[en] A spectrophotometric method is proposed for determining sulfonamides in pure form and in pharmaceutical preparations , based on the charge transfer (CT) complex formation between phenosefranine as an acceptor and sulphonamides as as donors in acetate buffer (pH3). The factors affecting the formation of CT-complex were studied ,linear calibration graphs were obtained in the concentration range 1.07-16.70ug/ml at 25C. The minimum detection limit is in the range 0.428-0.573 ug/ml. The same complexes have been studied in aqueous media for conductometric mesurement The method could be successfully adopted for pharmaceutical preparations.The molar conductivity coefficients were found to increase with increasing temprature (25-35C)in all systems studied .The stoichiometry of the sulfonamides phenosefranine complexes were found to be 1:1 in both techniquecs. (author)

[en] To evaluate direct drug susceptibility testing on MGIT 960 system for detection of multidrug resistant tuberculosis from smear positive pulmonary specimens. Study Design: Cross-sectional analytical study. Place and Duration of Study: Microbiology Department, Armed Forces Institute of Pathology, Rawalpindi, from July 2016 to September 2017. Methodology: Smear positive specimens were pretreated according to guidelines and then tested on MGIT 960 TB system for direct drug susceptibility testing (DST) of isoniazid and rifampin. Samples were also processed by gold standard indirect method, which comprises culture and then DST from positive growth by MGIT 960 TB system. Results: Out of 108 specimens, 95 (88%) DST results were reportable. Out of 95 reportable specimens, 17 isolates were resistant to both isoniazid (INH) and rifampin (RIF) by direct DST. The sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy for INH were 92%, 93%, 82%, 97% and 92.6%, respectively; and 95%, 96%, 86.3%, 98.6% and 95.7%, respectively for RIF. Average time to report DST by indirect method was 23.6 ±3.9 days, while it was 11.4 +-2.7 days for the direct method. Conclusion: Direct susceptibility testing on MGIT 960 system showed very good agreement when compared with indirect method. Time saving is crucial factor in initiation of early effective therapy, especially in drug resistant cases. Further studies on large scale are required for more accurate evaluation of this method. (author)

[en] UV-irradiation (254 nm, 10 or 20 J/cm²) of p-aminobenzoic acid (PABA) and p-aminosalicylic acid (NaPAS) potentiated their antimuta-genicity towards N-methyl-N'-nitro-N-nitrosoguanide metagenesis in Salmonella typhimurium. Their inhibitory action towards the formation of mutagen N-methyl-N-mitrosourea from the nitrosation mixture of N-methylurea and nitrite was also increased by UV-irradiation. In contrast, UV-irradiated PABA exhibited no inhibitory effects towards the mutagenicity of sodium azide or 3-azidoglycerol. Neither PABA nor NaPAS not their UV-irradiation products were themselves mutagenic in the Ames assay. 13 refs.; 5 tabs

[en] Self-decomposition and removal of antibiotics by ionic treatment was evaluated in this study. Seven sulfonamide classes (SA) and seven tetracycline classes (TA) of antibiotic were selected for this purpose. According to this study, self-decomposition of SAs and TAs was slow, and a considerable amount of antibiotics still remained after 15 days. Ionic treatment was effective for removal of SAs and TAs, but organic interference was observed. When dissolved organic (DOC) was present in raw water, the removal performance of antibiotics generally deteriorated due to competition with organics. SAs and TAs, which were present in ionic form at neutral pH, were removed through ion exchange. Their removal efficiencies were closely related to their chemical structure. Antibiotics with stronger electronegativity were easier to remove by ionic treatment. Equilibrium equations for removal of SAs and TAs by ionic treatment were also presented

[en] Sulfadiazine is an antibiotic used in animals and humans, this molecule is being released increasingly into the aquatic environment, which is why the depletion of this molecule in rainbow trout (Oncorhynchus mykkis) was studied using radiometric techniques with ¹⁴C, for which a specific activity of 3.5171 MBq mg^-1 was used, during 14 days in semi-static conditions. The study found accumulation in trout on day four 5.10 × 10^-4 mg g^-1 after the exposure phase, and 1.0 × 10^-4 mg g^-1 after the purification phase, indicates that the concentration used puts human health at risk because exceed the maximum residual limits. (author)

