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1.
Food Chem ; 358: 129856, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-33933975

RESUMO

W/O/W emulsions were easily prepared by oleogelation of the oil phase using rice bran wax (RBX) and their microstructure, stability, rheology and protection of proanthocyanidins and ß-carotene were investigated. Formation of the W/O/W emulsion was confirmed using confocal laser scanning microscopy and staining of the inner aqueous phase by tartrazine. The average particle size and viscosity of the emulsion increased as the RBX concentration increased. Moreover, RBX increased the stability of the emulsion and the emulsion was the most stable when the RBX concentration was 8.0% or 10.0%. On the other hand, the W/O/W emulsions were used to simultaneously encapsulate proanthocyanidins and ß-carotene. Specifically, proanthocyanidins and ß-carotene in RBX-containing emulsions were more stable and had higher bioaccessibility than in the emulsion without RBX. Besides, both their chemical stability and bioaccessibility reached the maximum value when the RBX concentration was 8.0% or 10.0%. In summary, the optimal RBX concentration was 8.0%.


Assuntos
Emulsões/química , Proantocianidinas/química , Óleo de Farelo de Arroz/química , beta Caroteno/química , Óleo de Milho/química , Armazenamento de Alimentos , Tamanho da Partícula , Proantocianidinas/farmacocinética , Reologia , Viscosidade , Água/química , beta Caroteno/farmacocinética
2.
Food Funct ; 12(9): 3978-3991, 2021 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-33977989

RESUMO

Tyrosinase is considered a molecular marker of melanoma, and few natural antitumor drugs targeting tyrosinase have been identified. In this study, proanthocyanidins (PAs) were isolated from the leaves of Photinia × fraseri and their structures were characterized by high performance liquid chromatography-electrospray ionization mass spectrometry (HPLC-ESI-MS), and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and the effects of antityrosinase activity were investigated. The results showed that the basic structural units of PAs are composed of catechin and epicatechin and that oligomer is the main component. PAs exhibited better antityrosinase activity via chelation of copper ions and by disturbing o-quinone production. Furthermore, analyses of the cell cycle, apoptosis rate, and regulation of melanin protein expression revealed preliminarily that PAs could affect melanin production by downregulating microphthalmia transcription factor (MITF) expression and by inhibiting the activities of tyrosinase and tyrosinase related protein 1 (TRP-1), leading to cell cycle arrest and apoptosis of melanoma cells. Collectively, our study demonstrated that PAs are potential tyrosinase inhibitors and have good antimelanoma effects. These findings provide a theoretical support for the application of tyrosinase inhibitors and for further drug development.


Assuntos
Apoptose , Ciclo Celular/efeitos dos fármacos , Melanoma Experimental/patologia , Monofenol Mono-Oxigenase/antagonistas & inibidores , Photinia/química , Proantocianidinas/farmacologia , Animais , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Forma Celular/efeitos dos fármacos , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Expressão Gênica/efeitos dos fármacos , Levodopa/química , Levodopa/metabolismo , Melaninas/biossíntese , Melaninas/genética , Melanoma Experimental/enzimologia , Melanoma Experimental/metabolismo , Camundongos , Fator de Transcrição Associado à Microftalmia/genética , Fator de Transcrição Associado à Microftalmia/metabolismo , Estrutura Molecular , Monofenol Mono-Oxigenase/genética , Monofenol Mono-Oxigenase/metabolismo , Oxirredução , Oxirredutases/genética , Oxirredutases/metabolismo , Ácido Periódico , Folhas de Planta/química , Proantocianidinas/química , Proantocianidinas/isolamento & purificação
3.
Molecules ; 26(9)2021 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-33919259

