents; Drug resistance; Children

Ag loaded WO3 nanoplates for efficient photocatalytic degradation of sulfanilamide and their bactericidal effect under visible light irradiation

Sulfonamides (SAs) are extensively used antibiotics and their residues in the water bodies propose potential threat to the public. In this study, degradation efficiency of sulfanilamide (SAM), which is the precursor of SAs, using WO3 nanoplates and their Ag heterogeneous as photocatalysts was investigated. WO3 nanoplates with uniform size were synthesized by a facile one step hydrothermal method. Different amount of Ag nanoparticles (Ag NPs) were loaded onto WO3 nanoplates using a photo-reduction method to generate WO3/Ag composites. The physio-chemical properties of synthesized nanomaterials were systematically characterized. Photodegradation of SAM by WO3 and WO3/Ag composites was conducted under visible light irradiation. The results show that WO3/Ag composites performed much better than pure WO3 where the highest removal rate was 96.2% in 5h. Ag as excellent antibacterial agent also endows certain antibacterial efficiency to WO3, and 100% removal efficiency against Escherichia Coli and Bacillus subtilis could be achieved in 2h under visible light irradiation for all three WO3/Ag composites synthesized. The improved performance in terms of SAM degradation and antibacterial activity of WO3/Ag can be attributed to the improved electron-hole pair separation rate where Ag NPs act as effective electron trapper during the photocatalytic process.

Hierarchically-structured Co–CuBi2O4 and Cu–CuBi2O4 for sulfanilamide removal via peroxymonosulfate activation

Herein, we report the syntheses of Co–CuBi2O4 and Cu–CuBi2O4 composites using a facile hydrothermal synthesis method for sulfanilamide (SA) removal via peroxymonosulfate (PMS) activation. The composites were characterized using FESEM, XRD and porosimeter and the results indicated that they were hierarchically-structured with several phases. The performance of the composites as catalysts for PMS activation was evaluated with respect to different initial pHs (4.5–9.5), catalyst loadings (L, 0.10–0.60gL−1) and Oxone® dosages (D, 0.03–0.30gL−1) and the empirical relationship between the kapp, L and D were obtained. The results also indicated that Cl− and humic acid exerted negative effect on SA degradation due to the intrinsic competition between Cl− and humic acid with SA for SO4− oxidation. The principal reactive radical in the Co–CuBi2O4/PMS and Cu–CuBi2O4/PMS systems was identified to be SO4−. A simple method to calculate the normalized steady-state concentrations of SO4− ([SO4−]Nss) and OH ([OH]Nss) in the heterogeneous catalyst/PMS system is proposed. The results indicated that the generated SO4− and OH in the Co–CuBi2O4/PMS system were utilized at least five times more efficiently than the Cu–CuBi2O4/PMS system. The proposed method for calculating [SO4−]Nss and [OH]Nss can be potentially employed to characterize and compare the intrinsic catalytic activity of various heterogeneous catalyst/PMS systems in future studies.

Towards a molecular level understanding of the sulfanilamide-soil organic matter-interaction

Sorption experiments of sulfanilamide (SAA) on well-characterized samples of soil size-fractions were combined with the modeling of SAA-soil-interaction via quantum chemical calculations. Freundlich unit capacities were determined in batch experiments and it was found that they increase with the soil organic matter (SOM) content according to the order fine silt > medium silt > clay > whole soil > coarse silt > sand. The calculated binding energies for mass-spectrometrically quantified sorption sites followed the order ionic species > peptides > carbohydrates > phenols and lignin monomers > lignin dimers > heterocyclic compounds > fatty acids > sterols > aromatic compounds > lipids, alkanes, and alkenes. SAA forms H-bonds through its polar centers with the polar SOM sorption sites. In contrast dispersion and π-π-interactions predominate the interaction of the SAA aromatic ring with the non-polar moieties of SOM. Moreover, the dipole moment, partial atomic charges, and molecular volume of the SOM sorption sites are the main physical properties controlling the SAA-SOM-interaction. Further, reasonable estimates of the Freundlich unit capacities from the calculated binding energies have been established. Consequently, we suggest using this approach in forthcoming studies to disclose the interactions of a wide range of organic pollutants with SOM.

