bluuebunny/crossref_metadata_2025 huggingface dataset:
Titrimetric and Spectrophotometric Determination of Metaprolol tartrate in Pharmaceuticals Using N‐Bromosuccinimide
Authors: Basavaiah K. , Somashekar B. C.
Published: March 2012

One titrimetric and two spectrophotometric methods are presented for the assay of metaprolol tartrate (MPT) in bulk drug and in tablets. The methods employ N‐bromosuccinimide (NBS) as the oxidimetric reagent and two dyes, methyl orange and indigo carmine as spectrophotometric reagents. In titrimetry, an acidified solution of MPT is treated with a known excess amount of NBS and after a definite time, the unreacted oxidant is determined by iodometric back titration. Spectrophotometry involves adding a measured excess of NBS to MPT in acid medium followed by determination of residual NBS by reacting with a fixed amount of either methyl orange and measuring the absorbance at 520 nm (Method A) or indigo carmine and measuring the absorbance at 610 nm (Method B). In all the methods, the amount of NBS reacted corresponds to the amount of MPT. Reaction conditions have been optimized. Titrimetry allows the determination of 1 ‐ 12 mg of MPT and the calculations are based on a 1: 4 (MPT: NBS) reaction stoichiometry. In spectrophotometry, the measured absorbance is found to increase linearly with the concentration of MPT serving as basis for quantitation. The systems obey Beer’s law for 0.5 ‐ 4.0 μg mL-1 and 1.25 ‐ 10.0 μg mL-1 for method A and method B, respectively. The apparent absorptivities are calculated to 1.07 × 105 be and 4.22 × 104 L mol cm-1 for method A and method B, respectively. The methods developed were applied to the assay of MPT in commercial tablet formulations, and the results were compared statistically with those of a reference method. The accuracy and reliability of the methods were further ascertained by performing recovery tests via standard‐addition method.
New Investigation of Millimeter‐Wave Rotational Spectrum of CF3CN in the Excited Vibrational States v7=1 and v8=1
Authors: Motamedi Masoud , Zargari Bahram Vahabzadeh
Published: March 2012

The millimeter‐wave rotational spectra of the excited vibrational states v7=1 and v8=1 of the symmetric top molecule trifluoroacetonitrile, CF3CN, have been analyzed again. The ζ=±1 series have been assigned and the rotational parameters including B7 =2944.9748(14) MHz, q+t=1.4505(16) MHz for v7=1 and B8 =2950.4853(4) MHz, q+t= 3.6035(20) MHz for v8=1states were determined accurately.
Studies on Novel Bisaryl Hydrazino‐s‐triazine Derivatives ‐ Part 2
Authors: Chaudhari J. A. , Patel R. P. , Hathi M. V.
Published: March 2012

Various 2(4‐chloro phenyloxy)‐4,6‐bisarylhydrazino‐1,3,5‐triazines(3a‐f) were prepared by reaction of 2(4‐chloro phenyloxy)‐4,6‐dichloro ‐1,3,5‐triazine and various aryl hydrazine derivatives. All the 3a‐f derivatives were characterized by elemental analysis and IR spectral studies. All the compounds were screened for microbial activity against gram‐positive and gram‐negative bacteria.
Interaction Studies of Dilute Aqueous Oxalic Acid
Authors: Kandpal Kiran , Joshi B. K. , Joshi S. K. , Kandpal N. D.
Published: March 2012

Molecular conductance λm, relative viscosity and density of oxalicacid at different concentration in dilute aqueous solution were measured at 293 K.The conductance data were used to calculate the value association constant.Viscosity and density data were used to calculate the A and B coefficient ofJone‐Dole equation and apparent molar volume respectively. The viscosityresults were utilized for the applicability of Modified Jone‐Dole equation andStaurdinger equations. Mono oxalate anion acts, as structure maker and thesolute‐solvent interaction were present in the dilute aqueous oxalic acid.
Potentiometric Studies on the Protonation Constants and Protonation Energies of Some Diamines in Methanol + Water Mixtures
Authors: Sharma Sangita , Shah Mayur C. , Patel Neha , Dalwadi Dipika , Vora J. J.
Published: March 2012

The protonation constants of diamines such as ethylenediamine, 1,2‐diaminopropane, 1,3‐diaminopropane, o‐phenylenediamine, m‐phenylene‐diamine, p‐phenylenediamine were determined on the basis of Bjerrum and Calvin method in methanol‐water mixtures. A pH metric method was used for calculation of protonation constants. The effects of solvents on protonation constant have been determined at ionic strength 0.2 M dm-3 (NaClO4) and temperature 30±0.1oC under nitrogen atmosphere. FORTRAN (IV) programs were used for calculation of protonation constants and distribution of species like H2L, HL, L in equilibrium state. The logarithm of the protonation constants decrease in aliphatic diamines and increase in aromatic diamines with increase in methanol content in mixed equilibria. The verification of constants are explained on the basis of solute‐solvent interaction, solvation, proton transfer processes and dielectric constant of equilibria. Protonation energies have been calculated theoretically using computational methods and these protonation energies for aromatic diamines are higher than aliphatic diamines.
Reactions of Chlorine Gas on Benzaldehyde‐di‐n‐alkyl Acetals
Authors: Vasu A. Edwin , Santhanaraj K. Joseph , Raja S.
Published: March 2012

Reactions of chlorine gas on six aromatic acetals, the benzaldehyde di‐n‐alkyl acetals, C6H4‐CH(OR)2 where R=ethyl (1a), n‐propyl (2a), n‐butyl (3a), isobutyl (4a), n‐amyl (5a) and isoamyl (6a) were studied. The products were analyzed by IR and 1H NMR spectroscopic techniques and were found to be ring chlorinated alkyl benzoates. A plausible mechanism has been proposed based on the experimental observations and the effect of the alkyl groups on the product yield.
High Performance Thin Layer Chromatographic Method for Estimation of Cefprozil in Tablet Dosage Form
Authors: Jagapathi Raju V. , Seshagiri Rao J. V. L. N.
Published: March 2012

