Acetic Acid In Ethanol Research Articles

Multifaceted Anticancer Potential of Gnidia glauca (Fresen.) Gilg Leaf Alkaloids: Impact on Multiple Cellular Targets.

Gnidia glauca (Fresen.) Gilg has demonstrated significant anticancer potential through multiple mechanisms, including apoptosis induction, as shown by the TUNEL assay against MCF-7 cells, modulation of tubulin polymerization, preservation of mitochondrial function indicated by the JC-1 assay, and inhibition of DNA polymerase α and β activities. Rationale for the present study is to investigate the potential anticancer properties of G. glauca leaf alkaloid extract. Fresh and healthy G. glauca leaves were cleaned, shade-dried, and the powder was defatted, extracted with 10% acetic acid in ethanol, and subjected for alkaloid extraction. The partially purified G. glauca leaf alkaloid extract was evaluated for its effects on tubulin polymerization, DNA polymerase activity, mitochondrial membrane potential, and apoptosis studies using human breast cancer (MCF-7) cells by flow cytometry. The extract was found to affect microtubule assembly in a concentration-dependent manner (15.125-250 μg/mL), indicating presence of alkaloids that function as spindle poison agents. Leaf alkaloid extract of G. glauca was also found to affect the mitochondrial membrane potential with IC50 value 144.51 μg/mL, and inhibited DNA polymerase α and β activities dose dependently, thus potentially interfering with DNA replication and repair processes. Leaf alkaloid extract also showed the potential to induce DNA damage of 53.6%, albeit somewhat less than the standard drug camptothecin (64.94%) as confirmed by the TUNEL assay. Additionally, the GgLAE (IC50 144.51 μg/mL) showed significant inhibition of MCF-7 cells proliferation after 24 h, revealing phase arrests in sub G0/G1, S, and G2/M. These findings suggest that G. glauca leaf alkaloid extract contains alkaloids that possess anticancer properties with multiple targets, making the plant a natural source for a promising phytochemical drug candidates for further evaluation in pre-clinical and clinical studies. Further investigations are warranted to determine the efficacy, safety, identification and characterization of the alkaloids, and evaluate and determine their potential applications in cancer therapy.

Para-Substituted Thiosemicarbazones as Cholinesterase Inhibitors: Synthesis, In Vitro Biological Evaluation, and In Silico Study.

The current research reports the synthesis of 14 para-substituted thiosemicarbazone derivatives in good to excellent yields using standard procedures. Initially, 4-ethoxybenzaldehyde (1) and 4-nitrobenzaldehyde (2) were refluxed with thiosemicarbazide in the presence of acetic acid in ethanol for 4-5 h. Then, various substituted phenacyl bromides were treated with the desired thiosemicarbazones (3 and 4) in the presence of triethylamine in ethanol with constant stirring for 5-6 h. The resulting derivatives were confirmed through electron impact mass spectrometry and 1H NMR spectroscopy and evaluated for anticholinesterase inhibitory activity. Among the series, four compounds, 19, 17, 7, and 6, showed potent inhibitory activity against the acetylcholinesterase (AChE) enzyme, having IC50 values of 110.19 ± 2.32, 114.57 ± 0.15, 140.52 ± 0.11, and 160.04 ± 0.02 μM, respectively, compared with standard galantamine (IC50 = 104.5 ± 1.20 μM). Similarly, compounds 19 (IC50 = 145.11 ± 1.03 μM), 9 (IC50 = 147.20 ± 0.09 μM), 17 (IC50 = 150.36 ± 0.18 μM), and 6 (IC50 = 190.21 ± 0.13 μM) were the most excellent inhibitors of butyrylcholinesterase (BChE) when compared with the standard drug galantamine (IC50 = 156.8 ± 1.50 μM). In silico studies were accomplished on the produced derivatives in order to explain the binding interface of compounds with the active sites of AChE and BChE enzymes.

