Structural, topological and vibrational properties of an isothiazole derivatives series with antiviral activities

Romani, Davide; Márquez, María Jimena; Márquez, María B.; Brandán, Silvia Antonia

doi:10.1016/j.molstruc.2015.07.038

Cited by 46 publications

(72 citation statements)

References 41 publications

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“…On the other hand, their behaviours in different media can also be predicted by using diverse descriptors such as, the chemical potential ( μ ), electronegativity ( χ ), global hardness ( η ), global softness ( S ), global electrophilicity index ( ω ) and global nucleophilicity index (E) descriptors [29, 30, 31, 32, 33]. In this work, we have calculated for APS in both media the gap values and those descriptors at B3LYP/6-31G* level of theory.…”

Section: Resultsmentioning

confidence: 99%

“…Moreover, two transitions observed by NBO calculation justify the shifting observed in solution, they are the ΔET π→π* and ΔET π→π* charge transfers (see Table 4). The deformation and torsion modes for both pyridinyl and phenyl rings are predicted by SQM calculations in the expected regions [4, 28, 29, 30, 31, 32] and only some deformation modes were assigned because the torsion modes are predicted in the lower wavenumbers region where there are not observed bands. The assignments for the remaining skeletal modes can be seen in Table 9.…”

Section: Resultsmentioning

confidence: 99%

“…Here, the MEP surface of the salt in the gas phase was built with the aid of the GaussView program [20] while the corresponding values were obtained using the Merz-Kollman (MK) charges [26]. Additionally, the frontier molecular orbitals and some descriptors were calculated in order to predict the reactivity and behaviours in the two media studied [27, 28, 29, 30, 31, 32, 33]. On the other hand, the Molvib program [19] was used to transform the force fields initially expressed in Cartesian coordinates to natural internal coordinates.…”

Section: Methodsmentioning

confidence: 99%

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Influence of atomic bonds on the properties of the laxative drug sodium picosulphate

Romani

Tonello

Brandán

2016

Heliyon

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In this work, the influence of the different S═O, S−O, N⋯H, O⋯H, Na⋯O bonds present in the structures of the powerful laxative drug, sodium picosulphate in gas and aqueous solution phases were studied combining the density functional theory (DFT) calculations with the experimental available infrared, 1H NMR and UV-visible spectra. The structural, topological, electronic and vibrational properties were investigated in both media by using the hybrid B3LYP/6-31G* method and the integral equation formalism variant polarised continuum model (IEFPCM). Here, the characteristics of the S═O, S−O, N⋯H, O⋯H, Na⋯O bonds were completely revealed by using atomic charges, natural bond orbital (NBO) and atoms in molecules (AIM) studies. The infrared, 1H NMR, 13C NMR and UV-visible spectra are in reasonable concordance with those experimental available in the literature. The vibrational analysis of sodium picosulphate was performed considering C3V symmetries for both SO42− groups and the complete assignments of the 126 vibration modes were reported in gas phase and aqueous solution together with their corresponding force fields. In addition, the reactivities of sodium picosulfate increase in solution due to their ionic characteristic which probably justifies their behaviour as a stimulant cathartic and their easy metabolic conversion, as reported in the literature.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Influence of atomic bonds on the properties of the laxative drug sodium picosulphate

Romani

Tonello

Brandán

2016

Heliyon

Self Cite

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“…On the other hand, the AIM2000 program [48] was used to compute the topological properties while the gap energies and some interesting descriptors were obtained using the HOMO-LUMO orbitals [37,49]. This way, the reactivities and behaviours of all the species were predicted using the gap values and the chemical potential (μ), electronegativity (χ), global hardness (η), global softness (S) and global electrophilicity index (ω) descriptors at the same level of theory [50][51][52][53][54]. Taking into account that the equations are generally known these were presented as supporting material.…”