A simple, fast, specific and precise HPTLC method has been developed for the estimation of cefprozil in pure and in tablet dosage forms. Aluminium plates precoated with silica gel G60F254 were used as stationary phase and a mixture of chloroform: methanol: toluene: diethyl amine: water in the ratio 4: 4.4: 3.2: 3: 0.8 v/v as mobile phase. Quantification was carried out by the use of a densitometer in absorbance mode at 286 nm. The Rf value of cefprozil was found to be between 0.37 and 0.40. The results of the analysis have been validated statistically and by recovery studies. Linearity was observed in the concentration range of 400‐2000 ng/spot.
Selective Transport of Silver(I) Ion Through Polymer Membranes Containing Thioether Donor Macrocycles as Carriers
Authors: Nezhadali A. , Akbarpour M.
Published: March 2012

The Preparation of polymer membrane and it′s selectivity to silver(I) ion from an aqueous solution containing seven metal cations, Co(II), Ni(II), Cu(II), Zn(II), Ag(I), Cd(II) and Pb(II), was studied. The source phase contained equimolar concentrations of the above mentioned cations with the source and receiving phases being buffered at pH 5.0 and 3.0 respectively. The effect of variation in the number of the macrocyclic sulfur atom donor set anssd the size of ring 9 and 16 member macrocycles on transport efficiency is presented. Silver(I) ion transport occurred (at 25°C) from the aqueous source phase across the polymer membrane (derived from cellulos triacetate) containing ligands 9‐membered, S3‐donor and16‐membered S4‐donor macrocycles as the ionophors in separate experiments into the aqueous receiving phase. Clear transport selectivity for silver(I) ion was observed using both thioether donor macrocycles. The efficiency of transport rate for silver(I) ion with using 9‐membered S3‐donor macrocycle as carrier was better than 16‐membered S4‐donor .
Synthesis and Characterization of Pine Needles Reinforced RF Matrix Based Biocomposites
Authors: Singha A. S. , Thakur Vijay Kumar
Published: March 2012

Synthesis and characterization of pine needles reinforced thermosetting resin (Resorcinol‐Formaldehyde) which is most suitable as composite matrix has been reported. The polycondensation reaction between resorcinol and formaldehyde (RF) in different molar ratios has been applied to the synthesis of RF polymer matrix. A thermosetting resin based composite, containing approximately 10, 20, 30 and 40% of natural fiber by weight, has been obtained by adding pine needles to the Resorcinol‐Formaldehyde (RF) resin. The mechanical properties of randomly oriented intimately mixed particle reinforced (Pine needles) composites were determined. Effect of fiber loading in terms of weight % on mechanical properties such as tensile, compressive, and flexural and wear properties have also been evaluated. The reinforcing of the resin with Pine needles was accomplished in particle size of 200 micron by employing optimized resin. Present work reveals that mechanical properties of the RF resin increases to extensive extent when reinforced with Pine needles. Thermal (TGA/DTA) and morphological studies (SEM) of the resin, fiber and polymer composites thus synthesized have also been carried out.
Inhibitors of Human Dihydrofolate Reductase: A Computational Design and Docking Studies Using Glide
Authors: Yamini Lingala , Vijjulatha Manga
Published: March 2012

Dihydrofolate reductase (DHFR) plays a vital role in the DNA synthesis by reducing dihydrofolic acid to tetrahydrofolic acid which is an essential component. Synthetic ligands like methotrexate (MTX), aminopterin (AMP) and their analogues act as potential anti metabolites by mimicking the coenzyme dihydrofolic acid (DHFA) they inhibit the activity of DHFR antagonistically. Several ligands which are similar to MTX analogues and 6, 8 substituted 2 – naphthyls (NAP) which can mimic the pteridyl group of DHFA have been computationally designed. These ligands were proposed to hinder the formation N5, N10 methylene tetrahydrofolic acid (THFA) coenzyme, which is essential for the DNA synthesis. The docking studies were done using grid, generated with the 0.9 Vander Waals scaling for non polar bonds in the active site of the receptor. These newly designed ligands such as 14 ‐21 ,23 and 28 have shown good docking scores and predicted activities when compared to already existing ligands MTX and its analogues.
Synthesis and Characterization of Easily Processable Polyaramides Containing Pendent Diamantan Moiety in the Main Chain
Authors: Mukul M. K. , Srivastava P. K.
Published: March 2012

Three new polyamides were synthesized by direct polycondensation of 1‐6 bis(carboxy methyl diamantan with three different aromatic amines in Nmethyl 2‐pyrrolidine containing lithium chloride using triphenyl phosphate and pyridine as condensing agent. 1‐6 bis(carboxy methyl)diamantan was prepared from 1‐6 dibromo diamantan and structure was conformed by 1H and 13C NNR spectroscopy. A comparison of the effect for introducing bulky side group in the diamine contribution was evaluated. This polyamide had inherent viscosity of 0.57‐1.18dL/g. It was found that all polyamides were soluble in polar aprotic solvents. Thermal stability of polymer was evaluated by TGA analysis. Molecular weights of all polyamides were determined by gel permeation chromatography. These have been found to be thermally stable up to 400°C with 1320% weight loss under nitrogen atmosphere.
Simple Extractive Colorimetric Determination of Oxaprozin by Acid‐Dye Complexation Methods in Solid Dosage Form
Authors: Ganesh M. , Thangabalan B. , Patil Rahul , Ganguly Swastika , Sivakumar T.
Published: March 2012

