bluuebunny/crossref_metadata_2025 huggingface dataset:
A Validated RP‐HPLC Method for the Estimation of Quetiapine in Bulk and Pharmaceutical Formulations
Authors: Suneetha D. , Lakshmana Rao A.
Published: March 2012

A new, simple, specific, sensitive, rapid, accurate and precise RP‐HPLC method was developed for the estimation of quetiapine in bulk and pharmaceutical formulations. Quetiapine was chromatographed on a reverse phase C18 Waters column (75x4.6 mm I.D., particle size 3.5 μm) in a mobile phase consisting of phosphate buffer (pH 3.0 adjusted with orthophosphoric acid) and acetonitrile in the ratio 40:60 v/v. The mobile phase was pumped at a flow rate of 0.8 mL/min with detection at 291 nm. The detector response was linear in the concentration of 20‐120 μg/mL. The limit of detection and limit of quantitation was found to be 0.2 and 0.75 μg/mL, respectively. The intra and inter day variation was found to be less than 1%. The mean recovery of the drug from the solution was 99%. The proposed method is simple, fast, accurate, precise and reproducible hence, it can be applied for routine quality control analysis of quetiapine in bulk and pharmaceutical formulations.
Preparation and Spectral Properties of Mixed‐Ligand Complexes of VO(IV), Ni(II), Zn(II), Pd(II), Cd(II) and Pb(II) with Dimethylglyoxime and N‐acetylglycine
Authors: Shaker Shayma A.
Published: March 2012

A number of mixed‐ligand complexes of the general formula [M(D)(G)] where D=dimethylglyoximato monoanion, G=N-acetylglycinato and M=VO(IV), Ni(II), Zn(II), Pd(II), Cd(II) and Pb(II) were prepared. Each complex was characterized by elemental analysis, determination of metal, infrared spectra, electronic spectra, (1H and 13C) NMR spectra, conductivity and magnetic moments. All these complexes were not soluble in some of the organic solvent but highly soluble in dimethylformamide. The conductivity data showed the non‐electrolytic nature of the complexes. The electronic spectra exhibited absorption bands in the visible region caused by the d‐d electronic transition such as VO(IV), Ni(II) and Pd(II). The IR and (1H, 13C) NMR spectra which have indicate that the dimethylglyoxime was coordinated with the metal ions through the N and O atoms of the oxime group and N‐acetylglycine was coordinated with metal ions through the N atom and terminal carboxyl oxygen atom.
Spectrophotometric Methods for the Assay of Fluvoxamine Using Chromogenic Reagents
Authors: Annapurna V. , Jyothi G. , Nagalakshmi V. , Sailaja B. B. V.
Published: March 2012

Simple, accurate and reproducible UV‐Visible spectrophotometric methods were established for the assay of FXA based on the oxidative coupling and condensation reactions. Condensation and coupling of the FXA with Ninhydrin‐Ascorbic acid is proposed in method A. Method B includes complexation of FXA with cobalt thiocyanate. The ligating property of FXA with sodium nitro prusside is incorporated in method C. The optical characteristics such as Beers law limits, molar absorptivity and Sandell’s sensitivity for the methods (A‐C) are given. Regression analysis using the method of least squares was made to evaluate the slope(b), intercept(a) and correlation coefficient (r) and standard error of estimation (Se) for each system. Determination of FXA in bulk form and in pharmaceutical formulations were also incorporated.
Micellization Studies on Binary Mixture of Methionine with Polyoxyethylene (10) Cetyl Ether (Brij‐56) and Polyoxyethylene (20) Cetyl Ether (Brij‐58)
Authors: Bhadane B. S. , Patil T. J.
Published: March 2012

The measurement of cloud point (CP) under the influence of additives provides an excellent tool for investigation of surfactant macromolecule interaction. The CP of pure surfactant polyoxyethylene (10) cetyl ether (Brij‐56) and polyoxyethylene (20) cetyl ether (Brij‐58) declined with increased [Bj‐56] and [Bj‐58]. The CP of mixed systems Brij‐56/methionine and Brij‐58/methionine shows same trends with increased [Met.]. This is mainly due to increased micelle concentrations. The influence of amino acid on the cloud point of Brij‐56 and Brij‐58 is a clear indication that the phenomenon of clouding is associated with the different micelles coalescing. The phase separation results from micelle‐micelle interaction. Considering cloud point as threshold temperature of the solubility, the energetic of clouding process (ΔG0cl, ΔH0cl and ΔS0cl) have been evaluated using “Phase Separation Model" It is found that the overall clouding process is exothermic and ΔH0cl > TΔS0cl indicating that the process of clouding is guided by both enthalpy and entropy. This work supports the conjecture that the cloud point is critical phenomenon rather than the growth of micelles.
Synthesis of Some Bromo‐Substituted 3‐Aroyl Flavanones and Flavones
Authors: Mahalle P. R. , Khaty N. T.
Published: March 2012

A series of bromo‐substituted 3‐aroyl flavanons and flavones have been synthesized. The identities of the new compounds synthesized have been developed on the basis of usual chemical transformation and IR, NMR spectral studies.
Synthesis, Characterization and Antibacterial Activity of Schiff Bases and their Metal Complexes Derived from 4‐Acyl‐1‐phenyl‐3‐methyl‐2‐pyrazolin‐5‐ones and 2‐Amino‐4(4′‐methylphenyl)‐thiazole
Authors: Thakar A. S. , Singh K. K. , Joshi K. T. , Pancholi A. M. , Pandya K. S.
Published: March 2012

4‐Acyl‐1‐phenyl‐3‐methyl‐2‐pyrazolin‐5‐ones condensed with 2‐amino‐4(4′‐methylphenyl)‐thiazole to form Schiff base. These Schiff bases from complexes of type ML22H2O (M=Mn, Fe, Co, Ni and Cu). Elemental analysis, magnetic susceptibility, electrical conductance, electronic and Infrared spectral data suggested octahedral structure for the complexes. All the compounds were tested for their antibacterial activity. The result indicates that the growth of the tested organism was inhibited by most of the compounds. These Schiff bases are characterized by elemental analysis, mass spectra, 1H‐NMR spectra, 13C NMR spectra and FT IR spectra.
Synthesis and Antimicrobial Activity of Some 3‐(5‐Phenyl‐4,5‐dihydro‐1‐substitutedpyrazol‐3‐yl) chromen‐2‐one
Authors: Lakshminarayanan B. , Rajamanickam V. , Subburaju T. , Rajkumar L. A. Pradeep
Published: March 2012

