Chemistry Articles

About Authors:
KALPESH PATEL, JAYACHANDRAN E.*, SREENIVASA G.M.
* P.G. Department of Pharmaceutical Chemistry,
S.C.S. College of Pharmacy, Harapanahalli-583131,
Karanataka, India.
*drjc_2006@rediffmail.com, kalpesh.m.pharm@gmail.com

Abstract
Various substituted 3-amino-1-(2,4-dinitro phenyl)-5-[(5-substituted-1,3,4-oxadiazol-2-yl)amino]-1-H-pyrazole-4-carboxyamide and (5E)-5-[4-(dimethylamino) benzylidene]-3-(5-substituted-1,3,4-oxadiazol-2-yl)-2-phenyl-3,5-di hydro-4H-imidazol-4-one have been synthesised and evaluated for antiinflammatory activity. Structure of these products has been established by IR, ¹H NMR data. Significant activity were observed for some members of the series.

About Authors:
Manoj Kumar Jadia^1*, U.L.Narayan^2
1 Department of Pharmaceutical Chemistry, Indira Gandhi Institute of Pharmaceautical Sciences, I.R.C. Village, Bhubaneswar, Dist:Khurda, Odhisa -751015
² Principal, Department of Pharmaceutical Chemistry, Indira Gandhi Institute of Pharmaceautical Sciences, I.R.C. Village,
Bhubaneswar,
Dist:Khurda, Odhisa -751015

Abstract:
Two methods are described for the simultaneous determination of Paracetamol and Chlorzoxazone in binary mixture. The first method was based on UV-spectrophotometric determination of two drugs, using simultaneous equation method. It involves absorbance measurement at 282.5 nm (λmax of Chlorzoxazone) and 248.0 nm (λmax of Paracetamol) in methanol; linearity was obtained in the range of 5 – 25 μg.mL-1 for both the drugs. The second method was based on HPLC separation of the two drugs in reverse phase mode using Promosil C18 column. Linearity was obtained in the concentration range of 100-500 μg.mL-1 for Paracetamol and 50-250 for  the Chlorzoxazone. Both these methods have been successively applied to pharmaceutical formulation and were validated according to ICH guidelines.

About Authors:
Rakesh Bhatia
School of Pharmaceutical Sciences, Department of Chemistry,
Jaipur National University, Jaipur-302025,
Rajasthan, India

ABSTRACT
QSAR has been applied extensively and successfully over several decades to find predictive models for activity of bioactive agents. QSAR have brought revolution in drug discovery process by thedevelopment of mathematicalrelationships linking chemical structures and pharmacological activity in quantitative manner of series of compound. The mathematical relationships between molecular descriptors and activity are used to find the parameters affecting the biological activity and/or estimate the property of other molecules. Description of the molecular structure, electronic orbital reactivity and the role of structural and steric components have been the subject of mathematical and statistical analysis. This review seeks to provide an evolution of QSAR and development of receptor theory.

About Authors:
Middha Akanksha*, Kataria Sahil, Sandhu Premjeet, Arora Praveen
Seth G. L. Bihani S.D. College of Technical Education,
Institute of Pharmaceutical Sciences and Drug Research,
Sri Ganganagar, Rajasthan,
INDIA
*Akankshamddh@gmail.com

Abstract
Nuclear Magnetic Resonance (NMR) Spectroscopy is not limited to the study of protons. Any element with a nuclear spin (¹³C, ¹⁷O, ¹⁹F, ³¹P and many others) will give rise to an NMR signal.Carbon-13 NMR (¹³C NMR or referred to as carbon NMR) is the application of nuclear magnetic resonance (NMR) spectroscopy applicable to carbon. It is similar to proton NMR (1 H NMR) and allows the identification of carbon atoms whereas in other identification of H. As such ¹³C NMR is an important tool in chemical structure elucidation in organic chemistry. ¹³C NMR detects only the 13C isotope of carbon, whose natural abundance is only 1.1%, because  the main carbon isotope, 12 C, is not detectable by NMR since it has zero net spin.

About Authors:
Kataria Sahil, Aggarwal Ashutosh, Middha Akanksha, Sandhu Premjeet
Seth G. L. Bihani S.D. College of Technical Education,
Institute of Pharmaceutical Sciences and Drug Research,
Sri Ganganagar, Rajasthan,
INDIA

INTRODUCTION
Diabetes is a chronic (lifelong) disease marked by high levels of sugar in the blood.
There are three major types of diabetes:
•    Type 1 diabetes is usually diagnosed in childhood. Many patients are diagnosed when they are older than age 20. In this disease, the body makes little or no insulin. Daily injections of insulin are needed. The exact cause is unknown. Genetics, viruses, and autoimmune problems may play a role.

•    Type 2 diabetes is far more common than type 1. It makes up most of diabetes cases. It usually occurs in adulthood, but young people are increasingly being diagnosed with this disease. The pancreas does not make enough insulin to keep blood glucose levels normal, often because the body does not respond well to insulin. Many people with type 2 diabetes do not know they have it, although it is a serious condition. Type 2 diabetes is becoming more common due to increasing obesity and failure to exercise.

About Authors:
Ali K. Akhtar, Waquar A. Khan,Lubna azmi
Faculty of Pharmacy,
Integral University Lucknow,
India

Abstact:
The broad and potent activity of benzofuran has established it as one of the biological importent scaffold. This article is covered the methods of synthesis of benzofuran and its derivatives, structural activity relationship and pharmacological activities so it is an effort to highlight the importance of the benzofuran in the present context and promise they hold for the future.

