Chemistry Articles

About Author: *Ghadage Ratnadeep V., Shah Vishal V., Bapat Bhushan A., Shirote Pramod J.
Department of Pharmaceutical Chemistry,
Appasaheb Birnale College of Pharmacy,
South Shivaji Nagar, Sangli, Maharashtra, India - 416 416

Abstract:
Quinoxaline and its derivatives are an important class of benzoheterocycles displaying a broad spectrum of biological activities which have made them privileged structures in pharmacologically active compounds.Quinoxaline also called benzopyrazine it has been considered as a wonder nucleus which posses almost all types of biological activities. This diversity in the biological response profile has attracted the attention of many researchers to explore this skeleton to its multiple potential against several activities. They are clinically effective as antibacterial, antifungal, anti-inflammatory, anticancer, anti-tubercular and antineoplastic agents. Interestingly, it also shows anti-HIV and anti-proliferative activity. Modification in their structure has offered a high degree of diversity that has proven useful for the development of new therapeutic agents having improved potency and lesser toxicity. Considering the extensive research on quinoxaline in the past, it was essential to review the wide spectrum of biological activity of quinoxalines. To conclude, this review will be beneficial for new drug discovery of quinoxaline moiety. Present article is sincere attempt to review wide range of biological activities of quinoxline moiety  given by researcher.

About Author: Dhaval G. Shah^*, Dr Manish J. Patel, Dr Laxman J. Patel
Department Of Pharmaceutical Chemistry,
Shree S. K. Patel College Of Pharmaceutical Education & Research,
Ganpat University, Kherva. Dist: Mahesana, Gujarat

Abatract
Human Immunodeficiency Virus is the causative agent of Acquired Immuno Deficiency Syndrome (AIDS), a disease which has claimed twenty millions lives worldwide in the last two decades. Recently Imidazole derivatives, such as N-aminoimidazoles (NAIMS) have been discovered as novel anti- HIV agents. Herein, the results of 2D-QSAR analysis on these inhibitors have been reported. Quantitative Structure Activity Relationship studies have been conducted on a series (25 compounds) of NAIMS with selective HIV inhibition activity using ChemOffice v.8.0 software. The best prediction have been obtained for anti-HIV activity (R²=0.82, Q²=0.73). The equation emphasized the importance of MORAN AUTOCORELATION (BY ATOMIC MASS), GAERY AUTOCORELATION (BY ATOMIC , SHAPE PROFILE(RANDIC MOLECULAR PROFILE), MAXIMAL  ELECTROTOPOLOGICAL EGATIVE VARIATION and Km parameters on biological activity. The equation is validated by test set (8 compounds). The information obtained from this 2D- QSAR may be utilized in the design of more potent NAIMS analogs and anti-HIV agents.

About Author: Mr. Naresh. M. Reddy
PG Diploma (Cheminformatics),
Nizam College, Osmania University
Hyderabad.

Abstract
Oral strontium ranelate is an alternative oral treatment, belonging to a class of drugs called dual action bone agents. The objective of this investigation was to characterize and determine the effect of the Strontium ranelate on Calcium sensor receptor (CASR) which is an important protein involved Osteophoresis. Homology modeling of CASR has been performed based on the crystal structure of the 2E4U (Chain A) by using Modeller software. With the aid of the molecular mechanics and molecular dynamics methods, the final model is obtained and is further assessed by procheck and verify 3D graph programs, which showed that the final refined model is reliable. With this model, a flexible docking study of CASR with a group of Ranelic acids were selected from the previous publications was performed. The results indicated that VAL1,SER18,SER2,GLU241 in CASR are important determinant residues in binding as they have strong hydrogen bonding with Ranelic acids. These hydrogen binding interactions play an important role for stability of the complex. Among the 15 compunds, 6th showed best docking result. Our results may be helpful for further experimental investigations.

About Author: Jadhav Ramulu 1, P. Goverdhan2
1 Vaagdevi College of Pharmacy, Hanamkonda-Warangal (Affiliated to Kakatiya University), A.P-506002, INDIA
2 Head of the department, pharmacology, Vaagdevi College of Pharmacy, Hanamkonda-Warangal, A.P-506002, INDIA

Abstract
Computer aided drug design(CADD) is an emerging tool for research and drug development process as it reduce the time taken for the process of drug development and expense. Several new technologies have been developed and applied in drug R & D to shorten the research cycle and to reduce the expenses. In computer aided drug design process so many computational tools are used such as over viewing tools, homology modeling, and homology modeling programs, molecular dynamics, molecular docking and QSAR descriptors. This article provides a brief idea on computer aided drug design process and list of software used.

About Author: Ashish Chauhan
M.Pharm (Pharmaceutical Chemistry)
Department of Pharmaceutical Sciences,
Lovely Professional University, Jalandhar (Punjab).

The Montreal Protocol on Substances that Deplete the Ozone Layer
(A Protocol to the Vienna Convention for the Protection of the Ozone Layer)

Ozone Layer

• The ozone layer is a layer in Earth's atmosphere which contains relatively high concentrations of ozone (O3).
• This layer absorbs 97–99% of the Sun's high frequency ultraviolet light, which is damaging to life on Earth.
• It is mainly located in the lower portion of the stratosphere from approximately 30 to 40 kilometres above Earth, though the thickness varies seasonally and geographically.
• The ozone layer was discovered in 1913 by the French physicists Charles Fabry and Henri Buisson.
• Its properties were explored in detail by the British meteorologist G. M. B. Dobson, who developed a simple spectrophotometer (the Dobson meter) that could be used to measure stratospheric ozone from the ground.
• Between 1928 and 1958 Dobson established a worldwide network of ozone monitoring stations, which continue to operate to this day.
• The "Dobson unit", a convenient measure of the columnar density of ozone overhead, is named in his honour.

