Structural study and vibrational assignments of anticonvulsant topiramate by using dft calculations and two harmonic force fields

B3LYP/6-311++G** calculations have been combined with the scaled quantum mechanical force field (SQMFF) methodology to study structural and vibrational properties of anticonvulsant topiramate (TPM) agent. The 123 vibration modes expected for TPM were completely assigned, considering two harmonic force fields. In one case, C2V symmetries were considered for both SO2 and NH2 groups, while in the other one C2V and C3V symmetries for the NH2 and SO3 groups, respectively. The calculated harmonic vibrational frequencies are consistent with the experimental IR and Raman spectra in the solid phase. Very good concordances were found between the theoretical structures in gas phase and aqueous solution and the corresponding experimental reported. Thus, the fused five-membered ring in TPM produces that the pyranose ring adopts distorted twist-boat conformation, as was experimentally observed. In solution, all calculations were performed with the self-consistent reaction force (SCRF) method by the integral equation formalism variant polarised continuum (IEFPCM) and universal solvation model density (SMD) models. The corrected solvation energy value for TPM in aqueous solution by total non-electrostatic terms and by ZPVE is-1066.10 kJ/mol. The bond orders have evidenced that the three O atoms are not linked of the same form to S atom. Hence, the S atom of TPM is practically tetra-coordinate in both media, as evidenced by the high negative MK and NPA charges on the O atoms linked to it. The AIM study supports the higher stability of TPM in the gas phase while the NBO calculations suggest higher stability in solution. Gap values support the higher reactivity of TPM in solution than in the gas phase. The scaled force constant for both cases are reported for the first time. Comparisons of predicted1H-and13C-NMR spectra with the corresponding experimental ones reveal very good concordances.Fil: Ruiz Hidalgo, José. Universidad Nacional de Tucuman. Facultad de Bioquimica, Quimica y Farmacia. Instituto de Quimica Inorganica. Cátedra de Química General.; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán; ArgentinaFil: Brandan, Silvia Antonia. Universidad Nacional de Tucuman. Facultad de Bioquimica, Quimica y Farmacia. Instituto de Quimica Inorganica. Cátedra de Química General.; Argentin

Structural and vibrational study on the acid, hexa-hydrated and anhydrous trisodic salts of antiviral drug Foscarnet

The structural and vibrational properties of acid species, hexa-hydrated and anhydrous trisodic salts of antiviral drug foscarnetin gas phase and in aqueous solution have been studied in this work by using the hybrid B3LYP method with the 6-31G* and6-311++G** basis sets. The properties in solution were carried out with the self consistent reaction force (SCRF) method by usingthe integral equation formalism variant polarised continuum (IEFPCM) and SD models while the complete vibrational assignmentsfor those three species were performed in both media by using the experimental available infrared spectrum of hexa-hydratedtrisodic salt and the scaled quantum mechanical force field (SQMFF) methodology. The natural bond orbital (NBO) studies suggestthat the hexa-hydrated salt in solution is most stable than the anhydrous one in the same medium but in gas phases the anhydroussalt shows a higher stability in solution. The atoms in molecules (AIM) analyses have revealed the ionic characteristics of the O---Na bonds in both salts supporting the higher stability of the hexa-hydrated salt in solution. The evaluation of the frontier orbitalsshow that the anhydrous salt is the most reactive species in solution, as supported by its higher solvation energy and volumevariation. Apparently, the presences of phosphate group in foscarnet probably increase its activity when it is used as drug. Theexperimental infrared bands observed in the hexa-hydrated species at 1059 and 983 cm-1 are clearly attributed to the stretchingmodes of phosphate group while the strong bands at 1445 and 1333 cm-1 are associated to the stretching modes of carboxylategroup. In addition, the force constants for the carboxylate and phosphate groups are reported.Fil: Iramain, Maximiliano Alberto. Universidad Nacional de Tucuman. Facultad de Bioquimica, Quimica y Farmacia. Instituto de Quimica Inorganica. Cátedra de Química General.; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán; ArgentinaFil: Brandan, Silvia Antonia. Universidad Nacional de Tucuman. Facultad de Bioquimica, Quimica y Farmacia. Instituto de Quimica Inorganica. Cátedra de Química General.; Argentin