RESUMO

Proanthocyanidins are natural glycosidase inhibitors with excellent antioxidant activity. This study aims to search for a new source of proanthocyanidins for the prevention and treatment of type 2 diabetes with higher content and better activity and get their structure elucidated. First, the total proanthocyanidins contents (TOPCs), antioxidant activity, antidiabetic activity of seven common Polygonaceae plants were analyzed and compared. Then proanthocyanidins from the rhizome of Fagopyrum dibotrys were purified, and the detailed structure was comprehensively analyzed by ultraviolet visible spectroscopy (UV-Vis), Fourier transform infrared spectroscopy (FT-IR), 13C nuclear magnetic resonance spectroscopy (13C NMR), reversed-phase high-performance liquid chromatography-electrospray mass spectrometry (RP-HPLC-ESI-MS), and matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS). The rhizome of F. dibotrys showed the highest TOPCs, the strongest antioxidant, and antidiabetic activities; the TOPCs, antioxidant and antidiabetic activities were all very significantly positively correlated. Proanthocyanidins purified from the rhizome of F. dibotrys showed better antidiabetic activity than grape seed proanthocyanidins (GsPs). Seventy-two proanthocyanidins from trimer to undecamer with a mean degree of polymerization (mDP) of about 5.02 ± 0.21 were identified with catechin and epicatechin as the dominant monomers. Conclusion: Proanthocyanidins are the main antioxidant and antidiabetic active substances of F. dibotrys and are expected to be developed into potential antioxidant and hypoglycemic products.


Assuntos
Antioxidantes/farmacologia , Fagopyrum/química , Hipoglicemiantes/farmacologia , Proantocianidinas/farmacologia , Antioxidantes/química , Antioxidantes/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Hipoglicemiantes/química , Hipoglicemiantes/isolamento & purificação , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Proantocianidinas/química , Proantocianidinas/isolamento & purificação , Rizoma/química , Espectrometria de Massas por Ionização por Electrospray , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
4.
Molecules ; 26(8)2021 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-33920529

RESUMO

Plant polyphenols have beneficial antioxidant effects on human health; practices aimed at preserving their content in foods and/or reusing food by-products are encouraged. The impact of the traditional practice of the water curing procedure of chestnuts, which prevents insect/mould damage during storage, was studied to assess the release of polyphenols from the fruit. Metabolites extracted from pericarp and integument tissues or released in the medium from the water curing process were analyzed by matrix-assisted laser desorption ionization-time of flight-mass spectrometry (MALDI-TOF-MS) and electrospray-quadrupole-time of flight-mass spectrometry (ESI-qTOF-MS). This identified: (i) condensed and hydrolyzable tannins made of (epi)catechin (procyanidins) and acid ellagic units in pericarp tissues; (ii) polyphenols made of gallocatechin and catechin units condensed with gallate (prodelphinidins) in integument counterparts; (iii) metabolites resembling those reported above in the wastewater from the chestnut curing process. Comparative experiments were also performed on aqueous media recovered from fruits treated with processes involving: (i) tap water; (ii) tap water containing an antifungal Lb. pentosus strain; (iii) wastewater from a previous curing treatment. These analyses indicated that the former treatment determines a 6-7-fold higher release of polyphenols in the curing water with respect to the other ones. This event has a negative impact on the luster of treated fruits but qualifies the corresponding wastes as a source of antioxidants. Such a phenomenon does not occur in wastewater from the other curing processes, where the release of polyphenols was reduced, thus preserving the chestnut's appearance. Polyphenol profiling measurements demonstrated that bacterial presence in water hampered the release of pericarp metabolites. This study provides a rationale to traditional processing practices on fruit appearance and qualifies the corresponding wastes as a source of bioactive compounds for other nutraceutical applications.


Assuntos
Aesculus/química , Antioxidantes/química , Extratos Vegetais/química , Polifenóis/química , Antioxidantes/isolamento & purificação , Antioxidantes/metabolismo , Biflavonoides/química , Biflavonoides/isolamento & purificação , Catequina/química , Catequina/isolamento & purificação , Frutas/química , Humanos , Nozes/química , Extratos Vegetais/farmacologia , Polifenóis/isolamento & purificação , Polifenóis/metabolismo , Proantocianidinas/química , Proantocianidinas/isolamento & purificação , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Taninos/química , Água/química
5.
Molecules ; 26(8)2021 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-33923470

