0000000000709191

AUTHOR

Juan A. Castillo-garit

showing 37 related works from this author

Applications of Bond-Based 3D-Chiral Quadratic Indices in QSAR Studies Related to Central Chirality Codification

2009

The concept of bond-based quadratic indices is generalized to codify chemical structure information for chiral drugs, making use of a trigonometric 3D-chirality correction factor. In order to evaluate the effectiveness of this novel approach in drug design, we have modeled several well-known data sets. In particularly, Cramer's steroid data set has become a benchmark for the assessment of novel QSAR methods. This data set has been used by several researchers using 3D-QSAR approaches. Therefore, it is selected by us for the shake of comparability. In addition, to evaluate the effectiveness of this novel approach in drug design, we model the angiotensin-converting enzyme inhibitory activity o…

Quantitative structure–activity relationshipTheoretical computer scienceComputer scienceChemistryOrganic ChemistryComparabilityComputer Science ApplicationsData setSet (abstract data type)Quadratic equationComputational chemistryDrug DiscoveryMolecular symmetryBenchmark (computing)TrigonometryQSAR & Combinatorial Science
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<strong>Predicting Proteasome Inhibition using Atomic Weighted Vector and Machine Learning</strong>

2018

Ubiquitin/Proteasome System (UPS) is a highly regulated mechanism of intracellular protein degradation and turnover. Through the concerted actions of a series of enzymes, proteins are marked for proteasomal degradation by being linked to the polypeptide co-factor, ubiquitin. The UPS participates in a wide array of biological functions such as antigen presentation, regulation of gene transcription and the cell cycle, and activation of NF-κB. Some researchers have applied QSAR method and machine learning in the study of proteasome inhibition (EC50(µmol/L)), such as: the analysis of proteasome inhibition prediction, in the prediction of multi-target inhibitors of UPP and in the prediction of p…

Quantitative structure–activity relationshipbusiness.industryProtein contact mapPerceptronMachine learningcomputer.software_genreCross-validationRandom forestStatistical classificationMolecular descriptorLinear regressionArtificial intelligencebusinesscomputerMathematicsProceedings of MOL2NET 2018, International Conference on Multidisciplinary Sciences, 4th edition
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Predicting antitrichomonal activity: A computational screening using atom-based bilinear indices and experimental proofs

2006

Existing Trichomonas vaginalis therapies are out of reach for most trichomoniasis people in developing countries and, where available, they are limited by their toxicity (mainly in pregnant women) and their cost. New antitrichomonal agents are needed to combat emerging metronidazole-resistant trichomoniasis and reduce the side effects associated with currently available drugs. Toward this end, atom-based bilinear indices, a new TOMOCOMD-CARDD molecular descriptor, and linear discriminant analysis (LDA) were used to discover novel, potent, and non-toxic lead trichomonacidal chemicals. Two discriminant functions were obtained with the use of non-stochastic and stochastic atom-type bilinear in…

Quantitative structure–activity relationshipDatabases FactualMolecular modelStereochemistryClinical BiochemistryDrug Evaluation PreclinicalPharmaceutical ScienceAntitrichomonal AgentsLigandsBiochemistryCross-validationChemometricsStructure-Activity Relationshipchemistry.chemical_compoundArtificial IntelligencePredictive Value of TestsMolecular descriptorDrug DiscoveryTrichomonas vaginalisAnimalsCluster AnalysisComputer SimulationMolecular BiologyStochastic ProcessesOrganic ChemistryComputational BiologyReproducibility of ResultsLinear discriminant analysisAntitrichomonal agentchemistryData Interpretation StatisticalTopological indexLinear ModelsMolecular MedicineBiological systemAlgorithmsBioorganic & Medicinal Chemistry
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Microesferas de ácido poliláctico marcadas con 166Ho. Una alternativa frente a las de 90Y en el tratamiento del carcinoma hepático mediante radioembo…

2021

Los tumores hepáticos constituyen un importante problema de salud a nivel mundial que en multitud de ocasiones va asociado a patologías previas y factores de riesgo como las hepatitis víricas B y C, el consumo excesivo de alcohol y el aumento de casos de esteatohepatitis no alcohólica, cada vez más relevante en los países industrializados.En hepatocarcinomas no susceptibles de resección quirúrgica, la braquiterapia se está mostrando muy eficaz frente a la quimioterapia sistémica y transarterial, por lo que se desarrollan nuevos tratamientos locorregionales mínimamente invasivos y con menor toxicidad.La radioembolización hepática es una forma de braquiterapia consistente en la administración…

Chemotherapymedicine.diagnostic_testbusiness.industrymedicine.medical_treatmentBrachytherapyMagnetic resonance imagingViral hepatitis bmedicine.diseaseLower energyMicrospheremedicineHigh dosesSteatohepatitisbusinessNuclear medicineNereis. Interdisciplinary Ibero-American Journal of Methods, Modelling and Simulation.
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Tyrosinase Enzyme: 1. An Overview on a Pharmacological Target

2014

The tyrosinase enzyme (EC 1.14.18.1) is an oxidoreductase inside the general enzyme classification and is involved in the oxidation and reduction process in the epidermis. These chemical reactions that the enzyme catalyzes are of principal importance in the melanogenesis process. This process of melanogenesis is related to the melanin formation, a heteropolymer of indolic nature that provides the different tonalities in the skin and helps to the protection from the ultraviolet radiation. However, a pigment overproduction, come up by the action of the tyrosinase, can cause different disorders in the skin related to the hyperpigmentation. Several studies mainly focused on the characteristics …

Models Molecularchemistry.chemical_classificationMolecular StructureEpidermis (botany)Monophenol MonooxygenaseTyrosinaseGeneral MedicineHyperpigmentationMelaninStructure-Activity RelationshipEnzymechemistryBiochemistryOxidoreductaseDrug DiscoveryMolecular mechanismmedicineAnimalsHumansEnzyme Inhibitorsmedicine.symptomOverproductionCurrent Topics in Medicinal Chemistry
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Comparative study to predict toxic modes of action of phenols from molecular structures.

