Classical chemical sciences
The oxidation of some vicinal and non-vicinal diols and two of their monoethers by [bis(trifluoroacetoxy)iodo]benzene (TFAIB) in aqueous acetic acid solution has been studied. The oxidation of vicinal diols leads to glycol-bond fission. The non-vicinal diols behave like monohydric alcohols and leads to the formation of hydroxy carbonyl compounds. The reaction is first order in TFAIB and a Michaelis- Menten kinetics was obtained with respect to the reductant. The reaction showed a first order dependence on hydrogen-ions. The oxidation of [1,1,2,2-2H4]ethandiol exhibited the absence of a kinetic isotope effect. Suitable mechanisms have been proposed.
Keywords: diols; hypervalent iodine; oxidation; kinetics; mechanism
Trichloroacetic acid, CCl3COOH, efficiently catalyzed the reaction of an aromatic aldehydes and 4-hydroxycoumarin in aqueous media under mild conditions to afford the corresponding α,α-benzylidene bis(4-hydroxycoumarin) derivatives in high yields. Ceric sulfate, (Ce(SO4)2.4H2O), has also been used as another solid catalyst for this reaction.
Keywords: 4-hydroxycoumarin, biscoumarin, trichloroacetic acid, ceric sulfate
Using density functional theory (DFT) at the OPBE/TZP level, the calculation of the geometric parameters of the molecular structures of M(II) (5656)macrotetracyclic complexes with a tetradentate macrocyclic ligand with (NNNN)-coordination of donor centers, resulting from “self-assembly” process in M(II)– dithiooxamide– propandiol-1,3 ternary systems, where M= Mn, Fe, Co, Ni, Cu, Zn was performed. The calculation of the molecular structure of this ligand itself was also carried out. The values of the bond lengths, bond and torsion angles in the resulting complexes and macrocyclic ligand indicated above, are presented. The values of the standard enthalpy, entropy and Gibbs free energy of formation of these compounds were also calculated.
Keywords: self-assembly; metalmacrocyclic chelate; 3d-element; dithiooxamide; propandiol-1,3; DFT OPBE/TZVP method; molecular structure
A series of binuclear acyclic polydentate complexes of Mn(II), Ni(II), Cu(II) and Cd(II) ions with a ligand derived from the condensation of dehydroacetic acid and diethylenetriamine (3,3'-[iminobis(ethane-2,1-diylnitrilo-(1E)-eth-1-yl-1-ylidene)]bis(4-hydroxy-6-methyl-2Hpyran- 2-one)]), [Mn2LCl2(H2O4)] and [M2LCl2], M=Ni, Cd and Cu(II), have been prepared and characterized by1H and 13C NMR, FT-IR and UV-Visible spectroscopy and micro-elemental analysis, as well as with the measurement of the magnetic moments of solid complexes and molar conductivity in DMSO solution. The new acyclic poly dentate ligand 3,3'-[iminobis(ethane-2,1-diylnitrilo-(1E)-eth-1-yl-1- ylidene)]bis(4-hydroxy-6-methyl-2H-pyran-2-one)] are identified on the basis of (CHN) elemental analysis, 1H, 13C NMR, as well as FTIR and UV-Visible spectroscopy. The antimicrobial activity of the free ligand and its Mn(II), Ni(II), Cu(II) and Cd(II) complexes were tested against Staphylococcus aureus and Escherichia coli and fungicidal activity against Aspergillus Niger and Candida albicans. The minimum inhibitory concentration (MIC) method revealed that all metal complexes showed enhanced activity toward the selected micro-organisms compared with the free ligand H2L and Amoxicillin. The octahedral geometry is proposed for Mn(II) complex, square planar for Ni(II) and Cu(II) complexes and tetrahedral symmetry is suggested for Cd(II) complex.
Keywords: binuclear complexes, dehydroacetic acid, biological activity; 3,3'-[iminobis(ethane-2,1-diylnitrilo-(1E)-eth-1-yl-1-ylidene)]- bis(4-hydroxy-6-methyl-2H-pyran-2-one)]
A novel water soluble cage sulfonamides was prepared and their neurotropic effects were evaluated. In vivo tests showed high level of analgesic and tranquilizing activity of trans-N-(bicyclo[2.2.1]hept-5-en-endo-2-ylmethyl)-4-hydroxytetrahydrothiophene-3-sulfonamide- 1,1-dioxide, greater than well known sodium metamizole used as the internal standard. Stereochemical structure of the title compounds was confirmed using the NOE and 2D NMR experiments.
