Methanol Medium Research Articles

Comparative study of MMO and BDD anodes for electrochemical degradation of diuron in methanol medium

Treating emerging pollutants at low concentrations presents significant challenges in terms of degradation efficiency. Anodic oxidation using active and non-active electrodes shows great potential for wastewater treatment. Thus, this study compared the efficiency of a commercial mixed metal oxide anode (MMO: Ti/Ti0.7Ru0.3O2) and a boron-doped diamond anode (BDD) for the electrochemical oxidation of diuron in methanol, in chloride and sulfate media. The MMO anode achieved diuron removal rates of 94.9% and 92.8% in chloride and sulfate media, respectively, with pseudo-first-order kinetic constants of 0.0177 and 0.0143 min−1. The BDD anode demonstrated slightly higher removal rates, achieving 96.2% in sulfate medium and 96.9% in chloride medium, with respective kinetic constants of 0.0193 min⁻1 and 0.0177 min⁻1. Increasing the current density enhanced diuron removal by up to 15% for both electrodes; however, excessively high current densities led to increased energy consumption due to side reactions. The present of water had antagonistic effects, resulting in removal rates of 91.1% for chloride media using the BDD anode; and 87.4% and 90.4% in sulfate media with MMO and BDD anodes, respectively. The MMO anode in chloride medium did not show significant difference in the degradation percentage, reaching 96% of diuron removals. The degradation mechanism was proposed based on the detection of various by-products. The primary reactions observed during the oxidation of diuron in methanol involved chlorine substitution in the aromatic ring and dealkylation. These processes generated several intermediates and by-products at low concentrations, ultimately leading to high diuron removal.

Synthesis and Characterization of s-Triazine Cored Schiff Base Containing β-lactam and Its [M(Salen/Saloph)] (M= Cr3+ and Fe3+) Capped Complexes

This study consists of a tripodal 6-iminopenicylanic acid ligand synthesized based on the s-triazine group and its four trinuclear complexes. For this purpose, 2,4,6-tri(p-formylphenoxy)-1,3,5-triazine (III) (TRIPOD) was obtained from the reaction of 2,4,6-trichloro-1,3,5-triazine and 4-hydroxybenzaldehyde. Then, tripodal target ligand (V) was obtained from the reaction of TRIPOD and 6-aminopenicylanic acid. Finally, tripodal trinuclear (ML) capped target complexes were obtained from the reactions of the initial complexes [(ML)2O] (M= Cr3+ or Fe3+, L= Salen or Saloph) with the target ligand in methanol media. The structures of all obtained ligands were elucidated using 1H NMR, FT-IR, and elemental analysis methods. The structures of the complexes were characterized using FT-IR, magnetic susceptibility, ICP-OES, and TGA methods.

Exploring the Potential of N‐Benzylidenebenzohydrazide Derivatives as Antidiabetic and Antioxidant Agents: Design, Synthesis, Spectroscopic, Crystal Structure, DFT and Molecular Docking Study

AbstractHydrazone‐type Schiff bases have been widely explored owing to their therapeutic properties. These compounds are known to have antibacterial, antifungal, anticancer, and antioxidant properties, among others. In the present study, six hydrazone‐based Schiff bases (BB1–BB6) were synthesized by the reaction between derivatives of benzaldehyde and benzo hydrazide in methanolic medium in the presence of catalytic amount of formic acid. The synthesized compounds were characterized using various spectroscopic techniques such as NMR (1H, 13C, COSY, DEPT, HSQC, HMBC, and NOESY), FTIR, UV‐Vis, elemental (CHN) analysis, and high‐resolution mass spectroscopy. In addition, single crystal structures of BB2, BB4, and BB6 were obtained. In vitro antidiabetic and antioxidant potential of the compounds was evaluated on glucosidase, amylase, NO, FRAP, and DPPH assays, respectively. In all the assays, compounds BB6, BB4, and BB2 showed higher activity than the others. To further explore the chemical reactivity properties and their mechanism of action against the tested assays, DFT and molecular docking study were performed, and the results obtained reinforce the experimental study data.

