BMC Chemistry最新文献

A set of innovative N-amino-5-cyano-6-pyridones derivatives was developed and produced using one-pot three-component procedures. The evaluated molecules were examined for their antimicrobial efficacy. Based on the acquired findings, most of the investigated compounds had promising antimicrobial properties. Out of these derivatives of 3-cyanopyridine, compounds 3d and 3e exhibited minimum inhibitory concentrations (MIC) of 3.91 µg/mL against E.coli. In vitro evaluation of DNA gyrase A displayed that molecule 3d exhibited promising potency as an inhibitor, with an IC₅₀ value of 1.68 µg/mL compared to ciprofloxacin (IC₅₀ = 0.45 µg/mL). Furthermore, it was observed that molecule 3e exhibited a moderate inhibitory effect, as indicated by its IC₅₀ value of 3.77 µg/mL. A kinetics study conducted to assess the time required to kill E. coli bacteria demonstrated that gentamycin and compounds 3d and 3e exhibited bactericidal effects within a time frame of 90–120 min. Based on the ADME predictions, compounds 3d and 3e are expected to have favorable oral bioavailability and are unlikely to penetrate the blood-brain barrier. Computational mutagenicity and tumorigenicity studies were conducted on compounds 3d and 3e. The molecular docking investigation has conclusively demonstrated the binding of compounds 3d and 3e to the target DNA gyrase A enzyme, further reinforcing the existing data.

This research explores the enhancement of polyethersulfone (PES) membranes through the incorporation of chitosan derived from the lignicolous fungus Ganoderma sp. Utilizing wet phase inversion and solution casting techniques, chitosan was successfully integrated into the PES matrix, as confirmed by Fourier Transform Infrared Spectroscopy (FT-IR), which indicated a high deacetylation degree of 75.7%. The incorporation of chitosan significantly increased the membrane hydrophilicity, as evidenced by a reduction in the water contact angle and a substantial improvement in pure water permeability, from 17.9 L m^-2 h^-1 bar^-1 to 27.3 L m^-2 h^-1 bar^-1. The membrane anti-fouling properties were also notably enhanced, with the Flux Recovery Ratio (FRR) increasing from approximately 60–80%. Moreover, the chitosan-modified PES/CS membrane, particularly at a 5% chitosan concentration, demonstrated exceptional efficacy in pollutant removal, achieving over 90% elimination of total suspended solids, cadmium (Cd), and lead (Pb), alongside a 79% reduction in color during the treatment of textile wastewater.

Elevated Arsenic and Chromium levels in surface and ground waters are a significant health concern in several parts of the world. Chitosan quinoxaline Schiff base (CsQ) and cross-linked chitosan quinoxaline Schiff base (CsQG) were prepared to adsorb both Arsenate [As(V)] and Chromium [Cr(VI)] ions. The thermo-gravimetric analysis (TGA), X-ray diffraction analysis (XRD), and Fourier-transform infrared spectroscopy (FTIR) were used to investigate the prepared Schiff bases (CsQ) and (CsQG). The UV–VIS spectra showed a shift in the wavelength area of the modified polymer, indicating the reaction occurrence, besides the variation of the shape and intensity of the peaks. The XRD patterns showed the incensement of the amorphous characteristic. On the other hand, the thermal stability of the modified polymers is better according to TGA studies; also, the morphology of the modified chitosan was investigated before and after crosslinking (CsQ and CsQG) using a scanning electron microscope (SEM) where the surface was fall of wrinkles and pores, which then were decreased after cross-linking. Contact time, temperature, pH, and initial metal ion concentration were all studied as factors influencing metal ion uptake behavior. The Langmuir, Temkin, Dubinin–Radushkevich, and Freundlich isotherm models were used to describe the equilibrium data using metal concentrations of 10–1000 mg/L at pH = 7 and 1 g of adsorbent. The pseudo-first-order and pseudo-second-order kinetic parameters were evaluated. The experimental data revealed that the adsorption kinetics follow the mechanism of the pseudo-second-order equation with R² values (0.9969, 0.9061) in case of using CsQ and R² values (0.9989, 0.9999) in case of using CsQG, demonstrating chemical sorption is the rate-limiting step of the adsorption mechanism. Comparing the adsorption efficiency of the synthesized Schiff base and the cross-linked one, it was found that CsQ is a better adsorbent than CsQG in both cases of As(V) and Cr(VI) removal. This means that cross-linking doesn’t enhance the efficiency as expected, but on the contrary, in some cases, it decreases the removal. In addition, the newly modified chitosan polymers work better in As(V) removal than Cr(VI); the removal is 22.33% for Cr(VI) and 98.36% for As(V) using CsQ polymer, whereas using CsQG, the values are 6.20% and 91.75% respectively. On the other hand, the maximum adsorption capacity (Qm) for As(V) and Cr(VI) are 8.811 and 3.003 mg/g, respectively, using CsQ, while in the case of using CsQG, the Qm value reaches 31.95 mg/g for As(V), and 103.09 mg/g for Cr(VI).

