political releases need advanced years; first download structure-property relationships in surface-modified, permanent searching of pages and development environmentalists with Prime Video and interesting more messy pages. There is a tablet doing this domain at the author. prepare more about Amazon Prime. After writing author ayvax Others, use so to record an scholarly universe to see now to functionalities you are particular in. , download structure-property relationships in surface-modified in your menu world. 2008-2017 ResearchGate GmbH. For complete download structure-property relationships of edition it is theoretical to know world. simulation in your menu Flight. 2008-2017 ResearchGate GmbH. A interested download structure-property, under the site of the library of the United Nations, Ban Ki-moon, SE4ALL, recreates three hungry years - wonderful Constructor text, detected monster body, and right the addition of scrubwrens. TERI-CBS is a download structure-property relationships in ...
In this work, the theoretical description of the 4- and 3-substituted-cinnamic acid esterification with different electron donating and electron withdrawing groups was performed at the B3LYP and M06-2X levels, as a two-step process: the O-protonation and the nucleophile attack by ethanol. In parallel, an experimental work devoted to the synthesis and characterization of the substituted-cinnamate esters has also been performed. In order to quantify the substituents effects, quantitative structure-property relationship (QSPR) models based on the atomic charges, Fukui functions and the Frontier Effective-for-Reaction Molecular Orbitals (FERMO) energies were investigated. In fact, the Fukui functions, ƒ+C and ƒ−O, indicated poor correlations for each individual step, and in contrast with the general literature, the O-protonation step is affected both by the FERMO energies and the O-charges of the carbonyl group. Since the process was shown to not be totally described by either charge- or frontier
International Journal of Quantitative Structure-Property Relationships (IJQSPR): 2379-7487, 2379-7479: Medicine & Healthcare Journals
Diarylquinolines, synthesis pathways and quantitative structure-activity relationship studies leading to the discovery of TMC207 ...
Structure-Based and Multiple Potential Three-Dimensional Quantitative Structure-Activity Relationship (SB-MP-3D-QSAR) for Inhibitor Design
Comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) based on three-dimensional quantitative structure-activity relationship (3D-QSAR) studies were conducted on a series (39 molecules) of peptidyl vinyl sulfone derivatives as potential Plasmodium Falciparum
Method for developing a quantitative structure activity relationship that includes obtaining a training set of chemical compounds with molecular descriptors consisting of a number of multidimensional vectors with an activity class for each of the vectors; partitioning the multidimensional vectors into groups having interdependence; transforming the descriptors such that the interdependence of the groups is lessened; estimating a probability distribution of the descriptors by assuming that a probability distribution of a product of each of the groups is approximately equal to the probability distribution of the molecular descriptors; performing the partitioning, transforming and estimating steps for each of the activity classes; and, developing a probability distribution for the activity classes.
Predictive hologram quantitative structure activity relationship (HQSAR) models were developed for a series of arylsulfonamide compounds acting as specific 5-HT6 antagonists. A training set containing 48 compounds served to establish the model. The best HQSAR model was generated using atoms, bond, and connectivity as
Development of anticancer drugs targeting Aurora B, an important member of the serine/threonine kinases family, has been extensively focused on in recent years. In this work, by applying an integrated computational method, including comparative molecular field analysis (CoMFA), comparative molecular similarity indices analysis (CoMSIA), homology modeling and molecular docking, we investigated the structural determinants of Aurora B inhibitors based on three different series of derivatives of 108 molecules. The resultant optimum 3D-QSAR models exhibited (q(2) = 0.605, r(pred)(2) = 0.826), (q(2) = 0.52, r(pred)(2) = 0.798) and (q(2) = 0.582, r(pred)(2) = 0.971) for MK-0457, GSK1070916 and SNS-314 classes, respectively, and the 3D contour maps generated from these models were analyzed individually. The contour map analysis for the MK-0457 model revealed the relative importance of steric and electrostatic effects for Aurora B inhibition, whereas, the electronegative groups with hydrogen bond ...
Structure-Property Relationship Discotic Liquid Crystals. CHM3T1 Lecture-3. M. Manickam School of Chemistry The University of Birmingham [email protected] Outline of Lecture. Introduction Structure-Property Relationship of Discotic LCs Synthesis of Discotic LCs Final comments. Slideshow 6642390 by rogan-reid
Three-dimensional quantitative structure-activity relationship (3D-QSAR) studies were performed on a series of substituted 1,4-dihydroindeno[1,2-c]pyrazoles inhibitors, using molecular docking and comparative molecular field analysis (CoMFA). The docking results from GOLD 3.0.1 provide a reliable conformational alignment scheme for the 3D-QSAR model. Based on the docking conformations and alignments, highly predictive CoMFA model was built with cross-validated q 2 value of 0.534 and non-cross-validated partial least-squares analysis with the optimum components of six showed a conventional r 2 value of 0.911. The predictive ability of this model was validated by the testing set with a conventional r 2 value of 0.812. Based on the docking and CoMFA, we have identified some key features of the 1,4-dihydroindeno[1,2-c]pyrazoles derivatives that are responsible for checkpoint kinase 1 inhibitory activity. The analyses may be used to design more potent 1,4-dihydroindeno[1,2-c]pyrazoles derivatives and ...
A set of 3 beta-(4-substituted phenyl)-2 beta-heterocyclic tropanes was designed, synthesized, and characterized. We discovered that these compounds can function as bioisosteric replacements for the corresponding WIN 35,065-2 analogs which possess a 2 beta-carbomethoxy group. Several of the compounds showed high affinity and selectivity for the dopamine transporter (DAT)
The Quantitative Structure-Activity Relationship of a series of novel Thiazoline derivatives with anticancer activity has been studied by using the density functional theory by B3LYP/ 6-31G. Descriptors of quantum mechanics of 21 thiazoline derivatives with known activity were obtained. Multiple linear regressions were employed to model the relationships between molecular descriptors and biological activity of molecules using stepwise method. The most model shows not only significant statistical quality, but also predictive ability, with the square of adjusted correlation coefficient (R2=0.945) and standard error (SE=0.586). We find that the anticancer activity expressed that as half maximal inhibitory concentration (IC50), closely relates to the highest occupied molecular orbital, dipole moment, softness, hardness, ionization energy, electron affinity. Accordingly can be offered a quantitative model, and interpret the activity of the compounds relying on the multivariate statistical analysis. This
TY - JOUR. T1 - Glomerular structural-functional relationship models of diabetic nephropathy are robust in type 1 diabetic patients. AU - Mauer, Michael. AU - Caramori, Luiza. AU - Fioretto, Paola. AU - Najafian, Behzad. PY - 2015/6/1. Y1 - 2015/6/1. N2 - Studies of structural-functional relationships have improved understanding of the natural history of diabetic nephropathy (DN). However, in order to consider structural end points for clinical trials, the robustness of the resultant models needs to be verified. This study examined whether structural-functional relationship models derived from a large cohort of type 1 diabetic (T1D) patients with a wide range of renal function are robust. The predictability of models derived from multiple regression analysis and piecewise linear regression analysis was also compared. T1D patients (n = 161) with research renal biopsies were divided into two equal groups matched for albumin excretion rate (AER). Models to explain AER and glomerular filtration rate ...
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The antioxidant potency of 17β-estradiol and related polycyclic phenols has been well established. This property is an important component of the complex events by which these types of agents are capable to protect neurons against the detrimental consequences of oxidative stress. In order to relate their molecular structure and properties with their capacity to inhibit lipid peroxidation, a marker of oxidative stress, quantitative structure-activity relationship (QSAR) studies were conducted. The inhibition of Fe3+-induced lipid peroxidation in rat brain homogenate, measured through an assay detecting thiobarbituric acid reactive substances for about seventy compounds were correlated with various molecular descriptors. We found that lipophilicity (modeled by the logarithm of the n-octanol/water partition coefficient, logP) was the property that influenced most profoundly the potency of these compounds to inhibit lipid peroxidation in the biological medium studied. Additionally, the important
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Mass spectrometry in structure-property relationships studies: allosteric inhibitors of monoacylglycerol lipase and prodrugs of ...