The title compounds were synthesized by condensation of 3‐acetyl chromen‐2‐one with benzaldehyde in presence of alcoholic sodium hydroxide to get intermediate 3‐(3‐phenyl acryloyl) chromen‐2‐one, which were further treated with hydrazine hydrate to get 3‐(5‐phenyl‐4,5‐dihydro‐1H‐pyrazol‐3‐yl) chromen‐2‐one. The latter were refluxed with various amino compounds and various aldehyde derivatives on water bath for 5 h to afford title compounds. All the compounds were tested for their antibacterial and antifungal activities by the cup plate method.
Chemometrics‐Assisted Simultaneous Determination of Atenolol and Furosemide in Synthetic Binary Mixtures and Combined Tablet Preparations
Authors: Sarrafi Amir H. M. , Konoz Elahe , Feyzbakhsh Alireza
Published: March 2012

In this work a numerical method, based on the use of spectrophotometric data coupled to PLS multivariate calibration, is reported for the simultaneous determination of furosemide (FUR) and atenolol (ATE) in synthetic samples and combined commercial tablets. The correlation coefficients (R2) and recovery range for ATE and FUR in synthetic mixtures were 0.9938, 0.9949 and 94.72‐103.72%, 95.60‐104.34% respectively. The results of optimized method in combined tablet preparations compared with British Pharmacopeia 2007 standard methods that have a good agreement. The proposed method are simple, fast, inexpensive and do not need to any separation or preparation methods.
A DFT Study on Selected Physical Organic Aspects of the Fischer Carbene Intermediates [(M(CO)4(C(OMe)Me)]
Authors: Irshaidat Tareq
Published: March 2012

Fischer carbenes are important starting materials for C‐C bond formation via coupling reactions between carbene and wide variety of substituted alkenes or alkynes. This DFT study shed light on unique fundamental organic/organometallic aspects for the C(OMe)Me carbene in the free form and in case of bonding with M(CO)4 (M= Cr, Mo, W). The data illustrate that the structures of the title intermediates include a unique structure stabilizing intramolecular M…C‐H interaction (agostic interaction). This conclusion was made based on calculated NMR data (for carbon and hydrogen), structural parameters, energy calculations of conformers (C‐C conformation), selected IR stretching frequencies (C‐O, C‐C, and C‐H), and atomic charges. The agostic interaction is most efficient in case of chromium and in general is described as an overlap between the σ‐bond electron pair of C‐H with an empty d‐orbital of the metal. These characterized examples are new addition to the orbital interaction theory.
Electrolytic Recovery of Nickel from Spent Electroless Nickel Bath Solution
Authors: Idhayachander R. , Palanivelu K.
Published: March 2012

Plating industry is one of the largest polluting small scale industries and nickel plating is among the important surface finishing process in this industry. The waste generated during this operation contains toxic nickel. Nickel removal and recovery is of great interest from spent bath for environmental and economic reasons. Spent electroless nickel solution from a reed relay switch manufacturing industry situated in Chennai was taken for electrolytic recovery of nickel. Electrolytic experiment was carried out with mild steel and gold coated mild steel as cathode and the different parameters such as current density, time, mixing and pH of the solution were varied and recovery and current efficiency was studied. It was noticed that there was an increase in current efficiency up to 5 A/dm2 and after that it declines. There is no significant improvement with mixing but with modified cathode there was some improvement. Removal of nickel from the spent electroless nickel bath was 81.81% at 5 A/dm2 and pH 4.23. Under this condition, the content of nickel was reduced to 0.94 g/L from 5.16 g/L. with 62.97% current efficiency.
One‐Pot Synthesis of Some New Pyrido[2,3‐d]pyrimidine Derivatives Catalyzed by Sodium Lauryl Sulfate in Aqueous Media
Authors: Li Sheng-Hui , Shen Yan-Hong , Gao Na , Li Ji-Tai
Published: March 2012

A series of pyrido[2,3‐d]pyrimidine derivatives were synthesized by the three‐component reaction of aromatic aldehyde, malononitrile and 6‐amino‐4‐hydroxy‐2‐mercaptopyrimidine catalyzed by sodium lauryl sulfate (SDS) in aqueous media. It was interesting that further aromatization took place automatically. This method provides several advantages such as easier work‐up, milder reaction conditions and environmental friendly.
Copper(II) Extraction from Nitric Acid Solution with 1‐Phenyl‐3‐methyl‐4‐benzoyl‐5‐pyrazolone as a Cation Carrier by Liquid Membrane Emulsion
Authors: Hamzah Baharuddin , Jalaluddin Noor , Wahab Abdul Wahid , Upe Ambo
Published: March 2012

Copper(II) extraction from nitric acid solution with 1‐phenyl‐3‐methyl‐4‐benzoil‐5‐pyrazolone (HPMBP) as a cation carrier by liquid membrane emulsion (LME) was investigated. The HPMBP initially was synthesized and the synthesis yield is a yellow crystal with melting point of 87‐89 °C. The synthesis efficiency is 72.04% and generally the spectra of IR, 1H NMR and 13C NMR agree with HPMBP structure. The optimum condition for copper(II) extraction were found as follows: concentration of mixed surfactant (span 80+span 20) was 3%, volume ratio of membrane and internal phase was 1, concentration of HPMBP was 0.020 M, concentration of HCl was 1 M, volume ratio of emulsion and external phase was 0.143. By using these optimum conditions, 30 mL of LME can extract 1000 ppm of copper(II) within 210 mL of nitric acid solution with extraction percentage of 97.97%.
Complexation and Antimicrobial Studies of Some Divalent Metal Chelates
Authors: Ghosh Suparna , Malik Suman
Published: March 2012

