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1.
Zhongguo Ying Yong Sheng Li Xue Za Zhi ; 36(1): 6-11, 2020 Jan 28.
Artigo em Chinês | MEDLINE | ID: mdl-32476366

RESUMO

OBJECTIVE: To observe the effects of dihydromyricetin (DHM) on obesity induced by high-fat diet in mice, and to explore whether its mechanism of action is related to the promotion of WAT browning. METHODS: Sixty c57bl/6j mice were randomly divided into 6 groups (n=10): ①normal control group (ND group): normal feed feeding; ②Normal control + low dose DHM group (ND+L-DHM group): normal feed feeding was treated with low dose DHM (125 mg/(kg·d)); ③Normal control + high dose DHM group (ND+H-DHM group): normal feed feeding was treated with high dose DHM (250 mg/(kg·d)); ④High-fat diet group (HFD): high-fat diet; ⑤high-fat diet + low-dose DHM group (HFD+L-DHM group): high-fat diet feeding with low-dose DHM; ⑥High-fat diet + high-dose DHM group (HFD+H-DHM group): High-fat diet was treated with high-dose DHM. After 16 weeks, the mice were fasted overnight, blood samples were collected for fasting blood glucose and blood lipids, then the animals were sacrificed, body length was measured, and Lee's index was calculated. After weighing the adipose tissue in the scapula, groin and epididymis, formaldehyde fixation and HE staining were used to observe the fat cells size, immunohistochemistry was used to detect the expression of uncoupling protein 1 (UCP1). The body weight was measured every 4 weeks during the experiment. RESULTS: Compared with the ND group, the body weight of the mice in the HFD group was increased significantly, suggesting that the obese mouse model replicated successfully. In addition, the body fat weight, fat cell diameter, Lee's index and blood glucose of the HFD group were increased significantly, and the expression of UCP1 in the adipocytes was increased. Body weight, fat cell diameter, Lee's index and blood glucose of HFD mice treated with L-DHM and H-DHM were reversed significantly, while the expression of UCP1 in adipocytes was more significantly increased; however, L-DHM and H-DHM had no significant effects on the above indicators in normal mice. CONCLUSION: Dihydromyricetin inhibited high fat diet induced mouse obesity; the mechanism might be associated with promoting WAT browning.


Assuntos
Tecido Adiposo Marrom/fisiologia , Dieta Hiperlipídica , Flavonóis/uso terapêutico , Obesidade/tratamento farmacológico , Animais , Peso Corporal , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Distribuição Aleatória
2.
Food Chem ; 314: 126182, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-31968293

RESUMO

Flavonoids are key determinants of grape quality and wine color. Grapevines growing in alkaline soil are prone to manganese deficiency, which can decrease the contents of secondary metabolites, including flavonoids. We determined the effects of a foliar Mn treatment (MnSO4·H2O) of Cabernet Sauvignon grapevines (V. vinifera L.) growing in alkaline soil on the flavonoid contents in grape skin, and the quality of wine. The Mn treatments were applied in 2017 and 2018, and tended to increase the grape sugars, berry weight, and the contents of phenolic compounds from veraison until harvest. The Mn treatments increased the amounts of acetylated, methylated, and total anthocyanins, as well as the total flavonol contents in grape berry skin at harvest. The wines prepared from these grapes had a higher color intensity than those prepared from grapes from control vines. Foliar-applied MnSO4·H2O can promote flavonoid biosynthesis in grape berries, and improve the color of wine.


Assuntos
Agricultura/métodos , Flavonoides/metabolismo , Compostos de Manganês/farmacologia , Sulfatos/farmacologia , Vitis/efeitos dos fármacos , Vinho/análise , Antocianinas/análise , Antocianinas/metabolismo , China , Cor , Flavonoides/análise , Flavonóis/análise , Flavonóis/metabolismo , Frutas/efeitos dos fármacos , Frutas/metabolismo , Fenóis/análise , Fenóis/metabolismo , Folhas de Planta , Solo/química , Vitis/metabolismo
3.
J Food Sci ; 85(2): 386-393, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31985832

