Classical chemical sciences
The self-association in the formation of copper tetrasulfophthalocyanine complex and 1,4-diazabicyclo[2.2.2.]octane (DABCO) in aqueous solution are reported. Formation of phthalocyanine π-π dimers and a CuPc-DABCO complex could be confirmed, however, formation of sandwich-type dimers could not be detected.
Keywords: water-soluble phthalocyanine, solution, complex formation, DABCO, spectroscopy
The methanolysis of N-acetoxy-N-n-propyloxy-N’,N’-dimethylurea in the presence of strong acids at room temperatures or in the boiling methanol yields N,N-dimethoxy-N’,N’-dimethylurea as final product. Primarily the nucleophilic substitution acetoxy group at nitrogen on methoxy group arises. At second stage the transesterification of N,N-dialkoxyamino group of formed N-methoxy-N-n-propyloxy-N’,N’- dimethylurea take place.
Keywords: nucleophilic substitution at nitrogen; N-acyloxy-N-alkoxyureas; N,N-dialkoxyureas; methanolysis
The kinetics of oxidation of L-ascorbic acid in absence and presence of silver(I) as catalyst has been studied in aqueous acid medium. The stoichiometry corresponds to the reaction as represented by eqn: S2O8 2- + C6H8O6 → 2SO4 2- + C6H6O6 + 2H+. The order with respect to ascorbic acid is unity in uncatalyzed reaction where as it is zero order in silver (I) catalyzed reaction. The reaction mechanism has been suggested in both the conditions delineating the role of sulfate radical ion.
Keywords: sulfate free radicals; ascorbic acid; peroxodisulfate; radical kinetics; acid aqueous medium
N-Anilinoacetohydrazobenzoylacetone (H2L) and their manganese(II), cobalt(II), nickel(II), copper(II) and zinc(II) complexes have been synthesized and characterized by IR, electronic spectra, molar conductivities, thermal analyses and magnetic susceptibilities. Binuclear complexes with molar ratios of M:L=2:1 are formed. IR spectra show that the ligand (H2L) coordinates to the metal ions in a tetradentate manner with O2N2 donor sites in Mn(II), Co(II), Ni(II) and Zn(II) complexes while in the Cu(II) complexes the ligand coordinates as bidentate via N and O donor atoms. The electronic absorption spectra and magnetic susceptibility measurements show that all the complexes have octahedral structure. The copper(II) complexes shows higher antibacterial activity towards G+ bacteria (Bacillus subtilis ) than the ligand and other complexes while Mn(II) complex shows higher antifungal activity than the free ligand.
Keywords: Schiff base; synthesis; IR; thermal analyses; biological activity
The starting material, 5-amino-3,4-diphenylthieno[2,3-c]pyridazine-6-carbonitrile was subjected to subsequent reactions with aromatic and heteroaromatic aldehydes, benzylchloride, cyclohexanone, phenyl isothiocyanate, hydroxylamine hydrochloride and hydrazine hydrate to afford new polycyclic compounds. The new synthesized compounds were confirmed by their infrared, mass spectrum, 1H-NMR, and elemental analyses, and further screened for antimicrobial activity.