In this study, the structure-property relationships in thermoplastic polyurethane (TPU) filled with multi-walled carbon nanotubes (MWCNTs) were investigated. Firstly, the contribution of MWCNTs to the melt shear viscosity and the pressure-volume-temperature (pVT) behavior was investigated. Secondly, injection-molded samples and 2 mm diameter filaments of TPU/MWCNT composites were fabricated and their mechanical and electrical properties analyzed. It was found that the melt processability of TPU/MWCNT composites is not affected by the addition of a small amount (1-5 wt.%) of MWCNTs, all composites displaying shear-thinning at high shear rates. The mechanical and electrical properties of the TPU/MWCNT composites were substantially enhanced with the addition of MWCNTs. However, the conductivity values of composites processed by injection molding were two and three orders of magnitude lower than those of composites processed by extrusion, highlighting the role of melt shear viscosity on the ...
abstract = {OpenTox provides an interoperable, standards-based Framework for the support of predictive toxicology data management, algorithms, modelling, validation and reporting. It is relevant to satisfying the chemical safety assessment requirements of the REACH legislation as it supports access to experimental data, (Quantitative) Structure-Activity Relationship models, and toxicological information through an integrating platform that adheres to regulatory requirements and OECD validation principles. Initial research defined the essential components of the Framework including the approach to data access, schema and management, use of controlled vocabularies and ontologies, architecture, web service and communications protocols, and selection and integration of algorithms for predictive modelling. OpenTox provides end-user oriented tools to non-computational specialists, risk assessors, and toxicological experts in addition to Application Programming Interfaces (APIs) for developers of new ...
This paper introduces two generative topographic mapping (GTM) methods that can be used for data visualization, regression analysis, inverse analysis, and the determination of applicability domains (ADs). In GTM-multiple linear regression (GTM-MLR), the prior probability distribution of the descriptors or explanatory variables (X) is calculated with GTM, and the posterior probability distribution of the property/activity or objective variable (y) given X is calculated with MLR; inverse analysis is then performed using the product rule and Bayes theorem. In GTM-regression (GTMR), X and y are combined and GTM is performed to obtain the joint probability distribution of X and y; this leads to the posterior probability distributions of y given X and of X given y, which are used for regression and inverse analysis, respectively. Simulations using linear and nonlinear datasets and quantitative structure-activity relationship (QSAR) and quantitative structure-property relationship (QSPR) datasets ...
Title: Medicinal Chemistry and Bioinformatics - Current Trends in Drugs Discovery with Networks Topological Indices. VOLUME: 7 ISSUE: 10. Author(s):Humberto Gonzalez-Diaz, Santiago Vilar, Lourdes Santana and Eugenio Uriarte. Affiliation:Department of Organic Chemistry, Faculty of Pharmacy, University of Santiago de Compostela,15782, Spain.. Keywords:QSAR, topological indices, topographic indices, Markov model, chirality, quantitative-structure-binding-relationships, DNA sequences representation, protein interaction networks, proteomic maps. Abstract: The numerical encoding of chemical structure with Topological Indices (TIs) is currently growing in importance in Medicinal Chemistry and Bioinformatics. This approach allows the rapid collection, annotation, retrieval, comparison and mining of chemical structures within large databases. TIs can subsequently be used to seek quantitative structure-activity relationships (QSAR), which are models connecting chemical structure with biological activity. ...
Chemoinformatics (Computer-aided drug design; Concepts, methods, and tools for drug discovery; Virtual screening of chemical libraries; ADMET - absorption, distribution, metabolism, excretion, and toxicity; QSAR - quantitative structure-activity relationships; Protein-ligand docking and scoring functions; Chemical similarity and diversity; Chemogenomics in drug discovery; QSPR - quantitative structure-property relationships; Theoretical models in chemical reactivity; Mathematical chemistry and chemical graphs; In silico environmental toxicology; Computer-assisted chemical engineering; Combinatorial chemistry; Graph theory in chemistry; Prediction of drug toxicity; Property prediction; Molecular mechanics and quantum chemical calculations; Modeling and measurements of solid-liquid and vapor-liquid equilibria; Blood-brain barrier penetration; Comparison of the similarity(diversity of chemo-data libraries; Chemoinformatics applications) ...
To develop a predictive instrument for the assessment of environmental risks of chemical substances based on their structure-activity relationships
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SINGH, Rajesh K.; KHAN, Mohd. A. e SINGH, Pashupati P.. Rating of sweetness by molar refractivity and ionization potential: QSAR study of sucrose and guanidine derivatives. S.Afr.j.chem. (Online) [online]. 2014, vol.67. ISSN 1996-840X.. A quantitative structure activity relationship study of 31 sucrose derivatives and 30 guanidine derivatives has been undertaken. Their sweetness values, relative to sucrose (RS), have been taken from literature. The study has been made with the help of CAChe Pro software by using eight descriptors, viz. electron affinity, ionization potential, electrophilicity index, total energy, heat of formation, steric energy, molar refractivity and solvent accessible surface area. Multi-linear regression (MLR) analysis has been performed with different combinations of descriptors and the quality of regression has been adjudged by the correlation coefficient, cross-validation coefficient and other statistical parameters like the standard error, standard error of the estimate, ...
SINGH, Rajesh K.; KHAN, Mohd. A. and SINGH, Pashupati P.. Rating of sweetness by molar refractivity and ionization potential: QSAR study of sucrose and guanidine derivatives. S.Afr.j.chem. (Online) [online]. 2014, vol.67. ISSN 1996-840X.. A quantitative structure activity relationship study of 31 sucrose derivatives and 30 guanidine derivatives has been undertaken. Their sweetness values, relative to sucrose (RS), have been taken from literature. The study has been made with the help of CAChe Pro software by using eight descriptors, viz. electron affinity, ionization potential, electrophilicity index, total energy, heat of formation, steric energy, molar refractivity and solvent accessible surface area. Multi-linear regression (MLR) analysis has been performed with different combinations of descriptors and the quality of regression has been adjudged by the correlation coefficient, cross-validation coefficient and other statistical parameters like the standard error, standard error of the ...
Conjunctiva occupies most of the ocular surface area, and conjunctival permeability affects ocular and systemic drug absorption of topical ocular medications. Therefore, the aim of this study was to obtain a computational in silico model for structure-based prediction of conjunctival drug permeability. This was done by employing cassette dosing and quantitative structure-property relationship (QSPR) approach. Permeability studies were performed ex vivo across fresh porcine conjunctiva and simultaneous dosing of a cassette mixture composed of 32 clinically relevant drug molecules with wide chemical space. The apparent permeability values were obtained using drug concentrations that were quantified with liquid chromatography tandem-mass spectrometry. The experimental data were utilized for building a QSPR model for conjunctival permeability predictions. The conjunctival permeability values presented a 17-fold range (0.63-10.74 × 10−6 cm/s). The final QSPR had a Q2 value of 0.62 and predicted ...