The synthesis of novel 2, 3‐disubstituted 1,6‐dihydropyrrolo[2,3‐g]indazole derivatives via one‐pot three component reactions

AbstractA concise and efficient synthetic approach was developed for the synthesis of functionalized 2,3‐disubstituted 1,6‐dihydropyrrolo[2,3‐g]indazole via a one‐pot, three‐component reaction of 1H‐indazol‐6‐amine, arylglyoxal monohydrates, and 4‐hydroxy‐2H‐chromen‐2‐one or 4‐hydroxyquinolin‐2(1H)‐one promoted by acetic acid in ethanol under reflux conditions. The attractive features of this protocol are operational simplicity, short reaction time, easy purification of products, and good to excellent yields.

Synthesis of Highly Functionalized Imidazopyridine: A Simple One-Pot Three-Component Synthesis of 6-Hydroxy-5 -(3-Phenylimidazo[1,2-a]Pyridin-2-yl)-2-Thioxo-2, 3-Dihydropyrimidin-4(1H)-Ones

In this research, synthesis of different imidazopyridine derivatives was performed using aryl glyoxals, thiobarbituric acid, and 2-aminopyridine in the presence of acetic acid in ethanol at 80 °C. Different aryl glyoxals can be used in this method. Finally, the desired products were separated by simple filtration in excellent yields. The salient features of this protocol are a simple operation, mild reaction conditions, simple work up, easy product isolation, and preparation of potentially bioactive compounds.

Determination of Chiral Impurity of Naproxen in Different Pharmaceutical Formulations Using Polysaccharide-Based Stationary Phases in Reversed-Phased Mode.

A novel, validated, reversed-phase (RP), chiral high performance liquid chromatography (HPLC) method was developed for the enantiopurity control analysis of naproxen, a frequently used non-steroidal anti-inflammatory agent using polysaccharide-type chiral stationary phase (CSP). In the screening phase of method development, seven columns were tested in polar organic (PO) mode using mobile phases consisting of 0.1% acetic acid in methanol, ethanol, 2-propanol, and acetonitrile. Enantiorecognition was observed only in five cases. The best enantioseparation was observed on a Lux Amylose-1 column with 0.1% (v/v) acetic acid in ethanol with a resolution (Rs) of 1.24. The enantiomer elution order was unfavorable, as the distomer eluted after the eutomer. When the ethanolic mobile phase was supplemented with water, enantiomer elution order reversal was observed, indicating a difference in the enantiorecognition mechanism upon switching from PO to RP mode. Furthermore, by changing ethanol to methanol, not only lower backpressure, but also higher resolution was obtained. Subsequent method optimization was performed using a face-centered central composite design (FCCD) to achieve higher chiral resolution in a shorter analysis time. Optimized parameters offering baseline separation were as follows: Lux Amylose-1 stationary phase, thermostated at 40 °C, and a mobile phase consisting of methanol:water:acetic acid 85:15:0.1 (v/v/v), delivered with 0.65 mL/min flow rate. Using these optimized parameters, a Rs = 3.21 ± 0.03 was achieved within seven minutes. The optimized method was validated according to the ICH guidelines and successfully applied for the analysis of different pharmaceutical preparations, such as film-coated tablets and gel, as well as fixed-dose combination tablets, containing both naproxen and esomeprazole.

Antibacterial and Antifungal Properties of Modified Chitosan Nonwovens.

Chitosan acquires bacteriostatic properties via protonation of its amino groups. However, much of the literature assumes that chitosan itself inhibits the growth of bacteria. This article presents a comparative study of chitosan nonwovens modified with various acids, including acetic, propionic, butyric, and valeric organic acids, as well as hydrochloric acid. The aim was to determine which acid salts influence the antibacterial and antifungal activity of chitosan-based materials. Two methods were used to modify (formation of ammonium salts) the chitosan nonwovens: First, acid vapors (gassing process) were used to find which salt of chitosan had the best antibacterial properties. Based on the results, the most effective acid was prepared in a solution in ethanol. The influence of the acid concentration in ethanol, the time of treatment of chitosan materials with acid solution, and the rinsing process of modified nonwovens on the antimicrobial activity of the modified materials was investigated. The modified materials were subjected to microbiological tests. Each of the modified materials was placed in bacterial inoculum. The cultures were tested on agar to observe their microbial activity. Toxicity to human red blood cells was also investigated. A reduction in the number of bacterial cells was observed for the S. aureus strain with chitosan salt modified with 10% acetic acid in ethanol. The antibacterial activity of the chitosan salts increased with the percentage of acid salts formed on the surface of the solid material (decreasing numbers of bacterial colonies or no growth). No reduction in growth was observed for the E. coli strain. The chitosan samples were either inactive or completely eliminated the bacterial cells. Antimicrobial activity was observed for chitosan salts with hydrochloric acid and acetic acid. Finally, 1H-NMR spectroscopy and FTIR spectroscopy were used to confirm the incorporation of the acid groups to the amino groups of chitosan.

