Acta Chimica Slovenica最新文献

A directed method for the preparation of hybrid compounds based on furan-2(3H)-ones and chromen-4(4H)-one, (E)-3-{[2-oxo-5-arylfuran-3(2H)-ylidene]methyl}-4H-1-benzopyran-4-ones, the structure of which was confirmed by elemental analysis, IR, UV, NMR spectroscopy, and X-ray single crystal analysis, was developed. The molecular geometry of the synthesized compound (E)-3-((2-oxo-5-phenylfuran-3(2H)-ylidene)methyl)-4H-chromen-4-one (3a) was analyzed and compared with X-ray diffraction data, DFT calculations were performed using 6-311G split-valence basis functions.

A novel chromogenic system for the liquid-liquid extraction and determination of trace amounts of tungsten(VI) was investigated. The system comprises 4-nitrocatechol (4NC) as a chromogenic reagent, sulfuric acid as a complexing medium, and benzalkonium chloride (BAC) as a source of bulky cations (BA+), which readily form chloroform-extractable ion-association complexes. The impact of foreign ions and reagents was studied, and the optimal conditions for the sensitive, selective, and inexpensive determination of tungsten(VI) were identified. The limit of detection, linear working range, and molar absorptivity at lmax (422 nm) were determined to be 31 ng cm-3, 0.1-4.4 µg cm-3, and 5.49 × 104 dm3 mol-1 cm-1, respectively. The composition of the extracted complex was 1:2:2 (W:4NC:BA). Two potential structures of its anionic component, [WO2(4NC)2]2-, were discussed based on optimizations at the B3LYP/CEP-4G theoretical level and comparison between theoretical and experimental spectra.

The biosynthesis of fatty acids constitutes a critical metabolic pathway in bacterial organisms. Prior investigations have highlighted the synthesis of antimicrobial compounds anchored in the benzodioxepin scaffold, noted for their pronounced antibacterial properties. Leveraging this foundational knowledge, the current research endeavors to meticulously engineer and synthesize a series of eight innovative benzodioxepin amide-biphenyl derivatives. This achievement was realized through the sophisticated optimization of synthetic methodologies. The scope of this study extends to a rigorous evaluation of the antibacterial prowess and biocompatibility of the aforementioned novel derivatives. Notably, Compound E4 emerged as a supremely potent antimicrobial agent. A detailed elucidation of the crystalline architecture of Compound E4 was conducted, alongside a thorough docking study to explore its interactions with the FabH enzyme.

The purpose of this study is to determine the phytochemical content and biological activities of the Astragalus gombo (endemic specie). While identification and quantification of individual secondary metabolites were performed by analysis HPLC. Antioxidant (DPPH and FRAP), anti-inflammatory, anti-hemolytic and antibacterial activities were evaluated. For analysis HPLC, we obtained 65 peaks and identified 6 major bioactive compounds. The total concentration in polyphenols, flavonoids and condensed tannins varied respectively from 66.306±0.88 mg GA eq/g, 34.312±1.4 mg Q eq/g and 5.343±2.74 mg Ca eq/g. In terms of antioxidant activity, we found that this extract had high inhibitory ratios equivalent to IC50=62.813±0.006 µg/mL for DPPH and IC50=19.375±0.041 µg/mL for FRAP.  A high anti-inflammatory activity was estimated at 1615.81µg/mL, and a weak anti-hemolytic activity, the other hand the antibacterial activity is somewhat moderate against the five strains studied. This study demonstrated that the aqueous extract of A. gombo from El Oued region has tremendous antioxidant, anti-inflammatory and antibacterial abilities.

A new method based on high-resolution continuum source flame atomic absorption spectrometry (HR-CS-FAAS) was validated for the determination of selected toxic and potentially toxic metals in wastewater resulting from mining activity. The results were compared with inductively coupled plasma optical emission spectrometry (ICP-OES). The HR-CS-FAAS method was characterized by detection limits in the range (µg L-1) 0.9(Mn)-33.6(Pb), better than ICP-OES for Cu, Fe, Ni, Co, Pb and Mn, and poorer for Cd, Zn and Cr. The Dunnett's and Tukey's statistical test showed that both methods were not affected by significant bias against certified value and between them. The recovery in HR-CS-FAAS method was in the range of 98-103% with relative extended uncertainty of 9-25%, and precision of 1.5-14.1%. The results indicated that the HR-CS-FAAS method is suitable for the determination of toxic and potentially toxic elements directly in filtered water samples without any chemical treatment.