RESUMO

Sugars, organic acids, and phenolic compounds were analyzed in the fruits of juneberry (Amelanchier lamarckii). Different food products were made from fresh juneberry fruits: jam, liqueur, juice, and tea. A detailed analysis of the phenolic component was performed using high-pressure liquid chromatography coupled with mass spectrometry, and the content of phenolics in different products was compared with the control treatment (fresh fruits extracted with 70% methanol: 27% water: 3% formic acid; v/v/v). Four sugars and six organic acids were determined in the fruits. The main sugars were glucose (61 g/kg fresh weight [FW]) and fructose (64 g/kg FW) and the acids: malic (5.85 g/kg FW) and citric acid (2.6 g/kg) were abundant. Hydroxycinnamic acids, anthocyanins, and flavonol glycosides were the major phenolic groups in juneberry fruits. Fruit processing significantly affected the content of phenolic compounds in the different fruit products. Liqueur had 17% higher phenolic acid contents than the control treatment (fresh fruits extracted with a solution of 70% MeOH/27% H2 O/3% formic acid) and jam had 14% higher content than the control, calculated on the dry mass of fruit. Juneberry juice had the highest content of total analyzed phenolics (298 mg/100 mL), followed by liqueur (108 mg/100 mL) and tea (8 mg/100 mL). Fruits of juneberry are rich in bioactive compounds and a useful source for the food industry for making various health snacks, jellies, marmalades, alcoholic drinks, juices, and so on. PRACTICAL APPLICATION: Juneberry is becoming a desirable organically grown fruit species with many views as new functional food. The content of phenolic compounds has been measured in different food products made from juneberries. The results could be useful for food and nutraceutical industry.


Assuntos
Manipulação de Alimentos/métodos , Sucos de Frutas e Vegetais/análise , Fenóis/química , Rosaceae/química , Antocianinas/análise , Antioxidantes/química , Cromatografia Líquida de Alta Pressão/métodos , Ácidos Cumáricos/análise , Flavonóis/análise , Frutas/química
4.
Phytochem Anal ; 31(3): 333-339, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31898384

RESUMO

INTRODUCTION: Polygonatum is widely used as a part of food in different regions of the world which covers five main categories such as drinks, vegetables, snacks, staple and seasoning foods. Presently, no analytical method is available for the quality control of Polygonatum. OBJECTIVE: Development and validation of a method using ultrahigh-performance liquid chromatography diode array detector quadrupole time-of-flight (UHPLC-DAD/QTOF) technique for the estimation of six compounds including a flavonol glycoside [rutin (1)], two flavonols [quercetin (2) and kaempherol (3)] and three homoisoflavonoids [5,7-dihydroxy-3-(2-hydroxy-4-methoxybenzyl)-chroman-4-one (4), 5,7-dihydroxy-3-(2-hydroxy-4-methoxybenzyl)-8-methylchroman-4-one (5) and 5,7-dihydroxy-3-(4-methoxybenzyl)-8-methylchroman-4-one (6)]. In addition, screening of extract, fractions and compounds of P. verticillatum for antioxidant activity was also determined. METHODOLOGY: The separation was achieved on C-18 column using acetonitrile and water containing 0.1% formic acid. The method was validated as per ICH (International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use) guidelines. The validated method was applied for the simultaneous identification and quantification of compounds 1-6 in extract (E) and fractions (F1-F4) of P. verticillatum. Furthermore, antioxidant potential of E, F1 and F2 and compounds was evaluated using DPPH (2,2-diphenyl-1-picrylhydrazyl) assay. RESULTS: The method was within the linear range (r2 ) of 0.982 to 0.999, precise (intra- and inter-day percentage relative standard deviations < 2.72 and 2.26) and accurate with recoveries (89.1-98.3%). The limit of detection and limit of quantification were in the ranges 0.02-0.16 and 0.06-0.48 ng/mL, respectively. Compounds 1-6 were quantified in all the samples. Compounds 1, 2 and 5 showed higher activity with half maximal inhibitory concentration (IC50 ) values 0.41, 0.39, 0.72 at 10, 20 and 30 µg/mL, respectively. CONCLUSION: Developed method will be helpful to assess the quality of P. verticillatum raw material and their derived products.