Metal chelates of Ni(II) and Cu(II) with the ligand 5‐acetamido‐1,3,4‐thiadiazole‐2‐sulphonamide have been synthesized. The isolated compounds have been characterized by elemental analysis, molar conductivity, magnetic moment, electronic and IR spectral studies. The analytical data reflects the metal to ligand stoichiometry to be 1: 2. The conductivity data of the complexes also suggests their non‐electrolytic nature. The stability constants and free energy change for the complexes have been calculated.. Ligand and their complexes have been screened for their biological activity and the data show good activity of these complexes and ligands.
Simultaneous Estimation of Glimepiride, Rosiglitazone and Pioglitazone Hydrochloride in the Pharmaceutical Dosage Form
Authors: Havaldar Freddy H. , Vairal Dharmendra L.
Published: March 2012

A simple, specific, accurate and economical gradient reversed phase liquid chromatographic (RP‐HPLC) method was developed and subsequently validated for the determination of glimipiride, rosiglitazone and pioglitazone hydrochloride. Separation was achieved with a nucleodur C–18 column having 250×4.6 mm i.d. with 5 µm particle size and water HPLC grade adjusted to pH 3.0 using diluted orthophosphoric acid and acetonitrile (80:20 v∕v) with gradient program as eluent at a constant flow rate of 0.8 ml per min. UV detection was performed at 215 nm. The retention time of glimipiride, rosiglitazone and pioglitazone hydrochloride were about 17.9 min, 6.31 min and 8.24 min respectively. This method is simple, rapid and selective and can be used for routine analysis of antidiabetic drugs in pharmaceutical preparation. The proposed method was validated and successfully used for estimation of glimipiride, rosiglitazone and pioglitazone hydrochloride in the pharmaceutical dosage form.
Rhodamine‐Sulphuric Acid ‐A New Visualization Reagent for the Determination of Sucralose by HPTLC
Authors: Idris Mohd , Srivastava Seema , Baggi T. R. , Shulka S. K. , Ganjoo A. K.
Published: March 2012

Sucralose a UV‐visible inactive compound was separated on silica gel plate without any plate treatment prior to analysis, derivatized with rhodamine ‐ sulphuric acid reagent and detected densitometrically at 456 nm as olive green band. With this reagent sucralose also shows golden yellow fluorescence at 366 nm. Two new solvent systems i.e. chloroform: methanol: toluene (v/v 5:3.5:1.5) (solvent system‐I) and chloroform: ethanol: benzene (v/v 5:3:2) (solvent system‐II) were developed and giving Rf values of 0.62 and 0.45 respectively. The method was found to be sensitive with good limit of detection (LOD) for two solvent systems. The method imparts specificity to the method as at 456 nm sucralose only gives olive green color spots where as other artificial sweeteners did not show any response to this reagent, where as carbohydrates gives black color spots. Similarly sucralose gives golden yellow fluorescence at 366 nm which is not given by any other artificial sweetener. The method was highly reproducible with relative standard deviation (RSD)≤3% (n=3) and was applied for the determination of sucralose in different matrices
like cola drinks, lemon juices, sugar free sweets, tabletop sweeteners etc.etc.
Ultrasonic Study of Molecular Interactions in Binary Mixtures at 303 K
Authors: Mullainathan S. , Nithiyanantham S.
Published: March 2012

The ultrasonic velocity, density and viscosity at 303 K have been measured in the binary systems of 1,4‐dioxane and acetone with water. From the experimental data, various acoustical parameters such as adiabatic compressibility (β), intermolecular free length (Lf), free volume (Vf), internal pressure (πi), Rao’s constant (R), Wada’s constant (W) and specific acoustical impedance (Z) were calculated. The results are interpreted in terms of molecular interaction between the components of the mixtures.
Corrosion Inhibition of Mild Steel in HCl by Isolated Compounds of Riccinus Communis (L.)
Authors: Goel Rinki , Siddiqi W. A. , Ahmed Bahar , Hussan J.
Published: March 2012

We have isolated three pyridine base alkaloids namely ricinine (C1), N‐demethylricinine (C2) and 4‐methoxy pyridine‐3‐carboxylic acid (C3) from methanolic extract of Riccinus Communis leaves and investigated corrosion inhibition effect on mild steel in 0.5 HCl solution using the weight loss and electrochemical techniques (Galvanostatic polarization and EIS). Polarization resistances calculated from the EIS measurements are in good agreement with those obtained from alternating current (AC) polarization measurements. The mild steel samples were also analyzed by Scanning Electron Microscopy (SEM). The results show that C1 is an excellent inhibitor for mild steel in acid medium. The inhibition was assumed to occur via adsorption of the inhibitor molecule on the metal surface. In the 298‐ 308 K temperature range, the C1, C2 and C3 adsorption follows Langmuir isotherm model. The protection efficiency increases with increasing the inhibitor concentration in the range of 250‐1000 ppm but slightly decreases with increasing temperature.
A New Cross‐Shaped Graphite Furnace with Ballast Body for Reduction of Interferences in Atomic Absorption Spectrometry
Authors: Asweisi A. A. , Kuss H. M.
Published: March 2012

A new crossed graphite furnace for atomic absorption spectrometry (GFAAS) was designed and installed in heated graphite atomizer (HGA500) combined with Perkin‐Elmer spectrometer (AAS1100). The Tungsten ballast body was inserted inside one part of the crossed furnace in a way perpendicular to light path. The analyzed sample was injected manually on the ballast body inside the cross and pushed into the measuring zone using the original inner and additional purge gas. The sample was adsorbed strongly on the ballast and evaporated and transferred with different rates at different temperatures during the temperature program allowing the separation of analyte and matrix signals. Analysis of middle volatile element such as copper and manganese in standard urine sample (seronorm 2525) showed complete separation of analyte and background signals with good sensitivity and repeatability.
Development and Validation of a Precise Method for Determination of Benzalkonium Chloride (BKC) Preservative, in Pharmaceutical Formulation of Latanoprost Eye Drops
Authors: Mehta J. , Patidar K. , Vyas N.
Published: March 2012

