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1.
Food Chem ; : 128478, 2020 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-33158682

RESUMO

Reaction mixtures of reactive carbonyls and creatinine were submitted to high temperature and studied to identify the reactive carbonyl(s) responsible for 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) formation. MeIQx was produced by reaction of acrolein and creatinine within a wide pH range and with an activation energy of 81.1 ± 1.4 kJ/mol. No additional reactants were required, although methylglyoxal, ammonia, and formaldehyde also participated in the reaction. Nevertheless, these additional reactants were produced in situ from either acrolein or creatinine. A reaction pathway that both explains the formation of MeIQx and is valid for the formation of other heterocyclic aromatic amines (HAAs) with the structure of quinoxaline is proposed. Obtained results demonstrate the key role of reactive carbonyls present in foods (the food carbonylome) on HAA formation. Because creatinine is ubiquitous in proteinaceous foods, the control of the food carbonylome seems to be the key point to control HAA formation in foods.

2.
J Agric Food Chem ; 68(28): 7474-7481, 2020 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-32564598

RESUMO

Food processing is responsible for the destruction of some health hazards, but it is responsible for the formation of new ones. Among them, the formation of heterocyclic aromatic amines (HAAs) has received a considerable attention because of their carcinogenicity. In spite of this, HAA formation is still poorly understood. This study was undertaken to identify precursors and formation pathways for 2-amino-3-methylimidazo(4,5-f)quinoline (IQ). IQ was produced by reaction of acrolein, crotonaldehyde, creatinine, and ammonia. Reaction conditions were studied, and its activation energy (Ea) was determined to be 77.0 ± 1.3 kJ/mol. IQ formation was always accompanied by the formation of the HAA 2-amino-3,4-dimethylimidazo(4,5-f)quinoline (MeIQ), which was produced with an Ea of 72.2 ± 0.4 kJ/mol. A reaction pathway for the competitive formation of IQ and MeIQ is proposed. Obtained results demonstrate the significant role of reactive carbonyls (the food carbonylome) in HAA formation and provide evidences for designing HAA mitigation strategies.

3.
Food Chem ; 324: 126898, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32361096

RESUMO

Reactions involving reactive carbonyls, creatinine, and ammonia-producing compounds were investigated in order to clarify the formation of the heterocyclic aromatic amine (HAA) 2-amino-3,4-dimethylimidazo(4,5-f)quinoline (MeIQ). Obtained results showed that MeIQ was only produced when 2-butenal (crotonaldehyde) was present. Reaction yields depended on the pH, with a maximum around pH 6.5, and on concentrations of crotonaldehyde and creatinine. Ammonia was also required for MeIQ formation, but ammonia was produced by creatinine decomposition. The amount of MeIQ formed increased with reaction time, temperature, and oxygen content in the reaction atmosphere. Activation energy for MeIQ formation from crotonaldehyde, creatinine, and glutamine was 72.2 ± 0.4 kJ·mol-1. A reaction pathway that explains MeIQ formation is proposed. Obtained results suggest a main role of reactive carbonyls formed in foods (the food carbonylome) on HAA formation. In addition, they provide scientific basis for the understanding of how HAAs are formed and could be mitigated.


Assuntos
Aldeídos/química , Creatinina/química , Quinolinas/química , Amônia/química , Cromatografia Líquida de Alta Pressão , Compostos Heterocíclicos/química , Concentração de Íons de Hidrogênio , Oxigênio/química , Quinolinas/análise , Espectrometria de Massas em Tandem , Temperatura
4.
Food Chem ; 328: 127100, 2020 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-32464558

RESUMO

Pyridines are produced during food processing and are important flavor compounds. In spite of that, their formation pathways are still poorly understood, in particular those related to 3-hydroxypyridines. In an attempt to fill this gap, this study describes, for the first time, precursors and reaction pathways leading to 3-hydroxypyridine formation. 3-Hydroxypyridines are produced by reaction of lipid-derived reactive carbonyls and ammonia-producing compounds and were studied by using gas chromatography coupled to mass spectrometry. Their main precursors resulted to be 4,5-epoxy-2-alkenals and 2,4-alkadienals. 3-Hydroxypyridines were produced at temperatures higher than 100 °C, at slightly basic pH values, and with an activation energy of about 50 kJ/mol. A reaction pathway that explains their formation in the course of the lipid oxidation pathway is proposed. The role of lipid oxidation on the production of 3-hydroxypyridines was confirmed by studying their formation in oxidized linseed and menhaden oils heated in the presence of glutamine.


