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Water Research Apr 2016The role of aquatic natural organic matter (NOM) in the removal of contaminants of emerging concern has been widely studied. Sulfamerazine (SMR), a sulfonamide...
The role of aquatic natural organic matter (NOM) in the removal of contaminants of emerging concern has been widely studied. Sulfamerazine (SMR), a sulfonamide antibiotic detected in aquatic environments, is implicated in environmental toxicity and may contribute to the resistance of bacteria to antibiotics. In aquatic systems sulfonamides may undergo direct photodegradation, and, indirect photodegradation through the generation of reactive species. Because some forms of NOM inhibit the photodegradation there is an increasing interest in correlating the spectroscopic parameters of NOM as potential indicators of its degradation in natural waters. Under the conditions used in this study, SMR hydrolysis was shown to be negligible; however, direct photolysis is a significant in most of the solutions studied. Photodegradation was investigated using standard solutions of NOM: Suwannee River natural organic matter (SRNOM), Suwannee River humic acid (SRHA), Suwannee River fulvic acid (SRFA), and Aldrich humic acid (AHA). The steady-state concentrations and formation rates of the reactive species and the SMR degradation rate constants (k1) were correlated with NOM spectroscopic parameters determined using UV-vis absorption, excitation-emission matrix (EEM) fluorescence spectroscopy, and proton nuclear magnetic resonance ((1)H NMR). SMR degradation rate constants (k1) were correlated with steady-state concentrations of NOM triplet-excited state ([(3)NOM(∗)]ss) and the corresponding formation rates ((3)NOM*) for SRNOM, SRHA, and AHA. The efficiency of SMR degradation was highest in AHA solution and was inhibited in solutions of SRFA. The steady-state concentrations of singlet oxygen ([(1)O2]ss) and the SMR degradation rate constants with singlet oxygen (k1O2) were linearly correlated with the total fluorescence and inversely correlated with the carbohydrate/protein content ((1)H NMR) for all forms of NOM. The total fluorescence and EEMs Peak A were confirmed as indicators of (1)O2 formation. Specific ultraviolet absorbance at 254 nm (SUVA254) and aromaticity showed potential correlations with the steady-state concentrations of hydroxyl radical ([HO]ss) and the corresponding formation rates (HO).
Topics: Anti-Bacterial Agents; Benzopyrans; Humic Substances; Hydroxyl Radical; Kinetics; Organic Chemicals; Photolysis; Proton Magnetic Resonance Spectroscopy; Rivers; Singlet Oxygen; Solutions; Spectrometry, Fluorescence; Spectrophotometry, Ultraviolet; Sulfamerazine; Sunlight; Water Pollutants, Chemical
PubMed: 26878479
DOI: 10.1016/j.watres.2015.11.036 -
Pharmaceutical Research Apr 1986Suspensions of sulfamerazine (10%) containing 0.2% docusate sodium were deflocculated because of repulsion between the negatively charged particles. Flocculation was...
Suspensions of sulfamerazine (10%) containing 0.2% docusate sodium were deflocculated because of repulsion between the negatively charged particles. Flocculation was induced by salts or by xanthan gum, which is anionic, in the presence of salts at concentrations below those at which salt flocculation resulted. The amount of gum necessary to produce a flocculated system was lower the higher the concentration of salt present. Calcium chloride and magnesium chloride were considerably more effective in this regard than sodium chloride. Gum flocculation produced aggregates with fewer particles and weaker bonding forces than did salt flocculation. The sedimentation rate of the suspensions decreased 5 to 10 times for each 0.1% increase in the gum concentration.
PubMed: 24271472
DOI: 10.1023/A:1016301721900 -
Journal of Pharmaceutical Sciences Dec 1979Flocculation by a cationic polymer of sulfamerazine suspensions containing a wetting agent was evaluated. Suspensions with sufficient surfactant concentrations to ensure...
Flocculation by a cationic polymer of sulfamerazine suspensions containing a wetting agent was evaluated. Suspensions with sufficient surfactant concentrations to ensure complete wetting were deflocculated. When the anionic surfactant, dioctyl sodium sulfosuccinate, was used as a wetting agent, the suspensions were flocculated over a limited polymer concentration range. Flocculation was attributed to simultaneous interaction of a polymer molecule with more than one particle. At higher polymer concentrations, the particles were covered completely with polymer, leading to repulsion between the particles and deflocculation of the suspensions. The polymer concentration required for flocculation provided evidence for interaction between the anionic surfactant and the cationic polymer. Suspensions containing a nonionic surfactant also were flocculated using various polymer concentrations. When a surfactant mixture was employed in the suspensions, the peak sedimentation volume of flocculated systems and the concentration of polymer at the peak depended on the surfactant mixture composition.