Robust carbon quantum dots supported cobalt oxide composite particles prepared by hydrothermal process for green hydrogen generation via sodium borohydride hydrolysis

Carbon quantum dots (CQDs), a new class of carbon nanostructures with a particle size of 10 nm, exhibit important properties such as easy surface functionalization, low cost, chemical inertness, water solubility and low toxicity. In this study, an effective catalyst was synthesized using cobalt oxide (Co3O4) metal nanoparticles dispersed on CQD support material obtained from sucrose by hydrothermal method (Co3O4-SCQD-HT). The resulting catalyst system was used for effective hydrogen (H2) production from sodium borohydride (NaBH4) hydrolysis. Hydrogen generation rate (HGR) values of 7041, 18,426 and 27,555 mlmin−1gcat−1 were obtained with Co3O4-SCQD catalysts synthesized during the hydrothermal process with water, ethanol and methanol solvents, respectively. The HGR values of the catalysts obtained in ethanol and methanol medium provided an improvement of approximately 2.5 and 4 times, respectively, compared to the catalyst prepared in water medium. The activation energy for NaBH4 hydrolysis by Co3O4-SCQD-HT was 29.92 kJmol−1. Transmission Electron Microscopy (TEM), Energy-dispersive X-ray spectroscopy (EDS), nitrogen adsorption/desorption, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Inductively coupled plasma optical emission spectroscopy (ICP-OES) and X-ray photoelectron spectroscopy (XPS) analyses were used for the characterization study. The average particle size for the Co3O4-SCQD-HT nanocomposite is approximately 3.27 nm. The presence of carbon (C), oxygen(O), nitrogen (N) and cobalt (Co) atoms was confirmed by XPS and EDS analysis.

Characterization of MAP c21873-1 as a new counter-selectable marker for unmarked genetic modification of Pichia pastoris

BackgroundSelection markers are useful in genetic modification of yeast Pichia pastoris. However, the leakage of the promoter caused undesired expression of selection markers especially those toxic proteins like MazF, halting the cell growth and hampering the genetic manipulation in procaryotic system. In this study, a new counter-selectable marker-based strategy has been established for seamless modification with high efficiency and low toxicity.ResultsAt first, the leaky expression of the enhanced green fluorescent protein (EGFP) as a reporter gene under the control of six inducible promoters of P. pastoris was investigated in two hosts Escherichia coli and P. pastoris, respectively. The results demonstrated that the DAS1 and FDH1 promoters (PDAS1 and PFDH1) had the highest leakage expression activities in procaryotes and eukaryotes, and the DAS2 promoter (PDAS2) was inducible with medium strength but low leakage expression activity, all of which were selected for further investigation. Next, Mirabilis antiviral proteins (MAPs) c21873-1, c21873-1T (truncated form of c21873-1) and c23467 were mined as the new counter-selectable markers, and hygromycin B (Hyg B) resistance gene was used as the positive-selectable marker, respectively. Then, modular plasmids with MAP-target gene-Hyg B cassettes were constructed and used to transform into P. pastoris cells after linearization, and the target genes were integrated into its genome at the BmT1 locus through single-crossover homologous recombination (HR). After counter-selection induced by methanol medium, the markers c21873-1 and c21873-1T were recycled efficiently. But c23467 failed to be recycled due to its toxic effect on the P. pastoris cells. At last, the counter-selectable marker c21873-1 under the tightly regulated PDAS2 enabled the encoding genes of reporter EGFP and tested proteins to be integrated into the target locus and expressed successfully.ConclusionsWe have developed MAP c21873-1 as a novel counter-selectable marker which could perform efficient gene knock-in by site-directed HR. Upon counter-selection, the marker could be recycled for repeated use, and no undesirable sequences were introduced except for the target gene. This unmarked genetic modification strategy may be extended to other genetic modification including but not limited to gene knock-out and site-directed mutagenesis in future.