Theoretical DFT studies on free base, cationic and hydrochloride species of narcotic tramadol agent in gas phase and aqueous solution

Theoretical studies based on the density functional theory (DFT) have been performed to study structural and vibrational properties of the free base, cationic, and hydrochloride species of narcotic tramadol agent in the gas phase and aqueous solution. In both media, B3LYP/6-31G* calculations were used while in solution, the self-consistent reaction field (SCRF) method together with the integral equation formalism variant polarised continuum (IEFPCM) and universal solvation model density (SMD) models have been employed because these models consider the solvent effects. The vibrational studies have revealed that the species cationic is present in the solid phase because the most intense band predicted for the hydrochloride in infrared and Raman spectra is not observed in the experimental spectra. The harmonic force fields, together with the normal internal coordinates and scaling factors, have allowed the complete vibrational assignments of 126, 129, and 132 vibration modes expected for the free base, cationic, and hydrochloride species, respectively, by using the SQMFF methodology. The cationic species evidence the most negative solvation energy and higher hydration in solution in agreement with its lower stability, while the hydrochloride species is the most reactive in solution. MK charges and NBO and AIM studies support cationic species' instability due to the positive charge on N atom. Comparisons of the experimental UV spectrum of hydrochloride tramadol with the predicted for the three species suggest that the free base, cationic, and hydrochloride species can be present in solution. Comparisons of predicted infrared, Raman,1H, and13 C NMR and electronic spectra for the free base, cationic, and hydrochloride species of tramadol with the corresponding experimental ones have evidenced reasonable correlations for the cationic species showing that this species present in the solid phase and in solution.Fil: Ruiz Hidalgo, José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán; Argentina. Universidad Nacional de Tucuman. Facultad de Bioquimica, Quimica y Farmacia. Instituto de Quimica Inorganica. Cátedra de Química General.; ArgentinaFil: Brandan, Silvia Antonia. Universidad Nacional de Tucuman. Facultad de Bioquimica, Quimica y Farmacia. Instituto de Quimica Inorganica. Cátedra de Química General.; Argentin

Vibrational study of S(-) and R(+) forms of analgesic camphor combining DFT calculations with normal internal coordinates and SQMFF methodology

B3LYP/6-311++G** calculations were performed to study structures and vibrationalproperties of Cis S(-) and R(+) forms of camphor. Comparisons between calculatedgeometrical parameters of both forms of Camphor in gas phase and aqueous solutionshow very good concordances with the experimental ones corresponding to (+)-3-bromocamphor. NBO calculations predict only →*, →* and n→* interactions althougth the expected n→* transitions due to ketone groups C=O were no predicted. Gap and electrophilicity index (ω) values of both forms of camphor are close to the valueobserved in antiviral thymidine. Such observations could be explained by the proximitiesbetween the acceptor groups H bonds (C=O) and the CH3 groups present in both camphorand thymidine species. Reasonable concordances were found among the predicted 1H- and 13C-NMR, UV-visible, ECD, IR and Raman spectra with the corresponding experimental ones. Complete vibrational assignments and scaled force constants for both forms camphor are reported for first time.Fil: Ruiz Hidalgo, José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán; Argentina. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Química Inorgánica. Cátedra de Química General.; ArgentinaFil: Brandan, Silvia Antonia. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Química Inorgánica. Cátedra de Química General.; Argentin

Life histories retold: reconceptualization of school biographies of trainee teachers

