Classical chemical sciences
Microwave-induced an efficient, rapid and enviromentally begin condensation of substituted 2’-hydroxychalcones with hydrazine hydrate in 2-methoxyethanol afford 2-pyrazolines 2a-h in high 88-95 % yields. The structure of newly synthesized compounds established on the basis of spectroscopic technique and laboratory chemical test. Further these compounds were screened for antimicrobial activity against Bacillus subtilis, Staphylococcus aureus, Aspergillus flavus and Candida albicans. The most of the compounds shows good to better inhibitory activity.
Keywords: 2-Pyrazolines; 2-methoxyethanol; 2’-hydroxychalcones; microwave irradiation; antimicrobial activity
The present work describes of a combined bio- and chemosorption of permanganate by Prosopis cineraria leaf powder using batch process. The plant is locally available in arid region and called as Khejari. The permanganate removal capacity of PCLP have been studied at various parameters like concentration of Mn (VII) ion, adsorbent dosage, pH, contact time, shaking speed, etc. The Langmuir and Freundlich adsorption models have been applied to describe the isotherms and isotherm constant are given.
Keywords: Permanganate; Prosopis cineraria leaf powder; adsorption isotherms; biosorption; chemosorption
Complete thermodynamic analysis of the system Ti-O-C both under pressure and vacuum resulted the following reaction: TiO2 + 3С = TiС + 2СO. The basic results for all structures are presented in the form of diagrams (dependence of the contents of components on temperature range 1000-2300 K).
Keywords: thermodynamic analysis, carbothermal reduction, vacuum
The 4-oxo-N,2,6-triphenylpiperidine-3-carboxamides (1a-f) were synthesized using arylaldehydes, ammonium formate and acetoacetanilide, which in turn converted into 4,5,6,7-tetrahydro-4,6-diphenyl-2H-pyrazolo[4,3-c]pyridine-3-ols (2a-f) and 4,5,6,7- tetrahydro-2,4,6-triphenyl-2H-pyrazolo[4,3-c]pyridine-3-ols (3a-f), by condensing with hydrazine hydrate or phenylhydrazine, respectively.
Keywords: 4-oxo-N,2,6-triphenylpiperidine-3-carboxamides, 4,5,6,7-tetrahydro-4,6-diphenyl-2H-pyrazolo[4,3-c]pyridine-3-ols, 4,5,6,7-tetrahydro-2,4,6-triphenyl-2H-pyrazolo[4,3-c]pyridine-3-ols
The title compound, C7H7N3S, (2-hydrazinyl-1,3-benzothiophene) was prepared from the reaction of 2-amino-benzothiazole treated with hydrazine hydrate. It crystallizes in the monoclinic space group P21/n with unit cell parameters a = 10.839(5), b = 5.752(5), c = 12.961(5) Å, ß = 110.005(5)º, Z = 4. The crystal structure is stabilized by N-H…N [N2-H5...N3, N1-H12...N1] intermolecular interactions, N2- H5...N3 interaction is responsible for the formation of dimers corresponding to R2 2(8) graph-set motif and the dimers are further connected by N1-H12…N1 hydrogen bonding forming dimeric chains. Besides this, there is N1-H11… interaction which is responsible for the stabilization of the crystal structure. The packing diagram of the title compound represents the dimeric chains extending along the b-axis.
Keywords: 2-hydrazinyl-1,3-benzothiazole; single crystal XRD; inter-molecular interactions; hydrogen bonding
The crystal structure of the title organic-inorganic hybrid material, [(3-Ampy)2CdCl4].0.305H2O (3-Ampy=3-aminomethylpyridine), contains two crystallographically independent but chemically equivalent cadmium complexes with essentially the same geometry (rms deviation of all atoms: 0.152 Å). The metal centers have a 6-coordinated octahedral geometry and both Cd atoms exhibit exact crystallographic inversion symmetry. Crystal packing is stabilized by intermolecular N-H...Cl hydrogen bonds that connect individual zwitter-ionic complexes into a three dimensional lattice, which is further stabilized through stacking interactions between aromatic rings of neighboring complexes, with centroid to centroid distances of 3.4406(14) and 3.7022(13) Å and interplanar separations of 3.299(1) and 3.302(1) Å. Interstitial space is partially filled with water molecules which are connected to the network through O-H...Cl and C-H...O hydrogen bonds. The 13C and 15N CP-MAS NMR spectra are in agreement with the X-ray structure. Four resonance peaks for the C3 carbon atom are observed due to the different environments of the aromatic rings caused by the presence of 0.305 water molecule per unit cell. DFT calculations allow the attribution of the carbon and nitrogen peaks to the different atoms.
