BMC Chemistry最新文献

Trigonelline is an alkaloidal plant derived bioactive compound reported for its various pharmacological activities. Recent advances in the utilization of this compound in drug development have highlighted the importance of establishing a reproducible and efficient analytical method for estimating trigonelline (TRG) in both its pure form and formulated nano systems. Current research aims to develop and validate a green RP-HPLC method for estimating TRG by integrating Analytical Quality by Design (AQbD) with the principles of Green Analytical Chemistry. Optimization of the chromatographic conditions was done by employing a rotatable central composite design with amount of mobile phase and its flow rate selected as critical variables and tailing factor (T_f), retention time (R_t) and theoretical plates as the responses. Optimal separation was achieved using ethanol and water (40:60, v/v) on a Phenomenex C18 (250 × 4.6 mm, 5 μm) column at 264 nm, yielding a sharp, symmetric peak at 5.60 min at a flow rate of 1.5 mL/min. Developed method exhibited excellent linearity over the range of 5-15 µg/mL (r² = 0.9986) with %RSD less than 2% and LOD & LOQ were found to be 0.628 µg/mL and 1.90 µg/mL, respectively. Forced degradation studies showed 12% degradation in acidic media and 9% in alkaline media after exposure of 8 h indicating moderate susceptibility to hydrolysis. Further, the validation was performed for the developed method according to ICH Q2(R1) guidelines. A comprehensive greenness assessment was performed using AES, GAPI, AGREE, AMGS, and AGSA tools, confirming that the newly developed method demonstrates superior greenness and its suitability for sustainable routine analysis compared to existing methods.

In this work, a new Co(II) complex, abbreviated as [Co(L)(bipy)(H₂O)₂]_n (1) was prepared using cobalt(II) acetate tetrahydrate, 2-((2'-carboxybenzyl)oxy)benzoic acid (H₂L), and 2,2'-bipyridine (bipy) ligands in a mixture solution of ethanol and water (v: v = 3: 1). The structure of the complex (1) was analyzed by elemental analysis (EA), infrared (IR) spectroscopy, ultraviolet-visible (UV-Vis) spectroscopy, thermogravimetric analysis (TG), and single-crystal X-ray diffraction techniques. The complex (1) crystallizes in the monoclinic space group C2/c, featuring a distorted octahedral [CoO₄N₂] coordination sphere, by two oxygen atoms from the carboxylate groups of two 2-((2'-carboxybenzyl)oxy)benzoate (L) ligands, two oxygen atoms from coordinated water molecules, and two nitrogen atoms (N1 and N2) from a single 2,2'-bipyridine (bipy) ligand. Bridging carboxylate ligands (L) form a 1D chain, which extends into a 2D layer via π-π interactions of the 2,2'-bipyridine ligands (bipy). The DFT calculations of the complex (1) indicates that the HOMO is predominantly distributed on the oxygen and nitrogen atoms bonded to Co(II) ion, but the LUMO is mainly localized around distributed in the six-membered carbon ring adjacent to the Co(II) ion. Electrostatic potential calculation of the complex (1) shows that the regions with higher electrostatic potential are mainly located on the aromatic ring, whilst the lower electrostatic potential regions are primarily located near the oxygen and nitrogen atoms. The electrochemical behavior of the complex (1) was investigated in acetonitrile and 1 mol·L⁻¹ sulfuric acid. In ACN/TBATFB, the complex (1) exhibits a well-defined, predominantly reversible Co(III)/Co(II) redox couple, indicating good electrochemical stability, whereas in 1 mol·L⁻¹ H₂SO₄, a significantly different redox response with enhanced anodic currents and a prominent oxidation peak is observed, arising from the synergistic effect of ligand protonation-oxidation processes and the metal-centered Co(III)/Co(II) redox couple under acidic conditions. The cytotoxicity of the complex (1) and CoCl₂ was evaluated against L02, PANC-1, and MCF7 cell lines using the MTT assay. The complex (1) exhibited lower IC₅₀ values and higher selectivity for cancer cells than CoCl₂, attributable to improved cellular uptake and ROS-mediated oxidative stress, whereas free Co²⁺, which stimulated cell proliferation at low concentrations, the complex (1) showed no growth-inducing effect, highlighting its potential as a cobalt-based anticancer agent.