2013

Quantitative structure-activity relationship models for the prediction of mode of toxic action (MOA) of 221 phenols to the ciliated protozoan Tetrahymena pyriformis using atom-based quadratic indices are reported. The phenols represent a variety of MOAs including polar narcotics, weak acid respiratory uncouplers, pro-electrophiles and soft electrophiles. Linear discriminant analysis (LDA), and four machine learning techniques (ML), namely k-nearest neighbours (k-NN), support vector machine (SVM), classification trees (CTs) and artificial neural networks (ANNs), have been used to develop several models with higher accuracies and predictive capabilities for distinguishing between four MOAs. M…

Antiprotozoal AgentsQuantitative Structure-Activity RelationshipBioengineeringMachine learningcomputer.software_genreConstant false alarm ratePhenolsArtificial IntelligenceDrug DiscoveryTraining setModels StatisticalArtificial neural networkCiliated protozoanMolecular StructureChemistrybusiness.industryTetrahymena pyriformisGeneral MedicineLinear discriminant analysisSupport vector machineTest setTetrahymena pyriformisMolecular MedicineArtificial intelligenceNeural Networks ComputerBiological systembusinesscomputerSAR and QSAR in environmental research
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Ligand-based discovery of novel trypanosomicidal drug-like compounds: In silico identification and experimental support

2010

Abstract Two-dimensional bond-based linear indices and linear discriminant analysis are used in this report to perform a quantitative structure–activity relationship study to identify new trypanosomicidal compounds. A database with 143 anti-trypanosomal and 297 compounds having other clinical uses, are utilized to develop the theoretical models. The best discriminant models computed using bond-based linear indices provides accuracies greater than 90 for both training and test sets. Our models identify as anti-trypanosomals five out of nine compounds of a set of already-synthesized substances. The in vitro anti-trypanosomal activity of this set against epimastigote forms of Trypanosoma cruzi…

Databases FactualMolecular modelCell SurvivalStereochemistryTrypanosoma cruziIn silicoNitro compoundQuantitative Structure-Activity RelationshipComputational biologyLigandsChemometricsDrug DiscoveryAnimalsHumansChagas DiseaseTrypanosoma cruziAmastigotePharmacologychemistry.chemical_classificationLife Cycle StagesbiologyOrganic ChemistryDiscriminant AnalysisBiological activityGeneral MedicineFibroblastsModels Theoreticalbiology.organism_classificationLinear discriminant analysisTrypanocidal AgentsHigh-Throughput Screening AssayschemistryAlgorithmsSoftwareEuropean Journal of Medicinal Chemistry
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Thorough evaluation of OECD principles in modelling of 1-[(2-hydroxyethoxy)methyl]-6-(phenylthio)thymine derivatives using QSARINS.

2020

The human immunodeficiency virus is a lethal pathology considered as a worldwide problem. The search for new strategies for the treatment of this disease continues to be a great challenge in the scientific community. In this study, a series of 107 derivatives of 1-[(2-hydroxyethoxy)methyl]-6-(phenylthio)thymine, previously evaluated experimentally against HIV-I reverse transcriptase, was used to model antiretroviral activity. A model of linear regression, implemented in the QSARINS software, was developed with a genetic algorithm for variable selection. The fit of its parameters was good and exhaustive validation, according to the OECD regulatory principles, was performed. Also, the applica…

010405 organic chemistryChemistryHuman immunodeficiency virus (HIV)Quantitative Structure-Activity RelationshipBioengineeringGeneral Medicinemedicine.disease_cause01 natural sciencesVirologyReverse transcriptase0104 chemical sciences010404 medicinal & biomolecular chemistryAnti-Retroviral AgentsModels ChemicalDrug DiscoverymedicineMolecular Medicine1-((2-hydroxyethoxy)methyl)-6-(phenylthio)thymineOrganisation for Economic Co-Operation and DevelopmentThymineSAR and QSAR in environmental research
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Protein linear indices of the ‘macromolecular pseudograph α-carbon atom adjacency matrix’ in bioinformatics. Part 1: Prediction of protein stability …

2005

Abstract A novel approach to bio-macromolecular design from a linear algebra point of view is introduced. A protein’s total (whole protein) and local (one or more amino acid) linear indices are a new set of bio-macromolecular descriptors of relevance to protein QSAR/QSPR studies. These amino-acid level biochemical descriptors are based on the calculation of linear maps on R n [ f k ( x m i ) : R n → R n ] in canonical basis. These bio-macromolecular indices are calculated from the kth power of the macromolecular pseudograph α-carbon atom adjacency matrix. Total linear indices are linear functional on R n . That is, the kth total linear indices are linear maps from R n to the scalar R [ f k …