Assuntos
Amônia/química , Manipulação de Alimentos , Lipídeos/química , Piridinas/química , Temperatura Alta , Óleo de Semente do Linho/química , Oxirredução
5.
J Agric Food Chem ; 68(19): 5448-5454, 2020 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-32319769

RESUMO

The formation of 6-(hydroxymethyl)pyridin-3-ol by ring expansion of 5-(hydroxymethyl)furfural (HMF) in the presence of ammonia-producing compounds was studied to determine the routes of formation of pyridin-3-ols in foods. 6-(Hydroxymethyl)pyridin-3-ol was produced from HMF in model systems, mostly at neutral pH values, as a function of reaction times and temperature and with an activation energy (Ea) of 74 ± 3 kJ/mol, which was higher than that of HMF disappearance (43 ± 4 kJ/mol). A reaction pathway is proposed, which is general for the formation of pyridin-3-ols from 2-oxofurans. Thus, it explains the conversions of furfural into pyridin-3-ol and of 2-acetylfuran into 2-methylpyridin-3-ol, which were also studied. When honey and sugarcane honey were heated, they produced different pyridin-3-ols, although 6-(hydroxymethyl)pyridin-3-ol was the pyridine-3-ol produced to the highest extent. Obtained results suggest that formation of pyridin-3-ols in foods is unavoidable when 2-oxofurans are submitted to thermal heating and ammonia (or ammonia-producing compounds) is present.

6.
Food Chem ; 313: 126128, 2020 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-31951882

RESUMO

Thermal food processing has many beneficial consequences, although it also produces some unintentional undesired effects, such as the formation of potentially mutagenic and carcinogenic substances. Among them, the formation of heterocyclic aromatic amines (HAAs) has been related to the declared carcinogenicity of processed meats. In spite of this importance, HAA formation pathways remain mostly unknown, which avoids the design of targeted procedures to inhibit HAA appearance. The objective of this review is to collect information recently appeared that allow advancing in the understanding of how these compounds are produced. Particularly, the possibility that aminoimidazoazarenes are produced similarly to PhIP is discussed, including their formation by cyclizations and oligomerizations of aldehydes and creatinine under usual cooking conditions. Present data suggest that HAA formation might be related to the pool of carbonyl compounds existing in foods, the food carbonylome, which can be controlled by carbonyl-trapping agents, such as amine and phenolic compounds.


Assuntos
Aminas/química , Análise de Alimentos , Compostos Heterocíclicos/química , Aldeídos/química , Carcinógenos/química , Creatinina/química , Ciclização , Manipulação de Alimentos/métodos
7.
Biol Blood Marrow Transplant ; 26(4): 615-624, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31756538

RESUMO

Polyphenols are a group of chemical substances found in plants, with immunomodulatory, antiproliferative, and anti-inflammatory properties that might be useful in the prophylaxis and treatment of graft-versus-host disease (GVHD). Polyphenolic extract (PE) obtained from extra virgin olive oil (EVOO) decreased the activation and proliferation of activated T cells. In addition, a decreased production of proinflammatory cytokines was observed upon exposure to PE. Western blot assays showed a marked inhibition of Akt phosphorylation and nuclear translocation of NF-κB in activated T cells. In a murine model of acute GVHD, we observed that mice that received a diet supplemented in PE (600 ppm) presented a higher survival rate and lower risk of developing GVHD when compared with the group that received a control diet. Histopathologic examination showed a significantly lower gut involvement in mice receiving PE, with a decrease in proinflammatory cytokines (IL-2, IL-17, and TNF-α) in serum and the reestablishment of butyrate concentration in the gut. In conclusion, PE obtained from EVOO exerted a potent immunomodulatory effect, reducing the activation and proliferation of activated T cells and the production of proinflammatory cytokines. In a murine model of acute GVHD, a PE-supplemented diet reduced the incidence and severity of the disease and increased survival after transplantation.