Keywords: sulfonamides; sulfolane; norbornene; adamantane; neurotropic activity; NOE experiments
In this study, the interaction of hesperidin with -CD, HP--CD, -CD sulfate was investigated by thin layer chromatography. The chromatographic conditions included: Kieselgel G25 stationary phase, mobile phase of butanol: acetic acid: water (4:1:5) and increasing concentrations of the three cyclodextrins. Visualization was performed by examination in UV light and by exposure to iodine vapors. Also, the thermodynamic parameters were calculated: the Gibbs free energy change (G0 tr), free energy change (ΔG0), enthalpy change (ΔH0) and entropy change (ΔS0). The results show that the best inclusion capacity is obtained for HP--CD, the inclusion process is favored by increasing the concentration of cyclodextrin, and by increasing the temperature.
Keywords: hesperidin, cyclodextrin, thin layer chromatography, thermodynamics
The crystal structure of dimethylformamide solvated 3,3,6,6-tetramethyl-9-(3-chlorophenyl)-3,4,6,7,9,10-hexahydroacridine-1,8-dione (C26H33ClN2O3) crystallizes in the triclinic space group P-1 with unit cell parameters: a=9.0814(4), b=11.5650(5), c=12.1354(5) Ǻ, =91.806(3)º, β=96.450(3)º, = 104.565(4)º and Z=2. The crystal structure was solved by direct methods and refined by full-matrix leastsquares procedures to a final R-value of 0.056 for 2691 observed reflections. The central ring of the acridinedione system adopts a boat conformation and the two outer rings adopt sofa conformations. The solvent moiety (dimethylformamide) is involved in the existence of intra and intermolecular C-H...O interactions.
Keywords: Acridinediones; Crystal structure; Direct methods; Dimer; N-H…O and C-H...O intra and intermolecular interactions
A new polymorph (II) of 2,5-dibenzylidenecyclopentanone (DBCP) has been obtained by slow evaporation of ethanol solvent at room temperature. Interestingly, two conformational isomers of the title compound with slight difference in their bond lengths, torsion angles and dihedral angles were found within the same crystal lattice of polymorph (II). The crystal structure of polymorph (II) showed monoclinic P21 space group with a = 6.0983 (2) Å, b = 14.9200 (7) Å, c = 15.0740 (6) Å, V= 1368.69 Å3, Z = 2 as compared to orthorhombic C2221 space group with a = 11.803 (2) Å, b = 5.698 (4) Å, c = 20.872 (2) Å, V= 1403.6 Å3, Z = 4 for previously reported polymorph (I) crystallized in CHC13/MeOH solvent. The concomitant origin of polymorphism and conformational isomerism was credited to C-H…O, π-π and C-H…π interactions resulting in intriguing supramolecular sheet-like multilayered molecular packing of polymorph (II). The results of the complementary electronic structure calculations, performed by DFT/B3LYP method using 6-31G* basis set were found in good agreement with the experimental results.
Keywords: polymorph; conformers; molecular packing; quantum chemical calculations; DFT/B3LYP; 2,5-dibenzylidenecyclopentanone
A 2,6-diacetylpyridine based novel acyclic tridentate compartmental ligand (E)-N-(1-(6-((E)-1-(thiazol-5-ylimino)ethyl)pyridin-2- yl)ethylidene)thiazol-2-amine was prepared by condensation of 2,6-diacetylpyridine and two equivalent of 2-thiazolamine in ethanol. The reaction of metal chlorides (Mn(II), Co(II), Ni(II), Cu(II), Zn(II)) and VOSO4.5H2O with the new ligand in methanol results the formation of deep colored metal complexes with the formula [MLCl]Cl (M=Mn, Ni, and Zn), [MLCl2(H2O)], M=Co, Cu(II), and [VOL(SO4)], respectively. The free ligand and its metal complexes were characterized by elemental analyses, conductivity measurements, magnetic susceptibility data, IR, UV-Vis and NMR spectral data. The physical measurements and FTIR spectral data showed that most of the complexes contain tetrahedrally coordinated central ion(II) except the square-pyramidal vanadyl complex and octahedral geometry for Co(II) and Cu(II) complexes.