Quantitative structure–activity relationshipClinical BiochemistryQuantitative Structure-Activity RelationshipPharmaceutical ScienceBiochemistryCombinatoricsViral ProteinsLinear formDrug DiscoveryLinear regressionViral Regulatory and Accessory ProteinsMolecular BiologyAlanineChemistryOrganic ChemistryTemperatureLinear modelComputational BiologyProteinsModels TheoreticalLinear discriminant analysisMatthews correlation coefficientRepressor ProteinsAmino Acid SubstitutionTopological indexMutationLinear algebraLinear ModelsMolecular MedicineSoftwareBioorganic & Medicinal Chemistry
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Prediction of Aquatic Toxicity of Benzene Derivatives to Tetrahymena pyriformis According to OECD Principles

2016

Background: Many QSAR studies have been developed to predict acute toxicity over several biomarkers like Pimephales promelas, Daphnia magna and Tetrahymena pyriformis. Regardless of the progress made in this field there are still some gaps to be resolved such as the prediction of aquatic toxicity over the protozoan T. pyriformis still lack a QSAR study focused in accomplish the OECD principles. Methods: Atom-based quadratic indices are used to obtain quantitative structure-activity relationship (QSAR) models for the prediction of aquatic toxicity. Our models agree with the principles required by the OECD for QSAR models to regulatory purposes. The database employed consists of 392 substitut…

PharmacologyQuantitative structure–activity relationshipTetrahymena pyriformisAntiprotozoal AgentsQuantitative Structure-Activity Relationship010501 environmental sciencesBiology01 natural sciencesAcute toxicity0104 chemical sciencesAquatic toxicologyToxicology010404 medicinal & biomolecular chemistryParasitic Sensitivity TestsTest setDrug DiscoveryBenzene derivativesLinear regressionTetrahymena pyriformisBenzene DerivativesBiological systemMonte Carlo MethodAlgorithmsBootstrapping (statistics)0105 earth and related environmental sciencesCurrent Pharmaceutical Design
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Atom-based 3D-chiral quadratic indices. Part 2: prediction of the corticosteroid-binding globulinbinding affinity of the 31 benchmark steroids data s…

2005

A quantitative structure-activity relationship (QSAR) study to predict the relative affinities of the steroid 'benchmark' data set to the corticosteroid-binding globulin (CBG) is described. It is shown that the 3D-chiral quadratic indices closely correlate with the measured CBG affinity values for the 31 steroids. The calculated descriptors were correlated with biological data through multiple linear regressions. Two statistically significant models were obtained when non-stochastic (R = 0.924 and s = 0.46) as well as stochastic (R = 0.929 and s = 0.46) 3D-chiral quadratic indices were used. A leave-one-out (LOO) approach to model validation is used here; the best results obtained in the cr…

Quantitative structure–activity relationshipClinical BiochemistryPharmaceutical ScienceQuantitative Structure-Activity RelationshipBiochemistryCross-validationStructure-Activity RelationshipQuadratic equationDrug DiscoveryLinear regressionApplied mathematicsComputer SimulationMolecular BiologyTranscortinChromatographyMolecular StructureChemistryOrganic ChemistryComputational BiologyRegression analysisAffinitiesData setDatabases as TopicModels ChemicalTopological indexMolecular MedicineSteroidsBioorganicmedicinal chemistry
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Atom-Based Quadratic Indices to Predict Aquatic Toxicity of Benzene Derivatives to <i>Tetrahymena pyriformis</i>

2009

The non-stochastic and stochastic atom-based quadratic indices are applied to develop quantitative structure-activity relationship (QSAR) models for the prediction of aquatic toxicity. The used dataset, consisting of 392 benzene derivatives for which toxicity data to the ciliate Tetrahymena pyriformis were available, is divided into training and test sets. The obtained multiple linear regression models are statistically significant (R2 = 0.787 and s = 0.347, R2 = 0.806 and s = 0.329, for non-stochastic and stochastic quadratic indices, respectively) and show rather good stability in a cross-validation experiment (q2 = 0.769 and scv = 0.357, q2 = 0.791 and scv = 0.337, correspondingly). In a…

Quantitative structure–activity relationshipQuadratic equationTest setToxicityLinear regressionTetrahymena pyriformisBiological systemStability (probability)MathematicsAquatic toxicologyProceedings of The 13th International Electronic Conference on Synthetic Organic Chemistry
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Computational discovery of novel trypanosomicidal drug-like chemicals by using bond-based non-stochastic and stochastic quadratic maps and linear dis…

2009

Herein we present results of a quantitative structure-activity relationship (QSAR) studies to classify and design, in a rational way, new antitrypanosomal compounds by using non-stochastic and stochastic bond-based quadratic indices. A data set of 440 organic chemicals, 143 with antitrypanosomal activity and 297 having other clinical uses, is used to develop QSAR models based on linear discriminant analysis (LDA). Non-stochastic model correctly classifies more than 93% and 95% of chemicals in both training and external prediction groups, respectively. On the other hand, the stochastic model shows an accuracy of about the 87% for both series. As an experiment of virtual lead generation, the …

Virtual screeningQuantitative structure–activity relationshipModels StatisticalMolecular StructureStochastic modellingOrganic chemicalsStereochemistryCell SurvivalBondTrypanosoma cruziLinear modelPharmaceutical ScienceValue (computer science)Discriminant AnalysisQuantitative Structure-Activity RelationshipLinear discriminant analysisTrypanocidal AgentsQuadratic equationDrug DiscoveryApplied mathematicsComputer-Aided DesignBiological systemCells CulturedMathematicsEuropean journal of pharmaceutical sciences : official journal of the European Federation for Pharmaceutical Sciences
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Multiple Linear Regression to predict larvicidal activity against <em>Aedes aegypti </em>mosquito