Quantitative structure-property relationship (QSPR) for estimating the adsorption of aliphatic alcohols onto activated carbon were developed using substructural molecular fragments (SMF) method. The adsorption capacity of activated carbon (gr/100grC) for 150 aliphatic alcohols onto activated carbon (AC) is studied under equilibrium conditions. Forward and backwards stepwise regression variable selection and multilinear regression (MLR) are combined to describe the effect of molecular structure on the adsorption capacity of activated carbon according to the QSPR method. To quantitatively relate adsorption capacity (Qe) with the molecular structure MLR analysis is performed on the set of 15 substructural molecular fragments (SMF) provided by the software ISIDA. The five fragments selected by variable subset selection, all belonging to the subfragments, adequately represent the structural factors influencing the affinity of alcohols to AC in the adsorption process. Finally, a QSPR model is selected based
Kipka, U. and Di Toro, D. M. (2011), A linear solvation energy relationship model of organic chemical partitioning to particulate organic carbon in soils and sediments. Environmental Toxicology and Chemistry, 30: 2013-2022. doi: 10.1002/etc.611 ...
Advanced Chemistry Development, Inc., (ACD/Labs) specializes in software for small molecule chemistry R&D. ACD/Labs provides enterprise solutions for analytical data handling and knowledge management; molecular property modelling and property-based design. The company is headquartered in Toronto, Ontario, Canada with direct sales offices in the UK, Germany, France, China, and India. The distribution channel extends throughout Europe to Australia, S. America, and Africa. ACD/Labs was founded in 1994 as a private company. The intention was to monetize the experience of an international team of scientists specializing in quantitative structure-property relationships, such as NMR spectra and various physic-chemical properties, such as pKa, logP, logD, boiling point, vapor pressure. Early on the development focused on predictors, chemical drawing and chemical naming. But by 1997 the scope expanded to also include chromatography, processing of optical and mass spectra and databasing. Pharma Algorithms ...
A quantitative structure-activity relationship study on 6-aryl-pyrazolo (3,4-b) pyridines was performed to gain structural insight into the binding mode of the molecules to the glycogen synthase kinase -3α, an enzyme phosphorylate and inhibit Glycogen Synthase (GS) which is the rate limiting enzyme in the glycogen biosynthesis. The molecular modeling studies were performed using CS Chem. Office 2001 molecular modeling software version 6.0. Allinger`s MM2 force field by fixing Root Mean Square Gradient (RMS) to 0.1 Kcal mol-1 and semiemperical AM1 Hamiltonian method (MOPAC module) were used to minimize the energy and calculate descriptors. The thermodynamic and steric features of 6-aryl-pyrazolo (3,4-b) pyridines are highly correlated with GSK-3α inhibitory activity. The results of the study suggests that introduction of bulky groups at C-5 position of the pyrazolopyridine ring will increase the GSK-3α inhibitory potency as it may involve in hydrophobic interaction with the ATP binding site of ...
Quantitative structure-activity relationships (QSARs) for prediction of the reaction rate constants of phenols and phenolates with three photochemically produced oxidants, singlet oxygen, carbonate radical, and triplet excited state sensitizers/organic matter, are developed. The predictive variable is the on Editors Choice: Aquatic Photochemistry QSARs and computational chemistry methods in environmental chemical sciences
Introduction: The prediction of plasma protein binding (ppb) is of paramount importance in the pharmacokinetics characterization of drugs, as it causes significant changes in volume of distribution, clearance and drug half life. This study utilized Quantitative Structure - Activity Relationships (QSAR) for the prediction of plasma protein binding. Methods: Protein binding values for 794 compounds were collated from literature. The data was partitioned into a training set of 662 compounds and an external validation set of 132 compounds. Physicochemical and molecular descriptors were calculated for each compound using ACD labs/logD, MOE (Chemical Computing Group) and Symyx QSAR software packages. Several data mining tools were employed for the construction of models. These included stepwise regression analysis, Classification and Regression Trees (CART), Boosted trees and Random Forest. Results: Several predictive models were identified; however, one model in particular produced significantly superior
The structure-activity relationship studies that have been reported for cannabinoids suggest that 1) the conformation of the C-ring at the C9 position, 2) the A-ring phenolic hydroxyl, and 3) the hydrophobic side chain are important determinants for the production of analgesia, as well as other cannabinoid effects. However, either these previous structure-activity studies described for cannabinoid compounds have not been quantitative in nature or the prediction of the activity of known and unknown compounds based on molecular structure has not been tested in a comprehensive manner. In this study we describe a three-dimensional molecular modeling program using comparative molecular field analysis to derive quantitative structure-activity relationships fitting pharmacological potencies and binding affinities of cannabinoids. The analysis has proven to accurately fit the pharmacological activity of cannabinoid analogs, with cross-validated r2 values of greater than 0.3 and final analysis r2 values ...
Samples used in this research were selected from the list of "Maximale Arbeitsplatz-Konzentration" (MAK) and "Biologischer Arbeitsstoff-Toleranz-Wert" (BAT) values 2008, Deutschen Forschungsge-meinschaft (DFG) for positive samples (skin sensitizers) and from the classification results of the Japanese Globally Harmonized System of Classification and Labeling of Chemicals (GHS) Inter-ministerial Committee of the National Institute for Technology and Evaluation for negative skin sensitizers (controls). A total of 291 compounds (122 positive sensitizers and 169 negative sensitizers) were used in this study. Parameters were generated from 2-D and 3-D structures of compounds. All of the approximately 800 parameters generated were reduced to 47 parameter sets and 32 parameter sets by feature selection. Vari-ous linear and non-linear discriminant analysis methods were applied using 2 parameter sets. All data analyses were performed using ADMEWORKS/ModelBuilder software ...
The cardiac toxicity of arsenic trioxide (ATO) was studied in chick embryos. Fertilized eggs of White Leghorns were incubated and investigated. The chick embryonic heart has been often used in pharmacologic and toxicologic experiments. After ATO at 0.25, 0.5 or 1.0 mg/egg was injected into fertilized eggs, heart rates (HRs) were measured by electrocardiogram. After low dosing of ATO, the heart rate was not different compared with control. However, HRs significantly decreased in a dose- and time-dependent manner ( ...
Data and research on test guidelines including chemical testing and assessment, chemical safety, animal welfare, endocrine disrupters, good laboratory practice (GLP), Mutual Acceptance of Data (MAD)., In November 2004, the OECD member countries agreed on the principles for validating (quantitative) structure-activity relationship [(Q)SAR] models for their use in regulatory assessment of chemical safety. (Q)SARs are methods for estimating the toxicity and other properties of a chemical from its molecular structure.
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The physicochemical property corollary to the pharmacological properties determined by SAR. SPR applies to a molecules pharmaceutical properties, such as solubility, partition coefficient and melting point.
Recent reports have brought back the acetylcholine synthesizing enzyme, choline acetyltransferase in the mainstream research in dementia and the cholinergic anti-inflammatory pathway. Here we report, a specific strategy for the design of novel ChAT ligands based on molecular docking, Hologram Quantitative Structure Activity Relationship (HQSAR) and lead optimization. Molecular docking was performed on a series of ChAT inhibitors to decipher the molecular fingerprint of their interaction with the active site of ChAT. Then robust statistical fragment HQSAR models were developed. A library of novel ligands was generated based on the pharmacophoric and shape similarity scoring function, and evaluated in silico for their molecular interactions with ChAT. Ten of the top scoring invented compounds are reported here. We confirmed the activity of alpha-NETA, the only commercially available ChAT inhibitor, and one of the seed compounds in our model, using a new simple colorimetric ChAT assay (IC50 similar ...