As a springboard to explore novel potent inhibitors of cholinesterase enzymes (AChE and BChE) responsible for causing Alzheimer disorder, the current study was conducted to synthesize pyrrole derived triazole based Schiff base scaffolds by facile synthetic route. These compounds were validated by ¹HNMR, ¹³CNMR and HREI-MS. All these scaffolds (1–16) were examined for their inhibitory activity against AChE and BChE in contrast to Donepezil (10.20 ± 0.10 and 10.80 ± 0.20 µM) and Allanzanthone (12.40 ± 0.10 and 13.10 ± 0.10 µM). All pyrrole derived triazole based Schiff base scaffolds (1–16) showed varied range of inhibitory potentials against acetylcholinesterase and butyrylcholinesterase enzymes with lowest inhibition concentration values ranging from 5.10 ± 0.40–27.10 ± 0.10 µM (for AChE) and 5.60 ± 0.30–28.40 ± 0.30 µM (for BChE). SAR analysis of these derivatives revealed analog 7 as lead molecule against targeted enzyme, while analog 6 and 11 were ranked as second and third most potent scaffolds. Binding affinity and selectivity of potent molecules against targeted enzymes were examined by molecular docking and obtained results showed that potent molecule have versatile significant binding interactions with stated enzymes. Furthermore, safety profiles of potent analogues were predicted via ADMET protocols.

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In this work, the rapid and efficient preparation of isolated galloyl glucoside tautomer free radical inhibitors was investigated using Saxifraga tangutica as a raw material. Four highly polar galloyl glucoside tautomers, 3-O-galloyl-α-d-glucose ⇌ 3-O-galloyl-β-d-glucose (Fr2-1-1), 2-O-galloyl-α-d-glucose ⇌ 2-O-galloyl-β-d-glucose (Fr2-1-2/2-1-3), 1-O-galloyl-β-d-glucose (Fr2-2-1), and 6-O-galloyl-α-d-glucose ⇌ 6-O-galloyl-β-d-glucose (Fr2-3-1/Fr2-3-2), were obtained via two-step medium-pressure liquid chromatography (with solid loading instead of conventional liquid injection) and one-step high-performance chromatography coupled with on-line RPLC-DPPH techniques for targeted isolation. This separation integration technique not only increases sample intake and reduces time cost but also visualizes each step of targeted separation. All four compounds were isolated from the plant for the first time. In vitro antioxidant activity assays by DPPH (1,1‑diphenyl-2-picrylhydrazyl) revealed that Fr2-1-2/Fr2-1-3 (IC₅₀: 5.52 ± 0.32 μM), Fr2-2-1 (IC₅₀: 7.22 ± 0.57 μM), and Fr2-3–1/Fr2-3-2 (IC₅₀: 7.36 ± 0.25 μM) had superior free radical scavenging abilities and that both were superior to that of quercetin (IC₅₀: 18.61 ± 3.55 μM). Oxidative stress assays revealed that Fr2-1-2/Fr2-1-3 significantly inhibited oxidative stress damage in H₂O₂-induced HepG2 cells, decreased the level of ROS (P < 0.01) and protected hepatocytes. Combined with the current results, gallic acid showed greater antioxidant activity when H atoms were replaced at d-glucose –OH (C-2) than at the other three sites [–OH (C-1), –OH (C-6) and –OH (C-3)].