A simple and sensitive extractive spectrophometric method has been described for the assay of oxaprozin (OXA) either in pure form or in pharmaceutical solid dosage form. The developed method involves formation of colored chloroform extractable ion‐pair complex of OXA with bromocresol green in aqueous acidic medium. The extracted complexes showed absorbance maxima at 421 nm. Beer′s law is obeyed in the concentration range of 10‐50 μg mL-1. This method has been applied to the determination of drug in commercial tablets. Results of analysis were validated statistically. The excipients present in the formulations do not interfere with the assay procedure.
Mild and Efficient Oxidation of Aromatic Alcohols and Other Substrates Using NiO2/CH3COOH System
Authors: Kooti Mohammad , Jorfi Mehdi
Published: March 2012

A variety of aromatic alcohols were efficiently oxidized to their corresponding aldehydes and ketones in good to excellent yields using nickel peroxide activated by acetic acid. Some thiols and amines were also readily oxidized by this oxidant under mild conditions.
Enhancement of Lipase Enzyme Activity in Non‐Aqueous Media through a Rapid Three Phase Partitioning and Microwave Irradiation
Authors: Saifuddin N. , Raziah A. Z.
Published: March 2012

Three phase partitioning is fast developing as a novel bio‐separation strategy with a wide range of applications including enzyme stability and enhancement of its catalytic activity. pH tuning of enzyme is now well known for use in non‐aqueous systems. Tuned enzyme was prepared using a rapid drying technique of microwave dehydration (time required around 15 minutes). Further enhancement was achieved by three phase partitioning (TPP) method. With optimal condition of ammonium sulphate and t‐butanol, the protein appeared as an interfacial precipitate between upper t‐butanol and lower aqueous phases. In this study we report the results on the lipase which has been subjected to pH tuning and TPP, which clearly indicate the remarkable increase in the initial rate of transesterification by 3.8 times. Microwave irradiation was found to increase the initial reaction rates by further 1.6 times, hence giving a combined increase in activity of about 5.4 times. Hence it is shown that microwave irradiation can be used in conjunction with other strategies (like pH tuning and TPP) for enhancing initial reaction rates.
Potentiometric Studies on Transition Metal Complexes of Substituted Derivative of Coumarin‐Part 1
Authors: Vyas K. B. , Jani G. R. , Hathi M. V.
Published: March 2012

The formation constants of binary complexes of d10 metal ions Cu(II), Ni(II), Co(II) and Mn(II) with 3‐[{3‐(3’‐chloro phenyl}‐prop‐2‐enoyl]‐4‐hydroxy‐6‐methyl‐2H‐chromen‐2‐one have been studied by using Irving‐Rossoti method at constant temperature 30±1 °C and ionic strength μ=0.1 M dM-3 was held constant using sodium nitrate as an electrolyte. The factors influencing formation and stabilities of binary complexes have been discussed.
Kinetics of Oxidation of Metochlopramide withChloramine‐T in HClO4 Medium
Authors: Meenakshi K. M. , Pai K. Vasant Kumar
Published: March 2012

The kinetics of oxidation of metochlopramide hydrochloride (MCP) with sodium N‐chloro p‐toluenesulfonamide (CAT) in perchloric acid solution has been studied at 313K. The reaction rate shows a first order dependence on [CAT], fractional order on [MCP] and inverse fractional order on [H+]. There is a negative effect of dielectric constant of the solvent. The addition of the reduction product of CAT has no significant effect on the rate. The rate remained unchanged with the variation in the ionic strength of the medium. The reaction fails to induce the polymerization of acrylonitrile. Thermodynamic parameters have been computed by Arrhenius plot. The stoichiometry of the reaction was found to be 1:2 and oxidation products were identified. The Michaelis‐Menten type of kinetics has been proposed. CH3C6H4SO2NHCl have been assumed to be the reactive oxidizing species. Thermodynamic parameters were computed by studying reactions at different temperatures. A mechanism consistent with observed kinetics is proposed.
Ion Exchange Properties of a Terpolymer Resin Derived from 2, 4‐Dihydroxybenzaldehyde, Oxamide and Formaldehyde
Authors: Tarase M. V. , Gurnule W. B. , Zade A. B.
Published: March 2012

Terpolymer resins (2,4‐DHBOF) were synthesized by the condensation of 2,4‐dihydroxybenzaldehyde and oxamide with formaldehyde in the presence of hydrochloric acid as catalyst, proved to be selective chelation ion exchange terpolymer resins for certain metals. Chelation ion exchange properties of these polymers were studied for Fe+3, Cu+2, Hg+2, Cd+2, Co+2, Zn+2, Ni+2 and Pb+2 ions. A batch equilibrium method was employed in the study of the selectivity of the distribution of a given metal ions between the polymer sample and a solution containing the metal ion. The study was carried out over a wide pH range and in a media of various ionic strengths. The polymer showed a higher selectivity for Fe+3, Cd+2 and Co+2 ions than for Cu+2, Hg+2, Zn+2, Ni+2 and Pb+2 ions.
Synthesis, Characterization and Antimicrobial Activity of Metal Chelates of 5‐[1(H)‐Benzotriazole methylene]‐8‐quinolinol
Authors: Patel H. S. , Oza K. K.
Published: March 2012

5‐Chloromethyl‐8‐quinolinol was condensed stoichiometrically with benzotriazole in presence of potassium carbonate. The resulting 5‐[1(H)‐benzo triazole methylene]‐8‐quinolinol (BTMQ) was characterized by elemental analysis and spectral studies. The transition metal chelates viz. Cu2+, Ni2+, Co3+, Mn2+ and Zn2+ of BTMQ were prepared and characterized by metal‐ligand (M:L) ratio, IR and reflectance spectral studies and magnetic properties. The antifungal activity of BTMQ and its metal chelates was screened against various fungi. The results show that all these samples are good antifungal agents.
Acoustical Studies on Molecular Interactions in Binary Liquid Mixtures at 303 K
Authors: Uvarani R. , Sivapragasam J.
Published: March 2012