Biological evaluation of a novel Schiff base ligand as an antioxidant agent: Synthesis, characterization and DFT computations of its Ni(II) and Cu(II) complexes

By condensation reaction in methanolic medium, a novel ligand using methoxy substituted amine and 5-bromosalicylaldehydic was synthesized. Then, its Cu- and Ni- complexes were also prepared under same experimental conditions. The final desired compounds, with high obtained yields, have been characterized and well discussed by EA-CHN, UV–Vis., FT-IR, NMR, SEM-EDX and MS spectrometry. The structure of the ligand was confirmed by X-ray crystallography showing an interesting intramolecular hydrogen bond and also intermolecular interactions (Br…CArom. and CH/π-type). The electronic properties were quantified by density functional theory (DFT) calculations using DFT- B3LYP/6-31 G (d,p) level basis set. The molecular structures, geometrical parameters, chemical reactivity, stability, molecular electrostatic potential (MEP) and Mulliken atomic charges were computed to identify the chemical reactive sites on the molecular surface. The antioxidant activities were studied theoretically involving various parameters such as bond dissociation enthalpy (BDE), ionization potentials (IPs), proton affinities (PA), proton dissociation enthalpy (PDE), electron transfer enthalpy (ETE) and radical stabilization energy (RSE). Experimentally, the antioxidant activities were also studied by using 2,2′-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS), ferric ion reducing antioxidant power (FRAP) and nitric oxide scavenging (SNP) methods. The computational study of antioxidant activity is well correlated with their experimental results.

Mechanism of formation H2 and CH4 by hydrolysis and alcoholysis of lignin: A density functional theory study

Hydrolysis and alcoholysis are considered as viable routes for efficient degradation and recycling high-quality gas fuel of lignin. Mechanism of formation H2 and CH4 by hydrolysis and alcoholysis of various phenylic lignin model compounds were studied using density functional theory method at M06–2X/6–31++G(d,p) level. Formation H2 by eight hydrolysis reaction pathways and formation CH4 by eight alcoholysis reaction pathways were designed. The standard kinetic and thermodynamic parameters of hydrolysis and alcoholysis reaction pathways were calculated. The results show that energy barriers for hydrolysis of phenyl (p-hydroxyphenyl, guaiacyl, and syringyl) formaldehyde paths (about 270.0 kJ/mol) are higher than those for hydrolysis of phenyl (p-hydroxyphenyl, guaiacyl, and syringyl) acetaldehyde paths (about 250.0 kJ/mol). Thus, H2 is easily formed during the decomposition of phenyl (p-hydroxyphenyl, guaiacyl, and syringyl) acetaldehyde. The energy barriers for alcoholysis of phenyl (p-hydroxyphenyl, guaiacyl, and syringyl) formaldehyde paths (about 370.0 kJ/mol) are lower than those for alcoholysis of phenyl (p-hydroxyphenyl, guaiacyl, and syringyl) acetaldehyde paths (about 355.0 kJ/mol). Thus, CH4 is easily formed during the decomposition of phenyl (p-hydroxyphenyl, guaiacyl, and syringyl) acetaldehyde. In addition, temperature is the key factor in the lignin degradation process, the calculation results indicate the reaction rate increases with the increase of temperature, and the reaction in water molecular environment is better than that in methanol medium.

Effect of traditional solvent on thermal decomposition mechanism of lignin: A density functional theory study

In order to understand the effect of traditional solvents on lignin pyrolysis, the decarbonylation and decarboxylation reactions of various phenylic lignin model compounds were theoretically investigated using DFT methods at M06-2×/6–31++G(d,p) level. The calculation results show that activation energy of the decarbonylation and decarboxylation reactions of lignin model compounds can be reduced when H2O/CH3OH existed. There are two types of reaction for the H2O/CH3OH during the pyrolysis. For first type, the synergistic reaction of lignin with H2O/CH3OH as hydrogen transfer carrier. The energy barriers of the main elemental reaction steps during this type of pyrolysis are about 285.0–300.0 kJ/mol (H2O) and 275.0–290.0 kJ/mol (CH3OH) (decarbonylation), 170.0–210.0 kJ/mol and 155.0–200.0 kJ/mol (decarboxylation). For another type, the synergistic reaction of lignin with H2O/CH3OH as hydrogen source. The energy barriers of the main elemental reaction steps during this type of pyrolysis are about 260.0–278.0 kJ/mol and 240.0–260.0 kJ/mol, 303.0–312.0 kJ/mol and 291.0–297.0 kJ/mol. Furthermore, the reaction temperature has the most significant impact on decomposition reaction of lignin in a methanol medium, suggesting that the reaction in the methanol medium is better than that in the water environment.

Heterocyclic fluorescent Schiff base chemosensors for the detection of Fe(III) and Cu(II) ions.