Assuntos
Polygonatum , Antioxidantes , Cromatografia Líquida de Alta Pressão , Flavonoides , Flavonóis , Glicosídeos , Humanos , Extratos Vegetais
5.
Xenobiotica ; 50(3): 332-338, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31092113

RESUMO

1. Dihydromyricetin (DMY) has anti-tumor and hepatoprotective activities and inhibits the activity of CYP enzymes and P-gp. In this research, we explored the effect of DMY on the pharmacokinetics of triptolide (TP), an anti-tumor Chinese medicine that is mainly metabolized by CYP enzymes and is the substrate of P-gp.2. Rats were administrated TP (1.2 mg/kg) with and without DMY in different dosage regimens, then a sensitive and reliable LC-MS/MS method was developed and applied to assess the pharmacokinetics of TP. The blood samples for TP were collected from each rat up to 120 min after administration of TP.3. When co-administrated with single dose of DMY (100 mg/kg), the AUC, Cmax and T1/2 of TP were significantly enhanced by 98, 83 and 66%, respectively. The T1/2 of TP was significantly prolonged from 23.6 ± 6.4 to 70.5 ± 12.5 min with 14-doses pretreatment of DMY (500 mg/kg), conversely, the Cmax was decreased by 30% and the AUC was enhanced by 24%.4. These results hinted that administration of DMY with TP did alter the pharmacokinetics of TP, and provided the theoretical pharmacokinetic basis to study on the protective effects of DMY against acute liver injury caused by TP.


Assuntos
Diterpenos/farmacocinética , Flavonóis/metabolismo , Fenantrenos/farmacocinética , Animais , Área Sob a Curva , Cromatografia Líquida , Compostos de Epóxi/farmacocinética , Masculino , Ratos , Espectrometria de Massas em Tandem
6.
Ecotoxicol Environ Saf ; 190: 110064, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31838230

RESUMO

Astilbin (ASB), a dihydroflavonol glycoside, is widely found in a variety of plants and in functional foods and acts as a powerful antioxidant. The aim of this study was to investigate the underlying mechanisms involved in the antagonistic effects of ASB on cadmium (Cd)-induced necroptosis in chicken peripheral blood lymphocytes. Peripheral blood lymphocytes were aseptically collected from Roman white hens and then randomly divided into five groups: the control group was incubated without additional reagents, while the other groups were incubated with Cd, ASB, a combination of Cd and ASB, and 0.1% DMSO. After a 24 h treatment, cell samples were collected. The results showed that some morphological changes consistent with necroptosis were observed in the Cd-treated groups, suggesting the occurrence of necroptosis. Simultaneously, antioxidant activity markers (CAT, SOD, GSH, GSH-px, and T-AOC) decreased and indicators of oxidative stress (MDA, iNOS, NO, H2O2, ·OH and ROS) increased. The production of ROS induced the activation of the PI3K/Akt signaling pathway, as the expression levels of PI3K, Akt and PDK1 were significantly elevated. Additionally, the expression levels of RIPK3, RIPK1, MLKL, TAK1, TAB2 and TAB3 were increased and that of Caspase-8 was decreased, which could cause the necroptosis. However, the most important our results was that ASB supplements remarkably attenuated the Cd-induced effects. We conclude that the Cd treatment promoted an imbalance of the antioxidant status and activated the PI3K/Akt pathway, leading to necroptosis in chicken peripheral blood lymphocytes, and that ASB was able to partially ameliorate the effect of Cd-induced necroptosis.


Assuntos
Cádmio/toxicidade , Flavonóis/farmacologia , Necroptose/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Animais , Antioxidantes/metabolismo , Cádmio/metabolismo , Galinhas/metabolismo , Feminino , Linfócitos/efeitos dos fármacos , Linfócitos/enzimologia , Linfócitos/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Substâncias Protetoras/farmacologia , Proteínas Proto-Oncogênicas c-akt/metabolismo
7.
Nat Prod Res ; 34(6): 773-781, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30445848

RESUMO

New allelochemicals were identified through bio-guided fractionation from the ethyl acetate of seeds extracts, which was the most autotoxic compared to the other plant parts. Phytochemical investigation of the seeds extracts of C. arabica by spectroscopy analyses has led to identify two new dammarane type triterpenes (4 and 9), with nine known analogues (1 - 3, 5 - 8, 10 and 11), a new cucurbitane triterpene (12), acylated dehydrodiconiferyl alcohol (13), and three highly oxygenated flavonols (14-16). The most autotoxic compounds on germination and seedling growth were elucidated as dammarane type triterpenes. However, less autotoxic effect was recorded by an inhibition under 50% for most of the identified flavonoids. These results suggest that those autotoxic substances may be used as a new bio-herbicide that may contribute to manage the distribution of C. arabica in agronomic field.[Formula: see text].