[en] Sorption of sulfonamides on biochars is poorly understood, thus sulfamethoxazole (SMX) sorption on biochars produced at 300–600 °C was determined as a function of pH and SMX concentration, as well as the inorganic fractions in the biochars. Neutral SMX molecules (SMX⁰) were dominant for sorption at pH 1.0–6.0. Above pH 7.0, although biochars surfaces were negatively-charged, anionic SMX species sorption increased with pH and is regulated via charge-assisted H-bonds. SMX⁰ sorption at pH 5.0 was nonlinear and adsorption-dominant for all the biochars via hydrophobic interaction, π–π electron donor–acceptor interaction and pore-filling. The removal of inorganic fraction reduced SMX sorption by low-temperature biochars (e.g., 300 °C), but enhanced the sorption by high-temperature biochars (e.g., 600 °C) due to the temperature-dependent inorganic fractions in the biochars. These observations are useful for producing designer biochars as engineered sorbents to reduce the bioavailability of antibiotics and/or predict the fate of sulfonamides in biochar-amended soils. -- Highlights: •Sulfamethoxazole (SMX) sorption on biochars at pH 5.0 was adsorption-dominant. •Removal of inorganic fractions in low-temperature biochars reduced SMX sorption. •Removal of inorganic fractions in high-temperature biochars enhanced SMX sorption. •Anionic SMX was adsorbed on negatively charged biochar via charge-assisted H-bond. -- Solution pH and biochar property control the sorption amount and mechanisms of antibiotic sulfamethoxazole

[en] A microwave-assisted extraction technique was developed for the determination of nine sulfonamide antibiotics (sulfaguanidine, sulfacetamide, sulfadiazine, sulfathiazole, sulfapyridine, sulfamethazine, sulfamerazine, sulfamethoxazole, and sulfadimethoxine) in six sediments and soils of varying organic carbon content. Method optimization was performed using Lake Erie sediment and revealed the optimum extraction solvent to be methanol, with an extraction time of 45 min. After extraction, samples were 'cleaned up' via filtration and quantified using LC-MS/MS spectroscopy. Method calibration curves were constructed in each environmental solid with sulfonamides ranging from 10 to 2000 ng/g; method detection limits were typically in the sub- to low nanograms per gram range. Method validation entailed spiking each solid at three different concentrations spanning the calibration curve (40, 300, and 800 ng/g); generally, method accuracy for spiked solids exceeded 80%, with precision being within 20%. Finally, we extracted sulfonamides from environmental solids (two sediments and one soil) that had been aged for 21 days and found that our method accuracy remained in excess of 80%. Moreover, absolute recoveries generally agreed with method accuracies (at the 95% confidence interval) in all environmental solids, demonstrating the efficiency of our microwave-assisted extraction procedure and its suitability for application to environmental samples. (author)

[en] A very sensitive catalytic spectrophotometric method for the determination of copper (II) in concentration as low as 0.01 ng/ml has been described. This method is based on the oxidation of iso nicotinic acid hydrazide by hydrogen peroxide in ammoniacal medium, catalysed by copper (II). various metal interferences have been studied and are reported in this study. Structure of the oxidation product is not known. (author)

[en] The directed ortho-lithiation is demonstrated as an excellent method for additional functionalization of chiral phenyl and naphthyl sulfonamides. The chirality was introduced through sulfonamide formation with a series of chiral amines prior to the lithiation process. In the case of naphthyl sulfonamides the regioselectivity of the directed ortho-lithiation was studied and optimized. The approach was shown to provide facile ortho-functionalization and was applied for the synthesis of chiral 1,2-sulfonamido phosphine derivatives. The latter were evaluated as P,O-ligands in Pd-catalyzed asymmetric allylic substitution. Graphical abstract: .

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