RESUMO

During kiwiberry production, different by-products are generated, including leaves that are removed to increase the fruit's solar exposure. The aim of this work was to extract bioactive compounds from kiwiberry leaf by employing microwave-assisted extraction (MAE). Compatible food solvents (water and ethanol) were employed. The alcoholic extract contained the highest phenolic and flavonoid contents (629.48 mg of gallic acid equivalents (GAE) per gram of plant material on dry weight (dw) (GAE/g dw) and 136.81 mg of catechin equivalents per gram of plant material on dw (CAE/g dw), respectively). Oppositely, the hydroalcoholic extract achieved the highest antioxidant activity and scavenging activity against reactive oxygen and nitrogen species (IC50 = 29.10 µg/mL for O2•-, IC50 = 1.87 µg/mL for HOCl and IC50 = 1.18 µg/mL for •NO). The phenolic profile showed the presence of caffeoylquinic acids, proanthocyanidin, and quercetin in all samples. However, caffeoylquinic acids and quercetin were detected in higher amounts in the alcoholic extract, while proanthocyanidins were prevalent in the hydroalcoholic extract. No adverse effects were observed on Caco-2 viability, while the highest concentration (1000 µg/mL) of hydroalcoholic and alcoholic extracts conducted to a decrease of HT29-MTX viability. These results highlight the MAE potentialities to extract bioactive compounds from kiwiberry leaf.


Assuntos
Antioxidantes/química , Micro-Ondas , Extratos Vegetais/química , Folhas de Planta/química , Fenóis/química , Proantocianidinas/química , Quercetina/química , Espécies Reativas de Oxigênio/metabolismo
6.
Molecules ; 26(9)2021 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-33922933

RESUMO

The content of polyphenols in chocolate depends on many factors related to the properties of raw material and manufacturing parameters. The trend toward developing chocolates made from unroasted cocoa beans encourages research in this area. In addition, modern customers attach great importance to how the food they consume benefits their bodies. One such benefit that consumers value is the preservation of natural antioxidant compounds in food products (e.g., polyphenols). Therefore, in our study we attempted to determine the relationship between variable parameters at the conching stage (i.e., temperature and time of) and the content of dominant polyphenols (i.e.,catechins, epicatechins, and procyanidin B2) in chocolate milk mass (CMM) obtained from unroasted cocoa beans. Increasing the conching temperature from 50 to 60 °C decreased the content of three basic flavan-3-ols. The highest number of these compounds was determined when the process was carried out at 50 °C. However, the time that caused the least degradation of these compounds differed. For catechin, it was 2 h; for epicatechin it was 1 h; and for procyanidin it was 3 h. The influence of both the temperature and conching time on the rheological properties of chocolate milk mass was demonstrated. At 50 °C, the viscosity and the yield stress of the conched mass showed its highest value.


Assuntos
Cacau/química , Leite/química , Fenóis/química , Polifenóis/química , Animais , Antioxidantes/química , Biflavonoides/química , Catequina/química , Bovinos , Chocolate/análise , Flavonoides/química , Flavonoides/isolamento & purificação , Manipulação de Alimentos , Humanos , Fenóis/isolamento & purificação , Polifenóis/classificação , Proantocianidinas/química , Espectrometria de Massas por Ionização por Electrospray
7.
Molecules ; 26(7)2021 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-33810382

RESUMO

In this study, we analyzed the proanthocyanidin (PA) composition of 55 plant extracts before and after alkaline oxidation by ultrahigh-resolution UHPLC-MS/MS. We characterized the natural PA structures in detail and studied the sophisticated changes in the modified PA structures and the typical patterns and models of reactions within different PA classes due to the oxidation. The natural PAs were A- and B-type PCs, PDs and PC/PD mixtures. In addition, we detected galloylated PAs. B-type PCs in different plant extracts were rather stable and showed no or minor modification due to the alkaline oxidation. For some samples, we detected the intramolecular reactions of PCs producing A-type ether linkages. A-type PCs were also rather stable with no or minor modification, but in some plants, the formation of additional ether linkages was detected. PAs containing PD units were more reactive. After alkaline oxidation, these PAs or their oxidation products were no longer detected by MS even though a different type and/or delayed PA hump was still detected by UV at 280 nm. Galloylated PAs were rather stable under alkaline oxidation if they were PC-based, but we detected the intramolecular conversion from B-type to A-type. Galloylated PDs were more reactive and reacted similarly to nongalloylated PDs.