Two simple, rapid, cost-effective, and environmentally friendly chromatographic methods were developed and validated for the simultaneous determination of metformin (MEF), linagliptin (LIN), and empagliflozin (EMP) in human plasma, with successful application to pharmacokinetic study. Plasma sample preparation was performed using a straightforward protein precipitation technique employing acetonitrile: methanol: trichloroacetic acid (50:49:1, by volume), which provided high extraction recovery and minimal matrix interference. The first method was based on high-performance liquid chromatography with diode array detection (HPLC-DAD) using an ODS Hypersil C18 column and isocratic elution with a mobile phase consisting of acetonitrile, methanol, and phosphate buffer (pH 3) in a ratio of (40:40:20, by volume), at a flow rate of 1.3 mL/min, with detection at 230 nm. The second method employed high-performance thin-layer chromatography (HPTLC) with densitometric detection at 225 nm, using silica gel 60 F254 plates and n-hexane: methanol: glacial acetic acid (6:3:1, by volume) as the developing system. Excellent linearity was achieved over concentration ranges of 85-1650 ng/mL for MEF, 50-1100 ng/mL for EMP, and 45-950 ng/mL for LIN using the HPLC method, and 500-2800, 100-800, and 50-550 ng/band, respectively, using the HPTLC method, with correlation coefficients exceeding 0.998. The lower limits of quantitation for the HPLC method were 85, 50, and 45 ng/mL for MEF, EMP, and LIN, respectively. Both methods demonstrated satisfactory accuracy, precision, recovery (> 92%), stability, and negligible matrix effects in accordance with European Medicines Agency guidelines. The validated methods were successfully applied to a pharmacokinetic study in healthy volunteers, yielding mean Cmax values of 877.5 ± 162.2 ng/mL (MEF), 576 ± 87.5 ng/mL (EMP), and 680.8 ± 7.9 ng/mL (LIN), with Tmax values of 2.42 ± 0.38, 1.5 ± 0.61, and 5.3 ± 0.52 h, respectively. The obtained pharmacokinetic parameters were consistent with reported literature, confirming the reliability and clinical applicability of the proposed green bioanalytical methods.

To effectively treat refractory azo dye wastewater, microwave advanced catalytic oxidation technology was adopted to degrade the model pollutant methyl orange using activated carbon fiber (ACF)/CuO as the catalyst and potassium persulfate (K₂S₂O₈) as the oxidant. The optimized experimental parameters and the degradation pathway of methyl orange were determined. The results showed that when the microwave power was 500 W, the irradiation time was 2 min, the dosage of potassium persulfate was 0.6 g/L, and the dosage of ACF/CuO was 10 g/L, the removal rate of methyl orange solution was close to 100%, the COD removal rate was 89.65%, and the TOC removal rate was 72.36%. Mechanism analysis indicated that the double bond was broken to generate acid and p-nitrophenol, which were gradually degraded to benzene and phenol under the oxidation of sulfate radical. Subsequently, the benzene and phenol underwent chain cleavage to form maleic anhydride, and part of the benzene, phenol, and the generated maleic anhydride were ultimately degraded to water and carbon dioxide.

Acemetacin (ACIN) is a poorly water-soluble nonsteroidal anti-inflammatory drug, which limits its effectiveness in topical therapeutic applications. This study aimed to enhance the delivery potential and dermal applicability of ACIN through the development of bilosome-loaded hydrogel formulations. Bilosomes were prepared using the thin-film hydration method and optimized using Box-Behnken Design (BBD). The amount of phosphotidylcholine (lecithin), cholesterol and sodium taurocholate were chosen as the formulation parameters and their effects were evaluated on the resulting vesicle size, zeta potential and entrapemnet efficiency percentage (EE%). The optimized formulation displayed a vesicle size of 137.3 nm, a zeta potential of -30.1 mV, a polydispersity index (PDI) of 0.384 and EE% of 84.5%. Bilosomes were incorporated into hydrogel bases containing hydroxypropyl methylcellulose (HPMC) or Carbopol. HPMC-based gels exhibited a favorable pH (~4) for skin application and were selected for further evaluation. These gels provided sustained drug release for up to eight hours. Cytocompatibility testing on L929 fibroblasts using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay demonstrated cell viability above 90% within the tested concentration range (0.05-2 µg/mL), indicating good biocompatibility. The bilosome-loaded HPMC gel formulation exhibited desirable physicochemical properties, sustained drug release, and excellent cytocompatibility, making it a promising vehicle for topical delivery of ACIN. Further anti-inflammatory and in vivo studies are recommended to confirm its potential for topical or anti-inflammatory applications.