Hay docentes que dejan en sus alumnos marcas profundas que perduran en el tiempo y que luego se manifiestan de diferentes maneras. Se trata de trazas dibujadas por experiencias que conmueven y perduran, que hacen que el alumno se retire de la clase pensando y sintiendo; nos referimos a las huellas que deja aquella práctica docente aggiornada, compleja y reflexiva, que va más allá de simplemente ofrecer un conjunto de hechos, datos y conceptos ya que tienen un entramado subyacente que les da sentido (Maggio, 2012). El presente artículo se desprende de una investigación de corte cualitativo que adopta un enfoque interpretativo, entendido como un proceso de comprensión de los significados cercanos de los propios actores involucrando también la construcción de una lectura constante e integrando los detalles inmediatos con la teoría relevada. Para explorar las huellas docentes en toda su variedad y complejidad, se adopta una perspectiva narrativa, que nos brinda una forma de co-construir la realidad abordándola desde diferentes planos. De esta manera, y mediante el análisis de los textos de campo la narrativa ofrece una particular reconstrucción de la experiencia, a partir de un proceso reflexivo que resignifica lo sucedido o vivido buscando responder el principal interrogante que motivó la investigación: ¿cuáles son aquellas enseñanzas que han dejado su traza en la construcción del perfil profesional de los alumnos del Profesorado de Inglés de la Universidad Nacional de Mar del Plata (UNMdP)?There are teachers who leave in their students deep marks that reveal themselves in different ways and last over time. These are traces drawn by experiences that move and last, that make the student leave the class thinking and feeling; we are referring to those traces left by updated, complex and reflective teaching practice, which goes beyond the simple fact of offering data and content as they have an underlying framework that gives them meaning (Maggio, 2012). This article follows a qualitative research that adopts an interpretative approach, perceived as a process of understanding the close meanings of the actors themselves, also involving the construction of a constant reading and integrating the immediate details with the relieved theory. To explore the teachers traces in all their variety and complexity, a narrative inquiry perspective is adopted, which gives us a way to co-construct reality by addressing it from different levels. In this way, and through the analysis of field texts, narrative inquiry offers a particular reconstruction of the experience, from a reflective process that resignifies what happened or was lived seeking answers to the main questions that motivated the research: which are those teachings experiences? who have left their trace in the construction of the professional profile of the students of the English Teaching Education Program of the National University of Mar del Plata (UNMdP)?Fil: Brandan, Silvia Antonia. Universidad Nacional de Mar del Plata. Facultad de Humanidades. Centro de Investigaciones Multidisciplinarias en Educación; ArgentinaFil: Porta Vazquez, Luis Gabriel. Universidad Nacional de Mar del Plata. Facultad de Humanidades. Centro de Investigaciones Multidisciplinarias en Educación; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentin

Vibrational assignments of two polymorphic forms of metaxolone by using DFT calculations and the SQM methodology

A theoretical study has been performed on the musclerelaxant 5-[(3, 5-dimethylphenoxy)methyl]-1,3-oxazolidin-2-one, of generic name metaxolone (MTX), by using the hybridB3LYP/6-31G calculations in the gas phase and theexperimental available infrared and Raman spectra in thesolid phase. Three C1, C2 and C3 isomers were found in thepotential energy surface (PES) but only two of them, C1 andC2 correspond to those experimentally reported polymorphicforms A and B, respectively. The absence of C3 isomer couldbe easily explained by the quite high values in the dihedralC5-C7-O2-C9 and O1-C5-C7-O2 angles different from thoseexperimental structures reported for the two polymorphicforms A and B of MTX. On the other hand, the higher bondorders values together with the high topological propertiesobserved for the oxazolidinone ring of C1 could possiblysupport their existence despite this isomer has highest energythan C2 and C3. The natural bond orbital (NBO) analysesreveal the high stabilities of C1 and C2 while the atoms inmolecules(AIM) study suggests that the ringdimethylphenoxy-methyl practically do not have influence onthe properties of MTX. The frontier orbitals show that theisomers of MTX have reactivities and electrophilicity indexessimilar to antiviral thymidine while their nucleophilicityindexes present values closer to antimicrobial thione. Inaddition, the complete vibrational assignments of those twostable isomers were performed by using the experimentalavailable FT-IR and FT-Raman spectra, their normal internalcoordinates,the scaled quantum mechanical force field(SQMFF) methodology and the Molvib program.Theharmonic force fields for the two isomers and theircorresponding force constants were also reported. The forceconstants values are in agreement with values reported in theliterature for species with similar groups.Fil: Iramain, Maximiliano Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Química Inorgánica; ArgentinaFil: Márquez, María J.. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Química Inorgánica; ArgentinaFil: Ledesma, Ana Estela. Universidad Nacional de Santiago del Estero. Facultad de Cs.exactas y Tecnologías. Departamento de Física y Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Brandan, Silvia Antonia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Química Inorgánica; Argentin