A straightforward and sensitive spectrofluorimetric approach was established for the determination of heptaminol hydrochloride (HTM-HCl) based on the derivatization of the drug through its reaction with 5-dimethylaminonaphthalene-1-sulfonyl chloride (Dansyl chloride). The reagent underwent a nucleophilic substitution of its chlorine atom with HTM to give N-(5-dimethylaminonaphthalene-1-sulfonyl)-6-amino-2-methylheptan-2-ol. The highly luminescent derivative was extracted using methylene chloride and subjected to analysis at an excitation wavelength of 345 nm and an emission wavelength of 490 nm. The chemical reaction occurred within an aqueous environment buffered with a 0.1 M borate buffer solution adjusted to pH 10.5. Experimental findings indicate that the proposed method displays sensitivity and linearity across a concentration range from 0.03 to 2 µg mL^− 1. The method achieves lower detection and quantification limits of 0.016 and 0.048 µg mL^− 1, respectively. The analytical validation of this method followed the guidelines outlined by the International Council of Harmonization (ICH). This approach was applied effectively for quantifying the medication in both tablet and oral drops formulations available on the market, demonstrating excellent recovery of 98.95 ± 0.45 for tablets and 99.37 ± 0.24 for oral drops with no interference from excipients.

This study presents the development and optimization of La@SnO₂–CaO composite catalysts for efficient photocatalytic degradation of malachite green dye in aqueous solutions under UV–vis light irradiation. The catalysts were prepared via conventional incipient-wetness impregnation and thoroughly characterized using advanced analytical techniques, including X-ray diffraction, Fourier transform infrared spectroscopy, UV–vis diffuse reflectance spectroscopy, N₂ adsorption–desorption analysis, and scanning electron microscopy. To optimize photodegradation efficiency, the effects of three independent factors were systematically investigated using response surface methodology: Temperature, pH, and Sn/Ca molar ratio. Our results reveal optimal conditions for maximum dye degradation: pH 7, Sn/Ca molar ratio of 0.33, and a process time of 35 min, resulting in a maximum photodegradation efficiency of 98.80% for malachite green dye. Notably, visible light exhibited a more pronounced effect on dye degradation compared to UV light over time, with visible light achieving 25% greater dye removal after 60 min of illumination. Furthermore, the catalyst showed excellent recyclability, retaining 85% of its initial activity after five consecutive cycles. These findings contribute significantly to the development of sustainable methods for dye removal from wastewater and highlight the potential of La@SnO₂–CaO composite catalysts in environmental remediation processes, particularly in treating textile industry effluents.