A simple and precise reversed phase high performance liquid chromatographic method has been developed and validated for the quantification of benzalkonium chloride (BKC) preservative in pharmaceutical formulation of latanoprost eye drops. The analyte was chromatographed on a Waters Spherisorb CN, (4.6×250 mm) column packed with particles of 5 μm. The mobile phase, optimized through an experimental design, was a 40:60 (v/v) mixture of potassium dihydrogen orthophosphate buffer (pH 5.5) and acetonitrile, pumped at a flow rate of 1.0 mL/min at maintaining column temperature at 30 °C. Maximum UV detection was achieved at 210 nm. The method was validated in terms of linearity, repeatability, intermediate precision and method accuracy. The method was shown to be robust, resisting to small deliberate changes in pH, flow rate and composition (organic ratio) of the mobile phase. The method was successfully applied for the determination of BKC in a pharmaceutical formulation of latanoprost ophthalmic solution without any interference from common excipients and drug substance. All the validation parameters were within the acceptance range, concordant to ICH guidelines.
Spectrphotometric Determination of Buclizine as Hydrochloride Using Various Chromogenic Reagents
Authors: Annapurna V. , Jyothi G. , Subbayamma A. V. , Sailaja B. B. V.
Published: March 2012

Simple, accurate and reproducible UV spectrophotometric methods were established for the assay of buclizine (BUCZ) based on the formation of precipitation, charge transfer complex and inner complex formation. Method A involves the precipitation, charge transfer complex formation of BUCZ with tannic acid/ p-N‐methyl aminophenol sulphate (PMAP)‐Cr(VI), the complex formation with cobalt thiocyanate (CTC) in method B and inner complex formation of BUCZ with sodium nitroprusside hydroxylamine hydrochloride and sodium carbonate in method C were proposed. The optical characteristics such as Beers law limits, molar absorptivity and Sandell’s sensitivity for the methods (A‐C) are given. Regression analysis using the method of least squares was made to evaluate the slope(b), intercept(a) and correlation coefficient (r) and standard error of estimation (Se) for each system Determination of BUCZ in bulk form and in pharmaceutical formulations were also incorporated.
A New Inhibition Kinetic Spectrophotometric Method for the Determination of Resorcinol
Authors: Keyvanfard Mohsen
Published: March 2012

A new, simple, inexpensive and fast kinetic spectrophotometric method was developed for the determination of trace amounts of resorcinol over the range of 0.02‐0.80 μg/mL. The method is based on the inhibitory effect of resorcinol on the formaldehyde catalyzed oxidation reaction of of cresyl violet by bromate in acidic media is reported. The reaction was monitored spectrophotometrically by measuring the decrease in absorbance of cresyl violet at 596 nm with a fixed‐time 0.5–2.5 min from initiation of the reaction.The detection limit is 0.017 μg/mL and relative standard deviation of 0.1 and 0.5 μg/mL resorcinol for six replicate measurements was 2.6 and 2.9 %, respectively. The method was applied to the determination of resorcinol in water samples.
Synthesis of Various Polyaniline / Clay Nanocomposites Derived from Aniline and Substituted Aniline Derivatives by Mechanochemical Intercalation Method
Authors: Kalaivasan N. , Shafi S. Syed
Published: March 2012

Polyaniline clay nanocomposite can be prepared by mechano‐chemical method in which intercalation of anilinium ion into the clay lattices accomplished by mechanical grinding of sodium montmorillonite (Na+MMT) in presence of anilinium hydrochloride at room temperature using mortar & pestle for about 30 min and subsequent grinding with oxidizing agent, ammonium peroxysulfate. The appearance of green colour indicates the formation of polyaniline/clay nanocomposite (PANI/Clay). Similarly aniline derivatives like o‐toludine and o‐anisidine in the form of HCl salt can form intercalation into the clay lattices. The intercalated aniline derivatives were ground mechanically in presence of oxidizing agent ammonium peroxysulfate lead to formation of substituted polyaniline/ clay nanocomposites. The characteristics of various polyaniline‐clay nanocomposites were investigated using UV‐Visible, FT‐IR, cyclic voltammetry studies.
Groundwater Quality of Southeastern Brazzaville, Congo
Authors: Laurent Matini , Marie Moutou Joseph
Published: March 2012

The groundwater in southeastern Brazzaville (Congo) was analyzed for their fluoride contents and others related parameters in rainy season. The fluoride contents in water samples (wells and spring) can be gather in three classes in the study area: low, optimal, high. Fluoride concentration in water samples presents a low significant correlation with Ca2+. This suggests that fluoride in the groundwater come from fluoride‐bearing minerals such as CaF2 (fluorite). Maps were drawn to show the geographical distribution of EC, Ca2+, Mg2+and F-. Factor analysis and cluster analysis were applied to the dataset. Factor analysis resulted in four factors explained 76.90% of the total groundwater quality variance. Factor 1 (hardness of the groundwater) includes total hardness, the concentration of K+, Ca2+ and pH. Factor 2 (low mineralization of the groundwater) includes concentrations of TDS, Cl-‐, SO42+ and EC. Factor 3 (anthropogenic activities with the impact of agricultural fertilizers, farming activities, domestic wastewater, septic tanks) includes concentrations of Na+ and NO3-. Factor 4 (weathering of calcium minerals) includes concentrations of F-. For cluster analysis, Ward’s method and the Euclidean distance were used. The findings of the cluster analysis are presented in the form of dendrogram of the well water sites (cases). The discriminating parameters between clusters have been highlighted from the Student test. In majority, they are in accordance with those highlighted by factor analysis.
Poly (furfural‐acetone) as New Adsorbent for Removal of Cu(II) from Aqueous Solution: Equilibrium Study
Authors: Najim Tariq S.
Published: March 2012

