European Journal of Chemistry

Garden cress seeds were analyzed for proximate composition and mineral content. The protein isolate (PI) was evaluated for chemical composition, mineral content, amino acid composition, biological values and some functional properties. The seed oil was evaluated for fatty acid profile; tocopherols and some of physicochemical properties were studied. Seeds were found to contain 29.11% oil and 25.12% protein. Phosphorus, magnesium and calcium constituted the major minerals of the seeds. The protein efficiency ratio (PER) of PI was 2.37. PI was found to possess relatively high values of water and fat absorption capacity, emulsification capacity and foam capacity. The fatty acid profile showed that linolenic acid (41.17%) and oleic acid (26.42%) were the major unsaturated fatty acids, whereas palmitic acid was the major saturated acid. Total tocopherol content of garden cress oil was 150.46 mg/100 g oil. The physicochemical characteristics of oil and biodiesel meet the norm specifications.

An efficient synthesis of 1,2,4-triazole derivatives, fused to five and six membered rings from 4-amino-5-[(quinolin-8-yloxy)methyl]-4H-1,2,4-triazole-3-thiole (2) was described. The structural formula of all derivatives was confirmed and characterized by elemental analysis and spectral studies. Some of the synthesized compounds were also investigated for their antibacterial and antifungal activities and compared with standard drugs. Most of the tested compounds demonstrated potent to weak antimicrobial activities.

Several 2-azetidinones 2a-e and 4-thiazolidinones 3a-e have been synthesized from halo-substituted Schiff bases using conventional as well as microwave technique. The newly synthesized compounds were established on the basis of spectroscopic technique. Further, all compounds screened for antimicrobial activity against Bacillus subtilis, Escherichia coli, Aspergillus niger and Aspergillus flavus. Most of the titled compounds show potent activity.

A new enamino ester, (E)-ethyl 3-(dipropylamino)acrylate, was prepared and used for synthesis of various pyrazole derivatives, 4a-k and 5a-d. Other new enaminone, (E)-ethyl 3-(3-(dimethylamino)acryloyl)-1-(4-nitrophenyl)-1H-pyrazole-4-carboxylate (8), was also prepared from compound 4a and utilized as precursor for synthesis of different functionalized 3,4'-bis-pyrazolyl ketones 9a-c, 10a-c. The site selectivity in hydrazinolysis of the latter was studied. The structures of the products namely pyrazolo[3,4-d]pyridazine derivatives 11(13) were confirmed by spectral and elemental analyses and by alternate unambiguous synthesis.

Alumina-supported cobalt vanadate multitransition-metal catalyst was prepared by impregnation method. The catalyst was characterized using X-ray diffraction, Fourier transform infrared spectroscopy, Brunauer-Emmett-Teller, X-ray fluorescence and Transmission electron microscopy. The cobalt/vanadium catalyst was employed for Fischer-Tropsch process in an autoclave reactor. The evaluation of this catalyst occurred at different temperature (423-623 K), over a pressure range of 10-50 bars with the Syngas H₂/CO ratio varying from 2 to 6. The catalyst gave a high and selective conversion of syngas into methane. The degree of syngas conversion increased with increasing temperature and pressure. The adaptive Neuro-Fuzzy inference system (ANFIS) model has been applied for the training of the fuzzy system and the test set was applied to evaluate the performance of the system including moving average error (MAE), mean square error (MSE), root mean square error (RMSE) and mean absolute percentage error (MAPE). The results exposed that the predicted values from the model were in good agreement with the experimental data.

Single crystals of the bis-tetrapropylammonium hexachlorodicuprate(II), [N(C₃H₇)₄]₂Cu₂Cl₆, were grown by slow evaporation solution technique at room temperature. The compound was characterized by Raman, IR and single crystal X-ray diffraction studies. Crystal data for C₁₂H₂₈Cl₃CuN (M = 356.24 g/mol): triclinic, space group P-1 (no. 2), a = 9.3851(2) Å, b = 9.3844(2) Å, c = 11.8837(3) Å, α = 106.3330(11)°, β = 100.0280(12)°, γ = 113.2830(12)°, V = 872.95(3) Å³, Z = 2, T = 293(2) K, μ(MoK_α) = 1.693 mm^-1, D_calc = 1.355 g/mm³, 8056 reflections measured (6.64 ≤ 2Θ ≤ 62.02), 5526 unique (R_int = 0.0303) which were used in all calculations. The final R₁ was 0.0427 (>2σ(I)) and wR₂ was 0.1312 (all data). The atomic arrangement can be described by alternating organic and inorganic layers parallel to the (101) plan, made up of tetrapropylammonium groups and Cu₂Cl₆ dimers, respectively. In crystal structure, the inorganic layers, built up by Cu₂Cl₆ dimers, are connected to the organic ones through hydrogen bonding C-H…Cl and Van der Waals interaction in order to build cation-anion-cation cohesion. These interactions cause to the formation of a three-dimensional supramolecular architecture.