Keywords: cadmium(II) coordination compound ; MAS-NMR spectroscopy ; infrared spectroscopy; intermolecular N-H..Cl hydrogen bond
A new complex formation process was occurred in the Zn(II)–ethanedithioamide–ethanedial three-components system when a nanoreactor consist of zinc(II) hexacyanoferrate(II)-gelatin immobilized matrix was contacted with an aq. alkaline (pH~12) solutions containing ethanedithioamide and ethanedial. It has been shown that self-assembly (template synthesis) of supramolecular (555)macrotricyclic Zn(II) coordination compound with chelating ligand 2,7-dithio-3,6-diazaoctadien-3,5-dithioamide-1,8 occurs under these conditions. Besides, ethanedithioamide and ethanedial act as ligand synthons in this process.
Keywords: template synthesis; gelatin-immobilized matrix; zinc(II) ethanedithioamide; DFT method; 2,7-dithio-3,6-diazaoctadien-3,5-dithioamide-1,8; self-assembly
The simple protocol for the synthesis of barbituryl isodithiobiurets without any catalyst has been developed. The reactivity of alkyl or aryl isothiocyanates towards barbituryl isothiocarbamide has been studied. The different reactivity, insolubility and high stability are output of our novel synthesized barbituryl isodithiobiurets. The mild reaction conditions, easy product workup and excellent yields, are the major advantages of present protocol.
Keywords: Barbituryl isothiocarbamide; alkyl isothiocyanates; aryl isothiocyanates, barbituryl isodithiobiurets
Two simple, sensitive and accurate spectrophotometric methods for the determination of mesalamine are described. The methods are based on charge-transfer complex formation reactions of the drug with two π-electron acceptors, p-chloranil and p-fluoranil, in aqueous medium. The coloured complexes having maximum absorbance at 346 nm and 347 nm by using p-chloranil and p-fluoranil reagents respectively. Under the optimized experimental conditions, the calibration curves showed a linear relationship over the concentration ranges of 1–35 and 1-30 μg ml−1 with molar absorptivity values 4.60×103 and 5.67×103 L mol-1 cm-1. using above reagents respectively. The limits of detection and quantitation were found 0.376 and 1.25 μg ml−1 using p-chloranil, respectively, and 0.333 and 1.111 μg ml−1 using p-fluoranil, respectively. The complexes were found to be formed in ratio of 1:1 species in both methods, with stability constants of 6.9x104 and 5.1x105 L mol-1 for mesalamine complexes with p-chloranil and p-fluoranil respectively. The methods were applied successfully to the assay of mesalamine in pharmaceutical formulations and was agreed well with its certified value.
Keywords: spectrophotometry, mesalamine, aqueous solution, p-chloranil, p-fluoranil
A new series of tetradentate N2O2 acyclic complexes of type [MLCl2] (M: Zn(II), Cd(II), Hg(II); L: tetradentate acyclic ligand) and [ZrOL]Cl2 have been prepared on the basis of condensation of 2,6-diaminopyridine and 1,4-dihydroquinoxalin-2,3-dione by template method. The ligand coordinates through the two imine nitrogen atoms formed up on condensation of -NH2 of 2,6-diaminopyridine with - C=O group in 2-position of quinoxalin-2,3-dione, as well as the lactam form of metal complexes confirm the participation of oxygen atoms in coordination with the metal ions. However, the pyridine nitrogen atoms do not take part in coordination with the metal ions. These complexes have been characterized with the help of various spectral techniques 1H and 13C NMR, FT-IR, electronic spectra, elemental analyses, and measurements of molar conductance in DMF solutions. Furthermore the determination of chloride content in the metal complexes assists in the investigation the concluded structures. The octahedral geometry was proposed for Zn(II), Cd(II) and Hg(II) while, Zr(IV) complex structure was proposed to be square pyramidal. The new metal complexes were investigated for antibacterial and antifungal properties of gram-positive bacteria (Staphylococcus auerus), gram-negative bacteria (Escherichia. Coli) and fungi Aspergillus fumigates and Candida were used in this study to assess their antimicrobial properties. The results showed that this skeletal framework exhibit marked potency as antimicrobial agents.