2017

Vector-borne diseases are one of the important health problems in most tropical countries. Aedes aegypti is an important vector for transmission of dengue, yellow fever, chikungunya, arthritis, and Zika fever. According to the World Health Organization, it is estimated that Ae. aegypti causes 50 million infections and 25,000 deaths per year. The emerging scenario highlights that the eco-friendly and effective control measures for mosquito vectors is of crucial importance. One of the most effective vector control measures has been the use of larvicidal compounds however; this success was short lived due to development of resistance against them in many mosquito strains, ecological imbalance …

Yellow feverAedes aegyptiBiologymedicine.disease_causebiology.organism_classificationmedicine.diseaseDengue feverVector (epidemiology)StatisticsLinear regressionmedicineChikungunyaLarvicideSelection (genetic algorithm)Proceedings of MOL2NET 2017, International Conference on Multidisciplinary Sciences, 3rd edition
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Bond-based bilinear indices for computational discovery of novel trypanosomicidal drug-like compounds through virtual screening

2014

Two-dimensional bond-based bilinear indices and linear discriminant analysis are used in this report to perform a quantitative structure-activity relationship study to identify new trypanosomicidal compounds. A data set of 440 organic chemicals, 143 with antitrypanosomal activity and 297 having other clinical uses, is used to develop the theoretical models. Two discriminant models, computed using bond-based bilinear indices, are developed and both show accuracies higher than 86% for training and test sets. The stochastic model correctly indentifies nine out of eleven compounds of a set of organic chemicals obtained from our synthetic collaborators. The in vitro antitrypanosomal activity of …

Quantitative structure–activity relationshipStereochemistryTrypanosoma cruziDrug Evaluation PreclinicalQuantitative Structure-Activity RelationshipBilinear interpolationSet (abstract data type)MiceDrug DiscoveryIc50 valuesmedicineAnimalsCells CulturedPharmacologyStochastic ProcessesVirtual screeningDose-Response Relationship DrugMolecular StructureChemistryMacrophagesOrganic ChemistryDiscriminant AnalysisGeneral MedicineLinear discriminant analysisTrypanocidal AgentsDiscriminantBenznidazoleBiological systemmedicine.drugEuropean Journal of Medicinal Chemistry
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An approach to identify new antihypertensive agents using Thermolysin as model: In silico study based on QSARINS and docking

2019

Thermolysin is a bacterial proteolytic enzyme, considered by many authors as a pharmacological and biological model of other mammalian enzymes, with similar structural characteristics, such as angiotensin converting enzyme and neutral endopeptidase. Inhibitors of these enzymes are considered therapeutic targets for common diseases, such as hypertension and heart failure. In this report, a mathematical model of Multiple Linear Regression, for ordinary least squares, and genetic algorithm, for selection of variables, are developed and implemented in QSARINS software, with appropriate parameters for its fitting. The model is extensively validated according to OECD standards, so that its robust…

Virtual screeningChemistry(all)StereochemistryGeneral Chemical EngineeringIn silicoThermolysinComputational biology01 natural sciencesDockinglcsh:ChemistryThermolysinLinear regressionVirtual screening010405 organic chemistryChemistryProteolytic enzymesGeneral Chemistry0104 chemical sciences010404 medicinal & biomolecular chemistrylcsh:QD1-999Docking (molecular)Multiple Linear RegressionQSARINSOrdinary least squaresOutlierChemical Engineering(all)AntihypertensiveArabian Journal of Chemistry
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Atom-based non-stochastic and stochastic bilinear indices: Application to QSPR/QSAR studies of organic compounds

2008

The recently introduced bilinear indices are applied to the QSAR/QSPR studies of heteroatomic molecules. These novel atom-based molecular fingerprints are used to predict the boiling point of 28 alkyl-alcohols and partition coefficient, specific rate constant and antibacterial activity of 34 2-furylethylenes derivatives. The obtained models are statistically significant and show rather very good stability in a cross-validation experiment. The comparison with other approaches exposes a good behavior of our method in this QSPR studies. The obtained results suggest that with the present method, it is possible to obtain a good estimation of physical, chemical and physicochemical properties for …

Partition coefficientBoiling pointQuantitative structure–activity relationshipReaction rate constantChemistryComputational chemistryGeneral Physics and AstronomyMoleculeAtom (order theory)Bilinear interpolationOrganic chemistryPhysical and Theoretical ChemistryStability (probability)Chemical Physics Letters
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Computational identification of chemical compounds with potential anti-Chagas activity using a classification tree

2021

Chagas disease is endemic to 21 Latin American countries and is a great public health problem in that region. Current chemotherapy remains unsatisfactory; consequently the need to search for new drugs persists. Here we present a new approach to identify novel compounds with potential anti-chagasic action. A large dataset of 584 compounds, obtained from the Drugs for Neglected Diseases initiative, was selected to develop the computational model. Dragon software was used to calculate the molecular descriptors and WEKA software to obtain the classification tree. The best model shows accuracy greater than 93.4% for the training set; the tree was also validated using a 10-fold cross-validation p…

Chagas diseaseComputer scienceTrypanosoma cruziAntiprotozoal AgentsQuantitative Structure-Activity RelationshipBioengineeringLigandsMachine learningcomputer.software_genre01 natural sciencesConstant false alarm rateSoftwareMolecular descriptorDrug DiscoveryChagas Diseaseclassification treeVirtual screeningMolecular Structure010405 organic chemistrybusiness.industryDecision tree learningGeneral Medicinevirtual screening0104 chemical sciences010404 medicinal & biomolecular chemistryIdentification (information)Tree (data structure)Anti-chagasic actionTest setMolecular MedicineArtificial intelligencebusinesscomputerSoftware
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Identification In Silico and In Vitro of Novel Trypanosomicidal Drug-Like Compounds