Molecular interaction studies using ultrasonic technique in the binary liquid mixtures of cyclohexanone with o‐cresol and p‐cresol have been carried out at 303 K. Using the measured values of ultrasonic velocity, density and viscosity, acoustical parameters and their excess values are evaluated. From the properties of these excess parameters the nature and strength of the interactions in these binary systems are discussed.
Bentonite Clay K‐10 as an Efficient Reagent for the Synthesis of Quinoxaline Derivatives at Room Temperature
Authors: Hasaninejad Alireza , Zare Abdolkarim , Shekouhy Mohsen , Reza Moosavi-Zare Ahmad
Published: March 2012

Bentonite clay K‐10 acts as an efficient reagent for the preparation of quinoxaline derivatives via the condensation of aryl and alkyl 1,2‐diamines with α‐diketones in ethyl alcohol as a green media at room temperature. Using this method, the title compounds are produced in high to excellent yields and short reaction times.
Analysis of Tocopherols by High Performance Liquid Chromatography
Authors: Edison B.
Published: March 2012

: Gas chromatography is the key technique for organic components and also for tocopherols analysis. High performance liquid chromatography has an important role to take part in applications such as the handling of less usual samples, prevention of degradation of heat sensitive functional groups and for micro preparative purposes. Many approaches for development of improved methods are suggested, especially for reversed phase applications.
A Sensitive UV Spectrophotometric Method for the Determination of Gabapentin
Authors: Singh Gujral R. , Manirul Haque S. , Shanker P.
Published: March 2012

An accurate and validated spectrophotometric method was developed for the determination of gabapentin. This is simple, sensitive and low cost UV spectrophotometric method. The method is based on the direct measurement of the native absorbance of the drug. The detection was done at 210 nm. The method was linear in the range of 0.25 ‐ 3.5 µ g/mL with correlation coefficient of 0.9999. It is validated according to the ICH guidelines with respect to linearity, selectivity, accuracy and precision, limit of quantitation and limit of detection. The method has been applied to assess gabapentin in pharmaceutical formulations with good accuracy and precision and relatively free of interference from coexisting substances.
Rhodamine B Adsorption‐ Kinetic, Mechanistic and Thermodynamic Studies
Authors: Ramuthai S. , Nandhakumar V. , Thiruchelvi M. , Arivoli S. , Vijayakumaran V.
Published: March 2012

Adsorption of rhodamine B from aqueous solution on the surface of Moringa oliefera bark carbon was accomplished under the optimize conditions of temperature, concentration, pH, contact time and quantity of adsorbent. Spectrometric technique was used for the measurements of concentration of dye before and after adsorption. The percentage removal of rhodamine B was calculated. The values of % adsorption data for Moringa oliefera bark carbon system show better adsorption capacity. The experimental data are fitted to the Langmuir and Freundlich isotherm equations. The values of their corresponding constant were determined from the slope and intercepts of their respective plots. Thermodynamic parameters like ΔG0, ΔH0 and ΔS0 were calculated. Rhodamine B-Moringa oliefera bark carbon system shows spontaneous and endothermic behaviour. The results of these investigations suggested that natural adsorbents can be utilized as adsorbent materials, because of their selectivity′s for the removal of dyes.
Novel Synthesis and Characterization of Thiosemicarbazone Compounds Containing 4‐Acyl‐2‐pyrazolin‐5‐ones
Authors: Rana Arjun K. , Parekh Nayan R. , Dabhi Harish R. , Nadkarni Sunil S.
Published: March 2012

A novel synthesis of 4‐acylthiosemicarbazone‐3‐methyl‐1‐(4`‐methylphenyl)‐2‐pyrazolin‐5‐one by condensation of 4‐acyl‐3‐methyl‐1‐(4`‐methylphenyl)‐2‐pyrazolin‐5‐one with thiosemicarbazide is carried out. The compounds were characterized on the basis of elemental analysis, IR, 1H NMR, Mass, DSC and 13C NMR spectral data. The structures were investigated for their antibacterial and antifungal activity. They are very essential to study on cerebral infarction (Free radical scavenger). A single crystal X‐ray study of this thiosemicarbazones and their metal complexes is in progress.
Development and Characterization of Novel Interpenetrating Network (IPN) Foams from Epoxy Ester and Aliphatic Epoxy Resin
Authors: Patel Kanuprasad , Desai Dhirubhai , Bhuva Santosh
Published: March 2012

Diglycidyl ether of bisphenol‐A (DGEBA) was reacted with acrylate monomer at variable molar ratios. The reaction between glycerine and epichlorohydrine form glycidyl ether of polyol aliphatic epoxy resin. The resultant resins were characterized duly. Both the resins were mixed at different ratios with constant high shear stirring. The obtained mixture and suitable additives were heated at 150oC for one and half hour. The so called Interpenetrating Network (IPN) transformed into foams. The performance of foams was evaluated by testing for compression in both parallel and perpendicular to rise direction. The tests were carried out at room temperature and at the elevated temperature. The compression properties showed a decreasing trend for increasing amounts of glycerine resin. The density and thermal properties of epoxy foams were also evaluated. The relation between the composition, density and properties of the foam was analyzed.
Determination of Pantoprazole Sodium and Lansoprazole in Individual Tablet Dosage Forms by RP‐HPLC Using Single Mobile Phase
Authors: Prasanna Kumar Reddy B. , Ramanjaneya Reddy Y. , Ramachandran D.
Published: March 2012

A simple, sensitive and precise high performance liquid chromatographic method for the analysis of pantoprazole sodium and lansoprazole has been developed, validated and used for the determination of compounds in commercial pharmaceutical products. The compounds were well separated an isocratically on a C18 column [Inertsil C18, 5μ, 150 mm x 4.6 mm] utilizing a mobile phase consisting of acetonitrile: phosphate buffer (60:40, v/v, pH 7.0) at a flow rate of 1.0 mL/min with UV detection at 230 nm. The retention time of pantoprazole sodium and lansoprazole was found to be 2.017 min and 2.538. The procedure was validated for linearity (Correlation coefficient=0.999). The study showed that reversed‐phase liquid chromatography is sensitive and selective for the determination of pantoprazole sodium and lansoprazole using single mobile phase.
Validated Spectrophotometric Estimation of Famciclovir in Tablet Dosage Form
Authors: Nesalin J. Adlin Jino , Babu C. Jose Gnana , Kumar G. Vijaya , Mani T. Tamizh
Published: March 2012