Keywords: template synthesis; 2,6-diaminopyridne; 1,4-dihydroquinoxaline-2,3-dione; zinc(II); cadmium(II); mercury(II) and zirconyl complexes; Schiff base, quinoxalines, benzopyrazine, antimicrobial activity, N2O2 metal complexes
This paper briefly describes the current physical model of metallic structure and bonding. An alternative model is introduced. It shows that the new model, which calculated internuclear distances of Group 1 and Group 2 crystalline binary salts to a remarkable degree of accuracy, can be applied to calculate metallic radii (equal to half the internuclear distances) of Group 1 and Group 2 metals precisely. A simple expression previously used to calculate lattice energies using the soft-sphere radii concept is applied to calculate enthalpies of formation of Group 1 and Group 2 metal ions and results compare well with observed values. A few of the limitations of the current models are described and properties of metals which can be accounted for by the soft-sphere model are discussed. The work functions of Group 1 and Group 2 metals are shown to be inverse functions of the soft sphere ionic radii.
Keywords: metallic structure, metallic bonding, metallic radii, free electrons in metals, enthalpy of formation, work function
An efficient and eco-friendly method for synthesis of 2-arylbenzimidazoles has been developed simply by grinding intimate mixtures of ortho-phenylenediamine, aromatic aldehyde and TLC grade silica gel at room temperature for 30-50 minutes. This one pot synthesis involves aerial oxidation of an intermediate 2-arylbenzimidazoline formed by condensation of the reactants followed by cyclization.
Keywords: Eco-friendly synthesis; 2-arylbenzimidazoles; silica gel catalyst; solvent-free synthesis
Materials and environmental chemistry
This study is aimed to analyze the content of heterocyclic aromatic amine compounds along with heavy metals (Ni, Pb, Hg and Cd) in milkfish fried in used cooking oil. Chemical components were identified using gravity chromatography with Gel 60 as the stationary phase and purified by column Sephadex LH20, and checked by UV spectrometry, IR, and HPLC. The compound PhIP (2-amino-1-methyl-6- phenyilimidazo[4,5-b]pyridine) was found to be formed is thought to be caused by the influence of cooking oil. By atomic absorption spectrophotometer nickel (Ni) was found to have an average concentration of 1.6075 ± 0.2405 mg kg-1. The role of nickel compounds in milkfish genotoxicity is suspected as a trigger effect on PhIP compound.
Keywords: fried milk fish; reused frying oil; nickel; 2-amino-1-methyl-6-phenyilimidazo[4,5-b]pyridine (PhIP)
This study uses solid phase extraction method to measure trace amount of metal ions of Cd2+, Pb2+, Cu2+, Ni2+ and Zn2+ in aqueous samples by using herbal absorbent called soft husk of Pistachio. To do so, aqueous solution of these metal ions was passed through a column containing adsorbent. Meanwhile, existing metal ions in solution were adsorbed, and then preconcentrated via eluting by nitric acid. Finally, they were measured by Flame Atomic Absorption Spectrometry (FAAS). Effective parameters such as pH, amount of adsorbent, volume and concentration of eluent, velocity of solution and interfering ions were examined Calibration curve related to metal ions: lead, nickel, cadmium, copper and zinc in the range of 30-800, 10-400, 5-90, 10-350 and 5-90 μg L-1 was linear and the limits of detection for metal ions lead, nickel, cadmium, copper and zinc were respectively: 2.581, 0.988, 0.139, 0.527 and 1.385 μg L-1. The proposed method was applied to measure metal ions in real samples with acceptable accuracy.
Keywords: Preconcentration, Heavy metals, Pistachio husk, FAAS
Adsorption of malachite green (MG) using sugarcane bagasse (SB) and rice husk (RH) were studied by batch method. Factors influencing dye adsorption such as the initial dye concentration, sorbent dosage, exposure time, temperature effect and pH, were investigated. The Langmuir, Freundich-Temkin and Dubinin–Radushkevich (D-R) isotherms were used to fit the equilibrium data, and the results showed that the Freundlich and Langmuir model provided the best correlation of the experimental data for SB and RH, respectively. Adsorption kinetic data were tasted using pseudo-first-order, pseudo-second-order and intra particle diffusion models. It was observed that the pseudosecond- order kinetic equation could explain the biosorption kinetics of dye on both adsorbents and intra particle diffusion showed that dye adsorption was controlled by multi-adsorption stages with bagasse surface area. The results showed that both of them can be an economical sorbent for removal of dye from aqueous systems.
Keywords: malachite green; isotherm; kinetics; rice husk; sugarcane bagasse
Biochemistry, molecular biology and biotechnology
In this present study, it was intended to examine the effects of different surface active agents (Tween 80, oleic acid, linoleic acid, palmatic acid, stearic acid , sodium laurylsulfate, laurylmethylgluceth-10-hydroxypropyldiammonium chloride, dimethyldicatadecylammonium chloride, tetramethyl ammonium hydroxide, Centimonium chloride and Bromidox), antibiotics(Penicillin G, Erythromycin, Chloramphenicol , Streptomycin, Tetracycline-HCl and Gentamycin) and chelating agents (EDTA, NTA, DTPA, Catechol, Protocatechuate and Citrate) on L-methionine fermentation by a multiple analogue resistant mutant Corynebacterium glutamicum X300. All these agents showed stimulatory effects on the fermentation process.
