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Thaysen Jessen posted an update 4 hours, 34 minutes ago
Objectives The aim was to modify carbon electrodes with (p-aminobenzene sulfonic acid) and use them as a sensor for sensitive and reliable detection of methyldopa (MD) and ascorbic acid. Materials and methods Electropolymerization was performed by cyclic voltammetry in 0.1 M KCl solution. The modified sensor has a high electrocatalytic effect for oxidation of MD, which appeared in the pH range of 2-11 by differential pulse voltammetry (DPV) techniques. Results For the voltammetric determination of MD, the best results were acquired by DPV in phosphate buffer solution (PBS) (pH 3). The calibration plot of the proposed sensor is linear in two concentration ranges of 1.0-30 and 30.0-300.0 μM. The calibration equations over these ranges are Ipa (μA)=1.21×C (μM)+30.81, R2 =0.994 and Ipa (μA)=0.53×C (μM)+53.30, R2 =0.9975, respectively. In the sensitivity studies, the limit of quantification and the limit of detection were 10.6 nM and 5.0 nM, respectively. The modified sensor was used for the simultaneous determination of interfering substances such as MD and ascorbic acid in real samples. Conclusion The obtained results revealed that the prepared modified electrode and the proposed method have good sensitivity, repeatability, reproducibility, and stability.Objectives Pseudomonas aeruginosa can cause life-threatening infections that are difficult to treat due to its high resistance to antibiotics and its ability to form antibiotic tolerant biofilms. Ceragenins, designed to mimic the activities of antimicrobial peptides, represent a promising new group of antibacterial agents that display potent anti-P. aeruginosa activity. The aim of this study was to evaluate the antibacterial and antibiofilm activities of ceragenins in comparison to colistin and ciprofloxacin against P. aeruginosa strains. this website Materials and methods Biofilm formation and determination of minimum inhibitory concentration (MIC) values of ceragenins (CSA-13, CSA-44, CSA-131, and CSA-138), ciprofloxacin, and colistin were evaluated against 25 P. aeruginosa isolates. Four good biofilm-producing strains were chosen for biofilm studies, and sessile MICs and inhibition of molecule adhesion and biofilm formation were evaluated. Results The MIC50 (μg/mL) values of CSA-13, CSA-44, CSA-131, CSA-138, ciprofloxacin, and colistin were 8, 8, 8, 16, 1, and 2, respectively. The sessile MICs for molecules were greater than planktonic MICs. CSA-13, CSA-44, and CSA-131 were more efficient after 4 h incubation while CSA-138, ciprofloxacin and colistin were more efficient after 1 h incubation. The most efficient agent for inhibition of adhesion was colistin (up to 45%). CSA-131, CSA-138, and colistin were the most efficient agents for inhibition of biofilm formation (up to 90%). Conclusion Our study highlights the potential of CSA-131 and CSA-138 as potential alternative agents to conventional antibiotics for the eradication of biofilms of P. aeruginosa.Objectives Vitex grandifolia belongs to family Lamiaceae; it consists of flowering plants and it is also called the mint family. The Yoruba people of southwest Nigeria called it “Oriri” or “Efo oriri”. This plant is classified as an underutilized vegetable and little is known about its phytochemistry or its biological evaluations. Materials and methods Methanol extracts of the dried leaves and stem of the plant were subjected to fractionation and isolation using vacuum layer and column chromatography methods. The structures of the compounds were elucidated using spectroscopic techniques including IR, 1D-, and 2D-NMR and by comparison with the data reported in the literature. They were evaluated in vitro for the inhibition of monoamine recombinant human MAO-A and -B and anti-inflammatory activities. Results Three known flavonoids were isolated from the methanolic extract of the leaves of V. grandifolia for the first time to the best of our knowledge, i.e. isoorientin (1), orientin (2), and isovitexin (3). Most of the isolated compounds showed selective inhibition of monoamine oxidase B, inhibition of MAO-B by isoorientin (1) and orientin (2) were 9-fold more potent (IC50 (μg/mL) of 11.08 and 11.04) compared to the inhibition of MAO-A (IC50 (μg/mL) of ˃100), while clorgyline and deprenyl were used as positive standards. The isolated flavonoids displayed good activity against the NF-ﭏb assay with IC50 (μg/mL) of 8.9, 12, and 18. This study establishes a link between the structure and the biological activities on the basis of the different patterns of substitution, particularly the C2=C3 double bond and the position of glucose moiety. Conclusion This study is the first to establish the phytochemistry of the polar part of V. grandifolia and the anti-inflammatory and neuroprotective role of these isolated compounds.Objectives The aim of this study was to synthesize, characterize, and screen some new 1-(4-((2-(4-substitutedphenyl)hydrazono)methyl)phenyl)-1H-1,2,4-triazole derivatives for their antimycobacterial activities. Materials and methods The target compounds (2a-h) were gained by condensation of 4-(1H-1,2,4-triazol-1-yl)benzaldehyde with appropriate phenylhydrazines. Their structures were elucidated by IR, 1H-NMR, and mass spectrometry. The antimycobacterial activities of the compounds were determined in vitro against Mycobacterium tuberculosis H37Rv. Results The biological assay results showed that the methylsulfonyl-substituted derivative 2f displayed the highest antimycobacterial activity in this series. Conclusion Although the methylsulfonyl-substituted derivative exhibited significant antimycobacterial activity, none of the synthesized compounds was as effective as isoniazid, rifampin, ethambutol, and ciprofloxacin against M. tuberculosis.Objectives Azithromycin dihydrate is a macrolide antibiotic used for the treatment of several types of bacterial infections. The drug shows low oral bioavailability due to its low solubility. In the present work solid lipid nanoparticles of azithromycin dihydrate were formulated, keeping in view enhancement of the solubility and rate of dissolution of the drug. Materials and methods Azithromycin dihydrate loaded stearic acid nanoparticles were formulated by high shear homogenization using three different surfactants, namely Tween 20, poloxamer 188, and poloxamer 407, at a varied lipid surfactant ratio while keeping the quantities of the active ingredient constant. Twelve such formulations were prepared. The nanoparticles obtained were evaluated for drug content, % drug loading, % entrapment efficiency, particle size analysis, zeta potential, surface morphology, Fourier transmission infrared spectroscopy, in vitro drug release, and stability. Results All the formulations showed good entrapment efficiency and high percentage of in vitro release with a particle size suitable for lymphatic absorption.