Rationale on the High Radical Scavenging Capacity of Betalains
Betalains are water-soluble natural pigments of increasing importance as antioxidants for pharmaceutical use. Although non-phenolic betalains have lower capacity to scavenge radicals compared to their phenolic analogues, both classes perform well as antioxidants and anti-inflammatory agents <i>...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
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MDPI AG
2019-07-01
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| Series: | Antioxidants |
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| Online Access: | https://www.mdpi.com/2076-3921/8/7/222 |
| _version_ | 1797762197485518848 |
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| author | Karina K. Nakashima Erick L. Bastos |
| author_facet | Karina K. Nakashima Erick L. Bastos |
| author_sort | Karina K. Nakashima |
| collection | DOAJ |
| description | Betalains are water-soluble natural pigments of increasing importance as antioxidants for pharmaceutical use. Although non-phenolic betalains have lower capacity to scavenge radicals compared to their phenolic analogues, both classes perform well as antioxidants and anti-inflammatory agents <i>in vivo</i>. Here we show that <i>meta</i>-hydroxyphenyl betalain (<i>m</i>-OH-pBeet) and phenylbetalain (pBeet) show higher radical scavenging capacity compared to their <i>N</i>-methyl iminium analogues, in which proton-coupled electron transfer (PCET) from the imine nitrogen atom is precluded. The 1,7-diazaheptamethinium system was found to be essential for the high radical scavenging capacity of betalains and concerted PCET is the most thermodynamically favorable pathway for their one-electron oxidation. The results provide useful insights for the design of nature-derived redox mediators based on the betalain scaffold. |
| first_indexed | 2024-03-12T19:24:49Z |
| format | Article |
| id | doaj.art-7683a8947c5a451d81ac3857b4285367 |
| institution | Directory Open Access Journal |
| issn | 2076-3921 |
| language | English |
| last_indexed | 2024-03-12T19:24:49Z |
| publishDate | 2019-07-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Antioxidants |
| spelling | doaj.art-7683a8947c5a451d81ac3857b42853672023-08-02T04:57:08ZengMDPI AGAntioxidants2076-39212019-07-018722210.3390/antiox8070222antiox8070222Rationale on the High Radical Scavenging Capacity of BetalainsKarina K. Nakashima0Erick L. Bastos1Departamento de Química Fundamental, Instituto de Química, Universidade de São Paulo, São Paulo, SP 05508-000, BrazilDepartamento de Química Fundamental, Instituto de Química, Universidade de São Paulo, São Paulo, SP 05508-000, BrazilBetalains are water-soluble natural pigments of increasing importance as antioxidants for pharmaceutical use. Although non-phenolic betalains have lower capacity to scavenge radicals compared to their phenolic analogues, both classes perform well as antioxidants and anti-inflammatory agents <i>in vivo</i>. Here we show that <i>meta</i>-hydroxyphenyl betalain (<i>m</i>-OH-pBeet) and phenylbetalain (pBeet) show higher radical scavenging capacity compared to their <i>N</i>-methyl iminium analogues, in which proton-coupled electron transfer (PCET) from the imine nitrogen atom is precluded. The 1,7-diazaheptamethinium system was found to be essential for the high radical scavenging capacity of betalains and concerted PCET is the most thermodynamically favorable pathway for their one-electron oxidation. The results provide useful insights for the design of nature-derived redox mediators based on the betalain scaffold.https://www.mdpi.com/2076-3921/8/7/222betalainantioxidantradical scavengernatural pigmentsredox mediator |
| spellingShingle | Karina K. Nakashima Erick L. Bastos Rationale on the High Radical Scavenging Capacity of Betalains Antioxidants betalain antioxidant radical scavenger natural pigments redox mediator |
| title | Rationale on the High Radical Scavenging Capacity of Betalains |
| title_full | Rationale on the High Radical Scavenging Capacity of Betalains |
| title_fullStr | Rationale on the High Radical Scavenging Capacity of Betalains |
| title_full_unstemmed | Rationale on the High Radical Scavenging Capacity of Betalains |
| title_short | Rationale on the High Radical Scavenging Capacity of Betalains |
| title_sort | rationale on the high radical scavenging capacity of betalains |
| topic | betalain antioxidant radical scavenger natural pigments redox mediator |
| url | https://www.mdpi.com/2076-3921/8/7/222 |
| work_keys_str_mv | AT karinaknakashima rationaleonthehighradicalscavengingcapacityofbetalains AT ericklbastos rationaleonthehighradicalscavengingcapacityofbetalains |