Keywords: surface active agents; antibiotics; chelating agents; analogue resistant; mutant; Corynebacterium glutamicum X300; Lmethionine; fermentation
Cyathula prostrata is a herbal recipe used in traditional medicine for the treatment of chest troubles, dysentery, diarrhea, craw-craw, scabies, sexual disease, rheumatism, tumours and inflammatory conditions amongst many others. There is not yet any claim on the use of the plant as an antioxidant agent, hence the need for this study. The crude extract, fractions and isolates tested positive for the characteristic rapid TLC free-radical scavenging activity with β-carotene and DPPH reagents. The ethyl acetate fraction gave marginally similar antioxidant activity (IC50) as the crude extract at 0.76 μg mL-1 while the activity demonstrated by the butanol fraction was equally marginal at 0.77 μg mL-1. However, HOO-1 and HOO-2 gave moderate activity at 0.53 μg mL-1 and 0.56 μg mL-1 respectively which were comparably better than the antioxidant activity obtained with vitamin E and A at 0.60 μg mL-1 and 1.11 μg mL-1 respectively. Furthermore, vitamin C recorded an IC50 of 0.49 μg mL-1 which was comparatively better than the activity given by either HOO-1 or HOO-2. The antioxidant activities given by the extract, fractions, HOO-1 and HOO-2 were instructive as the phytochemical screening of the C. prostrata indicated the presence of terpenes, flavonoids and tannins which have been reported in previous studies to exhibit antioxidant activities. The results of the antioxidant assays have revealed a novel potential for the use of C. prostrata as an antioxidant agent. Hence, it is proposed that the mechanism of action of the antioxidant activity obtained especially with HOO-2 could have proceeded in the same way (a 2H stabilized resonance) as that of the antiscurbitic activity of vitamin C in literature.
Keywords: Free-radical; antioxidant; β-carotene; DPPH; Cyathula prostrata
A series of fifty one pyrazinyl derivatives have been synthesized and evaluated for their activity against four cancer cell lines, exhibiting good citotoxicity (IC50 ranging from 1.1 to 5.6 μg mL-1). The structure-activity relationship (SAR) analysis indicated that the hydroxyl group located in ortho position is critical for the biological activity of these compounds. The presence of hydroxyl groups on benzene ring plays an important role in the anticancer activity of this series, feature especially observed in disubstituted derivatives.
Keywords: antitumor activity, pyrazinamide, hydrazones, drugs
Stem cells are the powerful cells derived both from human and animal source. They have the ability to divide innumerably and differentiate into different cell types in the body. HeLa cells are the first immortal human cell lines grown in culture. These cell lines have proved beneficial in the development of polio vaccines and study of various viral cells. The present review aims to cover the studies done through nuclear extracts prepared from HeLa cells. Nuclear extracts from HeLa cells have been used to study the activation of ATM and ATR by double stranded DNA breaks, production of transcriptionally active extracts, analysis of RNA splicing in vitro using T7 RNA polymerasederived splicing substrate RNAs and purification and characterization of proteins. By using these nuclear extracts, the mutational study of proteins still needs to be done to know exact reason of many unknown diseases. Wide variations of pH in extract preparation should be tested to get variations in extract obtained and methods should be modified for desired polypeptide length and to work with extracts at nano scale.
Keywords: HeLa cells; nuclear extracts; immortal; cell lines; vaccines; polypeptide; RNA; DNA
Industrial and engineering chemistry
The inhibition efficiency of polyvinylalcohol (PVA) in controlling corrosion of aluminium in well water in the absence and presence of Zn2+ has been evaluated by weight loss method. The formulation consisting of 250 ppm of PVA and 25 ppm of Zn2+ offers 85 % inhibition efficiency. It is found that the inhibition efficiency of PVA increases by addition of Zn2+ ion. A synergistic effect exists between PVA and Zn2+. The mechanistic aspects of corrosion inhibition have been studied using polarization study. Also FTIR spectra reveal that the protective film consists of PVA - Zn2+ complex and Zn(OH)2. The scanning electron microscopy confirms the protection of aluminium surface by strong adsorption of PVA. A suitable mechanism for corrosion inhibition is proposed based on the results from the above studies.
Keywords: polyvinylalcohol; aluminium; weight-loss method; synergistic effect; protective film