Keywords: Thienopyridazines; pyrrolothienopyridazines; pyrimidothienopyridazines, pyrazolothienopyridazines; pyridazinothienoquinolines; synthesis; antimicrobial activity
The reaction of L-ascorbic acid with the dichloroacetic acid in the presence of potassium hydroxide gave new product 3,4,6,7-O,O,O,Otetrakis( carboxy(chloro)methyl)-L-ascorbic acid (H4L), which was isolated and characterized by 1H,13C-NMR, elemental analysis (CHN), thermogravimetric analysis (TGA), UV-visible and Fourier Transform infrared (FTIR) methods. The complexes of the ligand (H4L) with metal ions, M+2= (Cu, Co, Ni, Cd and Hg) were synthesized and characterized by FTIR, UV-Visible, molar conductance, atomic absorption, magnetic susceptibility, thermogravimetric analysis (TGA) and molar ratio methods. The analysis showed the evidence of binding of the metal ions with (H4L) through the bidendate carboxylato group manner resulting in six-coordinated metal ion. The TLC for (H4L) and complexes showed one spot for each indicating the purity of these compounds. * Corresponding Authors E-Mail: Salahmohammadiraq@gmail.com [a] Department of Chemistry, College of Education for Pure Science, Ibn Al-Haitham, University of Baghdad Introduction L-Ascorbic acid (vitamin C) is an important molecule in both chemistry and biology, and its complexes with metals are of particular interest in both of these areas.1-3 This vitamin is present in various foods, particularly of plant origin, that are several orders of magnitude higher than those of other vitamins.4 Structurally, ascorbic acid (H2A) is a sugar acid, a -lactone and an ene-diol. As a weak dibasic acid (pKa1 = 4.25 and pKa2 = 11.79), the monoanion (HA) forms at pH 4–5 with deprotonation of O(3)–H and the dianion (A) forms at pH 11–12 with deprotonation of the O(2)–H.5 The mono-anionic form is more stable due to the delocalization of the negative charge between the oxygen atoms at the 1- and 3-positions.6 Musa et al.7-9 synthesized derivatives of L-ascorbic acid such as 5,6-O-isopropylidene- 2,3-(2-X,1-carboxyl)deoxy-L-ascorbic acid, where X = H, Cl, 1,2-dihydroxyethyl-1-(2-mercaptophenyl)-5-(2-mercaptophenyl)- 2,5-dihydro-1H-pyrrol-3,4-diol. In the
Keywords: synthesis, 3,4,6,7-O,O,O,O-tetrakis(carboxy(chloro)methyl)-L-ascorbic acid, metal complexes; analysis
The dissolution of fullerene C60 in oleum (fuming sulphuric acid 20 % free SO3) was followed simultaneously with ESR (Electron Spin Resonance) and NIR (Near Infrared Spectroscopy). It is shown that the intensity of the ESR signal associated to the formation of C60 radical cation (C60 +•) follows the same kinetics as the NIR absoption band at about 938 nm. Thus, the band at about 938 nm represents the optical counterpart of the ESR signal of C60 +•. After the formation of C60 +•, the evolution of the ESR spectrum and its optical counterpart in the NIR suggest the formation of other fullerene oxidation products as well. These products were recovered from the oleum solution and analyzed with FTIR and found to be fullerol (hydroxylated derivative of fullerene). The work-up of the oleum solution led to the desulfonation of the substrate. The ESR signal of C60 +• in oleum was followed for two weeks. Even after so long time, the ESR signal appeared strong and clear although under slow decay. Thus, the oxidation species of C60 +• (polycations, dimers and oligomers of C60, sultonated and sulfated derivatives) are persistent radicals in oleum.
Keywords: electron spin resonance, radical cation, fullerene C60, oleum, near infrared spectroscopy, kinetics
A template synthesis of copper(II) chelate coordination compound with 2,8-dithio-3,5,7-triazanonandithioamide-1,9 ligand has been achieved under soft conditions at room temperature. Reaction of Cu2[Fe(CN)6] biopolymer-polypeptide matrix with aqueous-alkaline solutions containing dithiooxamide, formaldehyde and ammonia yielded the aforesaid chelate. It has been noted that the chelate is formed only under the given conditions and not in solution or solid phase. The molecular structure of the complex has been calculated using DFT B3LYP technique.
Keywords: self-assembly, metalheterocycle, macrotricyclic ligand, molecular structure, DFT calculation
In the present work, we describe a low-cost, unreported and simple procedure for biosynthesis of zinc oxide nanoparticles (ZnO NPs) using Bacillus subtilis as eco-friendly reducing and capping agent. The synthesized ZnO NPs were characterized by UV-Vis spectroscopy, FTIR, XRD, SEM, TEM, PL and TGA techniques. The biosynthesis methods were carried out for its intrinsic advantages, as it is simple, costeffective, environment-friendly and can be easily scaled up for large scale synthesis. The prepared nano-particles were used as catalyst for the fast and efficient synthesis of steroidal thiophenes. The one pot three-component mixture of steroidal ketones (1-3), malononitrile/ethyl cyanoacetate and elemental sulfur were converted into the corresponding steroidal thiophenes (4-9) in moderate to high yields with excellent selectivity.