2012

Atom-based bilinear indices and linear discriminant analysis are used to discover novel trypanosomicidal compounds. The obtained linear discriminant analysis-based quantitative structure–activity relationship models, using non-stochastic and stochastic indices, provide accuracies of 89.02% (85.11%) and 89.60% (88.30%) of the chemicals in the training (test) sets, respectively. Later, both models were applied to the virtual screening of 18 in-house synthesized compounds to find new pro-lead antitrypanosomal agents. The in vitro antitrypanosomal activity of this set against epimastigote forms of Trypanosoma cruzi is assayed. Predictions agree with experimental results to a great extent (16/18…

PharmacologyDrugVirtual screeningbiologyStereochemistryIn silicomedia_common.quotation_subjectOrganic ChemistryLinear discriminant analysisbiology.organism_classificationBiochemistryIn vitroDrug DiscoverymedicineMolecular MedicineNifurtimoxTrypanosoma cruzimedicine.drugmedia_commonChemical Biology & Drug Design
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Computational Identification of Chemical Compounds with Potential Activity against Leishmania amazonensis using Nonlinear Machine Learning Techniques.

2019

Leishmaniasis is a poverty-related disease endemic in 98 countries worldwide, with morbidity and mortality increasing daily. All currently used first-line and second-line drugs for the treatment of leishmaniasis exhibit several drawbacks including toxicity, high costs and route of administration. Consequently, the development of new treatments for leishmaniasis is a priority in the field of neglected tropical diseases. The aim of this work is to develop computational models those allow the identification of new chemical compounds with potential anti-leishmanial activity. A data set of 116 organic chemicals, assayed against promastigotes of Leishmania amazonensis, is used to develop the the…

Models MolecularChemical compoundComputer scienceAntiprotozoal AgentsDrug Evaluation PreclinicalMachine learningcomputer.software_genre01 natural sciencesMachine Learningchemistry.chemical_compoundParasitic Sensitivity TestsMolecular descriptorDrug DiscoveryLeishmaniaComputational modelLeishmania amazonensisVirtual screeningbiologyArtificial neural networkbusiness.industryGeneral Medicinebiology.organism_classification0104 chemical sciencesSupport vector machine010404 medicinal & biomolecular chemistryIdentification (information)chemistryArtificial intelligencebusinesscomputerSoftwareCurrent topics in medicinal chemistry
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Identification <i>In Silico</i> and <i>In Vitro</i> of Novel Trypanosomicidal Drug-like Compounds

2012

Atom-based bilinear indices and linear discriminant analysis are used to discover novel trypanosomicidal compounds. The obtained linear discriminant analysis-based quantitative structure–activity relationship models, using non-stochastic and stochastic indices, provide accuracies of 89.02% (85.11%) and 89.60% (88.30%) of the chemicals in the training (test) sets, respectively. Later, both models were applied to the virtual screening of 18 in-house synthesized compounds to find new pro-lead antitrypanosomal agents. The in vitro antitrypanosomal activity of this set against epimastigote forms of Trypanosoma cruzi is assayed. Predictions agree with experimental results to a great extent (16/18…

DrugVirtual screeningChromatographybiologyChemistrymedia_common.quotation_subjectIn silicobiology.organism_classificationLinear discriminant analysisIn vitromedicineTrypanosoma cruziNifurtimoxmedia_commonmedicine.drugProceedings of The 16th International Electronic Conference on Synthetic Organic Chemistry
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Dry selection and wet evaluation for the rational discovery of new anthelmintics

2017

Helminths infections remain a major problem in medical and public health. In this report, atom-based 2D bilinear indices, a TOMOCOMD-CARDD (QuBiLs-MAS module) molecular descriptor family and linear discriminant analysis (LDA) were used to find models that differentiate among anthelmintic and non-anthelmintic compounds. Two classification models obtained by using non-stochastic and stochastic 2D bilinear indices, classified correctly 86.64% and 84.66%, respectively, in the training set. Equation 1(2) correctly classified 141(135) out of 165 [85.45%(81.82%)] compounds in external validation set. Another LDA models were performed in order to get the most likely mechanism of action of anthelmin…

0301 basic medicineBiophysicsNon-stochastic and stochastic atom-based bilinear indicesBilinear interpolationLDA-based QSAR modelQuBiLs-MAS module01 natural sciencesSet (abstract data type)03 medical and health sciencesMolecular descriptorStatisticsPhysical and Theoretical ChemistryMolecular BiologySelection (genetic algorithm)MathematicsFree and open source softwareTraining setTOMOCOMD-CARDD softwareExternal validationAnthelmintic activityAtom (order theory)Computational creeningCondensed Matter PhysicsLinear discriminant analysis0104 chemical sciencesIndazole010404 medicinal & biomolecular chemistry030104 developmental biologyLead generationMolecular Physics
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Isolation and characterization of extracellular vesicles in Candida albicans

2020

Background : The occurrence of systemic infections due to C. albicans has increased especially in critically ill patients. In fungal infections, secretory mechanisms are key events for disease establishment. Recent findings demonstrate that fungal organisms release many molecular components to the extracellular space in extracellular vesicles. Aims: We develop a method to obtain exosomes from yeast cultures of the Candida albicans . Methods : Yeast strains used in this work were C. albicans SC5314, C. parapsilosis (ATCC 22019) and C. krusei (ATCC 6258). Yeasts were grown at 37.º in liquid YPD medium. The cell cultures were centrifuged and the supernatant filtered through sterile nitrocellul…