Two simple and sensitive spectrophotometric methods have been developed for the estimation of Famciclovir (FCR) in bulk and tablet dosage form. Methods A and B are based on the formation of ion‐pair complexes of the drug with dyes such as orange II (OG‐II) and alizarin red S (AR‐S) in acidic medium followed by their extraction with chloroform to give colored chromogen with absorption maxima at 480 nm and 440 nm respectively. Beer’s law is valid in the concentration range of 2‐10 mcg/mL for both the methods. These developed methods were validated for precision, accuracy, ruggedness and robustness. Statistical analysis proves that the methods are reproducible and selective for the routine analysis of the said drug.
Thermal Degradation Study of Salicylic Acid, Diaminonaphthalene and Formaldehyde Terpolymer
Authors: Masram Dhanraj T.
Published: March 2012

The terpolymer resin salicylic acid‐diaminonaphthalene‐formaldehyde (SDNF) has been synthesized by the condensation of salicylic acid and diaminonaphthalene with formaldehyde in the presence of catalyst hydrochloric acid in 1:1:2 molar proportions of reactants. Detailed thermal degradation studies of the SDNF terpolymer resin has been carried out to ascertain its thermal stability. Thermal degradation curve has been discussed in order to determine their mode of decomposition, order of reaction, apparent activation energy, frequency factor, free energy change, entropy change, and apparent energy change. Freeman – Carroll and Sharp‐ Wentworth methods have been applied for the calculation of kinetic parameters while the data from the Freeman – Carroll methods have been used to determine various thermodynamic parameters.
Design, Synthesis and Evaluation of Schiff’s Bases of 4‐Chloro‐3‐coumarin aldehyde as Antimicrobial Agents
Authors: Bairagi Shriram , Bhosale Ashok , Deodhar Meenakshi N.
Published: March 2012

4‐Chloro‐2‐oxo‐2H‐chromene‐3‐carbaldehyde (2) was reacted with different anilines in rectified spirit as solvent to yield a series of the title compounds i.e. 4‐chloro‐3‐((substituted‐phenylimino) methyl)‐2H‐chromen‐2‐one (3a-i). These compounds were charaterised on the basis of their spectral (IR, 1H NMR) data and evaluated for antimicrobial activity in vitro against gram positive and gram negative bacteria and fungi. Compound 3C was found to be most active with an MIC of 15 μg /mL against all the tested organisms.
Mining the Information for Structure Based Drug Designing by Relational Database Management Notion
Authors: Balajee R. , Dhanarajan M. S.
Published: March 2012

Structure based drug design is a technique that is used in the initial stages of a drug discovery program. The role of various computational methods in the characterization of the chemical properties and behavior of molecular systems is discussed. The field of bioinformatics has become a major part of the drug discovery pipeline playing a key role for validating drug targets. By integrating data from many inter‐related yet heterogeneous resources, informatics can help in our understanding of complex biological processes and help improve drug discovery. The determination of the three dimensional properties of small molecules and macromolecular receptor structures is a core activity in the efforts towards a better understanding of structure‐activity relationships.
Spectrophotometric Evaluation of Stability Constants of Copper, Cobalt, Nickel and Zinc with 2‐Thiobarbituric Acid in Aqueous Solution
Authors: Ahmadi F. , Sarrafi A. H. M. , Ghashghaee M. M.
Published: March 2012

Stoichiometry and equilibrium study of ion‐ligand conducted in aqueous solution by spectrophotometry. Stability constants of the complexes are determined at 25 °C, ionic strength was adjusted to 0.2 (% w/v) with NaCl. The pH was adjusted to 6. 2‐Thiobarbituric acid‐ion complexesʼ stability was calculated in aqueous solution using DATAN (Data Analysis program). The results of this method denote formation specie ML2. The log K for ions Cu+2,Co+2, Ni+2 and Zn+2 were 4.89, 4.69, 4.47 and 4.82, respectively.
Microwave Assisted Synthesis of New 1‐{2, 4‐Dihydroxy‐5‐[5‐(aryl)‐1‐pyridine/pyrimidine‐4‐carbonyl)‐4, 5‐dihydro‐1H‐pyrazol‐3‐yl]‐phenyl}‐3‐(aryl)‐propenones and their Antibacterial Activity
Authors: Ashok D. , Aravind K.
Published: March 2012

A series of 1‐{2, 4‐dihydroxy‐5‐[5‐(aryl)‐1‐pyridine/pyrimidine‐4‐carbonyl)‐4, 5‐dihydro‐1H‐pyrazol‐3‐yl]‐phenyl}‐3‐(aryl)‐propenones (2a‐h) have been synthesized from 1‐[2,4‐dihydroxy‐5‐(aryl acryloyl)phenyl]‐aryl propenones(1a-h)by Micheal addition with isoniazide/pyrazinic acid hydrazide under microwave irradiation and classical heating. The synthesized compounds were characterized by IR, 1H‐NMR, 13C‐NMR and Mass spectral data. All the compounds were screened for their Antibacterial activity.
Spectral, Electrochemical and Molecular Modeling Studies of Some 3 (2 Hydroxy benzalhydrazino‐4‐thiazolyl)coumarins
Authors: Raju N. , Ramachandraiah A.
Published: March 2012