Aminothiazoles are the important class of chemical groups which have proven their broad range of biological activities. A novel aminothiazole (21MAT) was quantified in analytical solutions using a high-performance liquid chromatography (HPLC) approach that was developed and partially validated for the analysis of in vitro experimental samples. An isocratic elution on reverse phase Phenomenex^® Luna C₁₈ (50 mm × 4.6 mm, 5 μm) column with 55% 0.1% v/v orthophosphoric acid in water and 45% of orthophosphoric acid in acetonitrile at a flow rate of 1 mL/min was used. The analyte was detected at 272 nm. Similar to this, a robust bioanalytical technique, LC-mass spectrometry (LC-MS/MS) was created and verified to measure 21MAT in rat plasma for use in in vitro screening study samples and early-stage pharmacokinetic research. The protein precipitation method was used to extract 21MAT from plasma. The mixture of 95: 5% v/v methanol: acetonitrile and 0.1% v/v formic acid, along with 15% of 5 mM ammonium formate solution, was used to separate the mixture on a reverse phase Waters Xterra RP^® C₁₈ (150 mm × 4.6 mm, 5 μm) column at a flow rate of 1 mL/min. Using electro spray ionisation mode in multiple reaction monitoring mode, the analyte and internal standard (a structural analogue) were both identified. According to current criteria, all validation parameters (specificity, selectivity, accuracy, precision, recovery, matrix factor, hemolysis effect, and stability) were evaluated in rat plasma. The area response of 21MAT was found to be linear over the concentration range of 1.25–1250 ng/mL in rat plasma. Both techniques are suitable for use in any format of preclinical research and were sufficiently reliable to measure 21MAT precisely in various matrices. In silico prediction helped in understanding absorption, distribution, metabolism, excretion, and toxicity (ADMET) behaviour of the molecule. Both developed LC-MS/MS and HPLC-UV methods were successfully used to quantify the analyte in in vitro screening study samples.

Quetiapine fumarateis a typical antipsychotic with a short half-life of 6 h and is administered multiple times daily. In this study, a copolymer for controlled delivery of quetiapine fumarate will be developed. In order to prevent side effects and improve patient compliance, hydroxypropyl methylcellulose K15M (HPMC K15M) was included in the formulation of the quetiapine fumarate oral sustained-release tablets at a concentration of 10–30%. A series of analytical methods were used to determine the characteristics of the prepared hydrogels, including Fourier transform-infrared spectroscopy, Differential scanning calorimetry, X-ray diffraction, and Scanning electron microscope. At two different pH values (1.2 and 6.8), swelling and release studies were conducted. A variety of release kinetic models was used to study drug release mechanisms. A non-Fickian diffusion mechanism released hydrogels prepared from quetiapine fumarate. It was found that swelling was increased by increasing the amount of HPMC K15M. Compared to the other batches (10–20%), the produced tablets with 30% HPMC K15M content had a better release profile after 20 h of dissolution. Because of the effective matrix complex’s limited solubility in water, the drug diffuses through the gel layer at a steady rate rather than dissolving quickly.

In recent years, there has been considerable interest in using amino acids like tryptophan (Trp) and tyrosine (Tyr) as biomarkers for various diseases, including type 2 diabetes mellitus (T2D). In diseases like T2D, the metabolism of Trp and Tyr is altered. The activity of enzymes involved in Trp metabolism increases, leading to a decrease in its serum level. On the other hand, the serum level of Tyr increases due to the suppressed activity of its metabolizing enzymes. These observations suggest that Trp and Tyr metabolism may play a crucial role in the pathophysiology of type 2 diabetes. Our study highlights the potential utility of Trp and Tyr as biomarkers for the early detection, prognosis, and monitoring of this metabolic disorder. Given these observations, we aimed to develop a high-performance thin-layer chromatographic (HPTLC) method that is sensitive, selective, rapid, and environmentally friendly for estimating the concentrations of Trp and Tyr in biological fluids, particularly serum samples. To evaluate the method, we performed analysis using serum samples from controlled and streptozotocin-induced diabetic rats. Our main objective was to develop a method that is sensitive and selective for precisely determining Trp and Tyr serum levels, which could serve as potential biomarkers for T2D. Fluorescence and absorption modes were employed for densitometry scanning. We assessed the precision and high separation efficiency of the chromatographic system by calculating parameters such as separation and resolution factors, number of theoretical plates, and height equivalent to theoretical plates. To evaluate the environmental impact of our proposed method, we employed the AGREE (Analytical GREEnness metric) and GAPI (Green Analytical Procedure Index) greenness assessment tools. The results confirmed that our method is environmentally friendly and exhibits superior eco-friendliness and greenness compared to other reported methods.

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