Herein, two novel pyrazole-clubbed triazole scaffolds were synthesized, characterized, and evaluated as inhibitors for carbon steel dissolution in 0.5 M H₂SO₄ via open circuit potential (OCP), potentiodynamic polarization (PP), electrochemical impedance spectroscopy (EIS), potential of zero charge (PZC), surface characterizations, test solution analysis, and DFT studies. Maximum inhibition reached 95.3% and 93.5% for TBF and TMP, respectively, at 298 K. Based on PP, TBF and TMP function as mixed-type inhibitors, reducing current density from 324.0 µA cm^- 2 to 15.30 and 21.20 µA cm^- 2, whereas EIS showed an increase in charge transfer resistance from 41.90 Ω cm² to 812.6 and 633.2 Ω cm² for TBF and TMP, respectively. Inhibition peaked at 318 K and then decreased slightly at 328 K, indicating that a stable adsorbed layer had developed on the surface. Adsorption analysis revealed good agreement with the Langmuir isotherm. Following one day of immersion, Atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FT-IR), contact angle (CA), and X-ray photoelectron spectroscopy (XPS) confirmed the adsorption of the inhibitor. UV-visible spectroscopy verified chemical interactions among TBF/TMP and steel. Additionally, both compounds exhibited high antibacterial activity. Experimental findings were further supported via DFT computations and Monte Carlo (MC) simulations. The novelty of this study lies in the molecular structure of TBF and TMP, where electron-rich triazole and pyrazole rings are synergistically integrated with extended π-conjugation to enhance surface adsorption and inhibition efficiency. Moreover, the inhibitors were prepared using an eco-friendly, ultrasound-assisted method, combining high performance, cost-effectiveness, and environmental sustainability. Their outstanding thermal stability and superior inhibition efficiency in strongly acidic media underscore the innovative molecular architecture and demonstrate their potential as highly effective inhibitors under harsh conditions. Thus, the synthesized compounds effectively control corrosion, supporting future development of efficient, multifunctional, and eco-friendly inhibitors.

In this study, we report the first synthesis and comprehensive characterization of two positional isomers of iodo-substituted imino Schiff bases, Im1 was synthesized using 2-iodoaniline, whereas Im2 was obtained from 4-iodoaniline. Compound Im1 represents a new derivative, while Im2 is fully characterized crystallographically for the first time. The structures were confirmed by FT-IR, UV-Vis, ¹H and ¹³C NMR spectroscopy, and single-crystal X-ray diffraction, which revealed that Im2 crystallizes in the monoclinic space group P2₁/c. Hirshfeld surface and fingerprint analyses provided insights into key intermolecular interactions governing crystal stability. Among the two compounds, Im2 exhibited the highest antibacterial activity, forming an 11.00 ± 0.00 mm inhibition zone against Klebsiella pneumonia, whereas Im1 demonstrated the strongest inhibition (11.67 ± 0.47 mm) against Escherichia coli. DFT calculations (B3LYP/LANL2DZ) and molecular docking with the FimH receptor (PDB ID: 8BVD) revealed electronic and structural features influencing binding affinity (-3.737 to -4.266 kcal/mol). ADME-T predictions indicated favorable drug-likeness, suggesting these Schiff bases as promising scaffolds for further optimization toward antibacterial development. This novel comparative analysis of the two imines revealed the pronounced influence of ortho and para-iodine substitution on biological activity and inhibitory potency, demonstrating a clear structure-activity relationship (SAR) governing their antibacterial performance. In the future, Im1 and Im2, when combined with other bioactive scaffolds, may serve as promising candidates for enhanced therapeutic and biological applications.

Analysis of critical biomarkers like L-lactate is extremely important in clinical practice. Herein, a non-invasive and sensitive colorimetric biosensor for accurate L-lactate determination has been developed. The proposed method demonstrates the ability of Fe³⁺ ions of iron(III) chloride to substitute the traditional horseradish peroxidase enzyme in the colorimetric determination of L-Lactate. The biosensor is based on the release of H₂O₂ by lactate oxidase enzyme (LOx) after 30 min incubation in a 37 °C water bath. Subsequently, H₂O₂ reacts with 3,3',5,5'-tetramethylbenzidine substrate (TMB) catalyzed by Fe³⁺ ion utilizing its peroxidase-mimetic activity. Fe³⁺ ion has peroxidase-like activity which could rapidly catalyze the oxidation reaction of TMB by H₂O_2, producing a characteristic blue colored product at 30 °C water bath for 15 min. Based on the catalytic mechanism of fast electron transfer between TMB and H₂O₂ with the assistance of the intrinsic peroxidase-like activity of Fe³⁺ ion, a colorimetric biosensor for determination of L-lactate was developed. The obtained colored product of oxidized TMB could be measured spectrophotometrically at λmax 652 nm. The biosensor yielded a reproducible response over a linear range of 5 µM-20 µM of L-lactate with a limit of detection of 1.278 µM. Furthermore, satisfactory results were obtained upon application of the method to artificial saliva samples.

