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.

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.

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.

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.

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 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.

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.

Three mononuclear nickel(II), cadmium(II) and zinc(II) complexes, [NiL2]·2CH3OH·H2O (1), [CdI2(HL)]·CH3OH (2) and [ZnL2] (3), have been synthesized from 3-hydroxy-4-methoxy-N'-[(Z)-(pyridin-2-yl)methylidene]benzohydrazide (HL) by microwave irradiation method. All complexes were characterized by CHN elemental analyses and infrared spectra. Structures of the complexes were further studied by single crystal X-ray determination, which reveals that the Ni and Zn atoms in complexes 1 and 3 are in octahedral coordination, and the Cd atom in complex 2 is in square pyramidal coordination. The biological activity of the complexes on the bacterial strains Bacillus subtilis, Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli was evaluated. As a result, the zinc complex has interesting antibacterial activities.

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.

The coupling reaction of diazonium ion of 2-amino-6-nitrobenzothiazole at 0-5 °C with distinctly substituted 2-aminobenzothiazole derivatives produced new 1,2,3,5-tetrazine derivatives. It was found that diazotized 2-amino-6-nitrobenzo[d]thiazol reacts with the ring nitrogen atom of varyingly substituted 2-aminobenzothiazole derivatives to yield tetrazine nucleus. The benzene ring of benzothiazole bearing electron donor group and annelated to the tetrazine was further substituted in situ by other 6-nitrobenzo[d]thiazol-2-yl) diazinyl to yield the final product. The structure of the prepared compounds was elucidated using their physical, elemental, and spectroscopic data. The synthesized compounds were tested for their antimicrobial and antibiofilm activities against Staphylococcus aureus and Escherichia coli bacteria. Two of the synthesis tetrazine derivatives exhibited interesting antibiofilm potential.

Water supply is the great challenge for climate change and overpopulation. A Nanofiber mat consisting of Poly vinyl alcohol (PVA), nanoTiO2, and citric acid (PTC) was prepared using an electrospinning technique at a constant flow rate (0.5 ml/h). The morphology of the mat was detected using (FESEM) technique and image J software; they show that the mat has a Nanofiber morphology with an average diameter of 170 nanometers. This mat was used to remove methylene blue (MB) from water in two ways, the adsorption process and by photodegradation using UV light. The kinetic study of the adsorption of methylene blue MB on a PTC mat was carried out. results show that the pseudo-second order is best to describe the adsorption, of MB and the Intra- particle diffusion is the rate determining step. Seven isotherm models; four of two-parameters and three of three-parameters were used to examine the adsorption experimental data by applying linear and non-linear regression method using six error functions. The results showed comparable data between linear and non-linear regression methods for two parameters isotherms, and the best isotherm fitting with the data were Freundlich and Temkin models. On the contrary, three parameters isotherms showed distracted data between linear and non-linear regression methods. In addition, the results appear that the best predictive error function was ꭓ2.

In this study, GO/PAMAM4 was used as a biocompatible nanocomposite adsorbent to adsorb dichromate (DC) ions. In alkaline solutions, DC ions changed to chromate ions which were not adsorbed on the surface of adsorbent. Thus, experiments were carried out in acidic and neutral water solution. Under these conditions, adsorption sites of adsorbent were protonated primary and ternary amine groups of adsorbent shown as -NH3+  and -NHR2+, respectively, that adsorbed DC ions through electrostatic interaction. Adsorption isotherms of DC on GO/PAMAM4 were obtained under various ionic strengths, pHs and temperatures. Isotherms were analyzed by the ARIAN model. The highest observed adsorption capacity of this process was 246.7 mg g-1 at pH=0 and 318 K. Tests at pH=2 showed that this process was endothermic. Adsorption kinetic experiments were carried out under various initial DC concentrations, pHs, temperatures, shaking rates and ionic strengths and were analyzed by the KASRA model and intraparticle diffusion, ISO and NIPPON equations. Pb2+, Cd2+, Cr3+ and tannic acid (TA) were separated by GO/PAMAM4 from DC ions and the GO/PAMAM4 was recycled by using an alkaline solution.