Synthesis, Molecular Docking and Biological Evaluation of Napthyl N-Acyl Hydrazone Derivatives

A series of 2-(benzamido)-N′-((naphthalen-1-yl)methylene)-3-(substituted phenyl)acrylo hydrazides (4a-m, 5a-b) were synthesized by condensation of 2-(benzamido)-3-(substituted phenyl)acrylohydrazides with 1-naphthaldehyde in presence of few drops of acetic acid in ethanol. Structural elucidation of final compounds was confirmed by spectral data. Title compounds were evaluated for antioxidant and antibacterial activities and subjected to in silico studies and molecular docking studies with cyclooxygenase-II (COX-II, PDB I’d: 3LN1) and active compounds from docking studies were selected for in vivo evaluation of their antiinflammatory activity. Among the series, compound 4i showed good antioxidant activity; 5b showed good antibacterial activity. All the six derivatives with good docking scores were selected for in vivo evaluation of their antiinflammatory activity. Among the selected active compounds from docking studies, compound 4m showed good antiinflammatory activity which is comparable with that of standard drug diclofenac. In silico studies indicated that all the compounds followed Lipinski’s rule and exhibited good oral absorption and bioavailability.

Cadmium selenide and carbon nanodots modified magnetite nanospheres for the magnetic solid-phase extraction (MSPE) of malachite green prior to spectrophotometric determination

CdSe-carbon nanodots modified magnetic Fe3O4 nanospheres (CdSe-NDs@C-NDs@Fe3O4) were synthesized by a simple hydrothermal technique and characterized by Fourier transform-infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) with mapping, and energy dispersive X-ray spectroscopy (EDX). The prepared material was used as a magnetic solid phase microextraction (MSPE) adsorbent to determine malachite green (MG). Pasteurized cow’s milk was used as the carbon source to fabricate the carbon nanodots. The spectrophotometric determination of malachite green was performed at 625 nm. The parameters affecting the microextraction efficiency were optimized, including the pH (9.0), mass of adsorbent (5 mg), eluent type (0.1 M acetic acid in ethanol), eluent volume (0.75 mL), sample volume (10 mL), in addition to matrix studies. In order to evaluate the accuracy of the method, real samples were subjected to addition-recovery tests and the recovery values from 85% to 104% were obtained. The limits of detection (LOD) and quantitation (LOQ) of the developed method were 0.013 µg mL−1 and 0.042 µg mL−1, respectively.

Microwave-assisted Synthesis of Novel Pyrazole Derivatives and their Biological Evaluation as Anti-Bacterial Agents.

Microwave-assisted condensation of acetophenone 1 and aromatic aldehydes 2 gave chalcone analogs 3, which were cyclized to pyrazole derivatives 6a-f via the reaction with hydrazine hydrate and oxalic acid in the presence of the catalytic amount of acetic acid in ethanol. The structural features of the synthesized compounds were characterized by melting point, FT-IR, 1H, 13C NMR and elemental analysis. The antibacterial activities of the synthesized pyrazoles were evaluated against three gram-positive bacteria, such as Enterococcus durans, Staphylococcus aureus, Bacillus subtilis and two gram-negative bacteria such as Escherichia coli and Salmonella typhimurium. All the synthesized pyrazoles showed relatively high antibacterial activity against S. aureus strain, and none of them demonstrated antibacterial activity against E. coli.