Assuntos
Cleome/efeitos dos fármacos , Herbicidas/isolamento & purificação , Feromônios/farmacologia , Triterpenos/isolamento & purificação , Flavonóis/isolamento & purificação , Germinação/efeitos dos fármacos , Glicosídeos/isolamento & purificação , Herbicidas/química , Extratos Vegetais/química , Plântula/efeitos dos fármacos , Sementes/química , Triterpenos/química , Triterpenos/farmacologia
8.
Food Chem ; 311: 125881, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-31767487

RESUMO

The quality of a wine largely depends on the balance between its sourness, bitterness and sweetness. Recently, epi-dihydrophaseic acid-3'-O-ß-glucopyranoside (epi-DPA-G) and astilbin, two molecules obtained from grapes, have been shown to contribute notably to the sweet taste of dry wines. To study the parameters likely to affect their concentration, a new method was developed and optimized by LC-FTMS. Three gradients and five C18 columns were tested. Good results in terms of linearity (r2 > 0.9980), repeatability (RSD ≤ 3%), recovery (≥89%) and LOQ (≤20 µg.L-1) were obtained. The method was used to screen epi-DPA-G and astilbin in red wines of several vintages over one century. Both compounds were detected in all wines at concentrations varying from 1.2 to 14.7 mg/L for epi-DPA-G and from 0.5 to 42.6 mg/L for astilbin. Therefore, this new method can be used to quantify epi-DPA-G and astilbin reliably in wine.


Assuntos
Cromatografia Líquida de Alta Pressão , Espectrometria de Massas , Edulcorantes/análise , Vinho/análise , Ácidos Graxos Insaturados/análise , Flavonóis/análise , Glucosídeos/análise , Limite de Detecção , Reprodutibilidade dos Testes , Paladar , Vitis/química , Vitis/metabolismo
9.
Plant Physiol Biochem ; 146: 259-268, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31778931

RESUMO

The HD-ZIP Ⅳ transcription factors have been identified and functional characterized in many plant species. However, no tobacco HD-ZIP IV gene has been isolated, and it is not yet known whether HD-ZIP IV genes are involved in controlling flavonols accumulation in plants. Here, we cloned a HD ZIP gene named NtHDG2 from Nicotiana tabacum, which belongs to the class IV of HD-ZIP family, and the NtHDG2-GFP fusion protein is localized to the nucleus. We further observed that the flavonols contents in the NtHDG2 overexpression leaves increase to 1.9-4.5 folds of that in WT plants, but in the NtHDG2-RNAi plants the flavonols contents reduce to 20.9%-52.7% of that in WT plants. The transcriptions of one regulatory gene NtMYB12, and three structural genes (NtPAL, NtF3'H, NtF3GT), contributing to flavonols biosynthesis, were significantly induced by NtHDG2. However, the transcription level of NtNAC002, a flavonols biosynthesis repressor, was also significantly up-regulated in NtHDG2-overexpression lines, but significantly down-regulated in the RNAi lines, indicating that HDG2 regulates the synthesis of flavonols as a complex regulatory network. Moreover, ectopic expression of NtHDG2 gene promoted the transcription of several AP2/ERF genes, including NtERF1-5, NtERF109, NtDREB1, and NtCIPK11, which participate in regulating root development and resistance to abiotic stresses. Our findings reveal the new function of HD-ZIP IV transcription factors in flavonoids biosynthesis, and indicate that HD-ZIP IV members may play an important role in plant resistance to abiotic stress. The NtHDG2 gene provides a promising target for genetically manipulating to increase the amounts of flavonols in tobacco leaves.