Topics: Cations; Centrifugation; Drug Compounding; Molecular Weight; Polymers; Sulfamerazine; Surface Tension; Surface-Active Agents; Suspensions
PubMed: 529037
DOI: 10.1002/jps.2600681207 -
Angewandte Chemie (International Ed. in... Nov 2020The last decade has witnessed a burgeoning of new methods for the enantioselective vicinal difunctionalization of alkenes initiated by electrophilic sulfenyl group... (Review)
Review
The last decade has witnessed a burgeoning of new methods for the enantioselective vicinal difunctionalization of alkenes initiated by electrophilic sulfenyl group transfer. The addition of sulfenium ions to alkenes results in the generation of chiral, non-racemic thiiranium ions. These highly reactive intermediates are susceptible to attack by a myriad of nucleophiles in a stereospecific ring-opening event to afford anti 1,2-sulfenofunctionalized products. The practical application of sulfenium ion transfer has been enabled by advances in the field of Lewis base catalysis. This Review will chronicle the initial discovery and characterization of thiiranium ion intermediates followed by the determination of their configurational stability and the challenges of developing enantioselective variants. Once the framework for the reactivity and stability of thiiranium ions has been established, a critical analysis of pioneering studies will be presented. Finally, a comprehensive discussion of modern synthetic applications will be categorized around the type of nucleophile employed for sulfenofunctionalization.
Topics: Alkenes; Catalysis; Stereoisomerism; Sulfamerazine
PubMed: 32452077
DOI: 10.1002/anie.202005920 -
Spectrochimica Acta. Part A, Molecular... Apr 2014Inclusion complexation behavior and binding ability of sulfamerazine (SMRZ) with α- and β-cyclodextrins (α-CD and β-CD) were investigated. The formation of inclusion...
Inclusion complexation behavior and binding ability of sulfamerazine (SMRZ) with α- and β-cyclodextrins (α-CD and β-CD) were investigated. The formation of inclusion complexes are studied by UV-visible, fluorescence, time-resolved fluorescence, (1)H NMR, FT-IR, DSC, XRD, SEM, TEM and molecular modeling methods. Both experimental and PM3 results indicated that the SMRZ is partially encapsulated in the CD cavity. The different spectral shifts observed in both the CDs indicate that different types of inclusion complexes are formed. Nanosecond time-resolved fluorescence studies demonstrated that SMRZ exhibit biexponential decay in water and triexponential decay in CD solutions. The resonance of the aromatic protons of SMRZ showed remarkably upfield shift in the complexes suggested that the aniline ring deeply encapsulated in the CD cavity. The amino and amido stretching vibrations at 3483 cm(-1) and 3379 cm(-1) respectively are strongly affected in the inclusion complexes. DSC curves for the inclusion complexes exhibited a broad endothermic effect from 106.4 °C, 123.8 °C and 234.5 6 °C for α-CD and 118.2 °C and 231.4 °C for β-CD. TEM images of both inclusion complexes are forms a nanochain like agglomerated structures with a width ranging from 40 nm to 100 nm. Thermodynamic parameters and binding affinity of the inclusion complex formation were determined and discussed.
Topics: Absorption, Physicochemical; Calorimetry, Differential Scanning; Circular Dichroism; Microscopy, Electron, Scanning; Models, Molecular; Proton Magnetic Resonance Spectroscopy; Spectrometry, Fluorescence; Spectroscopy, Fourier Transform Infrared; Sulfamerazine; Thermodynamics; X-Ray Diffraction; alpha-Cyclodextrins; beta-Cyclodextrins
PubMed: 24508883
DOI: 10.1016/j.saa.2014.01.057 -
Journal of Molecular Graphics &... Oct 2008A density functional theory investigation was carried out to characterize (14)N electric field gradient tensors, EFG, in crystalline sulfamerazine and sulfathiazole. To...
A density functional theory investigation was carried out to characterize (14)N electric field gradient tensors, EFG, in crystalline sulfamerazine and sulfathiazole. To include hydrogen-bonding effects in the calculations, the most probable interacting molecules with the target were considered as tetrameric and pentameric clusters, respectively. The calculated EFG tensors were used to evaluate nuclear quadrupole coupling tensors (chi(ii)) and asymmetry parameters (eta(Q)) for the target molecule in the clusters. Results are in satisfactory agreement with the experimental data. The EFG calculations reveal different contributions of nitrogen atoms in hydrogen-bonding network of the sulfamerazine and sulfathiazole. Moreover, based on the results obtained via atoms in molecules (AIM) analyses, an acceptable linear relation between (14)N nuclear quadrupole coupling constants and charge density values at N-H...N and N-H...O bond critical points, rho(b)(r(cp)), is observed.