About Authors:
Dr. A. K. Pathak, Parul Sengar, Kamlesh Kumar*
Department of Pharmacy, Barkatullah University
Bhopal, M. P.

Abstract
A Quantitative Structure Activity Relationship study on a Series of 40 molecules of (4-Quinolylhydrazone compounds) with anti-tubercular activity analogues was made using combination of various physicochemical descriptors (Thermodynamic, electronic and spatial). Several statistical expressions for 2D QSAR & 3D QSAR were developed using stepwise partial least square (PLS) regression analysis and K-Nearest neighboring molecular field analysis (K-NNMFA) respectively. The studies on 2D-QSAR, suggested the four descriptors T_C_C_2, T_C_N_4, Surface area excluding P & S, SsCH3E-index, and H donor count were common and highly contributed the activity. 2DQSAR model developed using partial least square regression approach. Negative logarithmic value of (MIC) was taken as dependent variable and selected discriptors were taken as independent varable. The analysis resulted in the following 2D-equation suggest that, MIC50 = [+0.1587 T_C_C_2- 0.0593 SsCH3E-index- 0.1395 T_C_N_4+ 0.3888 H-Donor Count -3.1556], n =26; Degree of freedom = 22; r² = 0.75; q² = 0.67; F test = 22.63;  r² se = 0.20 ; q² se = 0.23; pred_r² = 0.46 ; pred_r² se = 0.24, a H-donor group at Ar, is important for guiding the design of a new molecule. 3DQSAR model developed using K-nearest neighbour method (training set =33 and test set = 7). The best model derived by the method have q2 = 0.51, q2_se = 0.25, Predr2 = 0.71, pred_r2se = 0.16, n=33, k Nearest Neighbor is 2, Degree of freedom =28. The steric and electrostatic descriptors at the grid points, E_916 (0.1865, 0.3006); S_591 (-0.2851, -0.2580); S_1027 (-0.3273, -0.3090); S926 (30.000, 30.000) plays important role for design of new molecule. 3DQSAR analysis of series of 4-Quinolylhydrazone compounds informed that electropositive and less bulky group increases the biological activity.

About Author:
D. J. Kalena^*, C. N. Patel
Department of Quality Assurance,
Shri Sarvajanik Pharmacy College,
Near arvind baug, Mehsana - 384 001, Gujarat, India

ABSTRACT
Combination therapy of Atorvastatin calcium (AT) and Olmesartan medoxomil (OLM) is used for the treatment of coexisting essential hypertension and hyperlipidemia in adult persons. In the present study a simple, precise, rapid, efficient and reproducible reversed?phase high performance liquid chromatography (RP?HPLC) method has been developed for the simultaneous estimation of AT and OLM present in its tablet dosage forms. Chromatographic separations were carried out isocratically at 30°C ± 0.5°C on a Kromasil C18 Column (5 μm, 250mm x 4.60mm) with a mobile phase composed of Methanol: Acetonitrile: Water (pH 3.65) in the ratio of 50:27:23 % v/v at a flow rate of 1.0 ml/min. Detection is carried out using a UV detector at 260 nm. The retention times for AT and OLM were 5.3 ± 0.5 min and 3.4 ± 0.5 min respectively. The linearity range for AT and OLM were found to be 10?60 μg/ml and 20?120μg/ml with correlation coefficient of 0.996 and 0.999 respectively. The %recovery of the proposed method was found in the range of 98.36-100.91 for AT and 99.27-100.99 for OLM. The relative standard deviations for three replicate measurements in three concentrations of standard solution were always less than 2%. The results of the study showed that the proposed RP?HPLC method is simple, rapid, precise and accurate, which may be useful for the routine estimation of AT and OM in bulk drug and in its pharmaceutical dosage form.

About Authors:
Ratnadeep V. Ghadage (M. Pharmacy)
Department of Pharmaceutical Chemistry,
Appasaheb Birnale College of Pharmacy,
South Shivaji Nagar, Sangli-416416,
Maharashtra

ABSTRACT:
Quinoxaline derivatives have emerged as an important class of benzoheterocycles because of their diverse pharmacological and biological properties, which make them privileged structures in combinatorial drug discovery libraries. Also Quinoxaline derivatives constitute useful intermediates in organic synthesis. The pharmaco-logical importance of quinoxalines and their utility as building blocks in organic synthesis have directed considerable research activities toward the synthesis of suitably substituted quinoxaline rings. Extensive researches have generated numerous synthetic approaches for the construction of the skeleton of such heterocycles. Quinoxalines are, in general, comparatively easy to prepare, and numerous derivatives have been designed and prepared for potential use as biologically active materials. Oxidation of both nitrogen of the quinoxaline ring dramatically increases the diversity of certain biological properties.
Quinoxalines, including their fused-ring derivatives, display diverse pharmacological activities.A number of synthetic strategies have been developed for the preparation of substituted quinoxalines. The classical synthesis of quinoxalines involves the condensation of an aromatic 1, 2-diamine with a 1, 2-dicarbonyl compound. The reaction is facile and is the most widely used synthetic method for both quinoxaline itself and its derivatives. Despite remarkable efforts,the development of an effective method for the synthesis of quinoxalines is still an important challenge.