8.
Food Chem ; 304: 125284, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-31476546

RESUMO

The reactions of different lipid-derived reactive carbonyls with ammonia-producing compounds were studied to investigate the formation of pyridines in foods. 2-Alkyl, 3-alkyl-, and 2,5-dialkylpyiridines were produced by oligomerization of short-chain aldehydes in the presence of ammonia. Thus, acetaldehyde/crotonaldehyde mixtures and 2,4-alkadienals were the main responsible for the formation of 2-alkylpyridines; acrolein or 2,4-alkadienals were needed for the formation of 3-alkylpyridines; and 2-alkenals were responsible for the formation of 2,5-dialkylpyridines. On the contrary, 2,6-dialkylpyridines were produced by cyclization of unsaturated ketones. Reactions pathways for formation of these pyridines are proposed, and confirmed by isotopic labelling experiments. Aldehydes and ketones required for their formation are produced in the course of lipid oxidation. Therefore, pyridine formation seems to be an additional consequence of the lipid oxidation pathway. This new knowledge can employed for the optimization of reactions to achieve the desired targeted flavor generation during food processing.


Assuntos
Aldeídos/química , Amônia/química , Manipulação de Alimentos , Temperatura Alta , Peroxidação de Lipídeos , Piridinas/química , Acetaldeído/química , Oxirredução
9.
BMC Plant Biol ; 19(1): 586, 2019 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-31881835

RESUMO

BACKGROUND: In soft fruits, the differential expression of many genes during development and ripening is responsible for changing their organoleptic properties. In strawberry fruit, although some genes involved in the metabolic regulation of the ripening process have been functionally characterized, some of the most studied genes correspond to transcription factors. High throughput transcriptomics analyses performed in strawberry red receptacle (Fragaria x ananassa) allowed us to identify a ripening-related gene that codes an atypical HLH (FaPRE1) with high sequence homology with the PACLOBUTRAZOL RESISTANCE (PRE) genes. PRE genes are atypical bHLH proteins characterized by the lack of a DNA-binding domain and whose function has been linked to the regulation of cell elongation processes. RESULTS: FaPRE1 sequence analysis indicates that this gene belongs to the subfamily of atypical bHLHs that also includes ILI-1 from rice, SlPRE2 from tomato and AtPRE1 from Arabidopsis, which are involved in transcriptional regulatory processes as repressors, through the blockage by heterodimerization of bHLH transcription factors. FaPRE1 presented a transcriptional model characteristic of a ripening-related gene with receptacle-specific expression, being repressed by auxins and activated by abscisic acid (ABA). However, its expression was not affected by gibberellic acid (GA3). On the other hand, the transitory silencing of FaPRE1 transcription by agroinfiltration in receptacle produced the down-regulation of a group of genes related to the ripening process while inducing the transcription of genes involved in receptacle growth and development. CONCLUSIONS: In summary, this work presents for the first time experimental data that support an important novel function for the atypical HLH FaPRE1 during the strawberry fruit ripening. We hypothesize that FaPRE1 modulates antagonistically the transcription of genes related to both receptacle growth and ripening. Thus, FaPRE1 would repress the expression of receptacle growth promoting genes in the ripened receptacle, while it would activate the expression of those genes related to the receptacle ripening process.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/fisiologia , Fragaria/fisiologia , Proteínas de Plantas/fisiologia , Fatores de Transcrição/fisiologia , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fragaria/efeitos dos fármacos , Fragaria/genética , Fragaria/crescimento & desenvolvimento , Frutas/genética , Frutas/crescimento & desenvolvimento , Regulação da Expressão Gênica de Plantas , Inativação Gênica , Proteínas Nucleares/genética , Proteínas Nucleares/fisiologia , Desenvolvimento Vegetal/genética , Reguladores de Crescimento de Planta/fisiologia , Proteínas de Plantas/genética , Fatores de Transcrição/genética , Triazóis/farmacologia
10.
Food Chem X ; 2: 100037, 2019 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-31432020

RESUMO

Lipid oxidation is a main source of reactive carbonyls, and these compounds have been shown both to degrade amino acids by carbonyl-amine reactions and to produce important food flavors. However, reactive carbonyls are not the only products of the lipid oxidation pathway. Lipid oxidation also produces free radicals. Nevertheless, the contribution of these lipid radicals to the production of food flavors by degradation of amino acid derivatives is mostly unknown. In an attempt to investigate new routes of flavor formation, this study describes the degradation of phenylalanine, phenylpyruvic acid, phenylacetaldehyde, and ß-phenylethylamine in the presence of the 13-hydroperoxide of linoleic acid, 4-oxononenal (a reactive carbonyl derived from this hydroperoxide), and the mixture of both of them. The obtained results show the formation of phenylacetic acid and benzaldehyde in these reactions as a consequence of the combined action of carbonyl-amine and free radical reactions for amino acid degradation.