In this study, the crosslinking of PVA nanofiber was increased using solvent vapor treatment. Then, Fe3O4 nanoparticles were synthesized by a simple hot water technique and composited with the nanofiber. The study focuses on applying the modified PVA nanofibers to remove malachite green (MG) from water using different pH, contact times, and dye initial concentrations. The surface morphology of the nanofiber was determined using SEM, FTIR, and XRD techniques. SEM showed that the crosslinking was increased, and Fe3O4 nanoparticles appeared as agglomerates on the surface of the nanofiber. The removal percentages at optimal pH and contact time were 99.76%, and 99.5%, respectively. Thereafter, kinetics was studied by the linear pseudo-first order, pseudo-second order, Elovich equation, and Intraparticle diffusion models. Results demonstrated that the adsorption kinetics follow the pseudo-second order. Moreover, the adsorption isotherm was discussed using Langmuir and Freundlich equations. The Langmuir equation best described the adsorption with R2 value of 0.9771, and the maximum removal was 128.205 mg/g. As a result, the MG dye molecules covered the PVA nanofiber/Fe3O4 nanoparticles in a monolayer and homogenous coverage. The results of this study are significant for industries' wastewater treatment as they provide a potential solution for the removal of MG dye from textile, paper, cosmetics, food, and aquaculture industries' wastewater.

Quinoline and its derivatives are a family with unique medicinal properties, including antibacterial effects. It was assumed that the four Quinoline Derivatives Q1 , Q2, Q3 and Q4 had significant activity against pathogenic bacteria. These compounds were synthesized and characterization by TLC, IR, 1H-NMR, and 13C-NMR analyses. The biological activity of compound Q1 was IZ (19 ± 0.22) against Klebsiella pneumoniae, IZ (18 ± 0.22) against Bacillus subtilis, IZ (17 ± 0.22) against Staphylococcus aureus. Q2 was IZ (18 ± 0.22) against both Klebsiella pneumoniae and Bacillus subtilis. Q3 was IZ (17 ± 0.22) against staphylococcus aureus. Q4 was IZ (21 ± 0.22), where showed a higher inhibitory activity against E. coli, than that of ciprofloxacin. These results demonstrate the potential of the synthesized compounds to work as antibacterial drugs against these strains by inhibiting or deactivating the target proteins.

This study aimed to develop a rapid method for separation of stigmasterol, campesterol and β-sitosterol in Prunus spinosa L. (sloe) fruit extracts by High Performance Liquid Chromatography system. Samples were prepared by Soxhlet extraction method and separated on a high strength silica C18 column using acetonitrile-methanol mobile phase and Photodiode Array Detector. The optimized method resulted in a linear calibration curve ranging from 1.7 ng mL-1 to 130 ng mL-1 for all three phytosterols. Analyses of internal and external phytosterol standards showed good linearity (R2 of 0.998 to 0.999); LOD and LOQ were determined to be 2.33×10-7-2.18×10-4 and 7.07×10-7-6.60×10-4 mg mL-1, respectively. Repeatability and reproducibility precision analyses showed acceptable values of RSD %. β-sitosterol was the predominant phytosterol (51.53-81.03 % of total) among all samples. Method validation parameters indicated that this analytical method can be applied for accurate and precise determination of campesterol, stigmasterol and β-sitosterol, in selected extracts.

The aim of this study is to optimize the extraction process and characterize the proteins found in fenugreek seeds. The water and oil holding capacities, coagulated protein content, foaming and emulsification properties of the isolated proteins at all extraction conditions were investigated. Also, solubility, molecular weights, structural and thermal properties were determined. In the extraction processes carried out at different pHs (pH 6.0-12.0) and solid:solvent ratios (20-60 g/L), it was determined that the highest extraction yield (94.3±0.3%) was achieved when the pH was 11.47 and the solid-solvent ratio was 34.50 g/L. Three distinct bands (46, 59 and 80 kDa) in the range of 22-175 kDa were determined for the fenugreek seed protein isolate obtained at optimum extraction conditions. Protein secondary structures were achieved using Fourier Transform Infrared (FT-IR) spectra and it was determined that β-sheet structures were highly present. In addition, denaturation temperatures and denaturation enthalpy were calculated as ~119°C and 28 mJ/g, respectively.