Two new Schiff bases were synthesized from 1-(2,4-dihydroxyphenyl)ethanone and pyridine derivatives. Both compounds were characterized using infrared, UV-Vis., 1H NMR, 13C NMR and mass spectral studies. Density functional theory (DFT) calculations were performed for both the Schiff bases with 6-31G(d, p) as the basis set. Vibrational frequencies calculated using the theoretical method were in good agreement with the experimental values. Both the Schiff bases were highly fluorescent in nature. The cation-recognizing profile of the compounds was investigated in aqueous methanol medium. The Schiff base 4-(1-(pyridin-4-ylimino)ethyl)benzene-1,3-diol (PYEB) was found to interact with Fe(III) and Cu(II) ions, whereas the Schiff base 4,4'-((pyridine-2,3-diylbis(azanylylidene))bis(ethan-1-yl-1-ylidene))bis(benzene-1,3-diol) (PDEB) was found to detect Cu(II) ions. The mechanism of recognition was established as combined excited state intramolecular proton transfer (ESIPT)-chelation-enhanced fluorescence (CHEF) effect and chelation-enhanced quenching (CHEQ) process for the detection of Fe(III) and Cu(II) ions, respectively. The stability constant of the metal complexes formed during the sensing process was determined. The limit of detection for Fe(III) and Cu(II) ions with respect to Schiff base PYEB was found to be 1.64 ×10-6 and 2.16 ×10-7M, respectively. With respect to Schiff base PDEB, the limit of detection for Cu(II) ion was found to be 4.54 ×10-4M. The Cu(II) ion sensing property of the Schiff base PDEB was applied in bioimaging studies for the detection of HeLa cells.

Mononuclear and binuclear dioxidomolybdenum(VI) chelates derived from a tridentate ONO donor aroylhydrazone: Spectral, structural, DFT and in silico biological investigations

Four dioxidomolybdenum(VI) complexes, [MoO2(L)]2·H2O (1), [MoO2(L)(py)] (2), [MoO2(L)(3-pic)]·H2O (3) and [MoO2(L)(4-pic)] (4) of a dibasic tridentate ONO donor aroylhydrazone, H2L (where H2L = 3-methoxy-2-hydroxybenzaldehyde-2-furoic acid hydrazone) have been synthesized and well characterized. The stoichiometric reaction of aroylhydrazone with MoO2(acac)2 in methanolic medium yielded phenoxobridged binuclear complex 1 whereas monomeric complexes, 2, 3 and 4 were formed as a result of incorporating different monodentate heterocyclic bases. The tridentate aroylhydrazone coordinates to the MoO22+ core through phenolate oxygen, azomethine nitrogen and iminolate oxygen atoms. Single crystal XRD studies established the coordination geometry of mononuclear dioxidomolybdenum(VI) complexes as distorted octahedron. The crystal structures and various solid state interactions were also investigated here. DFT investigations were conducted to explore the reactivity parameters of the studied aroylhydrazone and complexes. Furthermore, molecular docking analyses unveiled the superior putative binding energy of the investigated compounds in contrast to cisplatin. These findings were particularly pronounced in relation to the selected target proteins, which are indicative of their potential efficacy against lung and breast cancer cell lines.

Synthesis, Structural Characterization, Reactivity and Bioactivity Studies of Some Binuclear Salen Type Schiff Base Complexes of Manganese(III)

