Isotope dependence of band-gap energy

The results of the quantitative investigations of the renormalization of the absorption edge of different compounds by the isotope effect are described.Comment: 7 pages, 3 figure

A Multivariate QSAR Study on the Anticonvulsant Activity of Acetamido-N-Benzylacetamide Derivatives. Influence of Different Molecular Descriptors

A quantitative structure activity relationship analysis was applied to a library of 51 benzylacetamide derivatives with anticonvulsant activity. The molecular structures of 51 compounds were optimized with the Semiempirical Method PM6 (Parametric Method-6) included in the MOPAC2009 software. The optimized structures of all the examined compounds were represented by 1497 DRAGON-type descriptors. Using multiple linear regression (MLR), the influence of constitutional, topological, electronic, physicochemical and quantum molecular descriptors on the activity was investigated. The validation of models were performed through the leave-one-out cross technique in conjunction with external validation. From different types of molecular descriptors, six new QSAR models were developed. The models using 0D descriptors (constitutional descriptors) and quantum descriptors do not have high statistical quality. The combination of 2D and 3D descriptors produce a model of high predictive quality (Rcal= 0.888; Scal= 0.195; Rval= 0.814; Sval=0.431; Rloo=0.867; Sloo=0.212). Results show the important role of electronic and topologic features of molecules on their anticonvulsant activity in relative to constitutional parameters.Fil: Garro Martinez, Juan Ceferino. Universidad Nacional de San Luis. Departamento de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Duchowicz, Pablo Román. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentina. Universidad Nacional de La Plata; ArgentinaFil: Estrada, Mario Rinaldo. Universidad Nacional de San Luis. Departamento de Química; ArgentinaFil: Castro, Eduardo Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentina. Universidad Nacional de La Plata; Argentin

Conformation-independent QSPR approach for the soil sorption coefficient of heterogeneous compounds

We predict the soil sorption coefficient for a heterogeneous set of 643 organic non-ionic compounds by means of Quantitative Structure-Property Relationships (QSPR). A conformation-independent representation of the chemical structure is established. The 17,538molecular descriptors derived with PaDEL and EPI Suite softwares are simultaneously analyzed through linear regressions obtained with the Replacement Method variable subset selection technique. The best predictive three-descriptors QSPR is developed on a reduced training set of 93 chemicals, having an acceptable predictive capability on 550 test set compounds. We also establish a model with a single optimal descriptor derived from CORAL freeware. The present approach compares fairly well with a previously reported one that uses Dragon descriptors.Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicada

QSAR study and molecular design of open-chain enaminones as anticonvulsant agents

Present work employs the QSAR formalism to predict the ED50 anticonvulsant activity of ringed-enaminones, in order to apply these relationships for the prediction of unknown open-chain compounds containing the same types of functional groups in their molecular structure. Two different modeling approaches are applied with the purpose of comparing the consistency of our results: (a) the search of molecular descriptors via multivariable linear regressions; and (b) the calculation of flexible descriptors with the CORAL (CORrelation And Logic) program. Among the results found, we propose some potent candidate open-chain enaminones having ED50 values lower than 10 mg·kg-1 for corresponding pharmacological studies. These compounds are classified as Class 1 and Class 2 according to the Anticonvulsant Selection Project.Instituto de Investigaciones Fisicoquímicas Teóricas y AplicadasFacultad de Ciencias Exacta

Enhancing the Functional Properties of Tea Tree Oil: In Vitro Antimicrobial Activity and Microencapsulation Strategy