About Authors: Manoj Kumar Jadia1*, Dr. U. L. Narayan2
1. Department of Pharmaceutical Chemistry,
Indira Gandhi institute of Pharmaceautical Sciences,
IRC village, Bhubaneswar, Odhisa, India
2. Principal, Department of Pharmaceutical Chemistry,
Indira Gandhi institute of Pharmaceautical Sciences,
IRC village, Bhubaneswar, Odhisa, India

Abstract
The two methods are described for the simultaneous determination of Paracetamol and Etodolac in binary mixture. The first method was based on UV-spectrophotometric determination of both of the drugs, using simultaneous equation method. It involves absorbance measurement at 256.0 nm (λmax of Paracetamol) and 226.0 nm (λmax of Etodolac) 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 30-70μg.mL-1 for Paracetamol and 20-60 μg.mL-1 for Etodolac. The LOD and LOQ value of UV-Spectrophotometric determination was found to be 167.43 ng mL-1, 507.37 ng mL-1  and for HPLC determination was found to be 1653.12 ng mL-1, 5009.48 ng mL-1.Both these methods have beensuccessively applied to pharmaceutical formulation and were validated according to ICH guidelines.

About Authors: Aswini K. Reddy, Swetha Yasa, Srivally Challa, Masoom. md
Mallareddy Institute of Pharmaceutical Sciences, Hyderabad

ABSTRACT
Both solid- and liquid-phase combinatorial chemistry have emerged as powerful tools for identifying pharmacologically active compounds and optimizing the biological activity of a lead compound. Complementary high-throughput in vitro assays are essential for compound evaluation. Cell-based assays that use optical endpoints permit investigation of a wide variety of functional properties of these compounds including specific intracellular biochemical pathways, protein-protein interactions, and the subcellular localization of targets. Integration of combinatorial chemistry with contemporary pharmacology now represents an important factor in drug discovery and development.

This is an exceptionally exciting time in the field of pharmacology. The environment for the identification of new therapeutic targets and agents that interact with these targets has rapidly changed with the application of genetic tools and genomics. Extrapolation from the genomic sequencing of lower organisms suggests that there will be a 10-fold increase in the number of potential human therapeutic targets in the next several years with the completion of the Human Genome Project (Drews, 1996). This is leading to a fundamental transformation in pharmacology; no longer is there a dearth of molecular targets for small molecules. Rather, the emphasis is now on validating whether or not the targets are appropriate for therapeutic intervention, on generating large arrays of compounds that represent diverse portions of “chemical space”, and developing methods to quickly assess the credentials of small molecules as target disrupters. We believe many of the tools and reagents that are being developed to facilitate this scientific activity will emerge as vital for future academic pharmacological research. Perhaps most important will be the exploitation of combinatorial chemistry libraries, which are becoming widely available. Although we cannot comprehensively review this broad topic here, the goal of this brief commentary is to portray some of the strategies and potentials of combinatorial chemistry libraries as they relate to pharmacological studies.

About Authors: Sahil Sharma

Reference ID: PHARMATUTOR-ART-1083

Introduction
One hundred years ago Scottish chemist Andrew Norman Meldrum synthesized a substance [1] that later obtained his name. To date Meldrum’s acid is one of the most useful reagents in the synthesis of heterocycles. In contrast to the great popularity of Meldrum’s acid, its discoverer remains almost unknown for the majority of chemists.
Andrew Norman Meldrum [2] was born on 19th March, 1876, in a small burgh, Alloa, Scotland. In 1899 he received his B.Sc. with ?rst-class honors (chemistry) from the University of Aberdeen, where he worked as a research assistant with Francis Robert Japp [3].  
In his ?rst independent publication [1], he studied the reaction between acetone and malonic acid and, following the suggestion of Prof. Japp, employed a mixture of acetic anhydride and sulfuric acid as condensing agent. From elemental analysis data, in conjunction with previous results and the acidic properties of the ?nal compound, he formulated the structure of the product to be β-lactone of β-hydroxyisopropylmalonic acid 1 (Scheme 1).

About Authors: Venkata Suresh Babu Aluri*
Department of pharmaceutical Analysis,
Adhiparasakthi College of Pharmacy,
Melmarvathur, Kancheepuram District, Tamil Nadu - 603319 (INDIA)

Reference ID: PHARMATUTOR-ART-1077

Abstract
A simple, specific, sensitive, rapid, precise and economical high performance liquid chromatography (HPLC) method has been developed for the estimation of Olmesartan medoxomil (OLM) and Atorvastatin calcium (ATC) in tablet dosage form by using acetonitrile- phosphate buffer pH 3.0 (40:60 v/v) as a solvent system. The method was carried out on a Phenomenex Gemini C18 (15 cm x 4.6 mm i.d., 5µm particle size) column, at flow rate 0.9 mL/min. Detection was carried out at 252 nm. The retention time of OLM and ATC was 3.19 and 4.63 min, respectively. The two drugs follow Beer-Lambert’s law over the concentration range of 8 – 40 µg/mL for OLM and 4 – 20 µg/mL for ATC. Validation of proposed method was carried out for its accuracy, precision, specificity and ruggedness according to ICH guidelines. The proposed method can be successfully applied in routine work for the determination of Olmesartan medoxomil and Atorvastatin calcium in combined dosage form.