Assuntos
Tabaco , Flavonóis , Regulação da Expressão Gênica de Plantas , Proteínas de Homeodomínio , Zíper de Leucina , Proteínas de Plantas , Estresse Fisiológico , Fatores de Transcrição
10.
Food Chem ; 311: 125895, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-31780220

RESUMO

Pile-fermentation is the most important process of producing ripened pu-erh tea. To study the chemical changes of tea leaves during pile-fermentation (PF), liquid chromatography coupled with tandem mass spectrometry (LC-MS) was used. Untargeted metabolomics analysis revealed that the first stage of PF is crucial in transforming the original secondary metabolites, whereas the contents of flavan-3-ols and gallic acid were decreased after long-term PF. Targeted metabolomics analysis indicated that the levels of puerins (N-ethyl-2-pyrrolidinone substituted gallocatechin and catechin) were significant increased after the first stage of PF, but after long-term PF the levels of flavonol glycosides, procyanidins and galloylated flavan-3-ols were significantly decreased. Accordingly, long-term PF also decreased the inhibition of α-amylase and α-glucosidase activities of the extracts. As a conclusion, pile-fermentation is an important step of changing the polyphenols and bioactivities of pu-erh tea.


Assuntos
Camellia/metabolismo , Metabolômica , Amilases/antagonistas & inibidores , Amilases/metabolismo , Camellia/química , Análise por Conglomerados , Fermentação , Flavonóis/metabolismo , Ácido Gálico/metabolismo , Glicosídeos/metabolismo , Análise dos Mínimos Quadrados , Extratos Vegetais/química , Extratos Vegetais/metabolismo , Folhas de Planta/química , Folhas de Planta/metabolismo , Análise de Componente Principal , Proantocianidinas/metabolismo
11.
Food Chem ; 307: 125518, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31644976

RESUMO

The Greek vineyard is home to many minor, indigenous grape cultivar whose diverse polyphenolic content has remained largely unexploited. The study aimed at assaying and assessing the polyphenolic content and antioxidant capacity of: (a) five obscure cultivars; (b) Six biotypes of cultivar 'Liatiko'; (c) Five prominent cultivars; and (d) three French varieties included for comparison reasons. Results revealed all samples exhibiting high polyphenol content and antioxidant capacity levels. 'Vertzami' recorded the highest concentrations in berry skins total anthocyanins, flavanols, flavonols, antioxidant capacity. 'Mandilaria' scored the highest value in seed total flavanols compared to all biotypes and cultivars. All 'Liatiko' biotypes scored the highest concentrations in seed total flavonoids and flavonols. 'Liatiko' and its biotypes exhibited different polyphenolic profiles between them. Owing to the climate change, those indigenous varieties' substantial polyphenol amounts, and the differences between biotypes, will allow viticulturists to select the varieties/biotypes most appropriate for obtaining higher quality products.


Assuntos
Antioxidantes/química , Polifenóis/química , Vitis/química , Antocianinas/análise , Mudança Climática , Flavonoides/análise , Flavonóis/análise , Frutas/química , Frutas/metabolismo , Grécia , Polifenóis/análise , Sementes/química , Sementes/metabolismo , Vitis/metabolismo
12.
Food Chem ; 309: 125766, 2020 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-31718836

RESUMO

This study aimed to identify by UPLC-PDA-Q/TOF-MS and quantify by UPLC-PDA phenolic compounds (26 flavonols and 2 phenolic acids) and carotenoids (16) from berries of different cultivars of Hippophaë rhamnoides and determine correlations between these variables and in vitro anticholinergic and on-line antioxidant potential. Isorhamnetin derivatives presented over 65% of total flavonols, but quercetin and kaempferol derivatives were also determined. Carotenes accounted for 19 to 47%, xanthophylls 16 to 81% of total carotenoids. Pearson's correlations between AChE and BuChE inhibition and phenolic acid content were low (r = 0.388 and 0.355), moderate for carotenoids (0.504 and 0.437) and high for flavonols (0.851 and 0.614). The PCA biplot showed the highest correlation between anticholinergic activity and all-trans-ß-cryptoxanthin, quercetin-3-O-glucoside, isorhamnetin-3-O-(2-rhamnosyl)glucoside, kaempferol-3-O-hexoside-7-O-rhamnoside, isorhamnetin-3-O-(6-rhamnosyl)hexoside, isorhamnetin-3-O-rutinoside, and isorhamnetin-3-O-glucoside concentrations. The results obtained can be used to identify sea buckthorn cultivars, develop crops and production, and design functional products rich in flavonols and carotenoids with anticholinergic properties.