Future studiesbiologyCritically illChemistry3108.05 HongosProtein compositionbiology.organism_classificationExosomesExtracellular vesiclesMolecular biologyCorpus albicansExosomasCandida albicansCandida albicans
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Estimation of ADME Properties in Drug Discovery: Predicting Caco-2 Cell Permeability Using Atom-Based Stochastic and Non-stochastic Linear Indices

2007

The in vitro determination of the permeability through cultured Caco-2 cells is the most often-used in vitro model for drug absorption. In this report, we use the largest data set of measured P(Caco-2), consisting of 157 structurally diverse compounds. Linear discriminant analysis (LDA) was used to obtain quantitative models that discriminate higher absorption compounds from those with moderate-poorer absorption. The best LDA model has an accuracy of 90.58% and 84.21% for training and test set. The percentage of good correlation, in the virtual screening of 241 drugs with the reported values of the percentage of human intestinal absorption (HIA), was greater than 81%. In addition, multiple …

Absorption (pharmacology)Stochastic ProcessesVirtual screeningQuantitative structure–activity relationshipDrug discoveryStereochemistryLinear modelQuantitative Structure-Activity RelationshipPharmaceutical ScienceLinear discriminant analysisPermeabilityData setROC CurveDrug DesignTest setLinear regressionLinear ModelsHumansPharmacokineticsCaco-2 CellsBiological systemADMEMathematicsJournal of Pharmaceutical Sciences
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A Simple Method to Predict Blood-Brain Barrier Permeability of Drug- Like Compounds Using Classification Trees

2017

Background: To know the ability of a compound to penetrate the blood-brain barrier (BBB) is a challenging task; despite the numerous efforts realized to predict/measure BBB passage, they still have several drawbacks. Methods: The prediction of the permeability through the BBB is carried out using classification trees. A large data set of 497 compounds (recently published) is selected to develop the tree model. Results: The best model shows an accuracy higher than 87.6% for training set; the model was also validated using 10-fold cross-validation procedure and through a test set achieving accuracy values of 86.1% and 87.9%, correspondingly. We give a brief explanation, in structural terms, o…

0301 basic medicineQuantitative structure–activity relationshipComputer scienceDatasets as TopicQuantitative Structure-Activity Relationshipcomputer.software_genre01 natural sciencesPermeability03 medical and health sciencesMolecular descriptorDrug DiscoveryInternational literatureComputer SimulationTraining setDecision tree learningDecision Trees0104 chemical sciences010404 medicinal & biomolecular chemistry030104 developmental biologyPharmaceutical PreparationsBlood-Brain BarrierTest setData miningBlood brain barrier permeabilitycomputerAlgorithmsDecision tree modelMedicinal Chemistry
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Prediction of potential environmental toxicity of chemicals in <em>Lactuca sativa</em> seed germination using computational tools

2019

The main aim of the study was to develop quantitative structure-activity relationship (QSAR) models for the prediction of phytotoxicity effects of chemical compounds on the Lactuca sativa seeds germination. A database of 73 compounds, assayed against L. sativa and Dragon’s molecular descriptors are used to obtain a QSAR model for the prediction of the phytotoxicity. The model is carried out with QSARINS software and validated according to OECD principles. The best model showed good value for the determination coefficient (R2 = 0.917) and others parameters appropriate for fitting (s = 0.256 and RMSEtr= 0.236). The validation results confirmed that the model has good robustness and stability …

Quantitative structure–activity relationshipbiologyGerminationMolecular descriptorEnvironmental toxicologyPhytotoxicityLactucaBiological systembiology.organism_classificationMathematicsProceedings of MOL2NET 2019, International Conference on Multidisciplinary Sciences, 5th edition
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State of the Art Review and Report of New Tool for Drug Discovery

2017

BACKGROUND There are a great number of tools that can be used in QSAR/QSPR studies; they are implemented in several programs that are reviewed in this report. The usefulness of new tools can be proved through comparison, with previously published approaches. In order to perform the comparison, the most usual is the use of several benchmark datasets such as DRAGON and Sutherland's datasets. METHODS Here, an exploratory study of Atomic Weighted Vectors (AWVs), a new tool useful for drug discovery using different datasets, is presented. In order to evaluate the performance of the new tool, several statistics and QSAR/QSPR experiments are performed. Variability analyses are used to quantify the…

Models Molecular0301 basic medicineQuantitative structure–activity relationshipMolecular StructureOrthogonality (programming)Computer scienceQuantitative Structure-Activity RelationshipGeneral MedicineState of the art reviewInformation theorycomputer.software_genreStructure-Activity Relationship03 medical and health sciences030104 developmental biologyDrug DiscoveryLinear regressionPrincipal component analysisGenetic algorithmBenchmark (computing)Data miningcomputerSoftwareCurrent Topics in Medicinal Chemistry
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A novel approach to predict aquatic toxicity from molecular structure

2008

The main aim of the study was to develop quantitative structure-activity relationship (QSAR) models for the prediction of aquatic toxicity using atom-based non-stochastic and stochastic linear indices. The used dataset consist of 392 benzene derivatives, separated into training and test sets, for which toxicity data to the ciliate Tetrahymena pyriformis were available. Using multiple linear regression, two statistically significant QSAR models were obtained with non-stochastic (R2=0.791 and s=0.344) and stochastic (R2=0.799 and s=0.343) linear indices. A leave-one-out (LOO) cross-validation procedure was carried out achieving values of q2=0.781 (scv=0.348) and q2=0.786 (scv=0.350), respecti…