Synthesis, antimicrobial activity and modelling studies of some new metal complexes of Schiff base derived from sulphonamide drug in vitro

Palladium(II) and cobalt(II) complexes of Schiff base derived from 4-aminobenzene sulfonamide (Sulfonamide drug) were prepared by convenient method. Reaction of sulfonamide with 2-hydroxy-1-naphthaldehyde gave the Schiff base compound 1 in good yield. Treatment of compound 1 with CoCl 2 .6H 2 O and PdCl 2 yielded new metal complexes 2 and 3 , respectively. The synthesized compounds were screened for their antibacterial activity against Escherichia coli , Bacillus cereus , Salmonella spp. and Staphylococcus aureus . Additionally, the compounds were tested for antifungal activity against Aspergillus niger and Candida albicans . Some compounds exhibited good antibacterial and antifungal activity. Molecular modeling studies were performed and showed hydrogen binding and hydrophobic interactions.

Investigation of the adsorption characteristics of some selected sulphonamide derivatives as corrosion inhibitors at mild steel/hydrochloric acid interface: Experimental, quantum chemical and QSAR studies

Five sulphonamides derivatives namely, sulphanilamide (SNA), sulphamethoxazole (SMX), sulphadimethoxine (SDM), sulphisoxazole (SSZ), and sulphamethizole (SMZ) have been selected as corrosion inhibitors for mild steel in hydrochloric acid solutions utilizing electrochemical techniques as well as theoretical method (using DFT). These compounds were found to protect mild steel through spontaneous adsorption on to mild steel surface, thereby blocking the active sites. The obtained thermodynamic and kinetic parameters deduced that sulphonamides adopt a Langmuir adsorption isotherm mechanism. Results from electrochemical impedance and potentiodynamic polarization showed exceptional correlation and revealed that these compounds are mixed-type inhibitors. The formation of the adsorption film on the mild steel surface was confirmed by SEM, EDS and FTIR. Quantum chemical calculations and quantitative structure activity relationship (QSAR) were also utilized to investigate the preferred reactive sites on the molecules of the sulphonamides and to correlate the experimentally determined inhibition efficiency with the theoretically determined inhibition efficiency. The results indicate that the preferred sites for interaction between the inhibition and metal surface would be the aromatic ring as well as the heteroatoms present in each sulphonamide. Five quantum chemical parameters are sufficient in the development of QSAR to provide a strong correlation between inhibition efficiency obtained theoretically and that obtained experimentally.

Solar photocatalytic degradation of sulfanilamide by BiOCl/reduced graphene oxide nanocomposites: Mechanism and degradation pathways

Flower-like bismuth oxychloride (BiOCl) catalysts were synthesized with a facile hydrolysis reaction, where the synthesized BiOCl products were further decorated with the prepared graphene oxide (GO) to form novel BiOCl/reduced graphene oxide (BiOCl/RGO) composites. The as-synthesized materials were well characterized with the aid of various techniques, before they were used as photocatalysts for the degradation of sulfanilamide (SN) aqueous solution. The BiOCl/RGO composites contained 1 wt% RGO exhibited superior photocatalytic response, where the degradation rate of SN at 82.7% stayed 30% higher than that of pure BiOCl. The enhanced photocatalytic performances of BiOCl/RGO composites were neither related to the surface area values nor the bandgap of the fabricated photocatalysts, but associated with the enhanced visible light absorption and advanced electron transfer ability. On a basis of the analysis on the SN intermediate products by HPLC, IC, FTIR, 1H NMR, 13C NMR and MS, the degradation pathway of SN was speculated, where it was confirmed that the main intermediate product of SN was sulfanilic acid.