Section: Computational Detailsmentioning

confidence: 99%

“…Thus, the gap values for both cellulose forms were calculated according Parr and Pearson [37,49] in gas phase and in aqueous solution using the frontier orbitals, as can be seen in Table S6. Then, some descriptors [50][51][52][53][54] were also computed in order to predict the behavior of both forms and the equations used are presented in Table S6. Analyzing the gap values it is observed that both forms in gas phase have practically the same reactivities but the α-form is more reactive in solution than the other one.…”

Section: Homo-lumo and Descriptors Studies Vol-1 Issue-2 Sift Deskmentioning

confidence: 99%

Vibrational characterization of monomers and dimers of cellulose by using DFT calculations and the SQM methodology

Brandán¹,

Desk²

2017

SDRP-JCCMM

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In this work, monomeric and dimeric species of α-and β-cellulose were vibrationally characterized by using theoretical calculations derived from the density functional theory (DFT) and the scaled quantum mechanical force field (SQMFF) methodology. Here, the experimental available FT-IR and Raman spectra and the experimental available structure for the β-form were used in order to perform the assignments of the 129 normal vibration modes for both α-and β-cellulose forms. Raman bands and shoulders at 1258, 1153, 1123, 918, 907, 897, 864, 744, 727, 721, 483 and 281 cm -1 could probably support the presence of two proposed dimeric species of cellulose in the solid state. The structural properties reveal differences between both monomeric α-and β-cellulose species mainly evidenced by their molecular electrostatic potentials. The high dipole moment values and the higher populations for the β-form could support the major proportion found experimentally for this form. The volume contraction observed for the β-dimer could be related to their lower dipole moment in solution in relation to that observed in the gas phase. The reduction of the glycosidic angles for both forms in solution support their rigid structures, as was experimentally observed. The atomic charges on the O atoms belonging to the glucopyranose rings and to the glycosidic bonds (O33) present the lower values. The NBO and AIM studies suggest the presence of α-and β-cellulose in the two media but the major quantity of H bonds predicted for the β-form and their high donor-acceptor interaction values could support their most important proportion existent of this form in the earth. Similar reactivities were found in gas phase but the α-form is more reactive in solution than the other one probably because the electrophilicity and nucleophilicity for the β-form show lower values than the α ones.

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Normal internal coordinates, force fields, and vibrational study of species derived from antiviral adamantadine

Brandán

2020

Int J of Quantum Chemistry

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Complete vibrational assignments have been performed for free base, cationic, and hydrochloride species derived from antiviral adamantadine by a combination of hybrid B3LYP with the 6-31G* and 6-311++G** basis sets and the scaled quantum force field methodology. Normal internal coordinates and scaling factors were used to obtain the harmonic force fields and scaled force constants of three species in gas phase and in aqueous solution. Bond lengths and angles of cationic and hydrochloride species show very good concordances with experimental amantadinium azide. The cationic species reveals a higher solvation energy value compared with antiviral agents; however, brincidofovir, the antiviral used for Ebola disease, presents a higher reactivity in contrast to adamantadine. A positive value of Mulliken charge on N1 of hydrochloride species in solution could justify the ionic character of the H29ÁÁÁCl30 bond as it is possible to observe by bond order and atoms in molecules calculations. The hydrochloride species is the most reactive in both media, while the cationic species is the least reactive. High electrophilicity and nucleophilicity indices of cationic species in both media justify its higher hydration. Good concordances were observed between experimental and predicted 1 H and 13 C NMR and electronic spectra. In solution, the three species are present as demonstrated by the experimental ultraviolet-visible spectrum of hydrochloride amantadine.

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Structural, topological and vibrational properties of an isothiazole derivatives series with antiviral activities

Cited by 46 publications

References 41 publications

Influence of atomic bonds on the properties of the laxative drug sodium picosulphate

Influence of atomic bonds on the properties of the laxative drug sodium picosulphate

Vibrational characterization of monomers and dimers of cellulose by using DFT calculations and the SQM methodology

Normal internal coordinates, force fields, and vibrational study of species derived from antiviral adamantadine

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