A Raman, SERS and UV-circular dichroism spectroscopic study of: N-acetyl-l-cysteine in aqueous solutions
Autor(a) principal: | |
---|---|
Data de Publicação: | 2019 |
Outros Autores: | , , , , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Institucional da UNESP |
Texto Completo: | http://dx.doi.org/10.1039/c9nj02427a http://hdl.handle.net/11449/197977 |
Resumo: | The aim of this work is to evaluate the vibrational and structural properties of N-acetyl-l-cysteine (NAC), and its molecular structure and electronic properties in relation to the action of thiol and amine groups at different pH. Raman and Surface Enhanced Raman Spectroscopy (SERS) spectra were measured in aqueous solution. The influence of an aqueous environment on the NAC spectra was simulated by means of an implicit (polarizable continuum model) method. SERS spectra indicate that the S atom is interacting with the surface through the sulfur atom. One of the consequences of the interaction with the surface is the deprotonation of the SH group, as revealed by the disappearance of the ν(S-H) band. The calculations performed for the Ag-NAC complex confirm the experimental data obtained by SERS, where the S-Ag interaction is the most important. These results are very interesting when one can formulate the drug feasibility of NAC using silver nanoparticles as a carrier. Raman spectra were measured to compare the behavior of different functional groups in the molecule, both in the solid phase and in aqueous solution at different pH. Apparent ionization constants (pK′ values) for the S-H group at high ionic strengths were calculated from the intensity of the 2580 cm-1 frequency as a function of pH. UV and circular dichroism spectra were also measured in aqueous solution at different pH. Finally, the study was completed with natural bond orbital (NBO) analysis to determine the presence of hyper-conjugative interactions. It is important to observe the behavior of the C2-N bond with the delocalization effect; as the pH increases the hyperconjugative interaction of this bond decreases in the same way as in the case of νCN. The way in which the LP πO1 → σ∗C2-N interaction and νCN decrease is an inverse reflection of the fractional ionization αSH. |
id |
UNSP_4226872802955a62e5d116b06107a856 |
---|---|
oai_identifier_str |
oai:repositorio.unesp.br:11449/197977 |
network_acronym_str |
UNSP |
network_name_str |
Repositório Institucional da UNESP |
repository_id_str |
2946 |
spelling |
A Raman, SERS and UV-circular dichroism spectroscopic study of: N-acetyl-l-cysteine in aqueous solutionsThe aim of this work is to evaluate the vibrational and structural properties of N-acetyl-l-cysteine (NAC), and its molecular structure and electronic properties in relation to the action of thiol and amine groups at different pH. Raman and Surface Enhanced Raman Spectroscopy (SERS) spectra were measured in aqueous solution. The influence of an aqueous environment on the NAC spectra was simulated by means of an implicit (polarizable continuum model) method. SERS spectra indicate that the S atom is interacting with the surface through the sulfur atom. One of the consequences of the interaction with the surface is the deprotonation of the SH group, as revealed by the disappearance of the ν(S-H) band. The calculations performed for the Ag-NAC complex confirm the experimental data obtained by SERS, where the S-Ag interaction is the most important. These results are very interesting when one can formulate the drug feasibility of NAC using silver nanoparticles as a carrier. Raman spectra were measured to compare the behavior of different functional groups in the molecule, both in the solid phase and in aqueous solution at different pH. Apparent ionization constants (pK′ values) for the S-H group at high ionic strengths were calculated from the intensity of the 2580 cm-1 frequency as a function of pH. UV and circular dichroism spectra were also measured in aqueous solution at different pH. Finally, the study was completed with natural bond orbital (NBO) analysis to determine the presence of hyper-conjugative interactions. It is important to observe the behavior of the C2-N bond with the delocalization effect; as the pH increases the hyperconjugative interaction of this bond decreases in the same way as in the case of νCN. The way in which the LP πO1 → σ∗C2-N interaction and νCN decrease is an inverse reflection of the fractional ionization αSH.Consejo Nacional de Investigaciones Científicas y TécnicasMinisterio de Economía y CompetitividadINQUINOA-CONICET Instituto de Química Física Facultad de Bioquímica Química y Farmacia Universidad Nacional de Tucumán, San Lorenzo 456INFIQC-CONICET Instituto de Investigaciones en Físico-Química Orgánica de Córdoba Facultad de Químicas Universidad Nacional de CórdobaSão Paulo State University (UNESP) School of Technology and Applied SciencesInstituto de Estructura de la Materia, IEM-CSIC Serrano 121São Paulo State University (UNESP) School of Technology and Applied SciencesConsejo Nacional de Investigaciones Científicas y Técnicas: 1529Ministerio de Economía y Competitividad: FIS2017-84318-RConsejo Nacional de Investigaciones Científicas y Técnicas: PICT2013-0697Consejo Nacional de Investigaciones Científicas y Técnicas: PIP 002Universidad Nacional de TucumánUniversidad Nacional de CórdobaUniversidade Estadual Paulista (Unesp)Instituto de Estructura de la MateriaPicot, R. A. CobosPuiatti, M.Ben Altabef, A.Rubira, R. J.G. [UNESP]Sanchez-Cortes, S.Diaz, S. B.Tuttolomondo, M. E.2020-12-12T00:55:36Z2020-12-12T00:55:36Z2019-01-01info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/article15201-15212http://dx.doi.org/10.1039/c9nj02427aNew Journal of Chemistry, v. 43, n. 38, p. 15201-15212, 2019.1369-92611144-0546http://hdl.handle.net/11449/19797710.1039/c9nj02427a2-s2.0-85072834784Scopusreponame:Repositório Institucional da UNESPinstname:Universidade Estadual Paulista (UNESP)instacron:UNESPengNew Journal of Chemistryinfo:eu-repo/semantics/openAccess2021-10-23T07:40:04Zoai:repositorio.unesp.br:11449/197977Repositório InstitucionalPUBhttp://repositorio.unesp.br/oai/requestopendoar:29462024-08-05T15:12:43.890517Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP)false |