Four new phenoxy bridged binuclear Salen type Schiff base complexes of manganese(III), [MnLX]2 with tetradentate Schiff base, H2L [H2L = N,N′-O-phenylene bis(salicylaldimine)] containing anionic co-ligands, X (X = benzoate, p-hydroxy benzoate, p-aminobenzoate, 3,5-dinitrobenzoate) have been synthesized from manganese(II) acetate, Schiff base (H2L) and the corresponding co-ligands in methanol medium. Schiff base ligand (H2L) was obtained in situ by condensation of salicylaldehyde and o-phenylenediamine in aqueous methanol. Elemental analyses, FT-IR, molar conductance, UV-visible spectroscopic studies and magnetic moment measurements at room temperature were used to characterize the binuclear Schiff base complexes. The IR spectra of [MnLX]2 (X = benzoate, p-hydroxy benzoate, p-aminobenzoate, 3,5-dinitrobenzoate) complexes showed the characteristic absorptions due to coordinated azomethine nitrogen and phenolic oxygen atoms of the Schiff base. In addition, IR spectra of the compounds also suggest coordination of the co-ligands namely benzoate, p-hydroxy benzoate, p-aminobenzoate, 3,5-dinitrobenzoate in the respective complexes. A consistent presence of a band at ca. 755 cm-1 in all the binuclear complexes arises due to (Mn-O-Mn) moiety originated from interactions of phenoxy oxygen and manganese atoms, resulted in dimeric structure of the compounds. The magnetic moment values ranging from 4.74-4.91 B.M. per manganese centre for the complexes suggest presence of Mn(III) ion in the complexes. The overall coordination geometry around the manganese centres is distorted octahedral. Redox behaviour of the synthesized complexes was ascertained from cyclic voltametric studies. The Schiff base complexes, [Mn(L)X]2 (X = p-aminobenzoate, 3,5-dinitrobenzoate) have demonstrated their catalytic potentials in oxidizing selective organic substrates namely cyclohexene and styrene by hydrogen peroxide as oxidant. The oxidized products were characterized as trans-cyclohexane 1,2-diol and styrene epoxide, respectively. Complex 4 demonstrated a considerable level of effectiveness against a wide variety of pathogenic microorganisms.

Approach to synthesis and study of pharmacological effects of new 1,3,5-triazine derivatives

Introduction. Among the derivatives of 1,3,5-triazine, compounds with different biological activity are known, but there are few drugs of this structure on the pharmaceutical market. Thus, the production of new medicines based on a triazine core, as well as the study of their biological activity is an urgent direction. Objective: synthesis of new 1,3,5-triazine derivatives using the reaction of recycling of 2,5-disubstituted-4-hydroxy-6H-1,3-oxazine-6-ones by 1,3-binucleophiles to obtain different substituents at positions 2,4,6 in one stage, as well as assessment of acute toxicity, diuretic activity in silico and in vivo for synthesized products. Material and methods. The target compounds were obtained as a result of the interaction of 2,5-disubstituted-4-hydroxy-6H-1,3-oxazine-6-ones and S-methylisothiourea of hemisulfate in the presence of an equimolar amount of sodium methylate in a methanol medium. Prediction of acute toxicity of the studied compound was carried out using the local version of the GUSAR software. Computer screening of biological activity was carried out using the PASS program. Acute toxicity in vivo was determined on white male mice. For experimental evaluation of the diuretic activity of the obtained compounds in vivo, the Taylor, Topliss model was included in the work. Results. 2-(methylsulfanyl)-4-(4-nitrophenyl)-6-ethyl-1,3,5-triazine, 2-(methylsulfanyl)-4-(4-nitrophenyl)-6-(pentane-1-yl)-1,3,5-triazine were obtained with a yield of 72% and 69%, respectively. The structure of the obtained compounds was proved using 1H and 13C NMR spectroscopy. The predicted and experimental data of acute toxicity correlate with each other, and the studied compounds belong to the class "low-toxic". During the screening of biological activity using the PASS program, data on the estimated diuretic activity were obtained. Studies of biological activity in vivo have shown that the target compounds have pronounced diuretic activity. Conclusion. New compounds have been synthesized, their structure has been proved using modern physico-chemical analysis methods. The results of computer prediction made it possible to determine the potential class of toxicity and identify potential biological activity. With the help of experimental pharmacological studies, it has been proved that the studied compounds have low toxicity and exhibit pronounced diuretic activity.

Sustainable synthesis and extraction of 5-methyl-N-phenyl-2-pyrrolidone produced via reductive amination of levulinic acid