Quinazolines and pyrimidines are most important class of compounds and have received much attention from both synthetic and medicinal chemists, because of the diverse range of their pharmacological properties. Owing to their versatile chemotherapeutic importance, a number of quinazolin-2,4-dione derivatives were synthesized using appropriate synthetic routes and characterized by IR, ¹H NMR, MS, and elemental analysis.

Novel miniaturized polyvinyl chloride membrane sensors in all-solid state graphite and platinum wire supports were developed, electrochemically evaluated and used for the assay of naftidrofuryl oxalate. The naftidrofuryl oxalate sensors were based on the formation of an ion-association complex between the drug cation and tetrakis-(4-chlorophenyl)borateanionic exchanger as electroactive material and sulfocalix-8-arene as ionophore dispersed in a polyvinyl chloride matrix. Linear responses of 10^-2-10^-6 M and 10^-2-10^-5 M with cationic slopes of 56.9 mV and 54.1 mV over the pH range 2-5 were obtained by using the naftidrofuryl oxalate-coated graphite (Sensor 1) and platinum wire (Sensor 2) membrane sensors, respectively. The utility of 4-sulfocalix-8-arene as ionophore had a significant influence on increasing the membrane sensitivity and selectivity. The methods were also used to determine the intact drug in the presence of it’s degradate in Praxilene^® tablets, plasma and cerebrospinal fluid with good recovery. Sensor 1 was used to study the kinetics of naftidrofuryl oxalate alkaline degradation that was found to follow a pseudo first-order reaction. The activation energy could be estimated from the Arrhenius plot to be 12.572 Kcal/mol.

An environmentally benign, simple and efficient protocol for the synthesis of 2H-indazolo[2,1-b] phthalazine-triones by condensation of phthalhydrazide, aromatic aldehydes and dimedone under solvent-free ultrasound assisted conditions employing a safe, readily available iodine as catalyst has been described. This process is a valuable addition as it devoids the use of any solvent and takes place in short duration of time giving good yield of the products.

An efficient synthesis of the biologically active novel systems derived from the reaction of 4-methyl-2-oxo-2H-chromene-3-carbonitrile (1) with sodium hydroxide and/or DMF-DMA and cyclocondensation reactions of 4-[(E)-2-(dimethylamino)ethenyl]-2-oxo-2H-chromene-3-carbonitrile (5) with nitrogen nucleophilic reagents afforded the corresponding 4-iminochromeno[3,4-c]pyridine derivatives (6-14). The structures of the prepared compounds have been proved by elemental analysis, IR, ¹H  and ¹³C NMR and mass spectra. Significant antitumor activities in planta were observed for some of the prepared compounds.

A series of new curcumin analogues were obtained by Claisen-Schmidt condensation of substituted benzaldehydes with cyclohexanone derivatives using the ratio of 1:2 of ketone to aldehyde in dilute ethanolic solution under base catalyzed (NaOH) conditions at room temperature in good yields. The structures of the synthesized compounds were confirmed by data of IR, ¹H NMR, and ¹³C NMR spectra.

The synthesis of new triazine-core polyhydroxylated and multi-N-donor compounds are being reported. The reaction of 2,4,6-tris(4-n-butylaminophenyl)triazine (1) with cyanuric chloride provided star-shaped fragment (2) with six reactive chloro-substituents. Upon treatment of this fragment with bis(2-hydroxyethyl)amine (3a) and bis(2-pyridylmethyl)amine (3b), functionalized polyhydroxylated (4a) and multi-N-donor compounds (4b) were obtained in high yields through nucleophilic aromatic substitution. These functionalized compounds are expected to have unique applications in supramolecular self-assembly and material chemistry.

In this study, we report the synthesis of some new Schiff base compounds (1-5) from the reaction of amoxicillin with some aromatic aldehydes in classical Schiff base method. These derivatives were characterized by melting point, elemental analysis, FT-IR and ¹H NMR data. All the synthesized compounds were evaluated in vitro for their antibacterial activities against two Gram positive (Staphylococcus aureus, Streptococcus faecalis) and two Gram negative (Escherichia coli, Pseudomonas aeruginosa) microorganisms in different concentrations (10^-1, 10^-3, 10^-5 and 10^-7 M) by agar diffusion disk method. The results showed that some of these derivatives have good antibacterial activities compared to biological activity of parent drug.

The sulfonamide derivative, 4-((3-formyl-4-hydroxyphenyl)diazenyl)-N-(4-methyloxazol-2-yl) benzenesulfonamide (FDMB), was synthesized and characterized. Additionally, its Cu(II), Co(II), Ni(II), Mn(II) and Fe(III) complexes were prepared and their structures were investigated by elemental analysis, thermal analysis and (IR, electronic and EPR) spectroscopy. The mode of binding indicates that the ligand binds to the metal ion through carbonyl oxygen and OH phenolic with displacement of its proton. The Co(II) complex was applied for the hydrolysis of nerve agent-like compound, bis-(p-nitrophenyl) phosphate (BNPP). The results showed a significant rate enhancement of 2.5 million fold with respect to the auto-hydrolysis of BNPP under the same conditions.