Assuntos
Extratos Vegetais/química , Proantocianidinas/química , Cromatografia Líquida de Alta Pressão , Estrutura Molecular , Oxirredução , Plantas/química , Espectrometria de Massas em Tandem
8.
Food Chem ; 355: 129414, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-33773461

RESUMO

A screening of inhibitory activity of α-amylase, as well as pancreatic lipase (PL), under the influence of aqueous and ethanolic preparations from 12 plant materials was performed. The most active aqueous extracts from the fruits of Chaenomeles japonica (CJ) and Hippophaë rhamnoides (HR) were selected for artificial gastrointestinal digestion (GID). The aim of this study was to evaluate the inhibitory effect of the fractions obtained after GID on PL and α-amylase activities using a fluorescence assay. The changes in the composition of crude extracts in GID aliquots were followed by analysis with HPLC-DAD-MSn method in order to indicate active constituents. The main constituents of CJ and HR extracts were procyanidins and isorhamnetin derivatives, respectively. The most abundant compounds of extracts were found in all compartments of the digestion model correlated with relevant lipase/α-amylase inhibitory activity. What is more, the gastric and intestinal fractions inhibited enzymatic activity by at least 40%.


Assuntos
Hippophae/química , Lipase/antagonistas & inibidores , Extratos Vegetais/química , Rosaceae/química , alfa-Amilases/antagonistas & inibidores , Cromatografia Líquida de Alta Pressão , Digestão , Frutas/química , Frutas/metabolismo , Hippophae/metabolismo , Humanos , Lipase/metabolismo , Espectrometria de Massas , Extratos Vegetais/análise , Extratos Vegetais/metabolismo , Proantocianidinas/análise , Proantocianidinas/química , Proantocianidinas/metabolismo , Rosaceae/metabolismo , alfa-Amilases/metabolismo
9.
Carbohydr Polym ; 255: 117482, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33436242

RESUMO

A viscous solution of low molecular weight chitosan (CH) at 5% w/v (10.2 kDa, 75 % deacetylated, 1451 cP at 25 °C) was associated with a microemulsion (ME) that undergoes a phase transition after water absorption in situ (≈28 % w/w), forming a more viscous liquid crystal, which was potentially evaluated as a topical vehicle. The ME was selected from a phase diagram, selecting a composition based on Tween® 80 (52 %), myristate isopropyl (28 %), and the aqueous phase (water and polyethylene glycol 400, 60:40 w/w) (20 %), which was after replaced by CH and herbal medicines (HM). HM are alternatives to treat candidiasis, and Stryphnodendron adstringens shell extract, characterized by molecular networking, and Melaleuca alternifolia Chell essential oil (46 % of terpinen-4-ol), showed in vitro activity against Candida albicans. Associating CH in ME improved the mechanical properties of the topical formulation, as adhesiveness, which is an advantageous feature for the topical treatment of vulvovaginal candidiasis.


Assuntos
Candida albicans/efeitos dos fármacos , Quitosana/química , Fabaceae/química , Melaleuca/química , Óleo de Melaleuca/química , Candida albicans/crescimento & desenvolvimento , Catequina/química , Catequina/isolamento & purificação , Catequina/farmacologia , Emulsões , Flavonoides/química , Flavonoides/isolamento & purificação , Flavonoides/farmacologia , Cristais Líquidos/química , Testes de Sensibilidade Microbiana , Peso Molecular , Miristatos/química , Extratos Vegetais/química , Polietilenoglicóis/química , Polissorbatos/química , Proantocianidinas/química , Proantocianidinas/isolamento & purificação , Proantocianidinas/farmacologia , Reologia , Óleo de Melaleuca/farmacologia , Água/química
10.
Int J Biol Macromol ; 172: 503-514, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33454330