Synthesis of some novel 1H-indole derivatives with antibacterial activity and antifungal activity

The present research works a series of new 1H-Indole derivatives were synthesized. The title compound was obtained by the reaction of indole with chloroacetylchloride in toluene afforded 2-chloro-1-(indoline-1-yl) ethanone which reacts with 1,4 diamine benzene in chloroform afforded 2-((4-aminophenyl)amino)-1-(1H-indol-1-yl)ethan-1-one, on further reaction with various acetophenone in presence of acetic acid in ethanol gave various final derivatives. After synthesis of compounds, the synthesized compounds were characterized by their IR, 1HNMR spectral data and elemental analysis. These derivatives were screened for their antimicrobial activity (Paper-disk-plate technique (disc diffusion method) and Tube-dilution technique (broth microdilution technique), antifungal activity of all synthesized compounds were evaluated against Aspergillus niger and Candida albicans (ATCC 10231) using Fluconazole as the standard drug using the paper plate method and antibacterial activity against both Gram-positive (Bacillus subtilis) and Gram-negative bacteria (Escherichia coli) using Ampicillin as standard medication at a concentration of 50g/ml, 100g/ml. The collected compounds were evaluated for antibacterial activity and antifungal activity. All compounds exhibit significant antimicrobial activity.

Towards a generic method for ion chromatography/mass spectrometry of low-molecular-weight amines in pharmaceutical drug discovery and development.

Low-molecular-weight amines are encountered in pharmaceutical analysis, e.g. as reactants in chemical syntheses, but are challenging to analyse using ultrahigh-performance liquid chromatography/mass spectrometry (UHPLC/MS) due to their high polarity causing poor retention. Ion chromatography/mass spectrometry (IC/MS) is an emerging technique for polar molecule analysis that offers better separation. A generic IC/MS method would overcome problems associated with using UHPLC/MS in drug discovery and development environments. Amine standards were analysed using IC/MS with gradient elution (variety of column temperatures evaluated). An electrospray ionisation (ESI) quadrupole mass spectrometer was operated in positive ion polarity in scanning mode. The make-up flow composition was evaluated by assessing the performance of a range of organic modifiers (acetonitrile, ethanol, methanol) and additives (acetic acid, formic acid, methanesulfonic acid). The ESI conditions were optimised to minimise adduct formation and promote generation of protonated molecules. The performance attributes were investigated and optimised for low-molecular-weight amine analysis. Organic solvents and acidic additives were evaluated as make-up flow components to promote ESI, with 0.05% acetic acid in ethanol optimal for producing protonated molecules. The hydrogen bonding capability of amines led to abundant protonated molecule-solvent complexes; optimisation of source conditions reduced these, with collision-induced dissociation voltage having a strong effect. The detection limit was ≤1.78 ng for the amines analysed, which is fit-for-purpose for an open-access chemistry environment. This study demonstrates the value of IC/MS for analysing low-molecular-weight amines. Good chromatographic separation of mixtures was possible without derivatisation. Ionisation efficiency was greatest using a make-up flow of 0.05% acetic acid in ethanol, and optimisation of ESI source conditions promoted protonated molecule generation for easy determination of molecular weight.

Synthesis and Characterization of Novel Schiff's Bases from Ethylenediamine Tetraacetic Acid Derivatives.

A novel Schiff's base have been synthesized by reaction between ethylenediaminetetraacetic acid (EDTA) derivatives with (2-methoxyaniline, 4-bromoaniline, 4-amino antipyrine) are successfully prepared to obtain six Schiff's base through the reaction of the aldehyde group with compounds containing the amine group as a catalyst glacial acetic acid in ethanol under reflux in good yield (78–92%), the prepared compounds were characterized by were synthesized and characterized by (FT-IR) and 1HNMR, 13C spectroscopy, elemental analysis. The aim of this study is to use cheap EDTA to synthesize Schiff bases, which are thought to have effective biologic and antibacterial properties.