5-methyl-N-substituted-2-pyrrolidones (5MPs) have been proposed as alternatives to N-methyl-2-pyrrolidone, a solvent with industrial and commercial applications which is considered hazardous and undesired by regulators. 5MPs are produced via reductive amination of levulinic acid with a catalyst and a reducing agent like H2. However, the separation of 5MPs from the reaction media is scarcely studied to understand industrial and commercial viability. This work is centered on producing 5-methyl-N-phenyl-2-pyrrolidone from levulinic acid via reductive amination followed by its liquid–liquid extraction using specifically selected extracting solvents. The extraction step considers not only the separation performance but also the environmental, health, and safety (EHS) criteria of the selected solvents. Thus, COSMO-RS, along with EHS guides, were used to screen solvents to extract 5-methyl-N-phenyl-2-pyrrolidone from methanol or water, which are used as reaction solvents. Some promising extracting solvents were studied in ternary liquid–liquid equilibrium experiments based on the partition of 5-methyl-N-phenyl-2-pyrrolidone and the reactants in the extracting solvent + (water or methanol) biphasic system. Subsequently, the solvents were tested for the extraction of the 5-methyl-N-phenyl-2-pyrrolidone from a real reaction mixture, produced by a Pt/TiO2 catalyzed reductive amination at 25 °C and 1.013 bar. Predictions and further validations of the distribution coefficients and selectivities for the solute show that anisole and limonene are favorable solvents for extracting 5-methyl-N-phenyl-2-pyrrolidone from water and methanol media, respectively. Both solvents are attractive alternatives due to their biobased nature, with the former ranked as recommended by EHS guides and the latter having some concerns with environmental criteria. However, both solvents show advantages for a scale-up of the reaction + separation process.

Think before throw: waste chili stalk powder for facile scavenging of cationic dyes from water.

Chili stalk powder (CS), a non-conventional adsorbent, has been exercised for facile removal of cationic dyes from simulated and wastewater by batch technique. The prepared material has been characterized by Fourier-transform infrared spectroscopy (FTIR), Field emission scanning electron microscopy (FESEM), Brunauer-Emmett-Teller analysis (BET), powder X-ray diffraction (powder XRD), and pHZPC and tested best with methylene blue and crystal violet under ambient conditions. FTIR denotes the presence of carbonyl and polyphenolic groups, responsible for dye adsorption. BET surface area analysis evaluates the porous nature and specific surface area of the material, and powder XRD confirms its amorphous nature. The porous structure could be ascertained from the FESEM image, and energy dispersive X-ray analysis (EDX) confirms the elemental composition. The pH above pHzpc shows an increase in removal efficiency. The maximum adsorption capacities are 49.53 and 36.88mg/g for methylene blue (MB) and crystal violet (CV) respectively. Linear as well as non-linear plots for kinetic and isotherm models were studied. Both dye uptake fits the linear plot of Langmuir adsorption isotherm (R2 = 0.999 and 0.995) and pseudo-second-order kinetics (R2 = 0.998 and 0.999). In the non-linear plot, the adsorption process for both dyes fit Langmuir (R2 = 0.999 for MB and R2 = 0.983 for CV) as well as Freundlich adsorption (R2 = 0.999 for MB and R2 = 0.994 for CV). 75.48% crystal violet (CV) and 73.35% methylene blue (MB) regeneration were successful in 1:1 methanol medium and reused for up to three cycles. The uptake mechanism is suggested to be a union of π-π stacking, electrostatic interaction, and weak hydrogen bonding. The material was tested with industrial effluent to prove its application in real wastewater treatment. Moreover, the material shows superior adsorption capacity than contemporary phytosorbents. To conclude, a zero-cost adsorbent using green chili stalk has been demonstrated for wastewater treatment.

Synthesis, crystal structure, thermal stability and biological study of bis{(2-methoxy-6-[(E)-(propylimino)methyl]phenolato}nickel(II) complex

A Schiff base complex of nickel, bis{(2-methoxy-6-[(E)-(propylimino)methyl]phenolato}nickel(II) was synthesised by condensing bis(2-hydroxy-3-methoxybenzaldehyde) nickel (II) and n-propylamine in methanolic medium. Single crystal X-ray diffraction analysis of the complex revealed it to possess planar geometry with a monoclinic crystal system. The non-isothermal TG/DTA runs on this complex in a high purity (99.99 %) nitrogen environment at atmospheric pressure confirmed the absence of any coordinated water. A sharp endotherm in its DTA shows a melting temperature range of 168–171 °C. It is thermally stable up to 243 °C and decomposes in two steps, yielding NiO and carbon as residue. In addition to the methoxy group (-OCH3), infrared analysis (IR) confirmed the presence of the characteristic azomethine group (-CN-) which is also responsible for the biological action. It was further analysed by elemental analyser (C, H, N), 1H and 13C NMR as well as mass spectrometry. It showed considerable antibacterial activity towards Escherichia coli and Staphylococcus aureus when the concentration exceeds 200 μg/ml. The antifungal study shows significant inhibition with the antifungal drug imidazole as a positive control (PC). Small values of MIC, MBC/MIC indicate a lesser quantity of complex is required to inhibit the growth of micro-organisms.