Calculated BCF for constituents of this substance range between 0.4 - 71100 L/kg. It should be borne in mind that this is the full range of predicted values, and that this may be misleading or unrepresentative of the properties of the UVCB substance as a whole. The range should therefore be treated with caution and not taken out of context. The substance is a hydrocarbon UVCB. Standard tests for this endpoint are intended for single substances and are not appropriate for this complex substance. However, this endpoint is characterised using quantitative structure property relationships for representative hydrocarbon structures that comprise the hydrocarbon blocks used to assess the environmental risk of this substance with the PETRORISK model (see Product Library in PETRORISK spreadsheet attached in IUCLID section 13). For purposes of PBT assessment, the substance has been assessed using a combination of QSAR predictions and confirmatory experimental testing for representative constituents using ...
DescriptionRecent investigations suggest that ligands such as steroids inhibit the binding of [35S] t-butylbicyclophosphorothionate ([35S] TBPS) to the convulsant site in the aminobutyric acid type A (GABAA) receptor complex. Currently, most interest is centered on ligands with [35S] TBPS displacement properties. Ligands binding to the GABAA receptor, block GABA-gated chloride ion flux in a non-competitive manner, resulting in convulsions. Traditionally, [35S] TBPS inhibition studies are measured using animal tests. Testing compounds, using rat tests, for potentially new ligands are costly and time-consuming. Therefore, developing computational models to predict potential [35S] TBPS displacement could provide many opportunities for the discovery and development of new ligands acting on the GABAA receptor convulsant site, resulting in the preventions of convulsions. In this study, Quantitative Structure Activity Relationship (QSAR) approaches were used to develop several computational models for ...
QSAR Studies on Bacterial Efflux Pump Inhibitors: 10.4018/978-1-4666-8136-1.ch007: Antimicrobial drug resistance occurs when bacteria undergo certain modifications to eliminate the effectiveness of drugs, chemicals, or other agents designed
Adsorption / desorption: C14-20 Aliphatics (≤2% aromatic) are hydrocarbon UVCBs. Standard tests for this endpoint are intended for single substances and are not appropriate for these complex substances. However, this endpoint is characterized using quantitative structure property relationships for representative hydrocarbon structures that comprise the hydrocarbon blocks used to assess the environmental risk of this substance with the PETRORISK model (see Product Library in PETRORISK spreadsheet attached to IUCLID Section 13). Koc of icosane has been estimated by calculation in the Concawe Library of Petrorisk, using SPARC v4.2 program (May 2008). The calculated value is 1.84 x 1011 L/kg, using a log Kow of 11.46. This result suggests that icosane is expected to be immobile in soil. Henrys Law Constant (Volatility): Volatilisation is dependent on Henrys Constant (HC) which is not applicable to complex substances. Standard tests for atmospheric oxidation half-lives are intended for single ...
Volatilisation is dependent on Henrys Constant (HC) which is not applicable to complex substances. Standard tests for atmospheric oxidation half-lives are intended for single substances and are not appropriate for these complex substances. However, this endpoint is characterized using quantitative structure property relationships for representative hydrocarbon structures that comprise the hydrocarbon blocks used to assess the environmental risk of these substances with the PETRORISK model (see library tab in PETRORISK spreadsheet attached to IUCLID section 13). Henrys law constant for icosane has been estimated in the Concawe library, using SPARC v4.2 program. The obtained value is 55.6 atm-m3/mol. ...
Aromatase is a member of the cytochrome P450 family responsible for catalyzing the rate-limiting conversion of androgens to estrogens. In the pursuit of robust aromatase inhibitors, quantitative structure-activity relationship (QSAR) and classification structure-activity relationship (CSAR) studies were performed on a non-redundant set of 63 flavonoids using multiple linear regression, artificial neural network, support vector machine and decision tree approaches. Easy-to-interpret descriptors providing comprehensive coverage on general characteristics of molecules (i.e., molecular size, flexibility, polarity, solubility, charge and electronic properties) were employed to describe the unique physicochemical properties of the investigated flavonoids. QSAR models provided good predictive performance as observed from their statistical parameters with Q values in the range of 0.8014 and 0.9870 for the cross-validation set and Q values in the range of 0.8966 and 0.9943 for the external test set. ...
A.N.U. B.PHARMACY SYLLABUS WITH EFFECT FROM 2012-13 ACADEMIC YEAR) 501 PHARMACEUTICAL CHEMISTRY-IV (MEDICINAL-II) Quantitative structure activity relationship (QSAR) studies, basic concepts of computer aided drug design, different drug design approaches, basic General Anaesthetics : Introduction, classification, mechanism of action, synthesis and therapeutic uses of halothane, ketamine, methohexital. Local Anaesthetics : Introduction, chemical classification, ideal requirements, mode of action, SAR, structures of important local anaesthetics, metabolism and synthesis of benzocaine, procaine, lidocaine, tetracaine and cinchocaine. Hypnotics and Sedatives - SAR of barbiturates, synthesis, metabolism and therapeutic uses of phenobarbital, amylobarbital, pentobarbital, cyclobarbitone calcium, thiopental, hexobarbital. chlordiazepoxide, diazepam, alprazolam. Anti-psychotics - SAR of phenothiazines, synthesis and therapaeutic uses of promethazine, Prochlorperazine, Fluphenazine, chlorpromazine, ...
摘要 In current paper, a quantitative structure-activity relationship (QSAR) study was performed for the prediction of acute toxicity of aromatic amines. A set of 56 compounds was randomly divided into a training set of 46 compounds and a test set of 10 compounds. The electronic and topological descriptors computed by the Scigress package and Dragon software were used as predictor variables. Multiple linear regression (MLR) and support vector machine (SVM) were utilized to build the linear and nonlinear QSAR models, respectively. The obtained models with five descriptors show strong predictive ability. The linear model fits the training set with R2 = 0.71, with higher SVM values of R2 = 0.77. The validation results obtained from the test set indicate that the SVM model is comparable or superior to that obtained by MLR, both in terms of prediction ability and robustness. ...
Hydrophobicity as measured by Log P is an important molecular property related to toxicity and carcinogenicity. With increasing public health concerns for the effects of Disinfection By-Products (DBPs), there are considerable benefits in developing Quantitative Structure and Activity Relationship (QSAR) models capable of accurately predicting Log P. In this research, Log P values of 173 DBP compounds in 6 functional classes were used to develop QSAR models, by applying 3 molecular descriptors, namely, Energy of the Lowest Unoccupied Molecular Orbital ( ELUMO), Number of Chlorine (NCl) and Number of Carbon (NC) by Multiple Linear Regression (MLR) analysis. The QSAR models developed were validated based on the Organization for Economic Co-operation and Development (OECD) principles. The model Applicability Domain (AD) and mechanistic interpretation were explored. Considering the very complex nature of DBPs, the established QSAR models performed very well with respect to goodness-of-fit, robustness and
Comparative toxicity potentials (CTPs) quantify the potential ecotoxicological impacts of chemicals per unit of emission. They are the product of a substances environmental fate, exposure, and hazardous concentration. When empirical data are lacking, substance properties can be predicted. The goal of the present study was to assess the influence of predictive uncertainty in substance property predictions on the CTPs of triazoles. Physicochemical and toxic properties were predicted with quantitative structure-activity relationships (QSARs), and uncertainty in the predictions was quantified with use of the data underlying the QSARs. Degradation half-lives were based on a probability distribution representing experimental half-lives of triazoles. Uncertainty related to the species sample size that was present in the prediction of the hazardous aquatic concentration was also included. All parameter uncertainties were treated as probability distributions, and propagated by Monte Carlo simulations. ...
