A bioinspired nitrone precursor to a stabilized nitroxide radical

Pinheiro, Amanda Capistrano; Fazzi, Rodrigo Boni; Esteves, Larissa Cerrato; Machado, Caroline Oliveira; Pinto, Ernani; Hattori, Yocefu; Sá, Jacinto; Ferreira, Ana Maria da Costa; Bastos, E. L.

doi:10.1016/j.freeradbiomed.2021.03.030

Cited by 10 publications

(7 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The semisynthesis of betaxanthins is usually performed in ethyl acetate or water as solvents. In ethyl acetate, the reaction requires acid-catalysis and p -toluenesulfonic acid has been used as catalyst, which has the additional advantage of inducing the precipitation of the product [ 27 , 38 , 61 , 62 , 63 ]. Nevertheless, the reaction in ethyl acetate is limited to lipophilic reactants, which is not the case of most amino acids.…”

Section: Discussionmentioning

confidence: 99%

“…Consumers consider that natural ingredients promote health benefits; hence, the identification of biocompatible non-phenolic natural antioxidants has gained increasing economic importance [ 83 , 84 , 85 ]. Betalains emerged as redox mediators of natural origin [ 61 , 62 , 86 , 87 ], but they are still less understood than other classes of natural antioxidants [ 52 ]. The 1,7-diazaheptamethinium system of betaxanthins has been shown to stabilize radicals by resonance [ 15 , 88 , 89 ].…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Structural Effects on the Antioxidant Properties of Amino Acid Betaxanthins

et al. 2022

Self Cite

View full text Add to dashboard Cite

Betaxanthins are natural products with high antioxidant and anti-inflammatory properties. Here, we describe the semisynthesis of twenty-one betaxanthins derived from proteinogenic amino acids, including the elusive betaxanthin of l-cysteine and two betaxanthins derived from l-lysine, and rationalize their antioxidant properties in mechanistic terms. The antioxidant capacity and redox potential of these betaxanthins were compared to those of model betaxanthins derived from dopamine, l-DOPA (L-3,4-dihydroxyphenylalanine), and pyrrolidine and structure–property relationships were established by using matched molecular pair analysis and a model developed using a genetic algorithm. Either a phenol or indole moiety enhance the antioxidant capacity of betaxanthins, which is overall much higher than that of their amino acid precursors and standard antioxidants, except for the cysteine-betaxanthin. The one-electron oxidation of amino acid betaxanthins produces radicals stabilized in multiple centers, as demonstrated by quantum chemical calculations.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Structural Effects on the Antioxidant Properties of Amino Acid Betaxanthins

et al. 2022

Self Cite

View full text Add to dashboard Cite

show abstract

“…Nitrone is an amine that contains N-oxide. Nitrone derivatives preserve biological activity and are useful in pharmaceutical applications in which they are used as anti-microbial [1], electron spin spin-trapping [2][3], antioxidant [4][5], blood-brain barrier opening [6], and anti-cancer agents [7]. The nitrone group forms the electron density on the oxygen atom that assists the process of coordination bonding with metals to form a stable coordination complex [8].…”

Section: ■ Introductionmentioning

confidence: 99%

Synthesis and Biological Activity Study of Co and Cr Complexes with α-(2-Salsayl)-<i>N</i>-phenyl Nitrone and Oxide Nanoparticles

2023

View full text Add to dashboard Cite

This paper describes the synthesis of two complexes from the ligand α-(2-Salsayl)-N-phenyl nitrone with CoCl2 and CrCl2. The ligand was characterized by several spectroscopic techniques (ultraviolet/visible (UV/Vis), nuclear magnetic resonance (1H-NMR and 13C-NMR), Fourier-transform infrared spectroscopy (FTIR), and mass spectrometry (MS). While infrared, ultraviolet-visible (UV-Vis), thermal analysis, and job method studies were used to reveal the structure of the complexes. The synthesized complexes were then synthesized by the sonochemical method, and the copper and chromium oxide nanoparticles were produced using the thermal decomposition method. Scanning electron microscopy (SEM), Energy dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD) characterization confirmed the formation of Co3O4 and Cr2O3 nanoparticles. Antimicrobial studies of the complexes against some microorganisms, such as Staphylococcus epidermis and Escherichia coli, utilizing the disk diffusion method, revealed the antibacterial activity of the complexes.

show abstract

“…The fly agaric and other basidiomycetes of the genus Amanita are pigmented by betalains and hygroaurins, whose biosynthesis requires the enzymatic extradiol insertion of molecular oxygen into the catechol ring of l -DOPA (Figure ). − Betalains also impart bright red-violet and orange colors and occasionally green fluorescence , to most plants of the order Caryophyllales and have gained considerable attention because of their broad applicability, − prompt availability, and importance as molecular markers in phylogenetic studies. , In contrast, hygroaurins occur exclusively in some species of Amanita , Hygrocybe , and Hygrophorus fungi, and information on their occurrence, synthesis, and application is virtually nonexistent …”

Section: Introductionmentioning

confidence: 99%

Reannotation of Fly Amanita l-DOPA Dioxygenase Gene Enables Its Cloning and Heterologous Expression

et al. 2022

Self Cite

View full text Add to dashboard Cite

The l -DOPA dioxygenase of Amanita muscaria (AmDODA) participates in the biosynthesis of betalain- and hygroaurin-type natural pigments. AmDODA is encoded by the dodA gene, whose DNA sequence was inferred from cDNA and gDNA libraries almost 30 years ago. However, reports on its heterologous expression rely on either the original 5′-truncated cDNA plasmid or artificial gene synthesis. We provide unequivocal evidence that the heterologous expression of AmDODA from A. muscaria specimens is not possible by using the coding sequence previously inferred for dodA . Here, we rectify and reannotate the full-length coding sequence for AmDODA and express a 205-aa His-tagged active enzyme, which was used to produce the l -DOPA hygroaurin, a rare fungal pigment. Moreover, AmDODA and other isozymes from bacteria were submitted to de novo folding using deep learning algorithms, and their putative active sites were inferred and compared. The wide catalytic pocket of AmDODA and the presence of the His-His-His and His-His-Asp motifs can provide insight into the dual cleavage of l -DOPA at positions 2,3 and 4,5 as per the mechanism proposed for nonheme dioxygenases.

show abstract

A bioinspired nitrone precursor to a stabilized nitroxide radical

Cited by 10 publications

References 40 publications

Structural Effects on the Antioxidant Properties of Amino Acid Betaxanthins

Structural Effects on the Antioxidant Properties of Amino Acid Betaxanthins

Synthesis and Biological Activity Study of Co and Cr Complexes with α-(2-Salsayl)-<i>N</i>-phenyl Nitrone and Oxide Nanoparticles

Reannotation of Fly Amanita l-DOPA Dioxygenase Gene Enables Its Cloning and Heterologous Expression

Contact Info

Product

Resources

About