Keywords: ZnO nanoparticles; Bacillus subtilis; steroidal thiophenes
The determination of trace amount of sulfide based on the addition reaction of sulfide with malachite green at pH= 7.5 and 25 ºC has been investigated in micellar media. Surfactants studied include non-ionic surfactant, Trition-x-100, anionic surfactant, sodium dodecyl sulfate (SDS), cationic surfactant, cetyltrimethylammonium bromide (CTAB) and cetylpyridinium chloride (CPC). The reaction is followed spectrophotometrically by measuring the decrease in absorbance of the indicator at max= 630 nm by the fixed time method. The reaction in the presence of Trition-x-100 is faster than in the absence of surfactant in medium. No significant change was observed with SDS, CTAB and CPC. Under the optimum experimental conditions decreases in the absorbance of malachite green is proportional to the concentration of sulfide in the range 25-1750 ng ml-1 with a fixed time method at the first 5, 15 and 25 seconds from initiation of the reaction. The detection limit and quantification limit of the proposed kinetic method were 0.166, 0.207and 0.281 μg ml-1(t=5, 15 and 25 s )and 0. 555, 0.692and 0.959 μg ml-1(t=5, 15and 25) respectively. To confirm the usefulness of the proposed method, sulfide was determined in river, spring, fish farm, and tap water wastewater samples without any purification or using masking reagents.
Keywords: Kinetic spectrophotometry; sulfide determination; malachite green; micelle
Materials and environmental chemistry
The sorption of mercury(II) from aqueous medium on a chelating resin Chelex 100 has been studied in batch mode. Since the extraction kinetic was obtained, with a mixture of 0.1 g of resin and 5 mL of mercury(II) at 200.59 mg L-1 of initial concentration, extraction equilibrium was reached within 180 min of mixing. The influence of some parameters such as initial mercury(II) ion concentration, initial pH of aqueous solution, ion strength and the amounts of resin have been studied at fixed temperature (20±1 °C). The optimum pH value level for quantitative sorption was 5.7. The best performance obtained was 98.0 % of extraction yield equivalent to 14.19 mg g-1 of resin. The pseudo-first- order equation, pseudo-second-order equation, the intra-particle diffusion model and Boyd’s diffusivity model were used to describe the kinetics data and rate constants were evaluated. The Freundlich and Langmuir adsorption models were applied to describe the equilibrium isotherms.
Keywords: mercury(II); Chelex 100; adsorption; ion exchange; optimization
As the search for renewable resources for removal of pollutants from the environment grows, the use of biological sorbents has received a great deal of attention. Biological sorbents such as human hair have been explored due to their ready availability, renewability and effectiveness. This manuscript reports a study of the dynamics of copper(II) ions uptake by human hair using conductivity and pH measurements. The adsorption of these ions demonstrated a logarithmic behaviour, resembling first order kinetics, although the analysis showed a deviation from the first order kinetics. The maximum uptake of 288 μg g-1was reached after about 120 minutes of static equilibration using a solution of 100 ppm. Interestingly the adsorption seems to be intermediate between a simple chemisorption and ion exchange as evidenced by a deviation from the linearity when conductivity was plotted against the pH measurements. However there was a significant correlation (R2 = 0.9926) between conductivity and pH in the case of a classical ion exchange resin – Amberlite CG 50.
Keywords: Human hair; Amberlite; copper ions; extraction; conductivity; ion exchange
Chemical and biological aspects of life
The results of this study demonstrated that Nigella sativa seeds oil is beneficial for attenuating complications of obesity and possibly preventing it because of its essential polyunsaturated fatty acids; linoleic and linolenic acids and other nutrients such as liposoluble vitamins like tocopherols and also minerals, essential amino acids, some polyphenols, terpenoids and quinones, particularly thymoquinone that have shown potential medicinal properties in traditional medicine.