Effect of Media on the Properties of Monoterpene Cyclic Eucalyptol

Structural, electronic, topological and vibrational propertiesof Eucalyptol have been theoretically studied in the gas phaseand in acetone, chloroform, ethanol, and water solutions byusing the hybrid B3LYP/6-31G* level of theory. Theproperties were evaluated in function of the solvent´spermittivities. A higher dipole moment and lower volumevalues were observed for eucalyptol in water due probably tothe higher permittivity. Also, higher corrected solvationenergy is predicted for eucalyptol in water (-22.51 kJ/mol) inagreement with the higher volume contraction observed inthis medium (-0.4 Å3). Atomic charges reveal the mostnegative values on the O atoms and the most positive valueson the C3 and C4 atoms. MEP surfaces of eucalyptol in allmedia evidence clear nucleophilic sites on the O atoms. NBO analyses show two E→* and ELP→* transitions while theAIM studies reveal two new H---H interactions which supportvisibly the stabilities of eucalyptol in all studied media. Thegap values show a decreasing in the reactivity of eucalyptol ingas phase and mainly in chloroform and acetone solutionswhile in aqueous solution eucalyptol is slightly most reactive.Besides, the higher nucleophilic indexes of eucalyptol in allsolvents support the characteristic nucleophilic of eucalyptol,as compared with scopolamine and tropane alkaloids. Theharmonic force fields and their complete vibrationalassignments of 81 normal vibration modes were performed.The predicted IR, ATR, Raman, 1H- and 13C-NMR and UVvisiblespectra show reasonable concordance with thecorresponding experimental ones.Fil: Iramain, Maximiliano Alberto. Universidad Nacional de Tucuman. Facultad de Bioquimica, Quimica y Farmacia. Instituto de Quimica Inorganica. Cátedra de Química General.; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán; ArgentinaFil: Ruiz Hidalgo, José. Universidad Nacional de Tucuman. Facultad de Bioquimica, Quimica y Farmacia. Instituto de Quimica Inorganica. Cátedra de Química General.; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán; ArgentinaFil: Brandan, Silvia Antonia. Universidad Nacional de Tucuman. Facultad de Bioquimica, Quimica y Farmacia. Instituto de Quimica Inorganica. Cátedra de Química General.; Argentin

Structural Studies and Spectroscopic properties of Quinolizidine Alkaloids (+) and (-)-Lupinine in different media

The quinolizidine alkaloids, as numerous species of lupine (Lupinus spp.), are toxic andhave biological effect on the nervous system. Hence, four (+) and (-)- molecular structuresof quinolizidine alkaloid lupinine, named C0, C1a, C1b and C1c have been theoreticallydetermined in gas phase and in aqueous solution by using hybrid B3LYP/6-31G*calculations. The studied properties have evidenced that the most stable C1c form presentthe higher populations in both media while the predicted infrared, Raman, 1H-NMR and 13C-NMR and ultra-visible spectra suggest that probably other forms in lower proportioncould be also present in water, chloroform and benzene solutions, as evidenced by the lowRMSD values observed in the 1H- and 13C-NMR chemical shifts. The C1c form presentsthe lower corrected solvation energy in water while the NBO and AIM studies suggest forthis form a high stability in both media. In addition, the predicted ECD spectra of all (+)and (-)-lupinine forms in methanol solution evidence clearly that the C1b forms is presentin the solution because its spectrum presents a negative Cotton effect as observed in the experimental one.Fil: Ruiz Hidalgo, José. Universidad Nacional de Tucuman. Facultad de Bioquimica, Quimica y Farmacia. Instituto de Quimica Inorganica. Cátedra de Química General.; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán; ArgentinaFil: Iramain, Maximiliano Alberto. Universidad Nacional de Tucuman. Facultad de Bioquimica, Quimica y Farmacia. Instituto de Quimica Inorganica. Cátedra de Química General.; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán; ArgentinaFil: Brandan, Silvia Antonia. Universidad Nacional de Tucuman. Facultad de Bioquimica, Quimica y Farmacia. Instituto de Quimica Inorganica. Cátedra de Química General.; Argentin

Predicting properties of species derived from N-(1H-indol-3-ylmethyl)-N,N-dimethylamine, Gramine, a indol alkaloid.