Quantitative structure–activity relationshipEnvironmental EngineeringToxicity dataMolecular StructureLooHealth Toxicology and MutagenesisPublic Health Environmental and Occupational HealthGeneral MedicineGeneral ChemistryPollutionAquatic toxicologyToxicologyStructure-Activity RelationshipToxicity TestsBenzene derivativesTetrahymena pyriformisLinear regressionEnvironmental ChemistryBiological systemMathematicsChemosphere
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In silicoAntibacterial Activity Modeling Based on the TOMOCOMD-CARDD Approach

2015

In the recent times, the race to cope with the increasing multidrug resistance of pathogenic bacteria has lost much of its momentum and health professionals are grasping for solutions to deal with the unprecedented resistance levels. As a result, there is an urgent need for a concerted effort towards the development of new antimicrobial drugs to stay ahead in the fight against the ever adapting bacteria. In the present report, antibacterial classification functions (models) based on the topological molecular computational design-computer aided >rational> drug design (TOMOCOMD-CARDD) atom-based non-stochastic and stochastic bilinear indices are presented. These models were built using the li…

Virtual screeningQuantitative structure–activity relationshipVirtual screeninglinear discriminant analysisLinear discriminant analysisQSARTOMOCOMD-CARDD softwareIn silicoDegrees of freedom (statistics)Bilinear interpolationNanotechnologyGeneral Chemistryatom-based bilinear indexvirtual screeningLinear discriminant analysisRange (mathematics)antibacterial activityAtom-based bilinear indexAntibacterial activityBiological systemAntibacterial activityMathematicsJournal of the Brazilian Chemical Society
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Atom-based Stochastic and non-Stochastic 3D-Chiral Bilinear Indices and their Applications to Central Chirality Codification

2006

Abstract Non-stochastic and stochastic 2D bilinear indices have been generalized to codify chemical structure information for chiral drugs, making use of a trigonometric 3D-chirality correction factor. In order to evaluate the effectiveness of this novel approach in drug design we have modeled the angiotensin-converting enzyme inhibitory activity of perindoprilate's σ-stereoisomers combinatorial library. Two linear discriminant analysis models, using non-stochastic and stochastic linear indices, were obtained. The models had shown an accuracy of 95.65% for the training set and 100% for the external prediction set. Next the prediction of the σ-receptor antagonists of chiral 3-(3-hydroxypheny…

Models MolecularQuantitative structure–activity relationshipIndolesStereochemistryStatic ElectricityQuantitative Structure-Activity RelationshipBilinear interpolationAngiotensin-Converting Enzyme InhibitorsIn Vitro TechniquesSet (abstract data type)PiperidinesLinear regressionMaterials ChemistryReceptors sigmaOrder (group theory)Applied mathematicsComputer SimulationPhysical and Theoretical ChemistrySpectroscopyMathematicsTranscortinStochastic ProcessesChemistryAtom (order theory)StereoisomerismLinear discriminant analysisComputer Graphics and Computer-Aided DesignData setDrug DesignLinear ModelsSteroidsTrigonometryChirality (chemistry)Proceedings of The 10th International Electronic Conference on Synthetic Organic Chemistry
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<strong>New tool useful for drug discovery validated through benchmark datasets</strong>

2018

Atomic Weighted Vectors (AWVs) are vectors that contain the codified information of molecular structures, which can apply to a set of Aggregation Operators (AOs) to calculate total and local molecular descriptors (MDs). This article presents an exploratory study of a new tool useful for drug discovery using different datasets, such as DRAGON and Sutherland’s datasets, as well as their comparison with other well-known approaches. In order to evaluate the performance of the tool, several statistics and QSAR/QSPR experiments were performed. Variability analyses are used to quantify the information content of the AWVs obtained from the tool, by the way of an information theory-based algorithm. …

Set (abstract data type)Quantitative structure–activity relationshipOrthogonalityComputer scienceMolecular descriptorPrincipal component analysisGenetic algorithmBenchmark (computing)Data miningInformation theorycomputer.software_genrecomputerProceedings of MOL2NET 2018, International Conference on Multidisciplinary Sciences, 4th edition
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Bond-based 3D-chiral linear indices: Theory and QSAR applications to central chirality codification

2008

The recently introduced non-stochastic and stochastic bond-based linear indices are been generalized to codify chemical structure information for chiral drugs, making use of a trigonometric 3D-chirality correction factor. These improved modified descriptors are applied to several well-known data sets to validate each one of them. Particularly, Cramer's steroid data set has become a benchmark for the assessment of novel quantitative structure activity relationship methods. This data set has been used by several researchers using 3D-QSAR approaches such as Comparative Molecular Field Analysis, Molecular Quantum Similarity Measures, Comparative Molecular Moment Analysis, E-state, Mapping Prope…

Stochastic ProcessesQuantitative structure–activity relationshipIndolesProperty (programming)ChemistryComparabilityQuantitative Structure-Activity RelationshipAngiotensin-Converting Enzyme InhibitorsStereoisomerismGeneral ChemistrySet (abstract data type)Data setComputational MathematicsModels ChemicalPiperidinesComputational chemistryDrug DesignBenchmark (computing)Molecular symmetryCombinatorial Chemistry TechniquesReceptors sigmaThermodynamicsTrigonometryAlgorithmJournal of Computational Chemistry
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Prediction of acute toxicity of phenol derivatives using multiple linear regression approach for Tetrahymena pyriformis contaminant identification in…