The batch removal of Cu(II) from aqueous solution using poly (furfural‐acetone), (PFA) as adsorbent was investigated in this study. The influences of initial Cu(II) ion concentration (10 to 120 ppm), pH (4‐8) and contact time have been reported. Adsorption of Cu(II) is highly pH‐dependent and the result indicate that the optimum pH for the removal was found to be 6. At this pH a small amount of PFA, 2 g/L, could remove as much as 97% of Cu(II) from a solution of initial concentration 10 ppm. It was observed that an increase in initial concentration of Cu(II) leads to decrease in percent removal of Cu(II) and increase in amount of Cu(II) adsorbed per unit mass of PFA. The adsorption process of Cu(II) is tested with four isotherm models, Langmuir, Freundlich, Temkin and Dubinin–Radushkevich (D‐R). It was found that all models were applicable and the maximum adsorption capacity was found to be 13.66 mg/g. From the isotherm constants it was confirmed that, the sorption process was physisorption.
Effect of Benzyltrimethylammonium Ion as a Co‐directing Agent on Phase Transitions in a Nanostructure Silica/Surfactant Composite
Authors: Badiei Alireza , Goldooz Hassan , Ziarani Ghodsi Mohammadi
Published: March 2012

Effect of benzyltrimethylammonium ion as a co directing agent in phase transition from hexagonal to cubic and lamellar mesophases was studied in the constant pH at 130 °C. This phase transformation was carried out in constant surface charge and pore size distribution (2 nm). Influence of BTMA+ ions between head and tail of surfactant and phase transformation were observed by using the XRD and elemental analysis.
Physicochemical and Heavy Metals Assessments of Leachates from Aperin Abandoned Dumpsite in Ibadan City, Nigeria
Authors: Adewuyi G. O. , Opasina M. A.
Published: March 2012

Leachates from Aperin dumpsite and control site in Ibadan city, were analysed for physicochemical properties and heavy metals levels. These parameters were compared with control samples and established international standards (FEPA) and (WHO). The dumpsite leachates contained very high concentration of TDS (2436±1035 mg/L) and significant concentrations of COD (395±135 mg/L), BOD (170±33 mg/L), Alkalinity (1157±995 mg/L), Cl- (943±175 mg/L), NO3- (0.66±0.22 mg/L) PO4-(1.98±0.89 mg/L). High concentrations of Iron, Manganese, Copper, Zinc, Nickel, Cadmium and Lead were also observed. All, the parameters were above control and exceeded FEPA and WHO guidelines. The study revealed that this dumpsite is a major polluting source in the surrounding environment. This underlines the need for appropriate government agency Oyo State, Nigeria to initiate an active remediation process such as phytoremediation in combination with physicochemical methods to recover the dumpsite from contaminants and reduce the level of pollution in the surrounding environment.
Microwave Enhanced Synthesis of Chitosan‐graft Molecularly Imprinted Polymer (MIP) for Selective Extraction of Antioxidants
Authors: Saifuddin N. , Yasumira A. A. Nur
Published: March 2012

Polymers have been molecularly imprinted for the purpose of binding specifically to α‐tocotrienol (vitamin E). A molecularly imprinted polymer (MIP) material was prepared using α‐tocotrienol as the imprinted molecule, acrylamide as functional monomer and macroporous chitosan beads as functional matrix. Chitosan‐graft‐polyacrylamide was synthesized without any radical initiator or catalyst using microwave (MW) irradiation. The representative microwave synthesized graft copolymer was characterized by fourier transform‐infrared spectroscopy, taking chitosan as a reference. Microwave irradiation was exploited for polyacrylamide grafting on the cross‐linked chitosan beads to produce MIP, where both time as well as chemicals can be saved. It can be assumed that the chitosan coated polyacrylamide MIP will have better pH stability and enhanced adsorption capacity. The maximum adsorption capacity was observed to be 3.95 mg/g of MIP, which gave removal efficiency of 93%. After 4 h, the change of adsorption capacities for α‐tocotrienol did not show notable effects. The Langmuir and Freundlich adsorption models were also applied to describe the equilibrium isotherms.
Studies on Molecular Interaction in Ternary Liquid Mixtures
Authors: Uvarani R. , Punitha S.
Published: March 2012

Ultrasonic velocity, density and viscosity for the ternary liquid mixtures of cyclohexanone with 1‐propanol and 1‐butanol in carbon tetrachloride were measured at 303 K. The acoustical parameters and their excess values were calculated. The trends in the variation of these excess parameters were used to discuss the nature and strength of the interactions present between the component molecules.
Crystalline and Molecular Structure of Hexaaqua‐1,3‐diammoniumpropane Cobalt(II) Nitrate, Co(H2O) 6 [C3H12N2] (NO3)4
Authors: Mrad M. L. , Nasr C. Ben , Rzaigui M.
Published: March 2012

Chemical preparation and x‐ray characterization of a new compound hexaaqua‐1,3‐diammoniumpropane cobalt(II) nitrate, Co(H2O) 6 [C3H12N2] (NO3)4 are reported. This mixed organo‐mineral compound crystallizes in the orthorhombic system with Cmcm space group. The unit cell dimensions are: a = 10.795(7), b = 11.969(4), c = 14.685(5) Å, Z = 4 and V = 1897.5(12) Å3. The structure was solved using the direct method and refined to reliability R‐factor of 0.036 using 2554 independent reflections. In this atomic arrangement the different species built a three‐dimensional network.
Study of Non‐Isothermal Decomposition and Kinetic Analysis of 2,4‐Dihydroxybenzoic Acid‐ Melamine‐Formaldehyde Copolymer
Authors: S. Butoliya S. , B. Gurnule W. , B. Zade A.
Published: March 2012

A copolymer (2,4‐DHBAMF) synthesized by the condensation of 2,4‐dihydroxybenzoic acid and melamine with formaldehyde in the presence of acid catalyst using varied molar proportions of the reactants. A composition of the copolymer has been determined by elemental analysis. The number average molecular weight has been determined by conductometric titration in non‐aqueous medium. The copolymer has been characterized by UV‐Visible, IR and 1H NMR spectral analysis. Thermogravimetric analysis was carried out to study the decomposition and various kinetic parameters. Freeman Carroll and Sharp Wentworth methods have been applied for the calculation of kinetic parameters while the data from Freeman Carroll method have been used to determine various thermodynamic parameters such as order of reaction, energy of activation, frequency factor, entropy change, free energy change and apparent entropy change. The results indicate that given copolymer have potential as matrix resin for long term applications at temperature up to 350 °C.
Inhibitory Action of Borassus Flabellifer Linn. (Palmyra Palm) Shell Extract on Corrosion of Mild Steel in Acidic Media
Authors: Vijayalakshmi P. R. , Rajalakshmi R. , Subhashini S.
Published: March 2012