RESUMO

The study aimed to reveal the different mechanisms of delaying starch digestion by ECG, EGCG and Procyanidin based on the perspective of α-amylase-flavanol interaction and starch-flavanol interaction. The interaction characteristics of flavanols with α-amylase were studied from five aspects: enzyme inhibition, kinetics, fluorescence quenching, circular dichroism (CD) and computer simulation. The IC50 of flavanols (ECG, EGCG and Procyanidin) against α-amylase were 172.21 ± 0.22, 732.15 ± 0.13 and 504.45 ± 0.19 µg/mL according to the results of α-amylase inhibition experiment, respectively. ECG and Procyanidin showed mixed inhibition against α-amylase, while EGCG showed non-competition against α-amylase. However, thermodynamic parameters,computer-based docking and dynamic simulation proved that ECG and EGCG-α-amylase complexs were mainly driven by van der Waals and hydrogen bonds, while Procyanidin-α-amylase complexs was driven by hydrophobic interaction. In addition, it was indicated, by means of starch­iodine complex spectroscopy, that flavanols inhibited the digestion of starch not only through bind with α-amylase but also through bind with starch. Thus, flavanols as a starch-based food additive have the potential to be employed as adjuvant therapy for diabetes.


Assuntos
Biflavonoides/química , Catequina/análogos & derivados , Inibidores de Glicosídeo Hidrolases/química , Proantocianidinas/química , Amido/química , alfa-Amilases/química , Biflavonoides/metabolismo , Sítios de Ligação , Catequina/química , Catequina/metabolismo , Glucose/química , Inibidores de Glicosídeo Hidrolases/metabolismo , Hidrólise , Cinética , Maltose/química , Maltose/metabolismo , Simulação de Acoplamento Molecular , Proantocianidinas/metabolismo , Ligação Proteica , Conformação Proteica em alfa-Hélice , Conformação Proteica em Folha beta , Domínios e Motivos de Interação entre Proteínas , Amido/metabolismo , Especificidade por Substrato , Termodinâmica , Trissacarídeos/química , Trissacarídeos/metabolismo , alfa-Amilases/antagonistas & inibidores , alfa-Amilases/metabolismo
11.
Food Chem ; 346: 128952, 2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-33421900

RESUMO

Practical application of proanthocyanidins (PAs) as antioxidants is limited because of their hard-to-maintained activities during the processes and storage and in severe gastrointestinal environments. To overcome this challenge, we have developed an easy and green method to encapsulate PAs based on casein-maltodextrin Maillard conjugates. The current work entails the systematic study on the antioxidative potentials of fabricated casein-maltodextrin-PAs nanoparticles (CMPNs). In vitro antioxidant activities of CMPNs remained well during storage in 28 days and treatments under 40-80 °C. In vivo Caenorhabditis elegans (C. elegans) model further showed that the CMPNs could prolong the lifespan of nematodes and protected nematodes from oxidative stress and heat shock. Analyses of intracellular superoxide dismutase and catalase activities also confirmed the existence of an antioxidant protective effect. Besides, in vitro release test showed that the encapsulation enhanced the bioaccessibility of PAs. These results have important implications for the development of novel antioxidants in nutraceutical industries.


Assuntos
Antioxidantes/química , Caseínas/química , Polissacarídeos/química , Proantocianidinas/química , Animais , Antioxidantes/farmacologia , Caenorhabditis elegans/efeitos dos fármacos , Caenorhabditis elegans/enzimologia , Caenorhabditis elegans/fisiologia , Catalase/metabolismo , Longevidade/efeitos dos fármacos , Reação de Maillard , Nanopartículas/química , Estresse Oxidativo/efeitos dos fármacos , Proantocianidinas/farmacologia , Superóxido Dismutase/metabolismo
12.
J Agric Food Chem ; 69(5): 1466-1477, 2021 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-33507744

RESUMO

The purpose of this study was to construct a delivery system using a microfluidic chip to protect procyanidins (PCs) and to achieve their pH-controlled release in simulated gastrointestinal fluid. The microfluidic chip was designed and fabricated to generate water-in-water-in-oil (W/W/O) templates for the preparation of sodium alginate/chitosan microparticles with a uniform size and core-shell structure, using an internal-external gelation method. Compared with free PCs, the stability of PCs embedded in microparticles was improved and a pH stimulus-responsive release of PCs from microparticles was observed under neutral pH conditions. The delivery system of microparticles was nontoxic and showed an inhibitory effect on the decrease of mitochondrial membrane potential in Caco-2 cells caused by H2O2 and acrylamide. This work provided a method for fabricating compact microfluidic chips to prepare a pH stimulus-responsive PCs delivery system with improved stability, which may have potential applications in the delivery of other nutrients.


Assuntos
Biflavonoides/química , Catequina/química , Preparações de Ação Retardada/química , Composição de Medicamentos/métodos , Microfluídica/métodos , Proantocianidinas/química , Biflavonoides/farmacologia , Células CACO-2 , Catequina/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Preparações de Ação Retardada/farmacologia , Composição de Medicamentos/instrumentação , Humanos , Concentração de Íons de Hidrogênio , Microfluídica/instrumentação , Microesferas , Tamanho da Partícula , Proantocianidinas/farmacologia
13.
Food Chem ; 340: 127905, 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-32882474

RESUMO

Studies regarding composition and evolution of oligomeric proanthocyanidin-anthocyanin adducts in red wines have often focused only on a limited number of small dimers. Now, a group-specific liquid chromatography-tandem mass spectrometry method was utilized to measure two-dimensional (2D) chromatographic fingerprints of three different types of oligomeric adducts in commercial red wines. A new protocol was developed to visualize and summarize the chromatographic data. The 2D fingerprints showed how the compositions of the oligomeric adducts had typically only minor differences between wine varieties in young wines, excluding the Pinot Noir wines. Major quantitative differences were found between the wine varieties despite the lack of major compositional differences. The evolution of the concentrations differed between the three structural sub-groups, while similar general patterns were observed in the compositional evolution. Via statistical modelling, several characteristics in the polyphenolic starting material composition were tentatively suggested to affect the formation of the oligomeric adducts.


Assuntos
Antocianinas/análise , Proantocianidinas/análise , Vinho/análise , Antocianinas/química , Cromatografia Líquida , Cor , Visualização de Dados , Análise de Alimentos/métodos , Glicosídeos/análise , Proantocianidinas/química , Espectrometria de Massas em Tandem , Fatores de Tempo
14.
Food Chem ; 340: 127830, 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-32919355

RESUMO

Procyanidins from coffee pulp are responsible from the limited valorization of this by-product. Information about procyanidin structure is still scarce and imprecise. The aim of this work was to study the native and oxidized procyanidins from coffee pulp with respect to composition and structure. An aqueous acetone extract from coffee pulp was purified using Sephadex LH-20. Butanolysis, phloroglucinolysis and thioglycolysis coupled to HLPC-ESI-MS were applied for the characterization of the native and oxidized procyanidins. The purification allowed to recovery three fractions (aqueous, ethanolic and acetonic) and only acetone fraction showed a high concentration of procyanidins (98%, w/w). HPLC-ESI-MS of procyanidins-rich fraction without any reaction resulted in a UV-Vis chromatogram unresolved typical of the presence of procyanidins. The extracted ion chromatogram and MS2 analysis revealed the presence from dimers to pentamers of native procyanidins. Interestingly, by first time an A-type trimeric procyanidin (m/z of 863) was observed in coffee pulp. In our study, (-)-epicatechin was the constitutive unit of procyanidins with an aDP of 6.8 (oligomeric native procyanidins) according to the phloroglucinolysis assay. Two oxidation markers useful to characterization of oxidized procyanidins were observed in the procyanidins-rich fraction after thioglycolysis, a dimer A2-ext and a molecule that corresponds to a linkage between an extension and a terminal unit. Coffee pulp procyanidins were presented with only a minor class of oxidized procyanidins. As far as we know, this is the first study about characterization of the oxidized procyanidins from coffee pulp.


Assuntos
Biflavonoides/análise , Biflavonoides/química , Catequina/análise , Catequina/química , Coffea/química , Proantocianidinas/análise , Proantocianidinas/química , Espectrometria de Massas por Ionização por Electrospray/métodos , Cromatografia Líquida de Alta Pressão/métodos , Café/química , Glicólise , Oxirredução
15.
Food Chem ; 339: 127756, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-32979716

RESUMO

Water scarcity is a threat for food production because, water, is more and more limited and force farmers to use new deficit irrigation (DI) strategies without affecting fruit yield and quality. No information exists on almond polyphenols and proanthocyanidins (PAs) produced under DI. The present work studied the effect of 2 regulated DI (RDI) and one sustained (SDI) on the low molecular weight phenolics together with the antioxidant activity (AA) in almonds. Fifteen phenolic compounds were identified (13 flavonoids and 2 non-flavonoids) and 10 PAs. Kaempferol-3-O-galactoside was the predominant compound in almond skin and whole kernel but it was not found in deskinned kernels. The use of moderate RDI significantly increased the total phenolic content in skin (∼9.8%), PAs, and the AA. Consequently, after one season the application of DI positively affected the almond cv. Vairo phenols, however, several seasons must be evaluated in order to corroborate the present results.