A direct and fast voltammetric method of determination of 2,8-dihydroxyadenine (2,8-DHA), with a novel nanostructured carbon fiber sensor (CFS), is revealed in this work. To achieve high sensitivity required in biological determinations, before the determination of 2,8-DHA, carbon fiber sensors were activated by electrochemical pretreatment method. The electrochemical activation process generates a nanostructured carbon fiber surface, which is stable. The high stability of the active surface, and the high reproducibility of the activation process, leads to reproducible and sensitive fast scan voltammetric (FSV) determinations of 2,8-DHA. The 2,8-DHA sensitivity was determined in 31 mM phosphate buffer and Hank’s Balanced Salt solution (HBSS) : phosphate buffer (1:5) pH = 7.4, with different scan rates of 250, 500 and 1000 V/s. The potential window in the determinations was from -1.0 to 1.5 V (vs. SCE). A high sensitivity of the new method of 2,8-DHA determinations by FSV at 500 V/s was found to be 0.40±0.01 nA µM^-1 (r² = 0.998) from the calibration plot of 2,8-DHA, with a linear dynamic range from 1-20 µM, and a limit of detection of 1 µM under physiological conditions.

An efficient synthesis of (2,4-dioxo-1,4-dihydro-2H-quinazolin-3-yl)-acetic acid hydrazide (3) has been achieved and described. The obtained hydrazide (3) was used in building of some interesting heterocycles such as, triazole, oxadiazole, pyrazole, phthalazine, and indol-2-one rings at position 3. The structures of the obtained compounds were confirmed by IR, ¹H NMR, ¹³C NMR, MS spectral and elemental analysis.

Topical microbicides such as Nonoxynol-9 (N9) and KY jelly have been used as vaginal microbicides in clinical trials as anti-HIV-1 products. The objective of this study was to determine if the use of these microbicides may cause production of proinflammatory cytokines in vitro. Such cytokines include, tumor necrosis factor-α (TNF-α), interlukin-1β (IL-1β), interlukin-6 (IL-6), and Interlukin-8 (IL-8). Cellular viability was determined for the peripheral blood mononuclear cells (PBMCs) and Macrophages by culturing them for 24 hours in the presence of serial dilutions of product or placebo. Product and placebo dilutions that gave culture viabilities of ≥ 60% compared to control cultures were considered to be nontoxic. The non-toxic dilutions were 1:100 for KY jelly in both PBMCs and Macrophages. Whereas, the non-toxic dilutions were 1:1000 for N9 in both PBMCs and Macrophages. The values of IL1β, TNF-α, were 0.1 < 2.0 pg/mL for both PBMCs and macrophages. The levels of IL-8 ranged between 9-13 pg/mL and 12-16 pg/mL for PBMCs and macrophages, respectively. The levels of IL-6 were 0.11 g/mL and 0.019 pg/mL for PBMCs and macrophages, respectively. The results were not statistically significant in difference for IL-1β, IL-6, and IL-8 (p > 0.001) when N9 was compared to KY jelly. However, the results were significant when comparing N9 to KY jelly for TNF-α (p < 0.001) production. The two microbicides tested in their non-toxic formulation in the two models of PBMCs and macrophages showed relatively low levels of IL-1b, TNF-α and IL-6. This indicated safety and low toxicity of these microbicide in terms of cytokines release. On the other hand, IL-8 has shown relatively higher levels in all microbicide tested in their non-toxic formulation.

A series of 2-pyrazolines (3a-d) were obtained by reaction 1,3-dipolar cycloadditions of α,β-unsaturated cyclohexanone derivatives (2a-c) with hydrazine hydrate and 4-nitrophenylhydrazine in the presence of acetic acid and ethanol as solvents. The structures of the synthesized compounds were confirmed by spectroscopic methods; IR, ¹H and ¹³C NMR.

The reaction between 2-mercapto-3H-chromeno[4,3-d]pyrimidine-4,5-dione (1) or its 2-methylthio derivative (7) with hydrazonoyl halides (2) in dioxane under ultrasound irradiation in the presence of chitosan yielded chromeno[4,3-d][1,2,4]triazolo[4,3-a]pyrimidine derivatives (5a-r). On the other hand, the reaction of compound 1 with the appropriate active chloromethylene compounds (9b, h and m) followed by coupling the products with benzenediazonium chloride afforded the azo coupling products which converted in situ to compound 5. The reaction mechanism was proposed and the structure of the newly synthesized compounds were established on the basis of spectral data (Mass, IR, ¹H and ¹³C NMR) and elemental analyses.