11.
Angew Chem Int Ed Engl ; 58(44): 15646-15649, 2019 10 28.
Artigo em Inglês | MEDLINE | ID: mdl-31404473

RESUMO

The scarcity of effective means to deliver functional proteins to living cells is a central problem in biotechnology and medicine. Herein, we report the efficient delivery of an active DNA-modifying enzyme to human stem cells through high-density cell penetrating peptide brush polymers. Cre recombinase is mixed with a fluorophore-tagged polymer carrier and then applied directly to induced pluripotent stem cells or HEK293T cells. This results in efficient delivery of Cre protein as measured by activation of a genomically integrated Cre-mediated recombination reporter. We observed that brush polymer formulations utilizing cell penetrating peptides promoted Cre delivery but oligopeptides alone or oligopeptides displayed on nanoparticles did not. Overall, we report the efficient delivery of a genome-modifying enzyme to stem cells that may be generalizable to other, difficult-to-transduce cell types.

12.
J Agric Food Chem ; 67(7): 2043-2051, 2019 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-30702290

RESUMO

4-Hydroxy-2-alkenals disappear in the presence of food phenolics (i.e., cathechin or quercetin), and the corresponding carbonyl-phenol adducts are produced. In an attempt to identify structure(s) of formed adducts, the reactions between model phenolics (resorcinol, 2-methylresorcinol, orcinol, and 2,5-dimethylresorcinol) and hydroxyalkenals (4-hydroxy-2-hexenal and 4-hydroxy-2-nonenal) were studied and the produced adducts were isolated by column chromatography and unambiguously characterized by one- and two-dimensional nuclear magnetic resonance and mass spectrometry as dihydrobenzofuranols (1), chromane-2,7-diols (2), and 2 H-chromen-7-ols (3). These compounds were mainly produced at slightly basic pH values and moderate temperatures. Their activation energies ( Ea) of formation were ∼25 kJ mol-1 for adducts 1, ∼32 kJ mol-1 for adducts 2, and ∼38 kJ mol-1 for adducts 3. A reaction pathway that explains their formation is proposed. All of these results confirm that, analogously to other lipid-derived carbonyl compounds, phenolics can trap 4-hydroxy-2-alkenals in an efficient way. Obtained results provide the basis for the potential detection of carbonyl-phenol adducts derived from hydroxyalkenals in food products.


Assuntos
Aldeídos/química , Catequina/química , Alimentos , Fenol/química , Quercetina/química , Concentração de Íons de Hidrogênio , Peroxidação de Lipídeos , Espectroscopia de Ressonância Magnética , Reação de Maillard , Termodinâmica
13.
J Agric Food Chem ; 66(51): 13503-13512, 2018 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-30501175

RESUMO

Lipid hydroperoxides have been shown to produce amino acid decarboxylations. Because thermal decomposition of lipid hydroperoxides produces free radicals and reactive carbonyls, and phenolic compounds have been shown to scavenger both of them, phenolics are expected to inhibit these reactions and this protection should depend on the structures of the involved phenolics. In this study, the effect of a wide array of phenolics and their mixtures on 2-phenylethylamine formation by phenylalanine degradation in the presence of the 13-hydroperoxide of linoleic acid (LOOH) was studied. LOOH increased considerably the formation of the amine, and phenolics mostly exhibiting an inhibitory role that depended on their structure. Thus, 1,3-diphenols decreased the formation of 2-phenylethylamine because of their carbonyl trapping abilities. In contrast, the inhibition of 1,2- and 1,4-diphenols was lower because they could not trap the reactive carbonyls produced by LOOH decomposition. In addition, their free radical scavenging was likely accompanied by the formation of quinones, which acted as reactive carbonyls. The function of all other phenolics could be calculated by adding the individual functions of the different diphenols present in their structures. In fact, experimental values obtained for both mixtures of phenolics and complex phenolics correlated well with the calculated values obtained from their constituting diphenols. All of these results suggest that, when the reaction mechanisms are known, it is possible to predict the behavior of complex phenolics on the basis of their structure.


