In this study, boron-doped poly(vinyl) alcohol/HfO₂ nanofibers were prepared by electrospinning using PVA as a precursor. The effect of boron doping was investigated in terms of solution properties, morphological changes and thermal characteristics. Nanofiber mats were calcined first at 800°C. Then, the calcined products were pelleted and sintered at a rate of 8°C/min and remained 2 h at 850°C at atmospheric conditions to produce ultrafine ceramic nanocrystalline powders. The fibers and nanocrystalline powders were characterized by FT-IR, XPS, XRD and SEM. The addition of boron did not only increase the thermal stability of the fibers, but also their diameters, which yielded stronger fibers. The addition of boron did not only increase the thermal stability of the fibers, but also their diameters, which yielded stronger fibers.

In this study, three new Schiff bases have been synthesized by the reactions of commercially available phenylglycinol, phenylalaninol, and leuicinol with 4-{[2-(4-formylphenoxy)ethyl](methyl)amin}benzaldehyde and characterized by ¹H and ¹³C NMR, FTIR, and UV-Vis spectroscopy and LCMS/MS. In vitro effects of synthesized new Schiff bases on human erythrocyte carbonic anhydrase I (hCA I) and II (hCA II) isoenzymes and acetylcholinesterase (AChE) activity were investigated. Schiff base synthesized from phenylglycinol showed no meaningful effect on hCAI and hCAII. Schiff bases synthesized from phenylalaninol and leuicinol exhibited a strong activation effect on hCAI and hCAII. On the other hand, all of the synthesized three Schiff bases exhibited a strong inhibitory effect on AChE activity.

Three new Schiff bases bearing benzimidazole and p-toluen sulfonamide moiety were synthesized. Their structures were characterized by elemental analysis, FTIR, NMR and LCMS methods. The antimicrobial properties of the compounds were also evaluated. All compounds exhibit higher antimicrobial activity against all bacteria, Schiff bases (4a-4c) shows more activity than the parent aldehyde (3). 4c displays higher antibacterial activity against P. aeruginosa compare to reference drug Sulfioxazole. The compounds were found more potent against Gram-negative than Gram positive bacteria. One more free phenyl group increase the activity in 4c, but one more phenyl ring in 4b does not. In vitro antifungal activity of the compounds was also tested on fungi C. albicans C. tropicalis and C. krusei. However, our compounds exhibit no antifungal activity against three fungi.

Schiff bases are bioactive compounds that have been synthesized by many researchers in recent years. They may also exhibit strong antimicrobial activities against various pathogenic microorganisms in both medicine and veterinary applications. The synthesis of new Schiff base-derived compounds remains of interest due to the increasing problem of antibiotic-resistance in clinical practice. Seven new Schiff base derivatives were synthesized, and their chemical structures were characterized using FT-IR, ¹H/¹³C NMR, and LCMS-MS analyses. The antimicrobial activities of thesyntesized compounds against various pathogenic bacteria, yeasts, and fungi were evaluated using the disk-diffusion method, and their MIC values were also determined. In addition, one representative microorganisms from each class were selected for molecular docking studies. IFD analyses were performed for the 4f and 4g ligands using the dihydrofolate reductase enzyme. Spectroscopic analyses confirmed the structures of the synthesized compounds, revealing the presence of characteristic imine functionalities and validating the integrity of the molecular frameworks. Antimicrobial assays demonstrated that several derivatives exhibited measurable activity, with compounds 4f and 4g showing the most potent effects, displaying MIC values of 32 µg/mL against B. cereus and E. faecalis, respectively. Molecular docking studies further indicated that both 4f and 4g bind efficiently to the DHFR active site. These findings indicate that among the synthesized Schiff base derivatives, compounds 4f and 4g exhibit particularly promising antimicrobial activity, warranting further pharmacological evaluation and medicinal chemistry optimization.

Three new copper(II) complexes (1-3) with general formula [Cu(HL)CH3COO] of N-salicyl-β-amino alcohol Schiff bases containing, (S)-(+)-phenyl glycinol, (1S, 2R)-2-amino-1, 2-diphenylethanol and 1, 1, 3-triphenyl-(R)-(+)-2-amino propanol, were synthesized. Their structures were characterized by FTIR, LCMS, magnetic moment, molar conductance and elemental analysis data. DFT calculations proposed distorted square planar geometries for the complexes. The calculated IR spectra are in good agreement with the experimental IR spectra, confirming the proposed structures. Their interactions with calf thymus DNA were investigated and their binding constants Kb were found. Gel electrophoresis reveals that all complexes display significant nuclease activity against supercoiled pentry/d-topo plasmid DNA. Resumen. Tres nuevos complejos de cobre (II) (1-3) con la fórmula general [Cu (HL) CH3COO] de N-salicil-β-amino alcohol Schiff bases que contienen, (S) - (+) - fenilglicinol, (1S, 2R). Se sintetizaron -2-amino-1, 2-difeniletanol y 1, 1, 3-trifenil- (R) - (+) - 2-amino propanol. Sus estructuras se caracterizaron por FTIR, LCMS, momento magnético, conductancia molar y datos de análisis elemental. Los cálculos de DFT propusieron geometrías planas cuadradas distorsionadas para los complejos. Los espectros de IR calculados están en buena concordancia con los espectros de IR experimentales, confirmando las estructuras propuestas. Se investigaron sus interacciones con el ADN del timo de ternera y se encontraron sus constantes de unión Kb. La electroforesis en gel revela que todos los complejos muestran una actividad nucleasa significativa contra el ADN plasmídico pentry / d-topo superenrollado.

Gram-positive and Gram-negative bacterial infections are one of the most important causes of illness and death worldwide. Although antibiotics are the primary treatment for these infections, the increase in the number of drug-resistant bacteria has posed a serious threat to public health in a global scale. Benzimidazole derivatives possess a distinctive chemical structure that exhibits a wide range of biological and therapeutic properties, including notable antimicrobial activity. In this study, we performed molecular docking analyses of four benzimidazole derivatives targeting dihydrofolate reductase, DNA gyrase, and 7,8-dihydro-6-hydroxymethylpterin-pyrophosphokinase enzymes from C. albicans, Escherichia coli, and Staphylococcus aureus. The relative binding free energy of the protein-ligand complexes were also calculated by the molecular mechanics-generalized born surface area (MM-GBSA) method. The relative binding free energy of the protein–ligand complexes were also calculated by the molecular mechanics-generalized born surface area (MM-GBSA) method. All tested compounds showed good potential as dihydrofolate reductase inhibitors and antifungal activity against Candida albicans. Notably, the compound 9A demonstrates the highest antimicrobial activity. Furthermore, all compounds are anticipated to exhibit greater activity against DNA gyrase in both E. coli and S. aureus compared to their respective cognate ligands. Compounds 9A/9B caused higher antimicrobial activity than compounds 10A/10B.