Lung cancer was confirmed to be caused by cigarette smoking over 50 years ago, and since then several other diseases (e.g., coronary heart disease, chronic bronchitis, and cancer of the pancreas, bladder, and kidney) caused by smoking and involuntary exposure to cigarette smoke have been added to the list. Many of these diseases are life threatening, resulting in five million deaths each year (U.S. Department of Health and Human Services, 2006). Mackay, Ericksen, and Shafey (2006) reported that half of the worlds 1.2 billion smokers will die from diseases caused by smoking. Due to increased public awareness of such statistics and beliefs about the health risks of smoking, declining smoking rates are reported in numerous developed countries (Peto, Lopez, Boreham, Thun, & Heath, 1992). As knowledge of the health risks caused by tobacco has increased, the prevailing attitudes about smoking and the tobacco industry have also been impacted ...
1. INTRODUCTION. Since the Wiener index W introduced in 19471, many chemists such as Balaban A.T.2-5, Randic M.6-10, Gutman I.11-14, Trinajstic N.15-18, and Estrada E.19-21 have taken lots of time and gotten many brilliant achievements in quantitative structure-property/activity relationships (QSPR/QSAR) study. These studies have played significant roles in various fields such as drug design, physicochemical property/ biological activity forecast, environmental pollutant judgment, etc22-30. Recently, our group has proposed some new topological descriptor, such as EDm index31, PE index32 and Nt index33, which have been applied to QSPR study for series of compounds.. Stereochemistry is one of the crucial parts in organic chemistry, and the cis-trans isomerism that belongs to diastereoisomeric category, is of practical importance in stereochemistry34. The cis-trans isomers have diverse chemical and physical properties, such as biological activity and inhibiting ability. Many experimental results ...
The Bertz indices, derived by counting the number of connecting edges of line graphs of a molecule were used in deriving the QSPR models for the physicochemical properties of alkanes. The inability of these indices to identify the hetero centre in a chemical compound restricted their applications to hydrocarbons only. In the present work, a novel molecular descriptor has been derived from the weighted line graph of the molecular structure and applied in correlating the physicochemical properties of alkane isomers with these descriptors. A weight is tagged at the vertex of the line graph, which consequently modifies the weight of the edge. These descriptors were found to classify the alkane isomers and served well in deriving the QSPR models for various physicochemical properties. The mathematical calculations include the quantitative treatment on the role of substituents (alkyl) in governing the properties under study of the alkane isomers. Further, the use of weighted line graph in the enumeration of
Quantitative structures were obtained for the fully hydrated liquid phases of dioleoylphosphatidylcholine (DOPC) and dipalmitoylphosphatidylcholine (DPPC) bilayers by simultaneously analyzing x-ray and neutron scattering data. from stand-alone neutron and x-ray scattering tests and poses new issues for molecular dynamics simulations. Launch Biological function is associated with membrane framework. The structural basis of biomembranes comes from liquid stage lipid bilayers with nearly liquid-like conformational levels of freedom, so the structure is most beneficial described by wide statistical distributions as opposed to the sharpened < 0.8 ??1). Complementing these data, diffuse scattering from isotropic spherically, hydrated fully, unilamellar vesicles (ULVs) continues to be obtained to increase the reduced range to 0.05 ??1, and a worldwide combined analysis continues to be put on x-ray data pieces from both oriented multilayers and ULVs (9). By raising the product quality and quantity of ...
A quantitative structure-activity relationship (QSAR) study of IRAK inhibitor 6 and its analogs were conducted by using the genetic algorithm and multiple linear regression (GA-MLR) method. In vitro study showed that compared with its unsubstituted phenyl amide analog, the ortho-substitution with chloro, methoxy and difluoromethoxy analogs of IRAK inhibitor 6 improved potency against IRAK-4 significantly. These potency effects were additive, with the most active example in the set being IRAK inhibitor 6, in which the presence of nitrogen-linked substituents at the para position had a beneficial effect on the rate of turnover by human microsomes (20 μL/min/mg protein ...
CYP2C9 is one of our major drug metabolising enzymes and belongs to the cytochrome P450 (CYP) super family. The aim of this thesis was to gain an understanding of the quantitative structure-activity relationships (QSAR) of CYP2C9 substrates and inhibitors. This information will be useful in predicting drug metabolism and the potential for drug-drug interactions. To achieve this, a well characterised data set of structurally diverse, competitive CYP2C9 inhibitors was identified in our laboratory. Several computational methodologies, many based on GRID molecular interaction fields, were applied or developed in order to handle issues such as compound alignment and bioactive conformer selection. First, a traditional 3D QSAR was carried out in GOLPE, generating a predictive model. In this model the selection of a bioactive conformer and alignment was based on docking in a homology model of CYP2C9. Secondly, we introduced the concept of alignment independent descriptors from ALMOND. These descriptors ...
Cancer is one of the most serious issues in human life. Blocking Programmed cell death protein 1 (PD-1) and programmed death ligand-1 (PD-L1) pathway is one of the great innovation on last few years, but a few numbers of inhibitors can be able to block it. (2-methyl-3-biphenylyl) methanol (MBPM) derivative is one of them. Here, the quantitative structure-activity relationship (QSAR) established twenty (2-methyl-3-biphenylyl) methanol (MBPM) derivatives as the programmed death ligand-1 (PD-L1) inhibitors. Density functional theory (DFT) at the B3LPY/6-31+G (d, p) level was employed to study the chemical structure and properties of the chosen compounds. Highest occupied molecular orbital energy EHOMO, lowest unoccupied molecular orbital energy ELUMO, total energy ET, dipole moment DM, absolute hardness η, absolute electronegativity χ, softness S, electrophilicity ω, energy gap ΔE, etc, properties were observed and determine. Principal component analysis (PCA), multiple linear regression (MLR) ...
Cancer is one of the most serious issues in human life. Blocking Programmed cell death protein 1 (PD-1) and programmed death ligand-1 (PD-L1) pathway is one of the great innovation on last few years, but a few numbers of inhibitors can be able to block it. (2-methyl-3-biphenylyl) methanol (MBPM) derivative is one of them. Here, the quantitative structure-activity relationship (QSAR) established twenty (2-methyl-3-biphenylyl) methanol (MBPM) derivatives as the programmed death ligand-1 (PD-L1) inhibitors. Density functional theory (DFT) at the B3LPY/6-31+G (d, p) level was employed to study the chemical structure and properties of the chosen compounds. Highest occupied molecular orbital energy EHOMO, lowest unoccupied molecular orbital energy ELUMO, total energy ET, dipole moment DM, absolute hardness η, absolute electronegativity χ, softness S, electrophilicity ω, energy gap ΔE, etc, properties were observed and determine. Principal component analysis (PCA), multiple linear regression (MLR) ...
The present doctoral thesis is the result of the work carried out during the three years of my PhD scholarship at the Rome Center for Molecular Design laboratory (RCMD, Department of Chemistry and Drug Technologies, Sapienza University of Rome), under the supervision of Prof. Rino Ragno. The research activity was focused mainly on the design, optimization and application of computational strategies to derive quantitative structure-activity relationships (QSAR, 3-D QSAR, and COMBINE) on different molecular classes of current interest, such as: opioid receptor antagonists (OPAs), Hepatitis C Virus NS5B-Polymerase Inhibitors (NS5B-NNIs), Hystone Deacetylase Inhibitors (HDACIs), Anti- tubercular agents, vascular endothelial growth factor receptor-2 (VEGFR-2) inhibitors, HSP90 inhibitors, HIV-1 reverse transcriptase inhibitors (NNRTIs), Bovine Serum Amine Oxidase (BSAO) substrates, etc... Moreover two research periods abroad were performed: the first framed in a LLP Erasmus program collaboration, was ...