Assuntos
Peróxido de Hidrogênio/química , Ácido Linoleico/química , Fenetilaminas/química , Fenóis/química , Fenilalanina/química , Reação de Maillard , Modelos Químicos , Relação Estrutura-Atividade
14.
Food Chem ; 264: 471-475, 2018 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-29853403

RESUMO

As many studies are exploring the association between ingestion of bioactive compounds and decreased risk of non-communicable diseases, the scientific community continues to show considerable interest in these compounds. In addition, as many non-nutrients with putative health benefits are reducing agents, hydrogen donors, singlet oxygen quenchers or metal chelators, measurement of antioxidant activity using in vitro assays has become very popular over recent decades. Measuring concentrations of total phenolics, flavonoids, and other compound (sub)classes using UV/Vis spectrophotometry offers a rapid chemical index, but chromatographic techniques are necessary to establish structure-activity. For bioactive purposes, in vivo models are required or, at the very least, methods that employ distinct mechanisms of action (i.e., single electron transfer, transition metal chelating ability, and hydrogen atom transfer). In this regard, better understanding and application of in vitro screening methods should help design of future research studies on 'bioactive compounds'.


Assuntos
Antioxidantes/análise , Flavonoides/análise , Fenóis/análise , Antioxidantes/química , Quelantes/química , Cromatografia Líquida de Alta Pressão , Flavonoides/química , Humanos , Metais/química , Fenóis/química , Espectrofotometria , Relação Estrutura-Atividade
15.
Food Chem ; 263: 89-95, 2018 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-29784333

RESUMO

Phenolics can trap lipid-derived reactive carbonyls as a protective function that diminishes the broadcasting of the lipid oxidative damage to food macromolecules. In an attempt to clarify the trapping of 2,4-alkadienals by phenolics, this study analyzes the reactions of 2,4-hexadienal, 2,4-heptadienal, and 2,4-decadienal with 2-methylresorcinol. These reactions produced (E)-4-(alk-1-en-1-yl)-8-methyl-2,7-bis(prop-1-en-2-yloxy)chromanes, which were isolated and characterized by 1D and 2D NMR and MS. Carbonyl-phenol adduct formation was favored at pH > 7 and moderate temperatures (25-80 °C). Adducts were quantified and shown to be produced as a mixture of diastereomers. Diastereomers 2R,4S plus 2S,4R were formed to a higher extent than diastereomers 2R,4R plus 2S,4S under the different conditions assayed, although activation energies (Ea) for the formation of all of them was mostly the same (∼62 kJ·mol-1). These results show that phenolics can trap 2,4-alkadienals and provide the basis for the later detection of the formed adducts in food pro[ducts.


Assuntos
Alcadienos/química , Lipídeos/química , Resorcinóis/química , Aldeídos/química , Concentração de Íons de Hidrogênio , Espectroscopia de Ressonância Magnética , Oxirredução , Fenóis/química , Estereoisomerismo
16.
J Agric Food Chem ; 66(6): 1320-1324, 2018 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-29359932

RESUMO

Different from the well-characterized function of phenolics as antioxidants, their function as lipid-derived carbonyl scavengers is mostly unknown. However, phenolics react with lipid-derived carbonyls as a function of the nucleophilicity of their reactive groups and the electronic effects and steric hindrances present in the reactive carbonyls. Furthermore, the reaction produces a wide variety of carbonyl-phenol adducts, some of which are stable and have been isolated and characterized but others polymerize spontaneously. This perspective updates present knowledge about the lipid-derived carbonyl trapping ability of phenolics, its competition with carbonyl-amine reactions produced in foods, and the presence of carbonyl-phenol adducts in food products.