Keywords: Schiff base of 2,6-diacetylpyridine and 2-thiazolamine; metal complexes of acyclic ligands
Materials and environmental chemistry
In this study, the adsorption behavior of amitrole on acid activated clay (AC) was investigated using a spectrophotometric method to obtain information on the pesticide removal. The adsorption of amitrole from aqueous solutions by AC has been performed using a batchadsorption technique. The effect of various experimental parameters, such as initial concentration of pesticide, contact time, temperature and pH on the adsorption process, were investigated. Original pH at the beginning was 5. It was observed that the adsorption percentage of amitrole on AC remained practically constant with increasing temperature and contact time of around 3 h was sufficient to reach the equilibrium for all temperature. Temkin and Harkins-Jura adsorption models were applied to describe the equilibrium isotherms and the isotherm constants were calculated. It was found that the data were fitted Temkin adsorption model better than Harkins-Jura adsorption model. The present study showed that the asit activated clay was abundant snd low-cost. Clay can be used as sorbent for the removal of amitrole from aqueous solutions.
Keywords: Adsorption; amitrole; pesticide; acid activated clay; Temkin isotherm; Harkins-Jura isotherm
Four common species of fungi isolated A. niger, Rizopous, Cladpsporium and Curvularia lunata from archaeological site were subjected to laboratory experiment involving in vitro control of the fungal species using plant extracts. Aqueous leaves extract at 10 %, 20 %, 30 % and 40 % with the control (basal medium) concentrations tested on potato dextrose agar (PDA) for activity against mycelium growth were determined at 26±1 0C with three replicated plates. Fungal growth values recorded were generally low compared with the control (without extract petri plate). Inhibitory action of the extract on fungal growth increased with increases in concentration of extract. A study was carried out to evaluate the antifungal properties of Ocimum Sanctum Linn. Aqueous extract on common fungal species, isolated from Bhand Deol temple at Arang of Chhattisgarh state using the well in PDA media. The in vitro studies have been performed by using leaf aqueous extract of Ocimum Sanctum Linn. (Tulsi plant). Extract showed antifungal activity. Different concentration viz. 10 %, 20 %, 30 % and 40 % of solution prepared for the study. It was found that the plant extract at 40 % concentration were effective in reducing the mycelial growth of A. niger, Rizopous, Cladpsporium sp. whereas 30 % of plant extract effective for Curvularia lunata. Concentrations of extract which inhibit 75 % and above having known as effective in this study. Plant extracts readily available and affordable and environmentally friendly in the control of fungal disease.
Keywords: Mycelial growth; fungal species; Ocimum sanctum plant extract; antifungal activity; concentration and culture media
Short half life of propranolol hydrochloride (PPN), an antihypertensive drug is a prime requirement to develop a formulation which could sustain the release of PPN in the human body and also eliminate daily multiple dosage of propranolol. In this study organoclay Pluronic F68 modified montmorillonite (Mt) has been explored as a sustained release carrier for oral delivery of PPN. The developed organoclay PF68-Mt was compared for adsorption capacity of PPN with pristine Mt. A detailed and systematic study to evaluate the effect of pH, time and initial PPN concentration on drug loading capacity of organoclay PF68-Mt and pristine Mt has been evaluated. The synthesized PF68- Mt-PPN composites were characterized by XRD, FTIR, TGA techniques. XRD studies suggested the intercalation of PPN within the pristine Mt and organoclay PF68 - Mt. In vitro drug release profile of PPN from organoclay PF68-Mt composites is compared with that of pristine Mt and the pure PPN, in simulated gastric and intestinal fluids. The release profile of loaded PPN in organoclay PF68-Mt shows pH dependent release in simulated gastrointestinal fluid. The release behaviour of PPN from PF68-Mt-PPN composites was appeared to be in more sustained manner than prisine Mt and pure PPN over a period of 24 hours. This study suggests that the modification of Mt with a non ionic tri block co polymer Pluronic F68 provides better controlled on the release of PPN as compared to pristine Mt and pure drug. The obtained PF68-Mt-PPN composites with high drug loading capacity and sustained drug release characteristics supposed to be a better oral drug delivery system, for a highly hydrophilic low molecular weight antihypertensive drug PPN. The PF68-Mt-PPN composites developed have the potential to minimize the drug dosing frequency and hence improving the patient compliance. Thus, proposing a new promising formulation for oral sustained release drug delivery.