Keywords: Metabolic and antioxidant effect; Nigella sativa oil, obesity
In these studies Saccharomyces cerevisiae NRRL Y-566 was used to produce ethanol from a concentrated glucose (250-300 g L-1) solution. When fermentation media were supplemented with CaCO3 and CaCl2, ethanol concentrations, yield, and productivities were improved significantly. In control batch fermentation, the culture was able to produce 20.87 g L-1 ethanol with a productivity of 0.25 g L-1 h-1 when using 100 g L-1 sugar solution in feed. When supplemented with a solution of 0.40 g L-1 CaCl2, ethanol concentration, yield, and productivity were improved to 90.0 g L-1, 0.48, and 1.25 g L-1 h-1 (500 % increase), respectively. The effect of CaCO3 supplementation was not as pronounced as that of CaCl2. Using these parameters, the process economics for production of ethanol was performed and it was projected that supplementation with 0.40 gL-1 CaCl2 would result in the production of ethanol for $0.91 kg-1. It was also projected that improving productivity to 37.5 g L-1 h-1 using cell recycle and supplementation with CaCl2 would result in the production of ethanol for $0.70 kg-1 employing S. cerevisiae NRRL Y-566. Using Z. mobilis in membrane cell recycle reactors and application of CaCl2 can result in achieving high productivities (500-600 g L-1 h-1) and reduction in ethanol production price to $0.59 kg-1.
Keywords: Ethanol; calcium carbonate and calcium chloride additives; productivity; ethanol yield; cell recycle, process economics
It was shown that pulmonary arterial valve stenosis moderate changes in hemodynamic parameters of patients lead to a change in the structure of cardiomyocyte and blood vessel. Strengthening of plastic processes, lead to hypertrophy and proliferation of endothelial cells as well as to increase of blood vessels' lumen diameter. Quite interesting is the fact that new capillaries formed mostly by intuscusseptive angiogenesis. In the same way new arteries are formed. Hemodynamic changes of heart right compartment accompanied by structural vascular and cardiomyocyte remodeling. In the later stages of disease vascular remodeling goes by the mechanism of intussusceptions forming vessels of different caliber.
Keywords: Transmission electron microscopy, light optical microscopy, right heart atria, angiogenesis, arteriogenesis, pulmonary arterial valve stenosis
We study the metabolism of purine nucleosides and purine bases in suspension-cultured cells of the model plant Arabidopsis thaliana. [8- 14C]Adenosine, [8-14C]guanosine, [8-14C]inosine, [8-14C]xanthosine, [8-14C]adenine, [8-14C]guanine, [8-14C]hypoxanthine and [8- 14C]xanthine were administered to cells in the cell division phase, and the uptake and metabolic fate of these compounds were monitored for 4 h. The rates of uptake of most purines were within the range 60-70 nmol gFW-1. Xanthine and xanthosine were taken up more slowly. The rate of uptake was ordered as hypoxanthine > adenine > inosine > guanosine > guanine > adenosine > xanthosine > xanthine. A large amount of radioactivity from [8-14C]adenosine, [8-14C]guanosine, [8-14C]adenine and [8-14C]guanine, and a limited amount from [8- 14C]inosine and [8-14C]hypoxanthine, was incorporated into nucleotides and RNA. The so-called purine salvage pathways of adenosine, guanosine, adenine, guanine, inosine and hypoxanthine are therefore functional in A. thaliana. These tracer experiments also reveal that significant amounts of these compounds were converted to xanthine, and enter the catabolic pathway via allantoin. Neither xanthosine nor xanthine is used in the synthesis of nucleotides and RNA. These compounds are entirely catabolized via allantoin and allantoic acid. Deamination of adenine and guanine rings takes place at the stage of AMP deaminase and guanosine deaminase, respectively. The pattern of purine metabolism in A. thaliana is similar to that in other plants. Adenine salvage activity estimated from the metabolism of [8- 14C]adenine, the cellular concentration of ATP, and expression of the APT1 gene encoding adenine phosphoribosyltransferase all increased markedly at the lag phase of cell proliferation. These observations imply that the salvage pathway is important during the early stages of cell culture in A. thaliana.