dc.title.none.fl_str_mv |
A Raman, SERS and UV-circular dichroism spectroscopic study of: N-acetyl-l-cysteine in aqueous solutions |
title |
A Raman, SERS and UV-circular dichroism spectroscopic study of: N-acetyl-l-cysteine in aqueous solutions |
spellingShingle |
A Raman, SERS and UV-circular dichroism spectroscopic study of: N-acetyl-l-cysteine in aqueous solutions Picot, R. A. Cobos |
title_short |
A Raman, SERS and UV-circular dichroism spectroscopic study of: N-acetyl-l-cysteine in aqueous solutions |
title_full |
A Raman, SERS and UV-circular dichroism spectroscopic study of: N-acetyl-l-cysteine in aqueous solutions |
title_fullStr |
A Raman, SERS and UV-circular dichroism spectroscopic study of: N-acetyl-l-cysteine in aqueous solutions |
title_full_unstemmed |
A Raman, SERS and UV-circular dichroism spectroscopic study of: N-acetyl-l-cysteine in aqueous solutions |
title_sort |
A Raman, SERS and UV-circular dichroism spectroscopic study of: N-acetyl-l-cysteine in aqueous solutions |
author |
Picot, R. A. Cobos |
author_facet |
Picot, R. A. Cobos Puiatti, M. Ben Altabef, A. Rubira, R. J.G. [UNESP] Sanchez-Cortes, S. Diaz, S. B. Tuttolomondo, M. E. |
author_role |
author |
author2 |
Puiatti, M. Ben Altabef, A. Rubira, R. J.G. [UNESP] Sanchez-Cortes, S. Diaz, S. B. Tuttolomondo, M. E. |
author2_role |
author author author author author author |
dc.contributor.none.fl_str_mv |
Universidad Nacional de Tucumán Universidad Nacional de Córdoba Universidade Estadual Paulista (Unesp) Instituto de Estructura de la Materia |
dc.contributor.author.fl_str_mv |
Picot, R. A. Cobos Puiatti, M. Ben Altabef, A. Rubira, R. J.G. [UNESP] Sanchez-Cortes, S. Diaz, S. B. Tuttolomondo, M. E. |
description |
The aim of this work is to evaluate the vibrational and structural properties of N-acetyl-l-cysteine (NAC), and its molecular structure and electronic properties in relation to the action of thiol and amine groups at different pH. Raman and Surface Enhanced Raman Spectroscopy (SERS) spectra were measured in aqueous solution. The influence of an aqueous environment on the NAC spectra was simulated by means of an implicit (polarizable continuum model) method. SERS spectra indicate that the S atom is interacting with the surface through the sulfur atom. One of the consequences of the interaction with the surface is the deprotonation of the SH group, as revealed by the disappearance of the ν(S-H) band. The calculations performed for the Ag-NAC complex confirm the experimental data obtained by SERS, where the S-Ag interaction is the most important. These results are very interesting when one can formulate the drug feasibility of NAC using silver nanoparticles as a carrier. Raman spectra were measured to compare the behavior of different functional groups in the molecule, both in the solid phase and in aqueous solution at different pH. Apparent ionization constants (pK′ values) for the S-H group at high ionic strengths were calculated from the intensity of the 2580 cm-1 frequency as a function of pH. UV and circular dichroism spectra were also measured in aqueous solution at different pH. Finally, the study was completed with natural bond orbital (NBO) analysis to determine the presence of hyper-conjugative interactions. It is important to observe the behavior of the C2-N bond with the delocalization effect; as the pH increases the hyperconjugative interaction of this bond decreases in the same way as in the case of νCN. The way in which the LP πO1 → σ∗C2-N interaction and νCN decrease is an inverse reflection of the fractional ionization αSH. |
publishDate |
2019 |
dc.date.none.fl_str_mv |
2019-01-01 2020-12-12T00:55:36Z 2020-12-12T00:55:36Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://dx.doi.org/10.1039/c9nj02427a New Journal of Chemistry, v. 43, n. 38, p. 15201-15212, 2019. 1369-9261 1144-0546 http://hdl.handle.net/11449/197977 10.1039/c9nj02427a 2-s2.0-85072834784 |
url |
http://dx.doi.org/10.1039/c9nj02427a http://hdl.handle.net/11449/197977 |
identifier_str_mv |
New Journal of Chemistry, v. 43, n. 38, p. 15201-15212, 2019. 1369-9261 1144-0546 10.1039/c9nj02427a 2-s2.0-85072834784 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
New Journal of Chemistry |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
15201-15212 |
dc.source.none.fl_str_mv |
Scopus reponame:Repositório Institucional da UNESP instname:Universidade Estadual Paulista (UNESP) instacron:UNESP |
instname_str |
Universidade Estadual Paulista (UNESP) |
instacron_str |
UNESP |
institution |
UNESP |
reponame_str |
Repositório Institucional da UNESP |
collection |
Repositório Institucional da UNESP |
repository.name.fl_str_mv |
Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP) |
repository.mail.fl_str_mv |
|
_version_ |
1808128481152729088 |