Spectral, cyclic voltammetric and molecular modeling studies have been carried out on some 3‐(2‐hydroxybenzalhydrazino‐4‐thiozolyl)coumarins (1), to understand their solution and electrochemical characteristics. These investigations reveal structural alterations in the conjugates of their acid‐base equilibria as indicated by considerable bathochromic shift in electronic spectra and changes in electron transfer properties with rise in pH. The pKa values and electrochemical data such as Ep, ip, αna, k ° h, etc., of 1 were evaluated. Further, the compound 1 is found to be good chelating ligands. Molecular modeling studies were also performed to correlate the spectral and electrochemical observations. Voltammetric analysis of 1 is also presented.
Production of Polyhydroxybutyrate (Bioplastic) and its Biodegradation by Pseudomonas Lemoignei and Aspergillus Niger
Authors: Kumaravel S. , Hema R. , Lakshmi R.
Published: March 2012

The biodegradation of polyhydroxybutyrate (PHB) and its copolymer polyhydroxy butyrate‐co‐hydroxyvalerate (PHB‐co‐HV) was studied. Bacterial as well as fungal isolates were isolated from the local industrial ecosystem. All these isolates were tested for the degradation of the above polymers in assay agar medium as well in liquid cultures. The culture biomass and the clear zone around the colonies were measured to evaluate the activity of these isolates. In all, the fungal isolates were found to degrade these polymers more rapidly when compared to bacteria, due to their versatile depolymerase activities.
Electrochemical Reduction Behaviour of Zileuton at a Dropping Mercury Electrode by Polarography
Authors: Sreedhar N. Y. , Nayak M. Sankara , Prasad K. Srinivasa , Prasad P. R. , Reddy C. Nageswar
Published: March 2012

Electrochemical behaviour of anticancer drug zileuton was investigated by direct current polarography (DCP) and differential pulse polarography using a dropping mercury electrode (DME) as working electrode and Ag/AgCl reference electrode in universal buffer of pH range from 2.0 to 12.0. The drug was extracted from the dosage forms in dimethyl formamide (DMF). Kinetic parameters such as diffusion co‐efficient (D) and heterogeneous forward rate constants (k0f,h) are evaluated and reported. The differential pulse polarographic method has been developed for the determination of this drug in pharmaceutical formulations.
Studies on Deltamethrin Treated Mosquito Net
Authors: Tyagi A. , Sharma T. , Singh M. , Fatma K. , Rawat V. S. , Aggarwal M. , Khandal R. K.
Published: March 2012

The focus of the present studies is to characterize mosquito net for its material of construction and qualitative as well as quantitative determination of the mosquito repellent chemical deltamethrin present in it. Further, the assessment of the mode of incorporation of the deltamethrin in the fabric of the mosquito net was done, i.e. whether the deltamethrin was present as a coating on the surface of the mosquito net or it was incorporated in the bulk of the material of construction of the mosquito net. The chromatographic technique has been used for quantitative estimation of deltamethrin extracted by two different solvents from the net. It has been found that the determination of deltamethrin in mosquito nets can vary with the method of extraction used. While extraction with acetone is good enough for estimating the chemical adsorbed on the surface, extraction with xylene provides complete information about the chemical present even in the bulk of the material.
Conformational Studies on γ ‐ Benzyl‐ L‐ Glutamate and L‐ Valine Containing Block Copolypeptides
Authors: Kumar Ajay
Published: March 2012

Conformational studies on γ ‐ benzyl‐L‐ glutamate and L‐ valine containing block copolypeptides are reported using IR and CD spectra. The block copolypeptides contain valine block in the center and on both sides of the valine are γ ‐ benzyl‐ L‐ glutamate blocks. The changes in conformation with increase in chain length of γ ‐ benzyl‐ L‐ glutamate blocks are observed. When the chain length of γ ‐ benzyl‐L‐ glutamate block is 13, the block copolypeptide crystallized into beta conformation. With increase in chain length of γ ‐ benzyl‐L‐ glutamate block from 13 to 30 the conformation of the copolypeptide changes from beta sheet to alpha helix, but small amount of beta component also remains. With further increase in chain length of γ ‐ benzyl‐ L‐ glutamate block from 30 to 45 the copolypeptide crystallizes exclusively into alpha helix conformation.
Synthesis and Biological Evaluation of Some Novel 1, 3, 5‐Trisubstituted Pyrazolines
Authors: Revanasiddappa B. C. , Rao R. Nagendra , Subrahmanyam E. V. S. , Satyanarayana D.
Published: March 2012

A new series of chalcones (3a-j) were synthesized by condensation of simple aldehydes with substituted acetophenones in presence of alkali. The resulted chalcones upon cyclization in presence of glacial acetic acid with isoniazid (INH) will yields the title compounds (4a-j). The newly synthesized compounds were assigned on the basis of IR, 1H NMR, and Mass spectral data. All the final compounds were evaluated for their in vitro antimicrobial activity.
Production and Preliminary Characterization of Alkaline Protease from Aspergillus flavus and Aspergillus terreus
Authors: Chellapandi P.
Published: March 2012

Proteases are being an industrial candidate, which are widely used in food, bakery, and beverage and detergent industry. In leather industry, alkaline proteases are exhibiting a prominent role in unhairing and bating processes. An extensive use of filamentous fungi, especially Aspergillus species has been studied elaborately. Although, the significant application of alkaline protease produced from these strains in leather industry is being limited. Aspergillus flavus and Aspergillus terreus found as the potential strains for production of tannery protease in submerged fermentation. To improve the productivity of this enzyme in liquid broth, various media ingredients have been optimized. The crude and partially purified proteases preliminarily characterized and used for unhairing processes at lab scale in tannery. The protease obtained from these strains showed the good activity in wide alkaline condition at 50 °C suggesting the possibility of using in leather and detergent industry.
Structural, Spectroscopic and Biological Aspects of O, N‐ Donor Schiff Base Ligand and its Cr(III), Co(II), Ni(II) and Cu(II) Complexes Synthesized through Green Chemical Approach
Authors: Rathore Kavita , Singh Rajiv K. R. , Singh H. B.
Published: March 2012