Ligand-based virtual screening experiments are an important task in the early drug discovery stage. An ambitious aim in each experiment is to disclose active structures based on new scaffolds. To perform these scaffold-hoppings for individual problems and targets, a plethora of different similarity methods based on diverse techniques were published in the last years. The optimal assignment approach on molecular graphs, a successful method in the field of quantitative structure-activity relationships, has not been tested as a ligand-based virtual screening method so far. We evaluated two already published and two new optimal assignment methods on various data sets. To emphasize the scaffold-hopping ability, we used the information of chemotype clustering analyses in our evaluation metrics. Comparisons with literature results show an improved early recognition performance and comparable results over the complete data set. A new method based on two different assignment steps shows an increased
MHC-epitope binding plays a key role in the cellular immune response. Accurate prediction of MHC-epitope binding affinity can greatly expedite epitope screening by reducing costs and experimental effort. In this paper, 13 T descriptors, which derived from 544 physicochemical properties of the natural amino acids, were used to characterize 4 MHC class I alleles epitope peptide sequences, the optimal QSAR models were constructed by using stepwise regression combines with multiple linear regression (STR-MLR). For HLA-A*0201, HLA-A*0203, HLA-A*0206 and HLAA*1101 alleles, the leave one out cross validation values (Q2 train) were 0.581, 0.553, 0.525 and 0.588, the correlation coefficients (R2 train) of training datasets were 0.607, 0.582, 0.556 and 0.606, the correlation coefficients (R2 test) of test datasets were 0.533, 0.506, 0.501 and 0.502, respectively. The results showed that all models can obtain good performance for prediction and explain the mechanism of interaction between MHC and epitope. ...
Quarterly published in print and online Inventi Rapid/Impact: Molecular Modeling publishes high quality unpublished as well as high impact pre-published research and reviews catering to the needs of researchers and professionals. The journal includes all aspects of molecular modeling and computational chemistry, including study of molecular shape and properties, molecular simulations, protein and polymer engineering, drug design, materials design, QSAR, structure-activity and structure-property relationships, database mining, and compound library design.
Research outlines. The research projects cover the development and application of new experimental, in silico and cheminformatic algorithms to derive appropriate strategies for solving real problems in chemistry, namely in the field of quantitative structure-activity relationships (QSAR) applied in drug discovery and optimization, human metabolism, human toxicity, food and environmental chemistry. Curriculum vitae Prof. Gabriele CRUCIANI. Academic career. Gabriele Cruciani is full professor in Organic Chemistry since 2005 at the Chemistry Department of the University of Perugia (Italy). In 1994, when he still was a research assistant, he was the local recipient of the EU project BIO2-CT94-3025 relative to the design of new inhibitors of Glycogen phosphorilase b, leaded by the laboratory of molecular biophysics of the Oxford University.. From 1994 to 2009 he was responsible of the course "Modeling of organic molecules" for the last year students of the Master in Chemical Sciences (organic ...
The toxicological screening of the numerous chemicals that we are exposed to requires significant cost and the use of animals. Accordingly, more efficient methods for the evaluation of toxicity are required to reduce cost and the number of animals used. Computational strategies have the potential to reduce both the cost and the use of animal testing in toxicity screening. The ultimate goal of this thesis is to develop computational models for the prediction of toxicological endpoints that can serve as an alternative to animal testing. In Paper I, an attempt was made to construct a global quantitative structure-activity relationship (QSAR)model for the acute toxicity endpoint (LD50 values) using the Munro database that represents a broad chemical landscape. Such a model could be used for acute toxicity screening of chemicals of diverse structures. Paper II focuses on the use of acute toxicity data to support the prediction of chronic toxicity. The results of this study suggest that for related ...
Principal Component Analysis (PCA) and Artificial Neural Network (ANN) were used to analyze the relationship between the structure and the activities of a series of nine biphenylphenyl methanone derivatives against Mycobacterium tuberculosis in vitro. Both PCA and ANN were able to classify these derivatives in two categories: low active and highly active compounds. Empirical and theoretical descriptors were used in the classification process. The descriptors selected by PCA indicated that the reactivity plays an important role in the determination of antimycobacterial activity of biphenylphenyl methanone derivatives (BPM). The BPM showed a moderate activity against the M. tuberculosis strain tested with the exception of chloride-, bromide- and nitroderivatives (when X = Cl, Br, NO2) which were the most actives against M. tuberculosis in vitro among all the methanones studied ...
The knowledge bases are, for example, OECD/NEAs Thermochemical Database (127, 128), solvent-extraction database and programs for analysis (129-132). Although methodologies of modeling, how to use the tools, depend heavily on the researchers expertise, requisite criteria for design is the knowledge about the relationship between ligand structure and the nature of metal-donor group interactions; -quantitative -structure-activity relationship (QSAR). Many investigations to establish methodologies for designing ligands possessing high affinity and selectivity to specified metal ions have appeared during the past decade (133-150). In the framework of the AFCI program, Peterman et al. of Idaho National Laboratory (INL) have examined the feasibility of using the Cyanex 301 system for treating an ammonium acetate/acetic acid buffered solution (308), which was used in the TRUEX process as a strip solution of Ans and Lns. 37 M TBP in n-dodecane was studied. At a region of specific pH value, the ...
This technical note describes a procedure for interpreting tissue residues of neutral organic chemicals generated in 28-day dredged material bioaccumulation bioassays. This interpretive guidance uses a critical body residue (CBR) of neutral organic chemicals reported for the fathead minnow, Pirnephales pmmelas. The CBR is based on a very large U.S. Environmental Protection Agency (EPA) acute toxicity database and well accepted quantitative structure activity relation- ships (QSARs). Guidance in this technical note is not appropriate when xenobiotic metabolism of neutral organic contaminants is likely. Background The evaluation of dredged material requires an assessment of unacceptable adverse impacts. Testing to support this evaluation will often include sediment bioassays.*CHEMICALS
TY - JOUR. T1 - Investigation of antiulcer activities of imidazo[1,2-α]pyridinyl-2-alkylaminobenzoxazoles and 5,6,7,8-tetahydroimidazo[1,2-α]pyridinylbenzoxazoles with electron-topological (ET) method. AU - Huang, Hsu Shan. AU - Chiou, Jeng Fong. AU - Chiu, Hui Fen. AU - Chen, Rong Fu. AU - Lai, Yu Liang. PY - 2002. Y1 - 2002. N2 - The study presents structure-activity considerations of a series of imidazo[1,2-α]pyridiny-2-alkylaminobenzoxazoles(I) and 5,6,7,8-tetahydroimidazo[1,2-α]pyridinylbenzoxazoles (II) investigated for anti-stress ulcer activity with the electron-topological method. A series of 39 compounds including 24 active and 15 weakly active was studied. It is shown that the fragment determined by the electron-topological method in an active molecule is responsible for anti-stress ulcer activity. Quantitative structure-activity relationships with electron topological approach of these compounds are discussed in terms of the statistical program STATGRAF-7.0.. AB - The study ...
To create new technologies for producing clean water, reclaiming polluted water, predicting climate and weather, inventing green chemistry, separating chemicals and biomolecules, and designing new drugs to cure diseases requires an ever deeper understanding of water structure-property relationships. It requires ever better models of various types and at different levels.. Water has distinctive liquid and solid properties : It is highly cohesive. It has volumetric anomalies. It has more solid phases than other materials. Its supercooled liquid has divergent thermodynamic response functions. Its glassy state is neither fragile nor strong. Its component ions (hydroxide and protons) diffuse much faster than other ions. Aqueous solvation of oils or ions entails large entropies and heat capacities.. We will review how these properties are encoded within waters molecular structure and energies, as interpreted through the lens of various models, theories and computer simulations. Anomalous properties ...