Topics: Crystallography, X-Ray; Electricity; Hydrogen Bonding; Magnetic Resonance Spectroscopy; Nitrogen; Static Electricity; Sulfamerazine; Sulfathiazole; Sulfathiazoles
PubMed: 18603459
DOI: 10.1016/j.jmgm.2008.05.007 -
Journal of Pharmaceutical and... Nov 2014This study investigated the effect on solubility and release of ternary complexes of sulfamerazine (SMR) with β-(βCD), methyl-(MβCD) and hydroxypropyl-β-cyclodextrin... (Comparative Study)
Comparative Study
This study investigated the effect on solubility and release of ternary complexes of sulfamerazine (SMR) with β-(βCD), methyl-(MβCD) and hydroxypropyl-β-cyclodextrin (HPβCD) using meglumine (MEG) as the ternary component. The combination of MEG with MβCD resulted the best approach, with an increased effect (29-fold) of the aqueous solubility of SMR. The mode of inclusion was supported by 2D NMR, which indicated that real ternary complexes were formed between SMR, MEG and MβCD or HPβCD. Solid state analysis was performed using Fourier-transform infrared spectroscopy (FT IR), differential scanning calorimetry (DSC) and powder X-ray diffraction (XRD), which demonstrated that different interactions occurred among SMR, MEG and MβCD or HPβCD in the ternary lyophilized systems. The ternary complexes with βCD and MβCD produced an additional retention effect on the release of SMR compared to the corresponding binary complexes, implying that they were clearly superior in terms of solubility and release modulation.
Topics: 2-Hydroxypropyl-beta-cyclodextrin; Calorimetry, Differential Scanning; Chemistry, Pharmaceutical; Crystallography, X-Ray; Delayed-Action Preparations; Freeze Drying; Kinetics; Magnetic Resonance Spectroscopy; Meglumine; Powder Diffraction; Solubility; Spectroscopy, Fourier Transform Infrared; Sulfamerazine; Technology, Pharmaceutical; Thermogravimetry; beta-Cyclodextrins
PubMed: 25129645
DOI: 10.1016/j.jpba.2014.07.008 -
Journal of Pharmaceutical Sciences Jun 2014The effects of ball-milling and cryomilling on sulfamerazine forms I and II (SMZ FI, FII) were investigated using X-ray powder diffraction, infrared and near-infrared...
The effects of ball-milling and cryomilling on sulfamerazine forms I and II (SMZ FI, FII) were investigated using X-ray powder diffraction, infrared and near-infrared (NIR) spectroscopy. Cryomilling resulted in a complete amorphization of both polymorphs. Milling at room temperature gave mixtures of amorphous SMZ (FA) and FII. Calibration models were developed for the quantitative analysis of binary (FI/FII, FI/FA, and FII/FA) and ternary (FI/FII/FA) mixtures using NIR spectroscopy combined with partial least-squares (PLS) regression. The PLS models for binary (0%-100%), ternary (0%-100%), and low-level (0%-10%) binary mixtures had root-mean-square errors of prediction of ≤1.8%, ≤5.1%, and ≤0.80%, respectively. The calibration models were used to obtain a detailed quantitative picture of solid-state transformations during milling and any subsequent recrystallizations. FA prepared by cryomilling FI for less than 60 min recrystallized to mixtures of FI and FII, whereas samples milled for more than 60 min crystallized to pure FII. The effect of comilling SMZ with stoichiometric amounts of additives was investigated. SMZ formed amorphous materials with oxalic, dl-tartaric, and citric acids that were more stable toward recrystallization than FA. Amorphous SMZ/oxalic acid was found to recrystallize to a 2:1 cocrystal during storage.
Topics: Anti-Bacterial Agents; Calorimetry, Differential Scanning; Powder Diffraction; Spectroscopy, Near-Infrared; Sulfamerazine
PubMed: 24756899
DOI: 10.1002/jps.23978 -
The Cornell Veterinarian 1945
Topics: Animals; Horses; Humans; Lymphadenitis; Penicillins; Streptococcal Infections; Sulfamerazine
PubMed: 21005491
DOI: No ID Found -
Acta Crystallographica. Section C,... Aug 2006
Topics: Crystallography, X-Ray; Hydrogen Bonding; Molecular Conformation; Morpholines; Sulfamerazine
PubMed: 16891719
DOI: 10.1107/S0108270106021524