Assuntos
Fenóis/química , Prunus dulcis/química , Irrigação Agrícola , Antioxidantes/análise , Desidratação , Flavonoides/análise , Flavonoides/química , Peso Molecular , Nozes/química , Fenóis/análise , Polifenóis/análise , Polifenóis/química , Proantocianidinas/análise , Proantocianidinas/química , Prunus dulcis/crescimento & desenvolvimento , Espanha
16.
Food Chem ; 338: 128013, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33091995

RESUMO

Chitosan-procyanidin composite films (CS-PC films) with different mass ratios were prepared by solution casting method. Their structural, thermal, physical, and antioxidant properties, antibacterial activity and pH responsivity were determined. Compared with CS-control film, CS-PC films exhibited lower solubility and higher tensile strength. The antimicrobial properties against Escherichia coli and Aspergillus niger were improved by 20.0% and 30.4%, respectively. CS-PC films indicated good antioxidant activity through their DPPH and ABTS+ scavenging rates, which were 2.45 times higher than CS-control film. pH responsivity was represented by the outstanding changes in color, which were visible to the naked eye. Food packaging film with high antioxidant activity, bacteriostatic properties and pH responsivity was prepared by CS and PC. Compared with the initial properties of cheese, the characteristics of cheese packaged with CS-PC films were obviously better than those of the control groups.


Assuntos
Anti-Infecciosos/química , Antioxidantes/química , Biflavonoides/química , Catequina/química , Queijo/análise , Quitosana/química , Embalagem de Alimentos/métodos , Proantocianidinas/química , Anti-Infecciosos/farmacologia , Aspergillus niger/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Concentração de Íons de Hidrogênio
17.
Food Chem ; 339: 128145, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33152895

RESUMO

The solution turbidity and intrinsic fluorescence quenching increased after procyanidin was mixed with lactoferrin. The addition of procyanidin also caused a reduction in the surface hydrophobicity of the lactoferrin, suggesting procyanidin bound to non-polar patches on lactoferrin's surfaces. Moreover, the binding interaction caused an appreciable alteration in the structure of both the polyphenol and protein. Thermodynamic analysis indicated the interaction was spontaneous and mainly driven by entropy changes, suggesting that hydrophobic interactions dominated. A computational docking simulation provided insights into the location of the most-likely binding sites on the protein, as well as the nature of the interaction forces involved. In particular, both hydrophobic and hydrogen bonding were found to be important. The binding of the procyanidin to the lactoferrin enhanced its foaming properties. These results may lead to the development of a new class of natural functional ingredients that can be used in food products to improve their quality attributes.


Assuntos
Biflavonoides/química , Catequina/química , Lactoferrina/química , Proantocianidinas/química , Animais , Biflavonoides/metabolismo , Sítios de Ligação , Catequina/metabolismo , Bovinos , Fluorescência , Ligação de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Lactoferrina/metabolismo , Simulação de Acoplamento Molecular , Proantocianidinas/metabolismo , Espectrometria de Fluorescência , Termodinâmica
18.
Carbohydr Polym ; 252: 117172, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33183621

RESUMO

The inhibition effect of three common proanthocyanidins (PA) on the retrogradation properties of maize starch was investigated (including grape seed proanthocyanidins (GSPA), peanut skin proanthocyanidins (PSPA), and pine bark proanthocyanidins (PBPA)). Differential scanning calorimetry (DSC) and X-ray diffraction (XRD) analysis showed that PA could significantly decrease the values of melting enthalpy of retrogradation (ΔHr) and the degree of relative crystallinity, suggesting that the starch re-crystallization was retarded by PA. Scanning electron microscope (SEM) characterizations illustrated that retrograded PA-starch samples formed a looser matrix with less appearance of continuous flakes during storage. Overall, 0.5 %-2.0 % of three PAs exhibited suppression of starch retrogradation after 21-day cooling storage, mainly resulting from the PA-starch interaction. Among them, PSPA showed the most substantial inhibition effect on starch retrogradation, which might be attributed to its structural features. This study suggested that PA could be a new type of inhibitor to suppress starch retrogradation.