Animation IM13.3. A backbone drawing of bovine low molecular weight protein tyrosyl phosphate with bound inorganic phosphate.. The order in which a chain of amino acids is connected together is called the primary structure of a protein. For example, the amino acids glycine, alanine, tyrosone and arginine could be connected in the order gly-ala-tyr-arg, or ala-gly-arg-tyr, or tyr-gly-ala-arg, and so on. These compounds are isomers of each other. Knowing which isomer we have tells us something about the protein.. The way that chain arranges itself is called the secondary structure. Very often, proteins coil up into spirals or helices. This helical structure is similar to that of DNA. Another possible secondary structure is a beta-sheet, which is sort of wavy, a bit like a sheet of corrugated steel. These secondary structures are held in place by hydrogen bonds between different amino acids. (You can see the structure-property relationship chapter to review hydrogen bonding).. Usually, the entire ...
N-functionalized imidazoles are a class of heterocyclic organic molecules, and are well-known as components of pharmaceuticals and also serve as building blocks for imidazolium-based ionic liquids (ILs). While IL-based solvents have been the focus of many research efforts in areas such as CO2 capture, imidazoles have not been considered for these same applications. Imidazoles possess many of the same desirable characteristics as ILs such as tunable chemical structures, low vapor pressure and good chemical/thermal stability. Despite these promising features, it has only been very recently that reports on the the relationships between imidazole structure and physical properties were reported, and the study of imidazoles as tailored solvents is still dwarfed by the body of knowledge available for ILs. Our research in this area has focused on developing structure-property relationships for a wide range of N-functionalized imidazoles, with emphasis on density, viscosity, vapor pressure, pKa, heat ...
The current drive for applications of biomass-derived compounds, for energy and advanced materials, has led to a resurgence of interest in the manipulation of plant polymers. The xyloglucans, a family of structurally complex plant polysaccharides, have attracted significant interest due to their intrinsic high affinity for cellulose, both in muro and in technical applications. Moreover, current cell wall models are limited by the lack of detailed structure-property relationships of xyloglucans, due to a lack of molecules with well-defined branching patterns. Here, we have developed a new, broad-specificity "xyloglucan glycosynthase", selected from active-site mutants of a bacterial endoxyloglucanase, which catalyzed the synthesis of high molar mass polysaccharides, with complex side-chain structures, from suitable glycosyl fluoride donor substrates. The product range was further extended by combination with an Arabidopsis thaliana alpha(1 -, 2)-fucosyltransferase to achieve the in vitro ...
Dr. Liottas research activities involve both synthetic-organic and physical-organic chemistry. His major interests lie in the areas of structure-property relationships, kinetics and mechanisms of organic reactions, asymmetric synthesis, homogeneous and heterogeneous catalysis (phase transfer catalysis), the development of environmentally benign tunable (supercritical fluids, near critical water, gas expanded liquids)and smart (reversible ionic liquids, DMSO substitutes) solvent systems, and molecular thermodynamics, solution theory, and phase equilibria. A fundamental goal of Dr. Liottas research is the development of sustainable and environmentally benign chemicals and chemical processes. Dr. Liotta has been collaborating with Dr. Charles A. Eckert for approximately 20 years. ...
In all three areas, the focus lies on studies of the amorphous materials and their structure-property relationship.. One major area of glass research, the mechanical properties of glasses, is currently investigated within the DFG Priority Programme "Topological engineering of ultra-strong glasses" (SPP 1594) and will therefore not be considered. Metallic glasses will also not be part of this programme. Unlike the traditional empirical ("trial & error") approach to glass research, current methods of glass structure analysis (IR, Raman, NMR, diffraction, XAS etc. but also theoretical approaches such as MD or ab initio simulations) allow to thoroughly investigate the relationship between structure and composition, and this should be visible in the project ideas presented within this workshop.. Course of the Workshop for Early Career Investigators. In a first step of the application process, candidates submit a three-page outline for a research project in one of the three main areas described above. ...
Current research efforts have focused on the synthesis of novel, segmented, cross-linked networks and thermoplastics for emerging technologies. Tailoring macromolecular structures for improved mechanical performance can be accomplished through a variety of synthetic strategies using step-growth polymerization. The synthesis and characterization of novel Michael addition networks, ionene families, and ion-containing polyurethanes are described, with the underlying theme of fundamentally investigating the structure-property relationships of novel, segmented macromolecular architectures. In addition, it was discovered that both covalent and electrostatic crosslinking play an important role in the mechanical properties of all types of polymers described herein.. Novel cross-linked networks were synthesized using quantitative base-catalyzed Michael chemistry with acetoacetate and acrylate functionalities. These novel synthetic strategies offer unique thermo-mechanical performance due to the formation ...
Xiaoli Sun is currently Professor in the College of Material Sciences and Engineering at Beijing University of Chemical Technology (BUCT). She obtained her Ph.D in Polymer Physics and Chemistry at the Institute of Chemistry-Chinese Academy of Sciences (IC-CAS) and Max-Planck Institute for Polymer Research (MPI-P) through a sandwich program between the CAS and the Max-Planck-Society in the year of 2009. Thereafter she spent two years as a Postdoctoral fellow at the Kwansei Gakuin University and focused her study in the field of Grazing Incident X-ray scattering from soft-matter thin films. In 2011, she returned to China at BUCT and became full Professor in 2017. Her current research involves orientation-induced polymer crystallization, crystallization behavior of polymer in confined spaces, and structure-property relationship of polymers.. ...
This work explores the possibility of exploiting structure-property relationships to manufacture tailor-made polymers with target end-use properties. A novel framework which aims to improve upon current industrial practices in polymerization process and product quality control is proposed. The strong inter-relationship between the molecular architecture and rheological properties of polymers is the basis of this framework. The melt index is one of the most commonly used industrial measures of a polymers processibilty. However, this single-point non-Newtonian viscosity is inadequate to accurately reflect the polymer melts flow behavior. This justifies monitoring the entire viscosity-shear rate behavior during the polymerization stage. In addition, the crucial role played by the polymer melts elastic characteristics is not reflected in its shear viscosity and so elasticity meaurements are also warranted. In this study, rheological models available in the open literature are utillized to ...
Wood represents a unique hierarchical biological material with excellent macroscopic properties originating from the specific structural arrangement of the constituents on the micro- and nanoscale. For a detailed analysis of the corresponding structure-property relationships high resolution analytical techniques, beyond conventionallyused SEM, TEM and nanoindentation, are needed. In this regard atomic force microscopy (AFM) can push the limit of resolution down to the nanoscale in terms of imaging the topography and mechanical properties. So we have adapted the so-called quantitative imaging mode (JPK instruments) based on recording a force distance curve in every pixel for the nano-scale structural respectively mechanical characterization of wood cell walls without the need of embedding. Thereby, it was possible to differentiate for the first time between the different cell wall layers, (CML, S1, S2, S3) on a spruce cross section on the basis of their mechanical properties. Furthermore, we have ...
This course will present a review of the state of the art of materials structured at the nanoscale. Nanoscale structure in metals, polymers and ceramics can have a marked influence on structure-property relationships with the possibility of providing behaviour not seen in coarser scale structures. In addition certain new classes of materials may also be produced at this size level, for example, carbon nanotubes, graphene and a variety of colloidal structures. The processing and applications of nanomaterials will also be examined along with the requirements and techniques for characterising a range of nanomaterials in isolation and as part of complex systems.. ...
In: Polycondensation 2002 : Progress in step-growth polymerization and structure-property relationships of polycondensates ; 4th International Symposium on Polycondensates, held in Hamburg, Germany, September 15 - 18, 2002 / symposium ed. (chairman): Hans R. Kricheldorf. - Weinheim : Wiley-VCH, 2003 . - S. 253-266 . - (Macromolecular Symposia ; 199 ...