Kinetics on the valorization of hexoses with Sn-USY catalysts in methanolic media: glycosidation vs retroaldol cleavage

The catalytic performance of potassium-exchanged Sn-containing USY zeolite ([K]Sn-USY) for the transformation of hexoses into methyl lactate in methanol has been tackled. This work explores the effects of temperature and...

Spectrophotometric Determination of Atorvastatin Based on Charge Transfer Reaction with Quinalizarin

An easy and economical spectrophotometric method has been developed for the determination of atorvastatin from tablet formulation. This method is based on the formation of a blue-colored charge transfer complex of Atorvastatin with quinalizarin in methanol medium. The blue colored complex gives maximum absorbance at 573 nm. In order to develop the quantitative analysis method of atorvastatin, several parameters such as the type of solvent, the effect of reagent concentration, and the reaction time and temperature on absorbance of complex were investigated. It was determined that the optimum Quinz solution (0.5x10-³ M) was 3mL and the optimum temperature of the reaction was room temperature. Beer’s law range of proposed method is found 10-100 µg.mL-1. LOD and LOQ of the proposed method were found as 1.49 µg.mL-1 and 4.98 µg.mL-1, respectively. As a result, this proposed method can be used in the quantitative analysis of atorvastatin in tablet formulations

Unravelling the Metal Sensing Activity of a Biologically Relevant Fluorescent Crown Ether: A Unified Experimental and Theoretical Study.

1,4-dihydropyridines (DHPs) are biologically active. 1,4-DHP analogs with appropriate substituents also show characteristic fluorescence activity. Here, for the first time, we report a simple and easy synthesis of a novel fluorescent 1,4- DHP derivative of dibenzo[18]-crown-6 (2), which showed promising sensing ability towards physiologically important metal ions. The covalent linking of 1,4-DHP analog with dibenzo[18]-crown-6 instigates its fluorescence activity in (2) and makes it biologically relevant. (2) shows a noteworthy enhancement of fluorescence intensity toward Fe3+ and Ba2+ in methanol medium. DFT studies revealed that metal binding by the crown ether-O atoms leads to structural rigidity, enhancing the fluorescence intensity. Interestingly, (2) shows utility in the quantitative detection of Fe3+ ions in the biological (human blood serum) and food samples.

Some features of trichlorobiphenyls photolysis

The photolytic decomposition of the Trikhlorbifenil mixture, 2,4,5- and 2,4,6-trichlorobiphenyls under an influence of ultraviolet radiation in presence of tungsten oxide as a catalyst in a methanol medium was studied. A higher rate of photolysis of individual congeners of polychlorbiphenyls was established compared to the congeners of the Trikhlorbifenil mixture. The influence of structural features of polychlorarenes on a depth of photodecomposition and a routes of formation of photodestruction products was considered.

New Pd(II) complexes containing hydrazinyl oxazolyl coumarin derivatives: synthesis, spectral characterization and anti-cancer studies

Abstract New palladium(II) complexes containing coumarin derivatives such as (E)-3(2-(2-(1-(2-oxo-2H-chromen-3-yl)ethylidene)hydrazinyl)oxazol-4-yl)-2H-chromen-2-one (HL 1 ), (E)-7-hydroxy-3(2-(2-(1-(2-oxo-2H-chromen-3-yl)ethylidene)hydrazinyl)oxazol-4-yl)-2H-chromen-2-one (HL 2 ) were successfully designed and synthesized from the reaction of K2[PdCl4] with ligands HL 1&2 with in Methanol medium. The ligands and complexes were characterized by various analytical and spectral techniques such as FT-IR, UV–Vis, 1H NMR and 13C NMR spectral techniques. From the spectral data we confirmed that the ligands neutrally coordinated with Pd(II) ion via their lactone oxygen, azomethine nitrogen and oxazolyl ring nitrogen atoms. The electrolytic nature of the complexes was confirmed by using conductivity experiments. Further anticancer activity of the compounds has examined with HeLa (human cervical cancer) cells along with the cisplatin as positive control and the obtained results revealed that the complexes possess significant anticancer activity and non-toxic towards HUVEC (human umbilical vein endothelial) cells.