Kinetics of the Reaction of Pyrogallol Red, a Polyphenolic Dye, with Nitrous Acid: Role of •NO and •NO2
In the present work we studied the reaction under gastric conditions of pyrogallol red (PGR), a polyphenolic dye, with nitrous acid (HONO). PGR has been used as a model polyphenol due to its strong UV-visible absorption and its high reactivity towards reactive species (radicals and non-radicals, RS)...
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MDPI AG
2015-06-01
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| Series: | Molecules |
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| Online Access: | http://www.mdpi.com/1420-3049/20/6/10582 |
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| author | Estefania Hugo Jael Reyes Elisa Montupil Raquel Bridi Eduardo Lissi Ana Denicola María Angélica Rubio Camilo López-Alarcón |
| author_facet | Estefania Hugo Jael Reyes Elisa Montupil Raquel Bridi Eduardo Lissi Ana Denicola María Angélica Rubio Camilo López-Alarcón |
| author_sort | Estefania Hugo |
| collection | DOAJ |
| description | In the present work we studied the reaction under gastric conditions of pyrogallol red (PGR), a polyphenolic dye, with nitrous acid (HONO). PGR has been used as a model polyphenol due to its strong UV-visible absorption and its high reactivity towards reactive species (radicals and non-radicals, RS). The reaction was followed by UV-visible spectroscopy and high performance liquid chromatography (HPLC). A clear decrease of the PGR absorbance at 465 nm was observed, evidencing an efficient bleaching of PGR by HONO. In the initial stages of the reaction, each HONO molecule nearly consumed 2.6 PGR molecules while, at long reaction times, ca. 7.0 dye molecules were consumed per each reacted HONO. This result is interpreted in terms of HONO recycling. During the PGR-HONO reaction, nitric oxide was generated in the micromolar range. In addition, the rate of PGR consumption induced by HONO was almost totally abated by argon bubbling, emphasising the role that critical volatile intermediates, such as NO and/or nitrogen dioxide (NO2), play in the bleaching of this phenolic compound. |
| first_indexed | 2024-12-11T00:17:59Z |
| format | Article |
| id | doaj.art-8046ae1b02344fd2afa5080e87dd061b |
| institution | Directory Open Access Journal |
| issn | 1420-3049 |
| language | English |
| last_indexed | 2024-12-11T00:17:59Z |
| publishDate | 2015-06-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Molecules |
| spelling | doaj.art-8046ae1b02344fd2afa5080e87dd061b2022-12-22T01:27:52ZengMDPI AGMolecules1420-30492015-06-01206105821059310.3390/molecules200610582molecules200610582Kinetics of the Reaction of Pyrogallol Red, a Polyphenolic Dye, with Nitrous Acid: Role of •NO and •NO2Estefania Hugo0Jael Reyes1Elisa Montupil2Raquel Bridi3Eduardo Lissi4Ana Denicola5María Angélica Rubio6Camilo López-Alarcón7Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago 8320000, ChileDepartamento de Farmacia, Facultad de Química, Pontificia Universidad Católica de Chile, Santiago 7820436, ChileDepartamento de Farmacia, Facultad de Química, Pontificia Universidad Católica de Chile, Santiago 7820436, ChileDepartamento de Farmacia, Facultad de Química, Pontificia Universidad Católica de Chile, Santiago 7820436, ChileFacultad de Química y Biología, Universidad de Santiago de Chile, Santiago 8320000, ChileLaboratorio de Fisicoquímica Biológica, Facultad de Ciencias and Center for Free Radical and Biomedical Research, Universidad de la República, Montevideo 11400, UruguayFacultad de Química y Biología, Universidad de Santiago de Chile, Santiago 8320000, ChileDepartamento de Farmacia, Facultad de Química, Pontificia Universidad Católica de Chile, Santiago 7820436, ChileIn the present work we studied the reaction under gastric conditions of pyrogallol red (PGR), a polyphenolic dye, with nitrous acid (HONO). PGR has been used as a model polyphenol due to its strong UV-visible absorption and its high reactivity towards reactive species (radicals and non-radicals, RS). The reaction was followed by UV-visible spectroscopy and high performance liquid chromatography (HPLC). A clear decrease of the PGR absorbance at 465 nm was observed, evidencing an efficient bleaching of PGR by HONO. In the initial stages of the reaction, each HONO molecule nearly consumed 2.6 PGR molecules while, at long reaction times, ca. 7.0 dye molecules were consumed per each reacted HONO. This result is interpreted in terms of HONO recycling. During the PGR-HONO reaction, nitric oxide was generated in the micromolar range. In addition, the rate of PGR consumption induced by HONO was almost totally abated by argon bubbling, emphasising the role that critical volatile intermediates, such as NO and/or nitrogen dioxide (NO2), play in the bleaching of this phenolic compound.http://www.mdpi.com/1420-3049/20/6/10582kineticsnitrous acidnitric oxidenitrogen dioxidepyrogallol redphenols |
| spellingShingle | Estefania Hugo Jael Reyes Elisa Montupil Raquel Bridi Eduardo Lissi Ana Denicola María Angélica Rubio Camilo López-Alarcón Kinetics of the Reaction of Pyrogallol Red, a Polyphenolic Dye, with Nitrous Acid: Role of •NO and •NO2 Molecules kinetics nitrous acid nitric oxide nitrogen dioxide pyrogallol red phenols |
| title | Kinetics of the Reaction of Pyrogallol Red, a Polyphenolic Dye, with Nitrous Acid: Role of •NO and •NO2 |
| title_full | Kinetics of the Reaction of Pyrogallol Red, a Polyphenolic Dye, with Nitrous Acid: Role of •NO and •NO2 |
| title_fullStr | Kinetics of the Reaction of Pyrogallol Red, a Polyphenolic Dye, with Nitrous Acid: Role of •NO and •NO2 |
| title_full_unstemmed | Kinetics of the Reaction of Pyrogallol Red, a Polyphenolic Dye, with Nitrous Acid: Role of •NO and •NO2 |
| title_short | Kinetics of the Reaction of Pyrogallol Red, a Polyphenolic Dye, with Nitrous Acid: Role of •NO and •NO2 |
| title_sort | kinetics of the reaction of pyrogallol red a polyphenolic dye with nitrous acid role of •no and •no2 |
| topic | kinetics nitrous acid nitric oxide nitrogen dioxide pyrogallol red phenols |
| url | http://www.mdpi.com/1420-3049/20/6/10582 |
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