Assuntos
Antioxidantes/química , Carotenoides/análise , Inibidores da Colinesterase/análise , Cromatografia Líquida de Alta Pressão/métodos , Hippophae/química , Fenóis/análise , Acetilcolinesterase/química , Acetilcolinesterase/metabolismo , Butirilcolinesterase/química , Butirilcolinesterase/metabolismo , Inibidores da Colinesterase/química , Flavonóis/análise , Frutas/química , Frutas/metabolismo , Hippophae/metabolismo , Análise de Componente Principal
13.
Food Chem ; 311: 125969, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-31864186

RESUMO

The polyphenolic content in date seeds, a promising functional ingredient for food, was characterised in three forms viz., date seed powder (DSP), date seed pita bread (DSB) and date seed extract (DSE). Bioaccessibility of the polyphenols from the samples was assessed by in-vitro digestion coupled with transport using Caco-2 cells. HPLC-ESI-UV/MS/MS-(IT) analysis recorded the presence of phenolic acids, flavanols, flavonols and flavones. Flavan-3-ols was the most significant group with the highest concentration in DSP, 47.91 ± 0.13 g/kg, after depolymerisation. Phenolic acids such as protocatechuic acid, vanillic acid and caffeoylshikimic acid were recovered from DSP and DSE after in-vitro digestion. In comparison, the recovery was significantly lower in the bread sample. Similarly, transport of protocatechuic acid, p-hydroxybenzoic acid, caffeoylshikimic acid, p-coumaric acid, syringic acid hexoside and diosmin through Caco-2 monolayer was observed in DSP and DSE, while protocatechuic acid and p-hydroxybenzoic acid were the only polyphenols transported from digested DSB.


Assuntos
Cromatografia Líquida de Alta Pressão , Phoeniceae/química , Polifenóis/análise , Espectrometria de Massas em Tandem , Células CACO-2 , Flavonas/análise , Flavonóis/análise , Humanos , Hidroxibenzoatos/análise , Phoeniceae/metabolismo , Polifenóis/metabolismo , Sementes/química , Sementes/metabolismo
14.
J Agric Food Chem ; 68(1): 323-331, 2020 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-31880932

RESUMO

4G-α-Glucopyranosylrutin (monoglucosylrutin, MGR) is a flavonol glycoside with quercetin as an aglycone, is pale yellow in color, and engages in both copigmentation and anticopigmentation. In this study, we elucidated the mechanism underlying the copigmentation of MGR upon complexation with caffeine. Three approaches were used: binding analyses based on changes in the absorbance spectrum, NOESY experiments, and DFT and TDDFT calculations using an explicit solvation model. Our findings show that copigmentation mainly results from a bathochromic shift in the absorbance spectrum and not a from hyperchromic effect. MGR and caffeine form a complex in both 1:1 and 1:2 stoichiometric ratios. The calculated optimized 1:1 and 1:2 complex structures were supported by the NOESY spectrum and form a cluster with 13 and 11 water molecules, respectively, through hydrogen bonds. Although HOMO and LUMO contribute most to the excitation of both the MGR monomer and the complexes, these frontier molecular orbitals in the complexes are distributed more widely than those in the MGR monomer. In particular, LUMO in the complexes spreads into the copigment caffeine and the solvent water molecules. This increase in electron delocalization reduces the energy gap between the frontier molecular orbitals, resulting in copigmentation with a bathochromic shift.


Assuntos
Cafeína/química , Flavonóis/química , Glucosídeos/química , Cor , Ligação de Hidrogênio
15.
J Sci Food Agric ; 100(1): 401-409, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31637723