The inhibitory effect of extract obtained from destructive distillation of palmyra palm (Borassus flabellifer Linn.) shell on the corrosion of mild steel in 0.5 M H2SO4 and 1 M HCl was investigated using weight loss and electrochemical measurement techniques. The results show that the inhibition efficiency increases with increase of palmyra palm shell extract concentration. The maximum inhibition efficiency in 0.5 M H2SO4 and 1 M HCl was found to be 97.65% and 98.11% for a period of 24 h with 3%v/v concentration of the inhibitor respectively. Thermodynamic parameters were evaluated from temperature studies. Results were fitted into suitable adsorption isotherms. Electrochemical measurements infer that the extract acted through mixed mode of inhibition. Efforts were made to analyze the effectiveness of shell extract of palmyra palm in industrial processes.
Template‐Assisted Sol‐Gel Synthesis of Nanocrystalline BaTiO3
Authors: Anuradha T. V.
Published: March 2012

Nanocrystalline perovskite barium titanate with an average particle size less than ∼10 nm is produced using sol‐gel route involving ligand‐assisted templating. BaTiO3 is obtained by the controlled hydrolysis and condensation reaction of barium acetate (Ba(CH3COO)2) with titanium tetra chloride (TiCl4) in the reverse micelles of dodecylamine (DDA) which is used as the template. Our attempts to produce mesoporous BaTiO3 have resulted in the formation of nanocrystalline BaTiO3. The synthesis of nanostructured BaTiO3 is carried out using the ligand‐assisted templating approach which proceeds through the sol‐gel route. Dodecylamine is used as the template. The sol‐gel process in general presents inherent advantages because the nanostructure of the desired materials can be controlled together with their porous structure. Ligand‐assisted templating approach involves the formation of covalent bond between the inorganic analogue and the template. Ba(CH3COO)2 and TiCl4 are used as barium‐source and titanium‐source respectively. The reaction between Ba(CH3COO)2 and TiCl4 is found to take place deliberately on the pre‐assembled species which acts as the template or occurring with in them which in turn will lead to the generation of the desired nanoscale structure (nanopores or nanoparticles).
Identification of New Aromatic Compounds in the New Zealand Manuka Honey by Gas Chromatography‐Mass Spectrometry
Authors: Daher Sawsan , Gülaçar Fazil O.
Published: March 2012

Analysis of aromatic compounds in the New Zealand manuka honey was carried out by solid phase microextraction followed by gas chromatography‐mass spectrometry. A total of 38 compounds were detected. Seven of them such as; 1,4‐bis(x‐methoxyphenyl)‐but‐2‐en‐1‐one, 1,5‐bis(x‐methoxyphenyl)‐pent‐3‐en‐1‐one, 1,4‐bis(x‐methoxyphenyl)‐1‐pentanone, 1,6‐bis(x‐methoxyphenyl)‐3‐heptene, 1,6‐bis(x‐methoxyphenyl)‐hex‐2(3 or 4)‐en‐1‐one and 2(3, 4 or 5)‐hydroxy‐1,6‐bis(x‐methoxyphenyl)‐1‐hexanone, had never before been identified as natural products. Their structures were deduced from the mass spectral data. Seven other compounds; 2,3‐dimethoxynaphthalene, 4‐(x‐methoxyphenyl)‐1‐phenyl‐1‐butanone, desoxyanisoin, 2,6‐dimethoxybenzoic acid benzyl ester, 4,4′‐dimethoxystilbene, 3,3,4,5,5,8‐hexamethyl‐2,3,5,6‐tetrahydro‐s‐indacene‐1,7‐dione and 1,5‐bis(4‐methoxyphenyl)‐pentane‐1,5‐dione, were found in honey for the first time. Methyl syringate, ortho‐methoxyacetophenone and 3‐phenyllactic acid were the most abundant components.
Studies on the Removal of Red Industrial Dye Using Teak Leaf, Maize Corn and Babool Tree Bark Carbons ‐A Comparison
Authors: Kannan N. , Vijayakumar A. , Subramaniam P.
Published: March 2012

Activated carbons prepared from teak leaf (TLC), maize corn (MCC) and babool tree bark (BTBC) were used to study adsorption of red industrial dye under various experimental conditions. Effect of various experimental parameters such as initial concentration, adsorbent dosage, particle size, contact time and initial pH of solution was studied. Batch adsorption studies were carried out at room temperature (30±1°C). Adsorption parameters were modeled by Freundlich and Langmuir isotherm models. Adsorption data were fitted with the Natarajan and Khalaf, Lagergren and Bhattacharya ‐Venkobachar equations. The high value of 21.28 was obtained from Langmuir plot indicates maize corn carbon (MCC) is the best low cost adsorbent. The adsorption process followed first order kinetics, with intra‐ particle diffusion as one of the rate limiting steps
Conformational Studies of ε‐ CBz‐ L‐ Lysine and L‐ Valine Block Copolypeptides
Authors: Kumar Ajay
Published: March 2012

Conformational studies of ε‐CBz‐L‐lysine and L‐valine block copoylpeptides using x‐ ray diffraction and CD spectra are described. The block copolypeptides contain valine block in the center and on both side of the valine are ε‐CBz‐L‐lysine blocks. The conformation of the copolypeptides changes with increases in the chain length of ε‐ CBz‐L‐ lysine blocks. When length of ε‐ CBZ‐ L‐ lysine blocks is 9, the block copolypeptide has exclusive beta sheet structure. With the increase in chain length of ε‐CBz‐L‐lysine blocks from 9 to 14, the block copolypeptide shows presence of both alpha helix and beta sheet components. With further increase in chain length of ε‐ CBz‐ L‐ lysine blocks, the beta sheet component disappears and block copolypeptides exhibits exclusive α ‐helix conformation.
Application of Ratio Derivative Spectrophotometry for Simultaneous Determination of Naphazoline and Antazoline in Eye Drops
Authors: Hajian R. , Shams N. , Kaedi I.
Published: March 2012