Many conformers of 3-aminopropionitrile are known. Due to the biomedical importance of 3-aminopropionitrile a full investigation of structural, vibrational, and other associated properties of all possible conformers was performed. The geometrical structures, relative stability, and vibrational frequencies of the gauche and trans 3-aminopropionitrile conformers have been studied using ab initio (CCSD/6-311+G(d,p)) and DFT (B3LYP and M06 functionals at 6-311+G(d,p) and aug-cc-pVDZ basis set) calculations. The conformational and vibrational studies of 3-aminopropionitrile molecule were presented here are in very good interpretation of the calculated data compared with very poor interpretation in previous studies. The results showed that the gauche 2 conformer is more stable by 0.19 kcal/mol than gauche 1, outlined as enthalpy change ΔH between the conformers, at CCSD/6-311+G(d,p). Additionally, the population analysis shows that the gauche conformers are more prevalent than the trans conformers in the gas phase, present at 72.8%, with gauche 2 being the dominating gauche conformer at 40.1%. These results are in good agreement with earlier experimental and theoretical conclusions. All minima conformers' thermodynamic characteristics have also been studied. The relevant bond lengths, bond angles, and dihedral angles were calculated at a different level of theory for all possible conformers. The geometrical outcomes of the conformers agree very well with the previous experimental results. Electrostatic potential surface (ESP) has been used to interpret the structure-activity relationship. The atomic charges are examined, together with the energy difference between HOMO (Highest Occupied Molecular Orbital) and LUMO (Lowest Unoccupied Molecular Orbital). Additionally, the HOMO-LUMO energy gap and other relevant molecular properties are computed. The most stable conformers' stabilization energy has been determined by the Natural Bond Orbital (NBO) analysis.

The cellulose is the most abundant and renewable polymer in nature. It is characterized by its biodegradability that can help to establish a friendly environment. The main objective of this study is intended to characterize the nanocellulose obtained from waste date palm,  including the dried palms (DP) and the fresh palms (FP) by implementing chemical methods (hydrolysis with H2SO4). Physical properties, morphology, the elemental composition and the thermal stability were determined by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), zeta sizer, scanning electron microscopy (SEM), whereas energy dispersive X-ray (EDX) and thermogravimetric analysis (TGA), respectively. FTIR, SEM and EDX results, revealed the effective removal of impurities, hemicellulose and lignin. Palm sample residues contained 35.99% of cellulose and 33.12% of cellulose nanocrystals (CNC) for DP, and 36.17% of cellulose and 34.35% of CNC for FP. The CNCs have higher crystallinity than the raw fibers and Zeta sizer was between 25 and 1150 nm. TGA analysis showedthat DP exhibited greater thermal resistance.

Association behavior between quinizarin (1,4-dihydroxyanthraquinone), an analogue of the chromophore of anthracycline anticancer drugs and sodium dodecyl sulfate (SDS) micelles in the presence of glucose, NaCl and urea additives was studied using absorption spectroscopy and conductometric techniques. The spectral results indicate an increase of binding constant and partition coefficient values in the presence of glucose and NaCl whereas the addition of urea leads to a decrease of binding strength and quinizarin partitioning into SDS micelles. Thus, the rise of NaCl and glucose concentrations is favorable for the quinizarin distribution into SDS micelles. From electrical conductivity measurements it was found that the critical micelle concentration (CMC) of SDS/quinizarin system decreases by adding NaCl and glucose whereas urea has not influence on the micelization process at the concentrations used in the present study. Since biologically compounds like glucose, NaCl and urea are found in the human body, the attained outcomes can be important in finding of effective drug delivery systems.

A new azo compound [2-((4-hydroxy-3-(E)-(2-hydroxy-5-nitrophenyl)diazenyl)benzaldeyde and the azo schiff derivative [2-((4-hydroxy-3-((E)-(2-hydroxy-5-nitrophenyl)diazenyl)benzylidene)amino)-4-nitrophenol (Azo-S) has been synthesized. 13C-NMR, 1H-NMR, FT-IR, Mass apectroscopy and Uv-Visibl analysis was used to characterized new compounds. The new synthesized compound Azo-S was utilized to inhibit mild steel (MS) corrosion at little concentrations (0.001-0.006) M. Weight loss measurements studies in 1 M HCl and at 298 K  showed that Azo-S has a good corrosion inhibition efficiency, 75%  at 0.002 M of inhibitors.It was found that adsorption methods follow Lanngmuir isotherm with ΔG values around -23.8 kJ/mol, this confirms that a stable protective film is formed for the mild steel spontaneously during physical adsorption.