Keywords: Purine nucleotides, Biosynthesis, Salvage, Catabolism, Arabidopsis thaliana
This study includes an isolation, partial purification and study of the kinetic properties of Eosinophil peroxidase (EPO) enzyme from hemolysate blood cells in induced atherosclerosis and normal mice, then comparison between them. Isolation of two protein peaks I and II were carried out using ion exchange chromatography (DEAE cellulose), specific activity for these two peaks I and II for EPO enzyme for normal and induced atherosclerosis were (0.018, 0.02) and (0.126, 0.031). unit mg -1 of protein respectively, peak I has a high specific activity for EPO enzyme which was isolated from induced atherosclerosis mice. The optimum condition of EPO for the peak I separated from hemolysate blood cells in induced atherosclerosis mice showed an optimum reaction incubation time at 21 minutes, pH of sodium acetate buffer 6, temperature at 30 °C, volume of enzyme 500 μL and the substrate concentration was about, 200 μM. When we used Line Weaver-Burk plot, the maximum velocity (Vmax) and Michale’s - Menten constant (Km) were found to be 0.045 unit ml-1 and 400 μM L-1 respectively, all cationic metal ions such as Mg+2, Na+, Ca+2, K+, Mn+2, Hg+2 (10 mM) shows a catalytic effect on the activity of EPO enzyme but maximum that for Hg+2 ions. Also at this study shows an inhibition effect of some isoflavone compounds such as genistein, daidzein, biochanin A and formononetin on the activity of this enzyme. The results indicate different relative inhibition in enzyme activity, for these compounds, according to Line Weaver- Burk plot genistein compound shows a competitive inhibition whereas daidzein, biochanin A and formononetin shows non competitive inhibition for EPO enzyme..
Keywords: Atherosclerosis, inhibitors, eosinophil peroxidase enzyme, isoflavone compounds
The phenomenon of plasmatic membrane (PM) thickness was seldom noted at investigation of cells in different organs. However just presence of such a phenomena was noted, but no valuation of its biological importance was given. In a basis of excitable and unexcitable cells plasmatic membrane thickness changes lays cell submembrane layer thickness alteration. Reversible and irreversible damages of its structures can be a key of cell dysfunction at pathology.
Keywords: Transmission electron microscopy, cardiomyocyte subsarcolemma thickness, hepatocytes subcytolemma thickness, inoculation by CCl4, pulmonary arterial valve stenosis
Industrial and engineering chemistry, biotechnology
In this research, we report biodiesel production and viscometric analysis from mustard oil and coconut oil, by subjecting the oil to a temperature of 65 oC through base catalyzed transesterification with the use of KOH as a catalyst. The biodiesel synthesized from mustard oil was blended with petroleum diesel in the following percentage by volume 20 %, 40 %, 50 %, 70 % and 80 % corresponding to B20, B40, B50, B70 and B80, respectively. The fatty acid methyl ester of mustard oil was mixed with that of coconut oil in the ratio of 80:20, 60:40 and 50:50 respectively. Viscometric analysis was carried out and the results obtained.
Keywords: biodiesel; mustard oil; coconut oil; fuel blends; viscosity; petroleum diesel
Compounds formed in the reaction of napthenic acid amides of Baku crude oil with some of the alkyl halogenides are found to be multifunctional corrosion inhibitors. The structural features of compounds were studies with FT-IR spectroscopy. The efficiency of these inhibitors have also been tested against sulphate reducing bacteria (SRB) at 30 oC for and for a period of 15 days time.
Keywords: corrosion; biodamage; naphthenic acids; inibitors; sulphate reducing bacteria