Hybrid B3LYP/6-31G* calculations were employed to study the structural, electronic,topological and vibrational properties of free base, cationic and hydrochloride species ofindol alkaloid, N-(1H-indol-3-ylmethyl)-N,N-dimethylamine known as gramine. Theexperimental available IR, Raman, 1H- and 13C-NMR spectra were compared with thecorresponding predicted showing reasonable concordanceproperties were studies with the polarized continuum (PCM) and the universal solvationmodel. The cationic species of gramine presents a corrected solvation energy ofkJ/mol slightly higher than the corresponding to cocaine (studies have evidenced higher stabilities for free base and hydrochloride species while thecomparisons of N-CH3 distances obtained for three species of gramine with similarcompounds have evidenced that the hydrochloride species of gramine in solution presentspractically the same value than the corresponding species of heroin. The frontier orbitalsstudies suggest higher reactivities for the hydrochloride species in both media due to itslow gap values while on the contrary are observed for the cationic species in both media.Furthermore, the cationic species of gramine shows global nucleophilicity andelectrophilicity indexes closer to cocaine. Probably, these results could justify why thecorrected solvation energy value observed for the cationic species is approximately closerto the value corresponding to cocaine. The harmonic force fields, force constants and thecomplete vibrational assignments for the 75, 78 and 81 normal vibration modes of freebase, cationic and hydrochloride species are reported for first time.Fil: Iramain, Maximiliano Alberto. Universidad Nacional de Tucuman. Facultad de Bioquimica, Quimica y Farmacia. Instituto de Quimica Inorganica. Cátedra de Química General.; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán; ArgentinaFil: Ruiz Hidalgo, José. Universidad Nacional de Tucuman. Facultad de Bioquimica, Quimica y Farmacia. Instituto de Quimica Inorganica. Cátedra de Química General.; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán; ArgentinaFil: Brandan, Silvia Antonia. Universidad Nacional de Tucuman. Facultad de Bioquimica, Quimica y Farmacia. Instituto de Quimica Inorganica. Cátedra de Química General.; Argentin

Analizando the effects of halogen on properties of a halogenated series of R and S enantiomers analogues alkaloid cocaine-X, X=F, Cl, Br, I.

The volumes and weight molecular of all members of both series are relationed with the Van der Waals radius X distances with the electronegativities and R of X suggesting that these two properties have influence on the positions of the CO CH groups of VdW 2 3 both series. The NBO calculations have evidenced that the F and Cl derivatives of both series present the higher variations in the total energies while the AIM analyses reveal that the presence of halogen X in the benzyl rings generate a new H bonds no observed in the free base of cocaine whose topological properties are strongly dependent from the electronegativity of the halogen. Hence, the properties for the F derivatives are higher than the observed for the other ones. The NBO calculations also show clearly that the presence of the halogen X generates variations in the bond orders related to the inter-rings C-C bonds formed between the piperidine and benzyl rings and, in the C atoms that contain the CO CH groups. The frontier orbitals 2 3 demonstrate that the effects of halogen X on the halogenated series are to increase the gaps values and, as consequence decrease the reactivities of all members of both series. Finally, the higher dipole moment values observed for the Cl derivatives of both R and S series could be clearly explained by the higher Merz-Kollman (MK) charges values observed on all C atoms belong to the benzyl rings that contain the halogen X.Fil: Iramain, Maximiliano Alberto. Universidad Nacional de Tucuman. Facultad de Bioquimica, Quimica y Farmacia. Instituto de Quimica Inorganica. Cátedra de Química General.; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Ledesma, Ana Estela. Universidad Nacional de Santiago del Estero. Facultad de Cs.exactas y Tecnologías. Departamento de Física y Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Brandan, Silvia Antonia. Universidad Nacional de Tucuman. Facultad de Bioquimica, Quimica y Farmacia. Instituto de Quimica Inorganica. Cátedra de Química General.; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin