USE OF 3D-VISUALIZATION MEDIA IN NUCLEOPHILIC SUBSTITUTION REACTION MATERIAL TO IMPROVE STUDENTS' CONCEPT MASTERY

Development of technology is increasingly rapid today, including in the field of education. Technological developments are sometimes not used properly in the learning process, so that students not actively studying in class. The purpose of this study was to determine the effect of using 3D visualization media on nucleophilic substitution reaction material to improve students' concept mastery. Research method used was a quasi-experiment with pre-test and post-test design, involved 68 students from two different universities in West Java. The test instrument to measure concept mastery consisted of nine reasoned multiple-choice questions. The results showed that the use of 3D visualization media in nucleophilic substitution reaction materials can improve students' mastery of concepts. Based on the N-gain calculation results, University A was better than University B except for the indicators of determining that obtained a medium category and sorting that obtained a low category. There were four indicators of concept mastery used, including determining, analyzing, linking, and sorting indicators

Quantitative models for predicting antioxidant capacity in herbs based on molecular structures and compositions

Herbs are considered as a vital source of natural antioxidants that can neutralise free radicals which cause harmful health effects to the human body. Researchers have found that the phenolic compounds are the major phytochemicals in herbs that contribute to their antioxidant capacity. However, even though the herbs are grown in the same conditions and geographic origin, the components and composition of phenolic compounds may differ for each sample, contributing to different antioxidant capacities. Previous researchers have only studied the interactions between either their molecular structures or composition of phenolic compounds. The interaction and synergistic effect of the combined components and composition of phenolic compounds contributing to their antioxidant property are still unknown. The aim of this research is to understand the synergistic effect between the structure and composition of phenolic compounds in herbs by developing a quantitative model. Firstly, a Quantitative Structure-Activity Relationship (QSAR) model was developed in three different approaches, namely general, consensus and comprehensive models using literature data set of traditional Chinese medicine. Previous research have developed the QSAR models using all generated molecular descriptors without any classification that might overlooked the important variable. In this research, the general and consensus models were built using the molecular descriptors from the DRAGON software. The general model utilised all the molecular descriptors, while the consensus model classified the molecular descriptors according to the phenolic compound groups. In addition, quantum-chemical descriptors from the Gauss View 5.0 and Gaussian 09 software which were also added into the model to include 3D descriptors in the model, and therefore, the model is known as the comprehensive model. Then, a new Quantitative Structure-Composition-Activity Relationship (QSCAR) model was developed by using the experimental data set to further correlate between the molecular structure (from QSAR model) and composition ratio for each significant phenolic compound in Misai Kucing. Three variable selections, namely forward stepwise, interval-partial least square (i-PLS) and genetic algorithm and two multi-linear regression analysis methods were combined to developed all models. The best performance QSCAR model based on the robustness, reliability and predictivity was selected and the result was compared with QSAR model and experimental results. As a result, the consensus model produced overall performance better than the general model. The increment of antioxidant activity is correlated with the phenolic compound size through measurement of the bond indices distance between the atom, shape that is specifically calculated in the proportion of path/walk in length 3 from molecular Randic shape index and the number of bridge edges. The high ratio between EHOMO and ELUMO, the low of stability and total energy values of phenolic compounds increased the antioxidant activity as well. The QSCAR could predict the antioxidant capacity with 13.88 % more accurately than the QSAR model. The QSCAR model shows that the high compositions of apigenin and dalspinosin while the low composition of caffeic, ferulic and rosmarinic acids increased the antioxidant capacity in Misai Kucing. In conclusion, a quantitative model has been developed to predict the antioxidant capacity in herbs by combining the comprehensive QSAR and QSCAR models. The QSAR model is generic for phenolic compounds, but QSCAR needs to be simulated again with the other herb composition ratios. Thus, the future researchers can use the models to predict antioxidant capacity for other herbs. The research may also be beneficial by extending the model for predicting other biological activities

DRUG DISCOVERY: AN APPRAISAL

The process of drug discovery and development has undergone radical changes over the years. Introduction of several novel technologies in genomics, proteomics and other omics areas have enabled drug target identification and validation more specific. In silico virtual screening and other computational chemistry methods like QSAR (Quantitative Structure-Activity Relationship) and QSPR (Quantitative Structure-Property Relationship) have enabled the emergence of new drugs with minimal toxicity and higher efficacy in this post-genomics era. Moreover, initiative like Open Source Drug Discovery (OSDD) is playing a promising role in accelerating the pace of drug discovery process. Better understanding of these methods and initiatives by researchers will kindle interest towards adopting it. Hence, by this review, we intend to present a comprehensive view of overall transition and modernization of the drug discovery process and it's impacts on the scientific community.Â

Synteza wybranych pochodnych kwasu 8-hydroksy-2-metylochinolino-7-karboksylowego oraz jego analogów jako potencjalnych inhibitorów integrazy wirusa HIV oraz herbicydów

Niniejsza praca stanowi kontynuację badań podjętych w Zakładzie Chemii Organicznej Uniwersytetu Śląskiego, dotyczących syntezy związków zawierających fragment chinolinowy jako potencjalnych inhibitorów integrazy wirusa HIV oraz potencjalnych leków przeciwnowotworowych. Celem pracy była synteza wybranych pochodnych amidowych kwasu 8-hydroksy-2-metylochinolino-7-karboksylowego (Rys. I) oraz zbadanie aktywności biologicznej uzyskanych połączeń w zakresie zdolności do hamowania integrazy wirusa HIV, właściwości przeciwnowotworowych i przeciwgrzybicznych. Rys. I. Kwas 8-hvdroksv-2-metvlochinolino-7-karboksvlowv W zakres pracy wchodziła również próba syntezy kwasu 2-metylo-5,8-diokso-5,8- dihydrochinolino-7-karboksylowego (Rys. 2) oraz jego pochodnych zawierających w swojej strukturze fragment 5,8-chinolinodionowy, o znanych właściwościach przeciwnowotworowych. o Rvs. 2. Kwas 2-metvlo-5.8-diokso-5.8-dihvdrochinolino-7-karboksvlowv W trakcie realizacji pracy, zakres poszerzył się o wykorzystanie syntezowanych związków jako ligandów kompleksujących niektóre metale przejściowe (Ru, Re, Cu). W szczególności zainteresowałem się wykorzystaniem otrzymanych kompleksów do badań pozwalających na ustalenie struktur ligandów organicznych

Five-Component Self-Assembly of Cucurbituril-Based Hetero-pseudorotaxanes

[5]Pseudorotaxanes can be obtained by self-sorting using heteroditopic guests and various cucurbituril homologues as hosts. The assembly and chemically induced disassembly of the pseudorotaxanes can be monitored by measuring the fluorescence of the anthracene guest in solution. Mass spectral evidence for the supramolecular assemblies is obtained in the gas phase. The disassembly in the gas phase can be achieved by collision-induced dissociation leading to the corresponding [2]- and [3]pseudorotaxanes.Ministerio de Economia y Competitividad, Madrid, Spain [CTQ2011-28390, CTQ2014-54729-C2-1-P, BES2015-074458]; Junta de Andalucia [P12-FQM2140]; Fundacao para a Ciencia e a Tecnologia, Lisbon, Portugal [SFRH/BD/81628/2011]; Egyptian Ministry of Higher Education, Cairoinfo:eu-repo/semantics/publishedVersio

Novel Analytical Study For The Charge-Transfer Reactions Of Omeprazole With 2,3-Dichloro-Naphthoquinone And 2,3,5,6-Tetrabromo- 1,4-Benzoquinone: Application For The Development Of Microwell Assay Of Omeprazole

Novel analytical study was performed in order to develop and validate new high-throughput microwell-based spectrophotometric assays for determination of omeprazole (OMZ) in its pharmaceutical formulations. The proposed assays were based on the charge-transfer (CT) reaction of OMZ with 2,3-dichloronaphthoquinone (DCNQ) and 2,3,5,6-tetrabromo-1,4-benzo-quinone (BROM). In the present study, the CT reactions was carried out in microwell plates as reaction vessels in order to increase the automation of the assays and the efficiency of its use in quality control laboratories (QCLs). All factors affecting the CT reactions were carefully studied, and the conditions were optimized. Kinetics and stoichiometry of the CT reactions were investigated, and the mechanism was postulated. Activation energy of the CT reactions was determined and found to be 13.87 and 16.27 Kcal mol−1 for the reaction of OMZ with DCNQ and BROM, respectively. The initial rate and fixed time methods were applied for generating the calibration graphs for determination of OMZ concentrations. Under the optimum conditions, the linear range was 0.145 – 1.45 x 10-4 and 1.45 – 7.25 x 10-4 M with LOD of 0.6 and 6.0 microgram ml-1 for DCNQ and BROM, respectively. Analytical performance of the proposed methods, in terms of accuracy and precision, was statistically validated and the results were satisfactory; RSD was <2.8% for both repeatability and reproducibility. The proposed methods were successfully applied to the analysis of OMZ in its dosage forms and the recovery results (98.64 – 100.6 ± 0.25 -2.74 %) were comparable with those of the reported method. The developed method may provide a safer and economic tool for the analysis of OMZ in QCLs

Molecular modeling to study dendrimers for biomedical applications

© 2014 by the authors; licensee MDPI; Basel; Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution license (http://creativecommons.org/licenses/by/4.0/). Date of Acceptance: 17/11/2014Molecular modeling techniques provide a powerful tool to study the properties of molecules and their interactions at the molecular level. The use of computational techniques to predict interaction patterns and molecular properties can inform the design of drug delivery systems and therapeutic agents. Dendrimers are hyperbranched macromolecular structures that comprise repetitive building blocks and have defined architecture and functionality. Their unique structural features can be exploited to design novel carriers for both therapeutic and diagnostic agents. Many studies have been performed to iteratively optimise the properties of dendrimers in solution as well as their interaction with drugs, nucleic acids, proteins and lipid membranes. Key features including dendrimer size and surface have been revealed that can be modified to increase their performance as drug carriers. Computational studies have supported experimental work by providing valuable insights about dendrimer structure and possible molecular interactions at the molecular level. The progress in computational simulation techniques and models provides a basis to improve our ability to better predict and understand the biological activities and interactions of dendrimers. This review will focus on the use of molecular modeling tools for the study and design of dendrimers, with particular emphasis on the efforts that have been made to improve the efficacy of this class of molecules in biomedical applications.Peer reviewedFinal Published versio

Design, Development and Implementation of Tools in Drug Discovery

The main focus of our work is to develop, apply and assess cheminformatics tools and methods. In particular, we focus on the following three areas: Integration of open source tools with application to drug discovery, usability studies to assess the efficacy of these software tools and finally, developing novel techniques for database query. Rapid globalization in the present time has sparked a need in the scientific community to interact with each other at an economic and a fast pace. This is achieved by developing and sharing open source databases using World Wide Web. A web based open source database application has been developed to incorporate freeware from varied sources. The deployment of developed database and user interface in a university lab setting is discussed. To aid in connecting the end user and the software tools, usability studies are necessary. These studies communicate the end users’ needs and desires, resulting in a user-friendly and more powerful interactive software packages. Usability studies were conducted on developed database student application and on different drawing packages to determine their effectiveness. Developing new and interactive search engines to query publicly available databases helps researchers work more efficiently. The huge volume of data available and its heterogeneous nature presents issues related to querying, integration and presentation. In aiding the retrieval process, an innovative multi faceted classification system, called ChemFacets, is developed. This system provides dynamic categorization of large result sets retrieved from multiple databases