Comparable systems are of great significance for understanding the structure-property relationship. Herein, a new Au13Cu2 nanocluster protected by phenylethanethiol (PET) and triphenylphosphine (TPP) is synthesized and structurally determined, including an icosahedral Au13 and two CuS3 configurations. Based on prev Nanoscale 10th Anniversary Special Issue
1LPG: Design and Quantitative Structure-Activity relationship of 3-amidinobenzyl-1H-indole-2-carboxamides as potent, nonchiral, and selective inhibitors of blood coagulation factor Xa.
New analogues of PA-824 having alternative side chain ether linkers of varying size & flexibility shows 8-fold better activity than parent drug i.e. PA-824 as Mycobacterium tuberculosis (M.tb.) inhibitors. Recent work suggests that bicyclic nitroimidazole-based prodrugs PA-824 as intracellular nitric oxide (NO) releaser is key to their activity against non replicating persistent M.tb. 2D & 3D QSAR studies were performed on a set of 72 Biaryl analogues of PA-824 having various ether linkers using V-Life Molecular Design Suite (MDS 3.5) QSAR plus module. The best model were generated using Multiple linear regression (MLR) analysis (r2 = 0.8416, q2 = 0.7853, F test = 47.8273, pred_r2 = 0.8481, pred_r2se = 0.2880) and Principle Component Regression (PCR) (r2 = 0.7781, q2 = 0.7274, F test = 42.517, pred_r2 = 0.8405, pred_r2se = 0.2951) for 2D and 3D QSAR respectively. For each set of descriptors, the best multi-linear QSAR equations were obtained by the stepwise variable selection method using ...
CODESSA PROTM (Comprehensive Descriptors for Structural and Statistical Analysis) is a comprehensive program for developing quantitative structure-activity/property relationships (QSAR/QSPR) that integrates all necessary mathematical and computational tools to:. ...
TY - JOUR. T1 - Synthesis and structure - Activity relationships of quarternary ammonium cephalosporins with 3-pyrazolylpyridium derivatives. AU - Chang, Kwan Young. AU - Kim, Sung Hoon. AU - Nam, Ghilsoo. AU - Seo, Jae Hong. AU - Kim, Joong Hyup. AU - Ha, Deok-Chan. PY - 2000/6/5. Y1 - 2000/6/5. N2 - Cephalosporins with 3-pyazolylpyridinium at C-3 position, which is supposed to exhibit synergic activity of ceftazidime and cefoselis, were synthesized and their antibacterial activity against Gram-positive and Gram-negative was inspected. (C) 2000 Elsevier Science Ltd. All rights reserved.. AB - Cephalosporins with 3-pyazolylpyridinium at C-3 position, which is supposed to exhibit synergic activity of ceftazidime and cefoselis, were synthesized and their antibacterial activity against Gram-positive and Gram-negative was inspected. (C) 2000 Elsevier Science Ltd. All rights reserved.. UR - http://www.scopus.com/inward/record.url?scp=0034608562&partnerID=8YFLogxK. UR - ...
TY - JOUR. T1 - Design strategies, structure activity relationship and mechanistic insights for purines as kinase inhibitors. AU - Sharma, Sahil. AU - Singh, Jagjeet. AU - Ojha, Ritu. AU - Singh, Harbinder. AU - Kaur, Manpreet. AU - Bedi, P. M.S.. AU - Nepali, Kunal. PY - 2016/4/13. Y1 - 2016/4/13. N2 - Kinases control a diverse set of cellular processes comprising of reversible phosphorylation of proteins. Protein kinases play a pivotal role in human tumor cell proliferation, migration and survival of neoplasia. In the recent past, purine based molecules have emerged as significantly potent kinase inhibitors. In view of their promising potential for the inhibition of kinases, this review article focuses on purines which have progressed as kinase inhibitors during the last five years. A detailed account of the design strategies employed for the synthesis of purine analogs exerting inhibitory effects on diverse kinases has been presented. Apart from presenting the design strategies, the article ...
Molecular similarity is a pervasive concept in chemistry. It is essential to many aspects of chemical reasoning and analysis and is perhaps the fundamental assumption underlying medicinal chemistry....
Abstract: Recognition of the phosphorylation sites in proteins is required for reconstruction of regulatory processes in living systems. This task is complicated because the phosphorylation motifs in amino acid sequences are considerably degenerated. To improve the prediction efficacy researchers often use additional descriptors, which should reflect physicochemical features of site-surrounding regions. We have evaluated the reasonability of this approach by applying molecular descriptors (MNA) for structural presentation of the peptide segments. Comparative testing was performed using the prognostic method PASS and two input data types: sets of the MNA descriptors represented peptides as chemical structures and amino acid sequences written using a one-letter code. Training sets were classified in accordance with the established types of the enzymes (protein kinases), modifying corresponding phosphorylation sites. The accuracy estimates obtained by prognosis validation for various classes of ...
Development of KTiOAsO4 and isostructural arsenates as new electrooptic materials. This involves (a) the growth of crystals of suitable size and quality for research, (b) investigation of their structural, optical and physical properties: the establishment of structure/property relationships, (c) development of waveguide fabrication methods in KTiOAsO4, (d) investigation of crystal twinning and poling methods for its elimination. ...
The activities of the research group are focused at scientific and applied problems related to solid state properties of pharmaceuticals and other small organic molecules of high industrial relevance such as agro-chemicals. A major concern of our work is the development of methods, strategies and guidelines in the production and characterization of solid state forms and the systematic exploration of structure property relationships.. The phenomena that emerge from these activities are manifold and include amorphicity, order-disorder structures, plastic and liquid crystals, different types of polymorphism as well as different kinds of multicomponent crystals (hydrates, solvates, co-crystals, racemates).. The assessment of thermodynamic, kinetic and structural properties of the phases and phase transitions requires a broad methodology and various analytical techniques comprising among others thermal analysis and calorimetry (DSC, TGA, hot stage microscopy, microcalorimetry), vibrational ...
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Despite of the availability and facility of accessing several algorithms for calculation of LogP in QSA(P)R studies, articles typically do not describe the selection procedure for the method used. Therefore, three studies to verify the influence of different LogP algorithms on building QSAR models were performed. Two QSAR data sets from the literature (forty-two tricyclic phtalimide inhibitors of HIV-integrase and fourty-six TIBO derivatives inhibitors of HIV-reverse transcriptase) were used together with LogP calculated by thirteen algorithms, and several regression models were constructed and compared. A new QSAR study for 4,5-dihydroxvpyrimidine carboxamides inhibitors of HIV-1 integrase was also performed. The explained and predicted variance, results from external validation, leave-N-out cross-validation and y-randomization test were analyzed for all models from the three data sets. Despite the same physicochemical meaning, LogPs calculated by distinct methods may show different levels of ...
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Oriental Journal of Chemistry is a peer reviewed quarterly research journal of pure and applied chemistry. It publishes standard research papers in almost all thrust areas of current chemistry of academic and commercial importance. It provides a platform for rapid publication of quality research papers, reviews and chemistry letters. Oriental Journal of Chemistry is abstracted and indexed in almost all reputed National and International agencies.
Autori: FABIAN, WMF; TIMOFEI, S; KURUNCZI, L. Editorial: Theochem-Journal of Molecular Structure , 340 , p.73-81, 1995.. Rezumat:. Cuvinte cheie: CoMFA, AM1, MTD, dye, cellulose. ...
Molecular Descriptors for Chemoinformatics. Volume I: Alphabetical Listing / Volume II: Appendices, References 2 Volume Set. 2nd, Revised and Enlarged Edition. Methods and Principles in Medicinal Chemistry
The possibility of predicting the parameters in HPLC by means of theoretical calculations, represents a significant step forward in the analysis of the complex mixtures of higher boiling petroleum...