In the context of addressing antimicrobial drug resistance in periocular infections, Tea TreeOil (TTO) has emerged as a promising therapeutic option. This study aimed to assess the efficacy ofTTO against bacterial strains isolated from ocular infections, with a particular focus on its ability toinhibit biofilm formation. Additionally, we designed and analyzed microcapsules containing TTOto overcome certain unfavorable physicochemical properties and enhance its inherent biologicalattributes. The quality of TTO was confirmed through rigorous analysis using GC-MS and UV-Vistechniques. Our agar diffusion assay demonstrated the effectiveness of Tea Tree Oil (TTO) againstocular bacterial strains, including Corynebacterium spp., coagulase-negative Staphylococcus spp.,and Staphylococcus aureus, as well as a reference strain of Staphylococcus aureus (ATCC 25923). Notably, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC)for all tested microorganisms were found to be 0.2% and 0.4%, respectively, with the exception ofCorynebacterium spp., which exhibited resistance to TTO. Furthermore, TTO exhibited a substantial reduction in biofilm biomass, ranging from 30% to 70%, as determined by the MTT method.Through the spray-drying technique, we successfully prepared two TTO-containing formulationswith high encapsulation yields (80–85%), microencapsulation efficiency (90–95%), and embeddingrates (approximately 40%). These formulations yielded microcapsules with diameters of 6–12 µm,as determined by laser scattering particle size distribution analysis, and exhibited regular, sphericalmorphologies under scanning electron microscopy. Importantly, UV-Vis analysis post-encapsulationconfirmed the presence of TTO within the capsules, with preserved antioxidant and antimicrobialactivities. In summary, our findings underscore the substantial therapeutic potential of TTO and itsmicrocapsules for treating ocular infections.Fil: Manzanelli, Franco Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones y Transferencia de Villa María. Universidad Nacional de Villa María. Centro de Investigaciones y Transferencia de Villa María; ArgentinaFil: Ravetti, Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones y Transferencia de Villa María. Universidad Nacional de Villa María. Centro de Investigaciones y Transferencia de Villa María; ArgentinaFil: Brignone, Sofía Gisella. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Unidad de Investigación y Desarrollo en Tecnología Farmacéutica. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Unidad de Investigación y Desarrollo en Tecnología Farmacéutica; ArgentinaFil: Garro, Ariel Gustavo. Provincia de Córdoba. Ministerio de Ciencia y Técnica; ArgentinaFil: Martinez, Sol Romina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados; ArgentinaFil: Vallejo, Mariana Guadalupe. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Unidad de Investigación y Desarrollo en Tecnología Farmacéutica. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Unidad de Investigación y Desarrollo en Tecnología Farmacéutica; ArgentinaFil: Palma, Santiago Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Unidad de Investigación y Desarrollo en Tecnología Farmacéutica. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Unidad de Investigación y Desarrollo en Tecnología Farmacéutica; Argentin

Conformation-independent QSPR approach for the soil sorption coefficient of heterogeneous compounds

We predict the soil sorption coefficient for a heterogeneous set of 643 organic non-ionic compounds by means of Quantitative Structure-Property Relationships (QSPR). A conformation-independent representation of the chemical structure is established. The 17,538molecular descriptors derived with PaDEL and EPI Suite softwares are simultaneously analyzed through linear regressions obtained with the Replacement Method variable subset selection technique. The best predictive three-descriptors QSPR is developed on a reduced training set of 93 chemicals, having an acceptable predictive capability on 550 test set compounds. We also establish a model with a single optimal descriptor derived from CORAL freeware. The present approach compares fairly well with a previously reported one that uses Dragon descriptors.Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicada

QSAR study and molecular design of open-chain enaminones as anticonvulsant agents

Present work employs the QSAR formalism to predict the ED50 anticonvulsant activity of ringed-enaminones, in order to apply these relationships for the prediction of unknown open-chain compounds containing the same types of functional groups in their molecular structure. Two different modeling approaches are applied with the purpose of comparing the consistency of our results: (a) the search of molecular descriptors via multivariable linear regressions; and (b) the calculation of flexible descriptors with the CORAL (CORrelation And Logic) program. Among the results found, we propose some potent candidate open-chain enaminones having ED50 values lower than 10 mg·kg-1 for corresponding pharmacological studies. These compounds are classified as Class 1 and Class 2 according to the Anticonvulsant Selection Project.Instituto de Investigaciones Fisicoquímicas Teóricas y AplicadasFacultad de Ciencias Exacta