RESUMO

BACKGROUND: It is widely recognized that ambient levels of solar ultraviolet (UV) radiation strongly influence the phenolic composition of grape skins. However, it is unknown to what extent this influence is reflected in the resulting wines. RESULTS: Tempranillo grapevines were exposed or non-exposed to close-to-ambient solar UV levels using appropriate filters, and the phenolic profiles and antioxidant capacity of both grape skins and the resulting wines were analyzed. In total, 47 phenolic compounds were identified in skins and wines, including flavonols, anthocyanins, flavanols, stilbenes, and hydroxycinnamic and hydroxybenzoic acids. In UV-exposed grape skins, flavonols and anthocyanins increased, whereas flavanols and hydroxybenzoic acids showed no significant change. These characteristics were conserved in the resulting wines. However, for stilbenes, hydroxycinnamic acids and antioxidant capacity, the effect of UV on grape skins was not conserved in wines, probably as a result of changes during winemaking. In addition, color intensity, total phenols and total polyphenol index of wines elaborated from UV-exposed grapes increased (although non-significantly) compared to those made from non-UV-exposed grapes. CONCLUSION: The phenolic composition of grape skins exposed to close-to-ambient solar UV could predict, to some extent, the phenolic composition of the resulting wines, particularly regarding higher contents of flavonols and anthocyanins. Thus, manipulating the UV radiation received by grape skins could improve wine quality by positively influencing color stability and healthy properties. To our knowledge, this is the first study in which the effects of solar UV radiation on phenolic composition have been assessed from grape skins to wine. © 2019 Society of Chemical Industry.


Assuntos
Frutas/efeitos da radiação , Fenóis/química , Vitis/química , Vinho/análise , Antocianinas/química , Antioxidantes/química , Flavonóis/química , Frutas/química , Polifenóis/química , Estilbenos/química , Raios Ultravioleta , Vitis/efeitos da radiação
16.
J Sci Food Agric ; 100(2): 825-835, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-31646642

RESUMO

BACKGROUND: Seaweeds are defined as novel elicitors in many crops, allowing the synthesis of secondary metabolites to be triggered in different plant tissues. Currently, the phenolic composition of Tempranillo Blanco grapes and wines is unreported. The present study aimed to investigate the effects of an Ascophyllum nodosum seaweed extract applied to Tempranillo Blanco grapevines, at low (Ld) and high (Hd) dosages, on grape and wine phenolic compounds during two consecutive seasons (2017-2018). RESULTS: The results obtained showed that catechin was the most abundant phenolic compound in Tempranillo Blanco grapes and wines. Season affected the weight of 100 berries and some enological parameters. Catechin and flavonols concentrations in grapes were increased after Hd application to grapevines, independently of season. The concentration of hydroxycinnamic and hydroxybenzoic acids in wines was affected by vintage, probably as a result of oxidation reactions, as well as pinking phenomena, whereas the stilbenes content in wines was conditioned by the affect of cryptogamic diseases in grapes. CONCLUSION: Seaweeds might act as an elicitor of several phenolic compounds in grapes, enhancing the content of some phenolic compounds in wines. © 2019 Society of Chemical Industry.


Assuntos
Feófitas/química , Fenóis/química , Extratos Vegetais/farmacologia , Alga Marinha/química , Vitis/química , Cromatografia Líquida de Alta Pressão , Fertilizantes/análise , Flavonóis/análise , Flavonóis/metabolismo , Frutas/química , Frutas/efeitos dos fármacos , Frutas/metabolismo , Fenóis/metabolismo , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Estilbenos/análise , Estilbenos/metabolismo , Vitis/efeitos dos fármacos , Vitis/metabolismo , Vinho/análise
17.
Food Chem ; 305: 125430, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31518840

RESUMO

The distributions of total soluble solids, pectins, the sum of polyphenolic and terpenoid compounds as well as the antioxidative potency of fruit and their parts, such as peel, flesh, and seeds of Saskatoon berry genotypes are presented in this work. The contents of individual bioactive compounds of in this fruit fraction of Saskatoon berry cultivars and cultivation clones significantly depended on berry genotype and compounds distribution within particular parts of the fruit. The fruit peel contained mainly anthocyanins, polymerized compounds, hydroxycinnamic acids, triterpenoids, and tetraterpenids, as well as exhibited antioxidant activity. The major compounds identified in the fruit flesh included soluble solids, ash, flavonols. In turn, polymeric procyanidins was determined in the seeds of fruit. Individual parts of Saskatoon berry fruit contained many health-promoting constituents and could be deemed attractive materials for the production of functional foods or dietary supplements.