Keywords: Montmorillonite; Pluronic F68; organoclay; propranolol hydrochloride; adsorption; sustained release drug delivery
A simple method for the extraction and preconcentration of pesticides such as imidacloprid, flusilazole and atrazine from soil and water using dispersive liquid-liquid microextraction (DLLME) was described. The process was optimized by suitable selection of dispersive and extraction solvent. The sample was extracted by methanol (dispersive solvent) containing chloroform (extraction solvent) (3:7, v/v). Important factors such as the volume of extraction solvent, equilibration time, pH, and ionic strength were studied. pH and ionic strength found to have, significant influence for recovery and enrichment of solute. Extraction recovery value was found to be 98, 81 and 92 % respectively from water sample. The corresponding enrichment factor was found to be 742.01, 613.28 and 696.57 for imidacloprid, flusilazole and atrazine, respectively. The process was applied for extraction and recovery of the pesticides from soil and water system.
Keywords: Dispersive liquid-liquid microextraction; soil; water; pesticides; UV-Vis spectrophotometry
Biochemistry, molecular biology and biotechnology
A series of fifty-four commercial aldehydes have been synthesized and evaluated for their activity against peripheral blood mononuclear cells (PBMC) and four human cancer cell lines, exhibiting potent citotoxicity (IC50 ranging from 0.36 to 4.75 μg mL-1). The structureactivity relationship (SAR) analysis indicated that the number, the positions and the type of substituents attached into the aromatic and heteroaromatic ring are critical for the biological activity. The aldehydes 24, 26, 48 and 49 displayed a potent citotoxicity activity compared to the reference drug doxorubicin being, therefore, this discovery important for the rational design of new compounds against cancer.
Keywords: cytotoxicity, substituted aldehydes, drugs, SAR, glioblastoma, ovary, colon
The present work deals with the multivariate data analysis to elucidate the hypertension risk factors in children, which may contribute in some extent to their prospective medical treatment. Results of laboratory tests together with the data obtained from medical documentation were used to indicate as well as to predict the hypertension diagnosis in children. The best diagnostic classification outputs were obtained using artificial neural networks, the K-th nearest neighbour technique, general and linear discriminant analysis. In contrast to the assessment of single laboratory test results, a combination of several tests enables more comprehensive information that can help the physician in diagnosis. This work exemplifies a possible approach to computer-aided medical diagnosis.
Keywords: hypertension, prediction, classification, multivariate data analysis
Diabetes (type-2) is a chronic disorder affecting millions people all over the world. The disease is associated with long-term dysfunction, damage, and failure of various organs thus, affects almost every physiological system of the body. The chronic insulin resistance, progressive decline in β-cell function or increased rate of cell death results decreased insulin production and finally leads the disease. The sulfonylurea is known to regulate blood glucose homeostasis but have a characteristic profile of side effects. Some medicinal plant have showed hypoglycemic activities but the exact mechanism of action of these drugs at cellular level is yet not known and thus no better formulation of indigenous medicine could be developed till date for the treatment of type-2 diabetes. Therefore, the present study has been done to investigate the effect of the indigenous drugs, in-silico on the diabetic receptor, with a view to observe their effect on β-cell which could be helpful for the development of better formulation for the treatment of diabetes. Now days most of the drugs used in the treatment of type-2 diabetes either target the sulfonylurea receptor stimulating insulin release. Targeting of sulfonylurea may provide an important help for the development of drugs against type-2 diabetes. However, absence of tertiary structure of sulfonylurea limits the possibilities of structure based drug designing. In the present work we have explore the 3D structure of sulfonylurea receptor using homology approach. Based on the active sites we have screened the essential compound of Indigenous plants as a inhibitor as well as plant protein against modelled protein using iGEMDock 2.1 and Hex6.0 Cuda softwares. The Lead compound of plant as well as plant protein molecule would be scaled out on the basis of binding efficiency, starting from higher to lower and given the preference compare with the other one.