Synthesis of novel acridine bis-sulfonamides with effective inhibitory activity against the carbonic anhydrase isoforms I, II, IX and XII

By using a multi component reaction system (MCR), nitro acridine sulfonamides were obtained from cyclic-1,3-diketones, 4-aminobenzene sulfonamide and aromatic aldehydes. Some novel acridine bis-sulfonamides 6a–l were then synthesized by the reaction between sulfonyl chlorides and the novel amino-acridine sulfonamides 5a and 5b, obtained by reduction of nitro-acridine sulfonamide derivatives 4a and 4b. The newly synthesized compounds were investigated as inhibitors of 4 human carbonic anhydrase isoforms (hCA, EC 4.2.1.1). Several of the compounds showed low micromolar inhibition against the medically relevant isoforms hCA I, II, IX, and XII.

One-pot preparation of a sulfamethoxazole functionalized affinity monolithic column for selective isolation and purification of trypsin

A facile and efficient “one-pot” copolymerization strategy was used for the preparation of sulfonamide drug (SA) functionalized monolithic columns. Two novel SA-immobilized methacrylate monolithic columns, i.e. poly(GMA-SMX-co-EDMA) and poly(GMA-SAA-co-EDMA) were prepared by one-pot in situ copolymerization of the drug ligand (sulfamethoxazole (SMX) or sulfanilamide (SAA)), the monomer (glycidyl methacrylate, GMA) and the cross-linker (ethylene dimethacrylate, EDMA) within 100μm i.d. capillaries under optimized polymerization conditions. The physicochemical properties and column performance of the fabricated monolithic columns were characterized by elemental analysis, scanning electron microscopy and micro-HPLC. Satisfactory column permeability, efficiency and separation performance were obtained on the optimized poly(GMA-SMX-co-EDMA) monolithic column for small molecules, such as a standard test mixture and eight aromatic ketones. Notably, it was found that the poly(GMA-SMX-co-EDMA) monolith showed a selective affinity to trypsin, while the poly(GMA-SAA-co-EDMA) monolith containing sulfanilamide did not exhibit such affinity at all. This research not only provides a novel monolith for the selective isolation and purification of trypsin, but it also offers the possibility to easily prepare novel drug functionalized methacrylate monoliths through a one-pot copolymerization strategy.

Thermal Degradation Behavior of Composites with Liquid Crystalline Epoxy and Aluminum Nitride

Liquid crystalline epoxy, 4,4’-Diglycidyloxy-α-methylstilbene (DOMS) was synthesized and Aluminum Nitride reinforced DOMS composites were fabricated by melt blending with sulfanilamide (SAA) as a curing agent. Thermal degradation behavior was investigated by thermogravimetric analysis (TGA) under nitrogen atmosphere at the temperature range from 30 to 1000°C. Activation energies for decomposition (Ed) by TGA were determined as a function of conversion by weight loss process.

Interaction of sulfanilamide and sulfamethoxazole with bovine serum albumin and adenine: Spectroscopic and molecular docking investigations

Interaction between sulfanilamide (SAM) and sulfamethoxazole (SMO) with BSA and DNA base (adenine) was investigated by UV–visible, fluorescence, cyclic voltammetry and molecular docking studies. Stern–Volmer fluorescence quenching constant (Ka) suggests SMO is more quenched with BSA/adenine than that of SAM. The distance r between donor (BSA/adenine) and acceptor (SAM and SMO) was obtained according to fluorescence resonance energy transfer (FRET). The results showed that hydrophobic forces, electrostatic interactions, and hydrogen bonds played vital roles in the SAM and SMO with BSA/adenine binding interaction. During the interaction, sulfa drugs could insert into the hydrophobic pocket, where the non-radioactive energy transfer from BSA/adenine to sulfa drugs occurred with high possibility. Cyclic voltammetry results suggested that when the drug concentration is increased, the anodic electrode potential deceased. The docking method indicates aniline group is interacted with the BSA molecules.