Assuntos
Aminas/química , Lipídeos/química , Fenóis/química , Animais , Culinária , Análise de Alimentos , Temperatura Alta , Humanos , Lipídeos/toxicidade , Reação de Maillard , Oxirredução
17.
Food Chem ; 240: 822-830, 2018 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-28946347

RESUMO

The reaction between 4-oxo-2-alkenals (fumaraldehyde, 4-oxo-2-hexenal, and 4-oxo-2-nonenal) and phenolic compounds (resorcinol and 2-methylresorcinol) was studied to characterize the trapping ability of phenolic compounds for these lipid oxidation products. The reaction occurred rapidly under neutral or slightly basic conditions and different carbonyl-phenol adducts were produced. However, these compounds were unstable and their stabilization had to be achieved by means of either acetylation or reduction with sodium borohydride. Three different kinds of adducts were isolated and characterized by using mass spectrometry (MS) and 1D and 2D nuclear magnetic resonance spectroscopy (NMR). They were benzofuran-6-ols, 2,3,3a,8a-tetrahydrofuro[2,3-b]benzofuran-2,6-diols, and chromane-2,7-diols. Most of them were produced as mixtures of diasteromers and all of them had a carbonyl group in a free form or as hemiacetal. A reaction pathway that explains the formation of these compounds is proposed. These results provide the basis to understand the removal of 4-oxo-2-alkenals by phenolic compounds in foods.


Assuntos
Lipídeos/química , Aldeídos , Oxirredução , Resorcinóis
18.
J Agric Food Chem ; 66(1): 255-264, 2018 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-29224335

RESUMO

Phenolics can act as either promoters or inhibitors in 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) formation. In an attempt to clarify the structure-activity relationship (SAR) of phenolics for this reaction, the formation of PhIP in mixtures of phenylalanine, creatinine, 13-hydroperoxide of linoleic acid (LOOH) or 4-oxo-2-nonenal, and a wide array of phenolics was studied in the presence and in the absence of oxygen. The obtained results suggested that those phenolics having a high carbonyl scavenging ability inhibited the formation of PhIP. On the other hand, those phenolics that mainly acted as free radical scavengers and, therefore, were easily converted into quinones promoted the formation of PhIP. Phenolics of the first type were m-diphenols and 1,3,5-triphenols. Phenolics of the second type were o- and p-diphenols. Other phenolics, like 1,2,3- and 1,2,4-triphenols, exhibited a behavior either as carbonyl scavengers or as free radical scavengers depending on ring substitutions. Among the studied derivatives, the presence of a carboxylic or a methoxyl group at certain positions inhibited their behavior as carbonyl scavengers and, therefore, promoted the formation of PhIP. A procedure to classify phenolics as either carbonyl or free radical scavengers is proposed.


Assuntos
Creatinina/química , Imidazóis/química , Peróxidos Lipídicos/química , Oxigênio/química , Fenóis/química , Fenilalanina/química , Estrutura Molecular , Oxirredução , Relação Estrutura-Atividade
19.
Food Chem ; 237: 444-452, 2017 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-28764018

RESUMO

Lipid oxidation products have been shown to produce changes in food quality and safety as a consequence of carbonyl-amine reactions. Some of these reactions can be prevented by the use of phenolics, although the lipid-derived carbonyl trapping ability of phenolics is still poorly understood. In an attempt to fill this gap, the reactions of 4,5-epoxy-2-hexenal, 4,5-epoxy-2-heptenal, and 4,5-epoxy-2-decenal, with 2-methylresorcinol and 2,5-dimethylresorcinol were studied. These reactions produced diverse 1,3a,4,9b-tetrahydro-2H-furo[2,3-c]chromene-2,7-diols and 3,4,4a,9a-tetrahydro-1H-pyrano[3,4-b]benzofuran-3,7-diols, which were isolated and characterized by 1D and 2D nuclear magnetic resonance (NMR) and mass spectrometry (MS). The produced epoxyalkenal-phenol reaction was characterized and carbonyl-phenol adducts were produced firstly by epoxide-ring opening initiated by the attack of one phenolic hydroxyl group and, then, by addition of one aromatic phenol carbon to the carbon-carbon double bond of the epoxyalkenal. This reaction rapidly deactivated the most important reactive groups of epoxyalkenals, decreasing in this way their ability to modify amino compounds.


Assuntos
Compostos de Epóxi/análise , Fenóis/química
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