Studying the cold sintering process of zinc ferrite as an incongruent dissolution system

AbstractIn this research, cold sintering process (CSP) was successfully applied for zinc ferrite. A Pechini‐type sol‐gel method was used to synthesize two types of powders, a single‐phase powder and a multiphase powder consisting of zinc ferrite, hematite, and zinc oxide. The powders were chemically treated in 12 M solution of acetic acid in ethanol. Our investigations indicated that zinc dissolves incongruently from zinc ferrite with respect to iron. Then, the chemically treated powders were mixed with 18‐21 weight percent (wt%) treatment solution to utilize for the CSP. Our studies indicated that the CSP of the chemically treated multiphase powder results in single‐phase zinc ferrite samples. Conversely, the CSP of the chemically treated single‐phase zinc ferrite powder led to samples having hematite as the secondary phase. The CSP at 350°C under 300 MPa uniaxial pressure for four hours and postannealing at 750°C for six hours resulted in samples with 93% relative density. Microstructure studies revealed that the samples under CSP were sintered with well‐defined grains and grain boundaries. This study is an introduction to develop the CSP for the sintering of technologically important transition metal ferrites.

Quinazolin-4(3H)-ones and 5,6-Dihydropyrimidin-4(3H)-ones from β-Aminoamides and Orthoesters

Quinazolin-4(3H)-ones have been prepared in one step from 2-aminobenzamides and orthoesters in the presence of acetic acid. Simple 2-aminobenzamides were easily converted to the heterocycles by refluxing in absolute ethanol with 1.5 equivalents of the orthoester and 2 equivalents of acetic acid for 12–24 h. Ring-substituted and hindered 2-aminobenzamides as well as cases incorporating an additional basic nitrogen required pressure tube conditions with 3 equivalents each of the orthoester and acetic acid in ethanol at 110 °C for 12–72 h. The reaction was tolerant towards functionality on the benzamide and a range of structures was accessible. Workup involved removal of the solvent under vacuum and either recrystallization from ethanol or trituration with ether-pentane. Several 5,6-dihydropyrimidin-4(3H)-ones were also prepared from 3-amino-2,2-dimethylpropionamide. All products were characterized by melting point, FT-IR, 1H-NMR, 13C-NMR, and HRMS.

Electrospinning of Photocatalytic Electrodes for Dye-sensitized Solar Cells

This work demonstrates a protocol to fabricate a fiber-based photoanode for dye-sensitized solar cells, consisting of a light-scattering layer made of electrospun titanium dioxide nanofibers (TiO2-NFs) on top of a blocking layer made of commercially available titanium dioxide nanoparticles (TiO2-NPs). This is achieved by first electrospinning a solution of titanium (IV) butoxide, polyvinylpyrrolidone (PVP), and glacial acetic acid in ethanol to obtain composite PVP/TiO2 nanofibers. These are then calcined at 500 °C to remove the PVP and to obtain pure anatase-phase titania nanofibers. This material is characterized using scanning electron microscopy (SEM) and powder X-ray diffraction (XRD). The photoanode is prepared by first creating a blocking layer through the deposition of a TiO2-NPs/terpineol slurry on a fluorine-doped tin oxide (FTO) glass slide using doctor blading techniques. A subsequent thermal treatment is performed at 500 °C. Then, the light-scattering layer is formed by depositing a TiO2-NFs/terpineol slurry on the same slide, using the same technique, and calcinating again at 500 °C. The performance of the photoanode is tested by fabricating a dye-sensitized solar cell and measuring its efficiency through J-V curves under a range of incident light densities, from 0.25-1 Sun.

Electrospinning of Photocatalytic Electrodes for Dye-sensitized Solar Cells.