2016

In this article, the modeling of inhibitory grown activity against Tetrahymena pyriformis is described. The 0-2D Dragon descriptors based on structural aspects to gain some knowledge of factors influencing aquatic toxicity are mainly used. Besides, it is done by some enlarged data of phenol derivatives described for the first time and composed of 358 chemicals. It overcomes the previous datasets with about one hundred compounds. Moreover, the results of the model evaluation by the parameters in the training, prediction and validation give adequate results comparable with those of the previous works. The more influential descriptors included in the model are: X3A, MWC02, MWC10 and piPC03 wit…

Quantitative structure–activity relationshipEnvironmental EngineeringDatabases FactualHealth Toxicology and Mutagenesis0211 other engineering and technologiesQuantitative Structure-Activity Relationship02 engineering and technology010501 environmental sciencesBiologycomputer.software_genre01 natural sciencesAquatic toxicologyPhenolsLinear regressionEnvironmental Chemistry0105 earth and related environmental sciences021110 strategic defence & security studiesDatabaseTetrahymena pyriformisPublic Health Environmental and Occupational HealthLinear modelGeneral MedicineGeneral ChemistryModels TheoreticalchEMBLPollutionAcute toxicityTetrahymena pyriformisLinear ModelscomputerChemical databaseChemosphere
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Machine learning-based models to predict modes of toxic action of phenols to Tetrahymena pyriformis.

2017

The phenols are structurally heterogeneous pollutants and they present a variety of modes of toxic action (MOA), including polar narcotics, weak acid respiratory uncouplers, pro-electrophiles, and soft electrophiles. Because it is often difficult to determine correctly the mechanism of action of a compound, quantitative structure-activity relationship (QSAR) methods, which have proved their interest in toxicity prediction, can be used. In this work, several QSAR models for the prediction of MOA of 221 phenols to the ciliated protozoan Tetrahymena pyriformis, using Chemistry Development Kit descriptors, are reported. Four machine learning techniques (ML), k-nearest neighbours, support vector…

Quantitative structure–activity relationshipAntiprotozoal AgentsQuantitative Structure-Activity RelationshipBioengineeringModes of toxic action010501 environmental sciencesMachine learningcomputer.software_genre01 natural sciencesMachine Learningchemistry.chemical_compoundPhenolsMolecular descriptorDrug DiscoveryPhenols0105 earth and related environmental sciencesCiliated protozoanArtificial neural networkbusiness.industryTetrahymena pyriformisGeneral Medicine0104 chemical sciencesSupport vector machine010404 medicinal & biomolecular chemistrychemistryTetrahymena pyriformisMolecular MedicineArtificial intelligenceNeural Networks ComputerbusinesscomputerSAR and QSAR in environmental research
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Atom, atom-type and total molecular linear indices as a promising approach for bioorganic and medicinal chemistry: theoretical and experimental asses…

2004

Abstract Helminth infections are a medical problem in the world nowadays. In this paper a novel atom-level chemical descriptor has been applied to estimate the anthelmintic activity. Total and local linear indices and linear discriminant analysis were used to obtain a quantitative model that discriminates between anthelmintic and non-anthelmintic drug-like compounds. The discriminant model has an accuracy of 90.11% in the training set, with a high Matthews’ correlation coefficient (MCC = 0.80). To assess the robustness and predictive power of the obtained model, internal (leave-n-out) and external validation process was performed. The QSAR model correctly classified 88.55% of compounds in t…

AnthelminticsQuantitative structure–activity relationshipVirtual screeningCorrelation coefficientStereochemistryChemistryOrganic ChemistryClinical BiochemistryPharmaceutical ScienceDerivativeLinear discriminant analysisBiochemistrySet (abstract data type)Models ChemicalRobustness (computer science)Atom (measure theory)Drug DesignDrug DiscoveryMolecular MedicineBiological systemMolecular BiologyBioorganicmedicinal chemistry
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Enzimas de la biosíntesis del virus SARS-CoV-2 como dianas potenciales para el descubrimiento de nuevos antivirales

2021

La aparición de la pandemia producida por la COVID-19 (enfermedad producida por coronavirus 2019), cuyo agente causal es el SARS-CoV-2, ha provocado una gran preocupación a nivel mundial. Esta emergencia sanitaria ha puesto de manifiesto la necesidad urgente que existe de desarrollar o bien una nueva vacuna o bien agentes terapéuticos antivirales que permitan combatir al SARS-CoV-2. El reposicionamiento de fármacos es una de las estrategias más rápidas y prácticas de identificar rápidamente nuevos fármacos que permitirían prevenir, controlar o incluso erradicar el virus. Encontrar agentes terapéuticos que actúen directamente sobre enzimas específicas que tengan un rol esencial en la replica…

Medicaments antivíricsEnzimsVirus
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In silico Antibacterial Activity Modeling Based on the TOMOCOMD-CARDD Approach

2021

In the recent times, the race to cope with the increasing multidrug resistance of pathogenic bacteria has lost much of its momentum and health professionals are grasping for solutions to deal with the unprecedented resistance levels. As a result, there is an urgent need for a concerted effort towards the development of new antimicrobial drugs to stay ahead in the fight against the ever adapting bacteria. In the present report, antibacterial classification functions (models) based on the topological molecular computational design-computer aided ‘‘rational’’ drug design (TOMOCOMD-CARDD) atom-based non-stochastic and stochastic bilinear indices are presented. These models were built using the …

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