A bioinspired nitrone precursor to a stabilized nitroxide radical.

Autor: Pinheiro AC; Departamento de Química Fundamental, Instituto de Química, Universidade de São Paulo, 05508-000, São Paulo, SP, Brazil., Fazzi RB; Departamento de Química Fundamental, Instituto de Química, Universidade de São Paulo, 05508-000, São Paulo, SP, Brazil., Esteves LC; Departamento de Química Fundamental, Instituto de Química, Universidade de São Paulo, 05508-000, São Paulo, SP, Brazil., Machado CO; Departamento de Química Fundamental, Instituto de Química, Universidade de São Paulo, 05508-000, São Paulo, SP, Brazil., Dörr FA; Departamento de Análises Clínicas e Toxicológicas, Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, 05508-000, São Paulo, SP, Brazil., Pinto E; Departamento de Análises Clínicas e Toxicológicas, Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, 05508-000, São Paulo, SP, Brazil., Hattori Y; Physical Chemistry Division, Department of Chemistry, Ångström Laboratory, Uppsala University, 75120, Uppsala, Sweden., Sa J; Physical Chemistry Division, Department of Chemistry, Ångström Laboratory, Uppsala University, 75120, Uppsala, Sweden; Institute of Physical Chemistry, Polish Academy of Sciences, 01-224, Warsaw, Poland., da Costa Ferreira AM; Departamento de Química Fundamental, Instituto de Química, Universidade de São Paulo, 05508-000, São Paulo, SP, Brazil., Bastos EL; Departamento de Química Fundamental, Instituto de Química, Universidade de São Paulo, 05508-000, São Paulo, SP, Brazil. Electronic address: elbastos@iq.usp.br.
Jazyk: angličtina
Zdroj: Free radical biology & medicine [Free Radic Biol Med] 2021 May 20; Vol. 168, pp. 110-116. Date of Electronic Publication: 2021 Mar 30.
DOI: 10.1016/j.freeradbiomed.2021.03.030
Abstrakt: Nitrones derived from natural antioxidants are emerging as highly specific therapeutics against various human diseases, including stroke, neurodegenerative pathologies, and cancer. However, the development of useful pseudo-natural nitrones requires the judicious choice of a secondary metabolite as the precursor. Betalains are nitrogen-containing natural pigments that exhibit marked antioxidant capacity and pharmacological properties and, hence, are ideal candidates for designing multifunctional nitrones. In this work, we describe the semisynthesis and properties of a biocompatible and antioxidant betalain-nitrone called OxiBeet. This bio-based compound is a better radical scavenger than ascorbic acid, gallic acid, and most non-phenolic antioxidants and undergoes concerted proton-coupled electron transfer. The autoxidation of OxiBeet produces a persistent nitroxide radical, which, herein, is studied via electron paramagnetic resonance spectroscopy. In addition, femtosecond transient absorption spectroscopy reveals that excited state formation is not required for the oxidation of OxiBeet. The results are compared with those obtained using betanin, a natural betalain, and pBeet, the imine analog of OxiBeet. The findings of this study will enable the development of antioxidant and spin-trap nitrones based on the novel N-oxide 1,7-diazaheptamethinium scaffold and betalain dyes with enhanced hydrolytic stability in aqueous alkaline media.
(Copyright © 2021 Elsevier Inc. All rights reserved.)
Databáze: MEDLINE
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