This work demonstrates a protocol to fabricate a fiber-based photoanode for dye-sensitized solar cells, consisting of a light-scattering layer made of electrospun titanium dioxide nanofibers (TiO2-NFs) on top of a blocking layer made of commercially available titanium dioxide nanoparticles (TiO2-NPs). This is achieved by first electrospinning a solution of titanium (IV) butoxide, polyvinylpyrrolidone (PVP), and glacial acetic acid in ethanol to obtain composite PVP/TiO2 nanofibers. These are then calcined at 500 °C to remove the PVP and to obtain pure anatase-phase titania nanofibers. This material is characterized using scanning electron microscopy (SEM) and powder X-ray diffraction (XRD). The photoanode is prepared by first creating a blocking layer through the deposition of a TiO2-NPs/terpineol slurry on a fluorine-doped tin oxide (FTO) glass slide using doctor blading techniques. A subsequent thermal treatment is performed at 500 °C. Then, the light-scattering layer is formed by depositing a TiO2-NFs/terpineol slurry on the same slide, using the same technique, and calcinating again at 500 °C. The performance of the photoanode is tested by fabricating a dye-sensitized solar cell and measuring its efficiency through J-V curves under a range of incident light densities, from 0.25-1 Sun.

Dissociation of cerium(III) and neodymium(III) phthalocyanines

The kinetics of dissociation of phthalocyanine complexes with cerium(III) and neodymium(III) (X)LnPc (X = Cl−, Br−, AcO−) under the action of acetic acid in ethanol with isolation of the macrocyclic ligand depending on the temperature was studied. The kinetic equations with the numerical values of rate constants, activation parameters, and the stoichiometric mechanisms with the limiting simple reaction between the nonionized AcOH molecule and (phthalocyaninato)lanthanide(III) in the axially coordinated ((X)LnPc, cerium complexes) or axially ionized ([(AcOH)LnPc]+X−, neodymium complexes) state were derived by solving the direct and inverse problems. As shown by a comparative analysis of quantitative kinetic data, the state is determined by the electronic structure of the metal cation and the mutual effect of the axial and equatorial ligands in the first coordination sphere.

English

A new series of pyrazoline derivatives (4a-f) has been synthesized by ultrasonication methods and evaluated for its antibacterial and antifungal activity. The chalcones (3a-f) were transformed into respective pyrazoline derivatives by using hydrazine hydrate and few drops of glacial acetic acid in ethanol. All the synthesized compounds were confirmed by FTIR, 1HNMR and mass spectral data.

Synthesis and Antimicrobial Activity of New Schiff Base Compounds Containing 2-Hydroxy-4-pentadecylbenzaldehyde Moiety

Various novel Schiff base compounds have been synthesized by reaction of 2-hydroxy-4-pentadecylbenzaldehyde with substituted benzothiophene-2-carboxylic acid hydrazide and different substituted aromatic or heterocyclic amines in the presence of acetic acid in ethanol. The structures of all these compounds were confirmed by elemental analysis, IR, 1H-NMR, 13C-NMR, and mass spectral data and have been screened for antibacterial and antifungal activity.

Synthesis of a Novel Carbocyclic Analog of Bredinin

The natural nucleoside antibiotic, bredinin, exhibits antiviral and other biological activities. While various nucleosides related to bredinin have been synthesized, its carbocyclic analog has remained unknown. Synthesis of this heretofore unknown analog of bredinin is described. The key precursor, (3aS,4R,6R,6aR)-6-((methoxy-methoxy)methyl)-2,2-dimethyltetrahydro-3aH-cyclopenta[d][1,3]dioxol-4-amine (5), was prepared from the commercially available compound, (1R,4S)-2-azabicyclo[2.2.1] hept-5-en-3-one (4). Our initial approach used intermediate 6, derived in three transformations from 5, for the key photolytic step to produce the desired ring-opened precursor to the target compound. This photochemical transformation was unsuccessful. However, an appropriately protected and related precursor was synthesized from 5 through the following side-chain functional group transformations: elaboration of the amino group through malonyl ester formation, oximation at the central carbon, conversion of ester to amide and catalytic reduction of the oxime group. This precursor, on treatment with triethylorthoformate and catalytic acetic acid in ethanol, underwent cyclization to produce the desired 4-carbamoyl-imidazolium-5-olate ring. Deprotection of the latter product proceeded smoothly to give the carbocyclic analog of bredinin. This target molecule exhibits antiviral activity, albeit low, against a number of RNA viruses. Further biological evaluations are in progress.