| Full text | |
| Author(s): |
Pioli, Renan Moraes
;
Mattioli, Renan Rodini
;
Esteves, Larissa Cerrato
;
Dochev, Stefan
;
Bastos, Erick Leite
Total Authors: 5
|
| Document type: | Journal article |
| Source: | DYES AND PIGMENTS; v. 183, p. 7-pg., 2020-12-01. |
| Abstract | |
Betalains are antioxidant secondary metabolites that emerged as safe color additives for food and cosmetics, fluorescent dyes, and redox mediators. Herein, we describe the semisynthesis of N-methyl phenylbetalain (mepBeets) and N-aryl phenylbetalain (dipBeets) dyes and compare the effect of the structure on their hydrolytic stability and electronic properties. Eight model compounds were semisynthesized by coupling betalamic acid with either N-methyl anilines or N-aryl anilines in ethyl acetate using p-toluenesulfonic acid as catalyst. The presence of electron-withdrawing substituents in the aryl moiety of mepBeets and dipBeets results in faster hydrolysis, lower anodic potentials and increased fluorescence quantum yields compared to the corresponding unsubstituted parent compounds. The results are rationalized by considering the charge distribution in the 1,7-diazaheptamethinium chromophore and are useful for the development of new hydrolytically stable betalain dyes with tunable redox and optical properties. (AU) | |
| FAPESP's process: | 14/22136-4 - Use of green solvents and their mixtures for optimizing chemical processes |
| Grantee: | Omar Abou El Seoud |
| Support Opportunities: | Research Projects - Thematic Grants |
| FAPESP's process: | 16/21445-9 - Betalains: structure-property relationships |
| Grantee: | Erick Leite Bastos |
| Support Opportunities: | Regular Research Grants |
| FAPESP's process: | 17/20133-6 - Effect of N-methylation over the hydrolytic stability and fluorescence of betalainic probes |
| Grantee: | Renan Rodini Mattioli |
| Support Opportunities: | Scholarships in Brazil - Master |
| FAPESP's process: | 19/06391-8 - Photophysical characterization and anti-inflammatory potential of betalains |
| Grantee: | Erick Leite Bastos |
| Support Opportunities: | Regular Research Grants |