The monofunctional bidentate Schiff base ligand (o‐vanillin) p‐chloroaniline and its four new complexes of chromium(III), cobalt(II), nickel(II) and copper(II) have been synthesized by classical thermal and microwave‐irradiated techniques. All the new derivatives have been characterized by elemental analysis, molecular weight determinations, molar conductance measurements, UV‐Vis, IR and NMR spectral studies. The IR spectral data suggest the involvement of phenolic oxygen after deprotonation and azomethine nitrogen in coordination to the central metal ion. The growth inhibiting potential of the ligands and complexes has been assessed against a variety of fungal and bacterial strains.
Corrosion Inhibition and Adsorption Characteristics of Tarivid on Mild Steel in H2SO4
Authors: Eddy N. O. , Ebenso E. E.
Published: March 2012

The corrosion inhibition and adsorption characteristics of (+/‐)‐9‐fluoro‐2,3‐dihydro‐3‐methyl‐10‐(4‐methyl‐1‐piperazinyl)‐7‐oxo‐7H‐pyrido[1,2,3‐de]‐1,4‐benzoxazine‐6‐carboxylic acid (Tarivid) on the corrosion of mild steel has been studied using thermometric and gasometric methods. The study reveals that tarivid inhibits the corrosion of mild steel in H2SO4. The values of inhibition efficiency of tarivid were found to increase as its concentration increased but decreased with increase in temperature. Activation energies of the inhibited corrosion of mild steel ranged from 39.05 to 50.61 kJ/mol. Values of enthalpy change and free energy of adsorption were negative which indicated exothermic and spontaneous adsorption process. Physical adsorption mechanism is proposed from the obtained kinetic and thermodynamic parameters. Langmuir adsorption isotherm model is obeyed from the fit of the experimental data.
Synthesis, Physical Characterization and Biological Evaluation of Schiff BaseCr(III), Mn(III) and Fe(III) Complexes
Authors: Kumar Gajendra , Kumar Dharmendra , Devi Shoma , Kumar Amit , Johari Rajeev
Published: March 2012

M(III) complexes with Cr, Mn and Fe with Schiff base derived from 2‐amino‐4‐ethyl‐5‐hydroxy benzaldehyde and oxocarbohydrazide were synthesized and characterized by several techniques using elemental analysis (C, H, N), molar conductance measurements, magnetic measurements, electronic, mass and IR spectral studies. On the bases of these studies, a five coordinated square pyramidal geometry for all these complexes has been proposed and found to be potential antimicrobial agent. The Schiff base ligand and complexes were also tested for their antimicrobial activity (against the bacteria Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Bacillus megaterium and the fungi Kluyveromyces fragilis, Rhodotorula rubra, Candida albicans and Trichoderma reesei) to assess their inhibiting potential. An attempt is also made to correlate the antimicrobial activity with geometry of the complexes. All complexes were found to be less active against the pathogens E.coli, S.aureus and P.aeruginosa. Cr(III) complex showed the best antimicrobial activity, but ligand alone was found to be active against the fungus T.reesei.
A Selective High Performance Liquid Chromatographic Method to Follow the Hydrolytic Degradation of Nicardipine Hydrochloride
Authors: Ibrahim K. E. , Al-Ashban R. M. , Babiker L. B.
Published: March 2012

A simple, stability indicating, reverse phase high performance liquid chromatographic method was developed and validated for determination of nicardipine hydrochloride (NC) in the presence of its degradation products. The chromatographic separation was performed on Hypersil, BDS‐C18, 30 cm × 3.9 mm id, at ambient temperature with UV‐detection at 254 nm. A mixture of 20% (v/v) aqueous 0.01 M sodium acetate∕acetic acid buffer (pH 4.5) and 80% acetonitrile was used as the mobile phase at a flow rate of 1.5 mL min-1, losartan was used as internal standard. The calibration curve is linear over the concentration range 5‐40 μg mL-1, with a regression coefficient of 0.9984 and the % recovery was 99.78±0.17. The method was used to investigate the kinetics of alkaline, acids induced degradation, effect of buffer concentration and temperature. The degradation followed first‐order kinetics. The rate constant, half‐life time, and activation energy were calculated
Utilization of m‐Phenylenediamine‐Furfural Resin for Removal of Cu(II) from Aqueous Solution‐A Thermodynamic Study
Authors: Najim Tariq S. , Zainal Israa G. , Ali Dina A.
Published: March 2012

m‐Phenylenediamine was condensed with furfural in absence of catalyst at room temperature. The produced m‐phenylenediamine‐furfural resin was used for the removal of Cu(II) from aqueous solution. The pH for the optimum removal of Cu(II) was 6. The negative values of Gibbs free energy at low concentration of Cu(II) (20, 30 ppm) indicative of the spontaneous adsorption process, while, at higher Cu(II) concentration (40,50 ppm) the positive and weak values of ∆G° indicate that the process is feasible but non spontaneous. The values of ∆H° were positive indicating that the sorption process is endothermic. On the other hand, the values of activation energy (Ea) were inconsistent with the values of ∆H° both are positive and lie in the range of physisorption. The entropy ∆S° of the process was positive indicative of the randomness of the Cu(II) ions at the solid / liquid interface. The values of sticking probability S* were less than one which indicate a preferable adsorption process and the mechanism is physisorption.
Biosorption of Cr(VI) from AqueousSolution Using New Adsorbent: Equilibrium and Thermodynamic Study
Authors: Zainal Israa G.
Published: March 2012