Assuntos
Arachis/química , Extrato de Sementes de Uva/química , Pinus/química , Proantocianidinas/química , Amido/química , Zea mays/química , Cristalização , Conformação Molecular , Casca de Planta/química , Termodinâmica
19.
J Chromatogr A ; 1636: 461790, 2021 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-33340746

RESUMO

Epigenetic inheritance in mammals relies in part on propagation of DNA methylation patterns throughout development. UHRF1 (ubiquitin-like containing PHD and RING finger domains 1) is required for maintenance the methylation pattern. It was reported that UHRF1 is overexpressed in a number of cancer types, and its depletion has been established to inhibit growth and invasion of cancer cells. It has been considered as a new therapeutic target for cancer. In the present work, we described a method for screening inhibitors for blocking the formation of UHRF1-methylated DNA (mDNA) complex by using nonequilibrium capillary electrophoresis of the equilibrium mixture (NECEEM). A recombinant UHRF1 with the SRA domain (residues 408-643), a fluorescently labeled double strand mDNA (12 mer) and a known inhibitor mitoxantrone were employed for proof of concept. The method allows to measure the dissociation constant (Kd) of the UHRF1-mDNA complex as well as the rate kinetic constant for complex formation (kon) and dissociation (koff). A small chemical library composed of 60 natural compounds were used to validate the method. Sample pooling strategy was employed to improve the screening throughput. The merit of the method was confirmed by the discovery of two natural products proanthocyanidins and baicalein as the new inhibitors for blocking the formation of UHRF1-mDNA complex. Our work demonstrated that CE represents a straightforward and robust technique for studying UHRF1-mDNA interaction and screening of the inhibitors.


Assuntos
Antineoplásicos/análise , Antineoplásicos/farmacologia , Proteínas Estimuladoras de Ligação a CCAAT/metabolismo , Metilação de DNA/genética , Ensaios de Seleção de Medicamentos Antitumorais , Eletroforese Capilar/métodos , Ubiquitina-Proteína Ligases/metabolismo , Animais , Antineoplásicos/química , Metilação de DNA/efeitos dos fármacos , Flavanonas/química , Flavanonas/farmacologia , Humanos , Cinética , Mitoxantrona/química , Mitoxantrona/farmacologia , Proantocianidinas/química , Proantocianidinas/farmacologia
20.
Food Chem ; 335: 127647, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-32739816

RESUMO

The inhibition mechanism of the texture deterioration of tilapia fillets after treatment with polyphenols during partial freezing for 49 days was studied. Carnosic acid (CA), procyanidin (PA), quercetin (QE), and resveratrol (RSV) treatments had significantly higher hardness values (over 230 g) than the control group (183 g) on day 49 (P < 0.05). Polyphenol treatments were effective in delaying the protein degradation, lipid oxidation and spoilage microbe growth. Moreover, the kinetic model showed that the predicted shelf life of tilapia fillets treated with PA (102 d) was extended by 25 d compared to the control group (77 d). It was the proposed possible mechanism that polyphenols comprehensively maintained the protein conformation (increased hydrogen bonds and decreased disulfide bonds) and retarded protein denaturation and degradation, protecting the texture of the fillets. Therefore, polyphenols can be used to maintain texture and extend the shelf life of tilapia fillets during partial freezing.


Assuntos
Conservação de Alimentos/métodos , Conservantes de Alimentos/farmacologia , Carne/análise , Polifenóis/análise , Polifenóis/farmacologia , Animais , Biflavonoides/química , Catequina/química , Proteínas de Peixes/química , Conservação de Alimentos/instrumentação , Congelamento , Oxirredução/efeitos dos fármacos , Proantocianidinas/química , Desnaturação Proteica/efeitos dos fármacos , Tilápia
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