Ratio derivative spectrophotometrie method has been developed for the simultaneous determination of naphazoline (NAP) and antazoline (ANT) at micromolar levels in Britton Robinson buffer (pH 9) medium. In this method the overlapping spectra of naphazoline and antazoline were well resolved by making use of the first‐derivative of the ratios of their direct absorption spectra. The derivative ratio absorbances of naphazoline and antazoline were measured at 227.2 and 235 nm, respectively for their quantification. The method is simple, fast and does not require separation of naphazoline and antazoline. Another salient feature of the method is that simultaneous standard additions of both analytes permitted to resolve matrix effect and quantification at a unique standard addition plot. Naphazoline and antazoline were determined in the concentration range of 10‐150 μmol L-1 (NAP/ANT ratio varying from about 10 to 150) in the same aliquot with a precision and accuracy of about 1.7% and 1.8%, respectively. The recommended procedure was successfully applied for analysis of naphazoline and antazoline in eye drops.
A Facile Spectrophotometric Method for the Determination of Cobalt(II) Using Iodine Monochloride Reagent
Authors: Jayanna B. K. , Nagendrappa G. , Gowda Ninge
Published: March 2012

A novel, simple, sensitive spectrophotometric method is proposed for the determination of cobalt(II). Chloromine‐T with iodine in acetic acid produces iodine monochloride, which oxidizes promethazine hydrochloride and diphenylamine to absorbing cations. Those would associate later with cobalt complex to form an ion pair, [Ph+] [CoCl4]- and [Dh2+] [CoCl4]-2 in acid medium. These appear to provide exceptional color stability to the systems. The results compare favorably with those of reported method. The conditions required for the determination of cobalt(II) are described and related analytical parameters are also calculated.
Synthesis of Some Phenylpyrazolo Benzimidazolo Quinoxaline Derivatives as Potent Antihistaminic Agents
Authors: Sridevi C. H. , Balaji K. , Naidu A. , Sudhakaran R.
Published: March 2012

2,3‐Diphenyl quinoxaline (NI) was fused with benzimidazole (NII) by a methylene bridge, which was then allowed for acetylation. The acetylated product (NIV) was made to react with different aromatic aldehydes to give chalcones (NV1‐NV5). Chalcones refluxed with substituted acid hydrazides to afford different phenyl pyrazolo benzimidazole quinoxaline derivatives (NVI 1‐NVI 15). The structure of chalcones and phenyl pyrazolo benzimidazole quinoxaline derivatives were confirmed by m.p, TLC and spectral data. All the synthesized compounds were screened for their antihistaminic activity. Compounds NVI‐3, NVI‐12, NVI‐13, NVI‐14 and NVI‐15 were shown good % protection of antihistamic activity.
Synthesis and Biological Evaluation of 2‐(3‐Methyl‐2‐oxoquinoxalin‐1(2H)‐yl)‐N′‐(substituted phenyl‐methyledene/ethylidene)acetohydrazides
Authors: Rao Gopal Krishna , Kotnal R. B. , Pai P. N. Sanjay
Published: March 2012

A series of quinoxaline derivatives was prepared and evaluated for antitubercular, antibacterial and antifungal activities. The title compounds were prepared by condensation of substituted aromatic aldehydes and substituted acetophenones with 2‐(3‐methyl‐2‐oxoquinoxalin‐1(2H)‐yl) acetohydrazide. Structures of all these compounds were confirmed by their spectral studies. Among synthesized compounds (4r, 4t, 4u, 4w and 4x) have shown good anti tubercular activity (25 µg mL-1) when compared to reference drugs pyrazinamide (10 µg mL-1) and streptomycin (7.5 µg mL-1). In this study, few derivatives showed broad spectrum of antimicrobial activity at low concentration. The MICs (Minimum inhibitory concentration) of some compounds are 2‐4 µg mL-1.
A Study of Mild Steel Corrosion Using Adhatoda Vasica (AV) Extract as Inhibitor in Different Acid Medium
Authors: Matheswaran P. , Ramasamy A. K.
Published: March 2012

Corrosion behavior of mild steel in acidic medium using Adhatoda Vasica (AV) extract was investigated. The inhibitive effective of Adhatoda Vasica on the corrosion of mild steel in different acidic medium has been studied by weight loss and polarization methods. The Ecorr values are shifted slightly towards negative side in presence of inhibitors which indicate the inhibitors inhibit the corrosion of mild steel in acids solution by controlling both anodic and cathodic reactions due to the blocking of active sites on the metal surface. It is evident that inhibitors bring about considerable polarization of the cathode as well as anode. It was, therefore, inferred that the inhibitive action is of mixed type.
DFT Modelling of Tripeptides (Lysine‐Tryptophan‐Lysine) Interacting with Single Walled Carbon Nanotubes
Authors: Kuganathan Navaratnarajah
Published: March 2012

Model calculations are performed to predict the nature of interaction between SWNT and a tripeptide (Lys‐Trp‐Lys) and to calculate the binding energies and charge transfer between these two species using density functional theory. DFT calculations indicate that the interaction is of a non covalent nature. Minimal charge transfer is observed between SWNT and Lys‐Trp‐Lys.
Synthesis and Biological Activity of (Z) –n‐(5‐Benzylidene‐4‐oxo‐2‐substituted‐ phenylthiazolidin‐3‐yl)‐5‐((1, 3‐dioxoisoindolin‐2‐yl)methyl)‐2‐hydroxybenzamide
Authors: Patel M. C. , Dhameliya
Published: March 2012