Eutectics of pioglitazone were developed using citric acid (CA) as the co-former, and the effect on crystallite properties and dissolution has correspondingly been studied. Pioglitazone-citric acid eutectics (PC1, PC2, PC3, and PC4) in different molar ratios (3:1, 3:2, 1:1, and 3:4 respectively) were prepared by simple solvent evaporation method. Difference in dislocation density and strain value of the eutectics were observed, and the maximum strain value of PC1 might be due to the highest deformation activity compared to PC2, PC3, and PC4. Carbonyl-thiazolidine or carboxyl-pyridine weak bond formation might be the reason of producing eutectics of PGZ-CA rather than cocrystal with a docking score of - 2.2 Kcal/M. Likewise, lowest particle size was found with PC1 rather than that of pure PGZ and other eutectics. PC1 demonstrated highest dissolution of drug (68 %) rather than other eutectics (54 to 61 %) and PGZ (44 %) after 360 min.

The synthesis, characterization, and electronic properties of 4-((7-methoxyquinolin-4-yl)oxy), 4-(quinolin-2-ylthio), and 4-((7-(trifluoromethyl)quinolin-4-yl)thio) peripherally substituted oxo-titanium phthalocyanines are described for the first time. The structures of the compounds were determined by UV-Vis, FTIR, 1H NMR, and MALDI-TOF mass spectrometry. Electronic spectra and molecular and electronic properties of compounds were calculated by Density Functional Theory (DFT) and Time-Dependent Density Functional Theory (TD-DFT) methods. Solvent effects on the electronic, geometric, and reactivity properties of the compounds were also investigated. Global and local reactivity indices and Molecular Electrostatic Potential surfaces of compounds were calculated. The reactivities and electronic structures of molecules vary depending on the solvent and substituents. It has been found that the synthesized compounds can be used for different purposes such as dye-sensitized solar cells and photodynamic therapy applications.

This study examined how teachers teaching chemistry at different levels of education perceive their levels of technological pedagogical content knowledge (TPACK) and examined the relationship of TPACK with age, gender, teaching at different levels of education, time spent teaching chemistry, and frequency of information and communication technology (ICT) use. The study involved 261 teachers, 246 women and 15 men, from all over Slovenia, who have been teaching chemistry for an average of 18 years at different levels of education, with an average age of 45 years. The results showed that teachers teaching chemistry content perceive a high level of TPACK. There is a statistically significant correlation between age, time spent teaching chemistry, and frequency of ICT use with the perceived level of technological pedagogical content knowledge. Younger teachers, those with less professional experience and teachers who use ICT more frequently rated their TPACK higher. Based on the results of the survey, guidelines for planning the in-service teacher training that would support the development of TPACK of teachers teaching chemistry content were developed.

Efficient, economical, and durable adsorbents are required to remove volatile organic compounds (VOCs) from air. Cross-linked polyvinylic ionic liquids (PVIC) with porous structures were synthesized by quaternizing 1-vinylimidazole (1VI) with 1-bromobutane to obtain 3-butyl-1-vinylimidazolium bromide (VIC), which was then co-polymerized with divinylbenzene (DVB) radicals. 1H NMR, 13C NMR, scanning electron microscopy, X-ray photoelectron spectroscopy, Fourier-transform infrared spectroscopy, and N2 adsorption-desorption isotherms were applied in characterizing the composites. Through modification of the polymer structure by adjustment of DVB concentration（the ratio of DVB concentration to VIC concentration was x: 1 (x=0.4, 0.6, 0.8, 1.0) and the product was named PVIC-s (s=2, 3, 4, 5)）, the optimal PVIC-4 pore structure was obtained, with a specific surface area and total pore volume of 192.5 m2 g-1 and 0.192 cm3 g-1, respectively. A toluene adsorption test verified the adsorption capacity. The adsorption behavior for VOCs, based on toluene, was investigated using adsorption breakthrough curves, adsorption kinetics, and isotherms. The adsorption process is well describing by the Bangham kinetic and Langmuir isotherm models. The dynamic adsorption of toluene followed the order PVIC-4 > PVIC-5 > PVIC-3 > PVIC-2. The optimum toluene adsorption by PVIC-4 was 264.4 mg g-1 as a result of its excellent pore structure. PVIC-4 also performed well in terms of recovery and has potential for the removal of VOCs from air.