Biosorption is one such emerging technology which utilized naturally occurring waste materials to sequester heavy metals from polluted water. In the present study cinnamon was utilized for Cr(VI) removal from aqueous solutions.It was found that a time of two hours was sufficient for sorption to attain equilibrium. The optimum pH was 2 for Cr(VI) removal. Temprature has little influence on the biosorption process. The Cr(VI) removal decreased with increase in temperature. The biosorption data was well fitted to Dubinin ‐ Radushkevich (D‐R), Freundlich and Tempkin adsorption isotherm models, although the correlation coefficient of Langmuir model was high but the calculated adsorption capacity did not agree with the experimental. The thermodynamic study reveals that the biosorption process is spontaneous and the spontaneity decreased with temperature increase and the process is exothermic accompanied by highly ordered adsorbate at the solid liquid interface. ΔH° values were negative and lie in the range of physical adsorption.
Synthesis of New Chiral and Nonchiral Pyrido [3,2‐e],[1,3,4] oxadiazine Derivatives
Authors: Shet L. S. , Shelar A. R. , Manvi F. V.
Published: March 2012

A chiral series of 6,7‐dichloro‐3‐[3‐(2,2‐dihalovinyl)‐2,2‐dimethylcyclopropyl] ‐1H‐pyrido [3,2‐e],[1,3,4] oxadiazines (a-f) and a nonchiral series of 3‐substituted, 6,7‐dichloro‐1H‐pyrido [3,2‐e][1,3,4] oxadiazines (a-g) have been synthesized. The synthesized compounds were characterized by IR, 1H NR, HPLC and mass spectral data.
Validated Reverse Phase HPLC Method for the Determination of DEHP Content in Reconstituting Diluents and in Reconstituted Solutions of Imipenem and Cilastatin for Injection
Authors: Chaudhary A. K. , Waske S. Ankushrao , Yadav S. , Chandrashekhar T. G. , Singh Vandana
Published: March 2012

A simple, rapid, accurate and economic reverse phase HPLC method was developed and validated for determination of di‐(2‐ethylhexyl)phthalate (DEHP) in reconstituting diluents and reconstituted solutions of imipenem and cilastatin for injection The method was applied to detect any leaching enhancement in presence of imipenem and cilastatin in reconstituted injections. Imipenem and cilastatin for injection is a widely used broad spectrum beta‐lactam antibiotic. As per requirements of various regulatory authorities of different countries, DEHP content needs to be monitored in the reconstituting diluents used to reconstitute injections. The proposed method is a unique method wherein DEHP can be determined directly without any sample pre‐treatment before analysis. The method can be used as a good quality control tool to control the leaching of DEHP in the reconstituting diluents and reconstituted injections. The method utilizes C18 column (250 × 4.6 mm, 5μ) and a mixture of methanol, propan‐2‐ol and water as mobile phase. DEHP was detected at 225 nm. The method has low limit of quantification (0.058 μg mL-1) which is much below the acceptance limit calculated as per USFDA tolerance criteria (3.5 μg mL-1 for adults and 0.3 μg mL-1 for neonates and infants).
Spectrophotometric Determination of Lorsartan Potassium and its Dosage Form by Bromothymol Blue and Phosphate Buffer
Authors: Latheeshjlal L. , Parthiban P. , Alagarsamy V. , Sunil M. , Mahul J. Vaidhya , Mohan T. Rama
Published: March 2012

Simple, rapid and accurate, spectrophotometric method for the determination of losartan potassium by using bromothymol blue as a chromogen and phosphate buffer solution (pH 3‐4) as a diluting agent was developed. The developed colour shows maximum absorbance at 620 nm and it was observed that the absorbance of different dilution from the plots the calibration curve between the concentrations in x‐axis, absorbance at y‐axis. The recovery studies were also carried out to ensure the reproducibility and repeatability. This recovery studies shows between 96.82‐100.08% for the different formulation. Hence, it was concluded that the developed simple, precise and accurate method can be effectively used for the routine analysis of losartan potassium
Activity‐Guided Isolation of Antioxidant Compounds from Andrographis stenophylla Leaf
Authors: Thangavel Neelaveni , Gupta Jayanta Kumar
Published: March 2012

The antioxidant potency of various extracts of Andrographis stenophylla leaf was evaluated in vitro using ferric thiocyanate method. Reductive ability and free radical scavenging activity of the extracts were also investigated. Amounts of phenolic compounds in each of the extracts were determined using Folin‐Ciocalteau reagent and compared to observe the correlation between antioxidant activities and total phenolic content. Methanol extract exhibited maximum antioxidant activity and was found to contain 2% of total phenolic compounds. Methanol extract was subjected to column chromatographic separation over silica gel G using ethyl acetate: formic acid: acetic acid: water. Fractions thus obtained were screened for their antioxidant activity. Among the eleven fractions screened, fraction C was more active than the standard butylated hydroxyanisole. Fraction C on further fractionation with n‐butanol: acetic acid: water afforded two flavanoids namely acacetine and isosakuranetine. Fraction A was also shown to possess good antioxidant activity which was developed using TLC and indicated the presence of a terpenoid, Andrographolide. The structures of the isolated compounds were confirmed by UV, IR, MS, 1H and 13C NMR spectral data. This is the first report wherein Andrographolide, Acacetine and Isosakuranetine are isolated from Andrographis stenophylla leaf.
Determination of Bromate at Trace Level in Sudanese Bottled Drinking Water Using Ion Chromatography
Authors: Musa Mei , Ahmed Ibrahim M. , Atakruni Ismat
Published: March 2012

Bromate ion was determined by ion chromatography with spectro‐photometric detection after post column reaction with o‐dianisidine reagent in acidic medium. IonPac AS19 anion‐exchange column was used with 20 mM sodium hydroxide eluent. The eluent from the column was then allowed to react with o‐dianisidine at 60 °C. The developed colour of the final product was measured spectrophotometrically at 450 nm. Linearity of the method was checked up to 200 μg/L by using 200 μL sample injection volume and the linear correlation coefficient was 0.9998. The method detection limit was 0.56 μg/L and the precision was 6.2% at 100 μg/L. The spiked recovery for bromate in water samples was 93%. Interferences from some anions eg. nitrate, chloride and nitrite were studied. The method was applied for the determination of bromate ion in ten sudanese bottled drinking water. Bromate was detected in 60% of the samples at concentrations ranged between 5‐169 μg/L.