Keywords: diabetes mellitus type II; SUR1 receptor; medicinal plant; essential compound; docking; modeling
It was established that at increasing concentration of inhibitors (or activators) in the enzyme-substrate system the vector lengths of enzyme inhibition (and activation) retain a permanent tendency to increase, while the constants of enzyme inhibition (and activation) either remain unchangeable or change in any direction by studying the dependence of a course of change of vector length (li) and constants of enzyme inhibition (Ki) Examples are given of using the Ki constants and the vector lengths for the characterization of the strength of enzyme binding to inhibitor and the intensity of enzyme inhibition, respectively.
Keywords: Intensity of enzyme inhibition and activation; vector lengths
The polyphenolic compounds of several plant products are not known, nor are the biotic and abiotic factors that influence their evaluation. Thus we have very few data about the effects of growing factors in case of root vegetables – for example soil type, light intensity, growing method (on open field, under glass, in soil or without soil cultivation). Our experiment were aimed to prove the effects of genotypes and growing method (direction of rows) on the enrichment of polyphenol, flavonoid and vitamin C content. In the experiments it was established that varieties reacted differently on to the incidence of light originated from the direction of rows. Polyphenol, flavonoid and dry material content of Prágai óriás were higher at North-South row directions, which originated from the favourable light luminous influence without fail. Variety Neon produced better results in nutritional values of leaves at South West row directions. The opposite was found for the polyphenol, flavonoid and dry matter contents of tubers. In this direction the sunshine from South warmed up the bed in which the tubers were developing. This factor was favourable for their production. The results of our experiments showed differences between the genotypes regarding their sensitivity, that is, the intensity of light that differed in the rows of different direction influenced the formation of secondary metabolites. Results proved that celery leaves contain more bioactive compounds (total polyphenols, flavonoids, vitamin C) than tubers. The difference in polyphenol content was threefold and six fold in flavonoid content. Vitamin C content in the tubers was 30 percent of the amount that was measured in leaves at very similar dry material content. Our data document the nutritional importance of celery leaves and emphasize the selection of the growing method to the needs of varieties to produce good quality vegetables for our foods.
Keywords: celery, bioactive compounds, leaves, tuber, polyphenols, flavonoids, vitamin C, growing method, row direction
Industrial and engineering chemistry
Textile effluent containing unused dye when released in surroundings pollutes water bodies. It requires processing before disposal. Iron ore reject created during mining creates environmental pollution but contains minerals of technological importance. It has ~30-50 % iron in the form of γ-Fe2O3, α-Fe2O3 and Fe3O4 is wasted if thrown in fields, so can be used to degrade organic dyes. Mineralization of methylene blue, MB a model dye is carried out using photocatalyst either iron ore reject, synthesized ZnO or ZnO1-xNx and the results are compared. ZnO is synthesised from oxalate and nitrogen doped ZnO from hydrazinated oxalate precursors. FTIR study of zinc complexes indicates formation of precursors and XRD of decomposed complexes reveal formation of zinc oxide with wurtzite structure. The presence of nitrogen in ZnO1- xNx is confirmed by chemical estimation and XPS studies. SEM reveals the particle size of ZnO1-xNx ~69 nm and ZnO ~0.5-1μm. ZnO1-xNx absorbs in the visible region and ZnO in UV region. Band gap energy calculated using Diffuse reflectance Spectrum is 2.48 eV for the former, 3.19eV for the later and 2.38 eV for ore reject. Mineralizing property of ore reject, ZnO and ZnO1-xNx are compared by electrons spray ionisation mass spectrometry study (ESI-MS) of degradation products, COD measurement and CO2, NO3 - and SO4 -2 estimation. Reusability study, kinetic study of degradation of MB dye using photocatalysts and ESI-MS study of degraded products of MB reveal better efficacy of iron ore rejects amongst three. Thus efficiency of iron ore reject > ZnO1-xNx. > ZnO as photocatalyst.
Keywords: dye degradation; zinc oxide; N-doped ZnO; iron ore reject; methylene blue