In recent years, high-performance thin-layer chromatography (HPTLC) has gained prominence as a cost-effective, straightforward, and dependable analytical technique, particularly in forensic and pharmaceutical laboratories. With the rapid evolution of smartphone technologies, a novel dimension in analytical detection has emerged. Advent of smartphones with superior imaging modalities combined with simplicity of use and easy transition into the healthcare ecosystem has made the existing benchtop-based techniques much sleeker, cost-effective and rapid screening approaches. The developed and validated HPTLC method employing smartphone camera detection for simultaneous determination of Diazepam (DZP), its metabolite Oxazepam (OXP) and its degradation product 2-methylamino-5-chlorobenzophenone (ACB) was intended to meet this requirement and provide a useful replacement for the usual densitometric analysis. The chromatographic separation was performed on silica gel HPTLC plates with green mobile phase of heptane: ethyl acetate (7.0:3.0, v/v). After chromatographic development, the Dragendorff's reagent was applied for visualization, and the plates were photographed with smartphone camera. Spot intensities were quantitatively analyzed using ImageJ software in the concentration range 3.0-35.0 µg/spot for both DZP and ACB, and 5.0-35.0 µg/spot for OXP. The data developed by the proposed method were compared with benchtop densitometric method. Linearity was established from 0.2 to 1.0 µg/spot for the three analytes detected at 230.0 nm using HPTLC/densitometry while the HPTLC/smartphone method exhibited linearity from 3.0 to 35.0 µg/spot for both DZP and ACB, and 5.0-35.0 µg/spot for OXP. The developed HPTLC/smartphone method showed that it could successfully be employed to quantify DZP in pharmaceutically marketed formulations in terms of speed, eco-friendly and simplicity. Additionally, the enhanced sensitivity of the densitometric technique enabled successful determination of DZP and OXP in spiked human plasma samples using ACB as an internal standard. To assess the environmental and practical merit of the methods, greenness and sustainability were evaluated using the Green Analytical Procedure Index (GAPI), Analytical Greenness Metric (AGREE), White Analytical Chemistry (WAC), and Blue Applicability Grade Index (BAGI). Results confirmed the developed methods' analytical efficiency, environmental compatibility, and alignment with the principles of green and white analytical chemistry.

Covalent Organic Frameworks (COFs) have emerged as a promising class of crystalline porous materials with potential applications in various fields, including catalysis, gas storage, and energy conversion. A novel COF was prepared from the reaction of terephthalaldehyde and tris(2-aminoethyl)amine and characterized using various techniques including Fourier-transform infrared spectroscopy (FT-IR), powder X-ray diffraction (PXRD), scanning electron microscope (SEM), Brunauer-Emmett-Teller (BET) surface area measurement, and thermal analysis. BET analysis revealed a surface area of 507.56 m²/g and an average pore diameter of 8.34 nm. Chromium modification applied to increase its electrocatalytic activity to be used in fuel cells applications. The electrochemical evaluation demonstrated superior catalytic activity of Cr-COF-coated Pt and Au electrodes toward methanol oxidation in alkaline media with current densities of 4.89 mA cm^- 2 and 1.79 mA cm^- 2 for Pt and Au electrodes, respectively. Also, the Tafel slpoe for Cr-COF/Pt (149 mV dec^- 1) and Cr-COF/Au (198 mV dec^- 1) were described. Specifically, the Cr-COF/Pt electrode exhibited a current density 2.2 times higher than bare Pt, while Cr-COF/Au achieved a 2.75-fold enhancement compared to bare Au. Moreover, chronoamperometry and electrochemical impedance spectroscopy revealed high stability, low resistance, and efficient charge transfer dynamics. These findings highlighted the potential of Cr-COF as a promising electrocatalyst for direct methanol fuel cells (DMFCs), offering improved activity, stability, and reduced reliance on noble metals.