5‐((1, 3‐Dioxoisoindolin‐2‐yl)methyl‐2‐hydroxybenzohydrazide (1) undergoes facile condensation with aromatic aldehydes to afford the corresponding N′‐substituted‐phenyl‐5‐((1,3‐dioxoisoindolin‐2‐yl) methyl)‐2‐hydroxybenzohydrazide (2a-h) in good yields. Cyclocondensation of compounds (2a-h) with thioglycolic acid yields 5‐((1,3‐dioxoisoindolin‐2‐yl) methyl)‐2‐hydroxy‐N‐(4‐oxo‐2‐substituted phenylthiazolidin‐3‐yl)benzamide (3a-h). These (3a-h) compounds were further reacted with benzaldehyde in the presence of sodium ethanolate affords, (Z) –N‐(5‐benzylidene‐4‐oxo‐2‐substituted phenyl‐thiazolidin‐3‐yl)‐5‐((1,3‐dioxoisoindolin‐2‐yl)methyl)‐2‐hydroxybenzamdie(4a-h). The structures of these compounds were established on the basis of analytical and spectral data. All the newly synthesized compounds were evaluated for their antibacterial and antifungal activities.
Influence of Benzotriazole on Corrosion Inhibition of Mild Steel in Citric Acid Medium
Authors: Matheswaran P. , Ramasamy A. K.
Published: March 2012

Benzotriazole an organic compounds has been studied as corrosion inhibition for mild steel in 1 N citric acid by weight loss method. The result showed that the corrosion inhibition efficiency of the compound was found to be varying with the temperature and acid concentration. Also it was found that the corrosion inhibition behaviour of benzotriazole is better when the concentration of inhibitor is increased. The kinetic treatment of the results shows first order kinetics.
New Piperazine Derivatives Synthesized from Thio‐Substituted Polyhalogeno‐2‐nitro‐1,3‐butadienes
Authors: Aydinli S. Goksin , Ibis Cemil
Published: March 2012

It is known that polyhalogeno‐nitro‐1,3‐butadienes are important starting materials for the synthesis of polyfunctionalized bioactive heterocycles. Novel N,S‐substituted nitrobutadienes (4a-j) were synthesized from the reaction of the monothio‐substituted nitrodiene derivatives (2a) and (2b) with some piperazine derivatives. These new compounds are stable and the structures of these products were characterized by spectroscopic data. The structure of the novel N,S‐substituted nitrodiene compound (4g) synthesized in this study was also elucidated by single crystal x‐ray analysis.
Synthesis, Characterization and Thermal Analysis of New Cu(II) Complexes with Hydrazide Ligands
Authors: Rajaei Saber , Ghammamy Shahriare , Mehrani Kheyrollah , Sahebalzamani Hajar
Published: March 2012

A number of new complexes have been synthesized by reaction of novel ligands acetic acid(4‐methyl‐benzylidene)hydrazide (L1) and acetic acid(naphthalen‐1‐ylmethylene)hydrazide (L2) with copper(II) nitrate. These new compounds were characterized by elemental analysis, TG, DTA, IR spectroscopy, UV spectral techniques. The changes observed between the FT‐IR and UV‐Vis spectra of the ligands and of the complexes allowed us to establish the coordination mode of the metal in complexes. The results suggest that the Schiff bases L1 and L2 coordinate as univalent anions with their bidentate N,O donors derived from the carbonyl and azomethine nitrogen. Also the probing of thermal analysis complexes can detect which complex has excellent thermal stability.
Coordination Polymers of N, Nʼ‐di‐(8‐Hydroxyquinolinolyl‐ 5‐methyl)‐N, N‐diethyl‐1,3‐propane diamine (QEPD)
Authors: Patel Asha D. , Patel Rignesh S. , Patel Ganpat R.
Published: March 2012

Coordination polymers containing a novel bis(oxine) bidentate ligand, namely N,Nʼ‐di(8‐hydroxyquinolinolyl‐5‐methyl)‐N,Nʼ‐diethyl‐1,3‐propane diamine (QEPD) have been prepared with the metal ions Zn(II), Cu(II), Ni(II), Co(II) and Mn(II). The novel bis‐(bidentate) ligand was synthesized by condensation of 5‐chloromethyl‐8‐hydroxyquinoline hydrochloride with N,Nʼ‐diethyl‐1,2‐ propane diamine in the presence of a base catalyses. All of these coordination polymers and the parent ligand were characterized by elemental analyses, IR spectral and diffuse reflectance spectral studies. The thermal stability and number‐ average molecular weights () of all of the coordination polymers were determined by thermogravimetric analyses and non‐aqueous conductometric titrations, respectively. In addition, all of the coordination polymers have been characterized by their magnetic susceptibilities.
Binding of Dumbbell Oligonucleotides to MoMuLV Reverse Transcriptase: Inhibitory Properties of RNase H Activity
Authors: Kumar Ajay
Published: March 2012

Dumbbell oligonucleotides with loops of various chemistry were synthesized. Incubation of dumbbell oligonucleotides containing phosphorothioate bonds or trimethylene phosphate linkages in loops with S1 nuclease did not result in significant cleavage under conditions which led to the degradation of dumbbell oligonucleotide containing phophodiester bonds in the loops. The binding of reverse transcriptase of Moloney Murine Leukemia Virus (MoMuLV) was evaluated with all the five oligonucleotides. The protein binds to all the dumbbell oligonucleotides with similar affinity. The dissociation constants evaluated using PAGE band mobility shift assays were of the order of 10-7. The inhibitory properties of the retroviral RNase H activity was evaluated using 3H –UTP‐labeled RNA:RNA‐DNA hybrid. It was found that the best dumbbell oligonucleotide, inhibitor contained phosphorothioate residues in both the loops. Our value studies demonstrated that this particularly designed oligonucleotide displays an IC50 of 18 nM in its inhibition on the reverse transcriptase RNase H activity, a magnitude lower than that of first nucleotide reverse transcriptase of HIV‐1, tenofovir, introduced by Gilead Science in the market.
Corrosion Inhibition Property of Some 1, 3, 4‐ Thiadiazolines on Mild Steel in Acidic Medium
Authors: Begum A. Shamitha , Mallika J. , Gayathri P.
Published: March 2012

The present work deals with the corrosion behavior of mild steel in acidic medium. The inhibitive effect of substituted 1, 3, 4‐Thiadiazol‐2‐amines on the corrosion of mild steel in 1 M H2SO4 has been studied by weight loss and electrochemical methods. The electrochemical parameters for mild steel in acidic solution with and without inhibitor were calculated. The effect of temperature on the corrosion rate, activation energy and free energy of adsorption were also calculated. The synergistic effect has been studied by weight loss and electrochemical methods. The electrochemical parameters for mild steel in acidic solution were also calculated.