Assuntos
Antioxidantes/análise , Frutas/química , Compostos Fitoquímicos/análise , Rosaceae/química , Antocianinas/análise , Ácidos Cumáricos/análise , Flavonóis/análise , Proantocianidinas/análise , Sementes/química , Terpenos/análise
18.
Food Chem ; 310: 125912, 2020 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-31841938

RESUMO

Apples cv. 'Jonagold' of the same quality were collected from four orchards in three European countries. The orchards differed in terms of longitude, latitude and microclimate. The apples were stored in controlled atmosphere storage for six months. Both after harvest and after storage the apples were compared in terms of physical and chemical properties. Differences in firmness, titratable acidity, total soluble solids, mass varied not >11%. Storability was little affected by harvest location. The sum of polyphenols was more strongly influenced by storage than by orchard location. The strongest degradation of flavonols after storage was in apples grown in the most southern region of harvest (Italy). The content of (+)- catechin and (-)-epicatechin depended on harvest location and its strong increase resulted in higher content of procyanidins and flavanols after storage. Changes in individual polyphenols were significant after storage and depended on harvest location.


Assuntos
Antioxidantes/análise , Malus/química , Fenóis/análise , Catequina/análise , Europa (Continente) , Flavonóis/análise , Armazenamento de Alimentos/métodos , Frutas/química , Polifenóis/análise
19.
Food Chem ; 311: 125902, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-31865113

RESUMO

Phosphate buffered saline (PBS) is a commonly used buffer in biological research. Herein, the stability of a series of flavonoids, i.e. myricetin, kaempferol, baicalein, luteolin and quercetin, were assessed in PBS within 5 s. Apigenin proved very stable in PBS and was therefore used as a control. Kaempferol and baicalein were less stable with small amounts of oxidized and hydroxylated products being detected. The other flavonoids were unstable and their dimers were identified in PBS at 4 °C under normal atmospheric conditions. Flavonols with a catechol or pyrogallol substitution pattern on ring B readily formed stable dimers and oxidized products in PBS (pH = 7.4) at 4 °C within 5 s. The chosen experimental conditions improved the stability of dimers and allowed their detection.


Assuntos
Catecóis/química , Flavonóis/química , Pirogalol/química , Tampões (Química) , Temperatura Baixa , Dimerização , Flavanonas/química , Flavonoides , Quempferóis/química , Luteolina/química , Estrutura Molecular , Oxirredução , Fosfatos/química , Quercetina/química
20.
Molecules ; 24(23)2019 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-31783632

RESUMO

Climate models predict an increase in the frequency and duration of heatwaves with an increase in intensity already strongly evident worldwide. The aim of this work was to evaluate the effect of two heatwave-related parameters (intensity and duration) during berry ripening and identify a threshold for berry survival and flavonoid accumulation. A Doehlert experimental design was used to test three temperature intensities (maxima of 35, 46, and 54 °C) and five durations (3 to 39 h), with treatments applied at the bunch level shortly after véraison. Berry skin and seeds were analysed by liquid chromatography-triple quadrupole-mass spectrometry (LC-QqQ-MS) for flavonoids (flavonols, anthocyanins, free flavan-3-ols, and tannins). Berries exposed to 46 °C showed little difference compared to 35 °C. However, berries reaching temperatures around 54 °C were completely desiccated, and all flavonoids were significantly decreased except for skin flavonols on a per berry basis and seed tannins in most cases. Some compounds, such as dihydroxylated flavonoids and galloylated flavan-3-ols (free and polymerised), were in higher proportion in damaged berries suggesting they were less degraded or more synthesised upon heating. Overall, irreversible berry damages and substantial compositional changes were observed and the berry survival threshold was estimated at around 50-53 °C for mid-ripe Shiraz berries, regardless of the duration of exposure.


Assuntos
Antocianinas/análise , Flavonoides/análise , Flavonóis/análise , Frutas/química , Temperatura Alta/efeitos adversos , Taninos/análise , Vitis/química , Antocianinas/química , Antocianinas/metabolismo , Cromatografia Líquida de Alta Pressão , Flavonoides/metabolismo , Flavonóis/química , Flavonóis/metabolismo , Frutas/crescimento & desenvolvimento , Frutas/metabolismo , Espectrometria de Massas , Sementes/química , Taninos/metabolismo , Fatores de Tempo , Vitis/fisiologia
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