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1.
J Agric Food Chem ; 68(28): 7434-7443, 2020 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-32564600

RESUMO

During barrel aging, wines and spirits undergo sensory changes as a result of the release of aroma and taste molecules. Among the nonvolatile compounds, various coumarins have already been identified in oak wood but their sensory role remained unclear. In this study, the presence of coumarins in oak wood extract, wine, and spirits was first assessed by targeted screening. Fraxetin was identified for the first time in these matrices. After development and validation of a liquid chromatography-high-resolution mass spectrometry quantitation method, esculetin, scopoletin, fraxetin, umbelliferone, 4-methylumbelliferone, and coumarin were assayed in various wines and spirits. The concentrations measured were generally below the gustatory detection thresholds determined in wines and spirits. Nevertheless, by adding a mixture of coumarins in wines and spirits, a significant increase in bitterness was observed, thus demonstrating their potential contribution to the taste of wines and spirits through perceptive interactions.

2.
Anal Bioanal Chem ; 412(17): 4195-4207, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32377866

RESUMO

To mimic the activity of hyaluronidase in natural environment, the hydrolysis of hyaluronic acid (HA) by hyaluronidase was investigated for the first time in the presence of crowding agents using capillary electrophoresis (CE) as a simple and reliable technique for conducting enzymatic assay. Polyethylene glycol (PEG) 6000 was selected as a model crowder and the hyaluronic acid degradation catalyzed by bovine testes hyaluronidase (BTH) was carried out at different PEG concentrations (0%, 10%, and 17%). After optimization of the CE analytical method and enzymatic assay, the degradation products were monitored at different HA concentrations. At 10% of PEG and 0.3 mg mL-1 of HA, the activity of the enzyme was significantly reduced showing inconvenient interactions of PEG with the hyaluronidase blocking the release of hydrolysis products. A similar reduction of hyaluronidase activity was observed at 1 mg mL-1 of HA due to the presumable formation of the BTH-substrate complex. The experimental curves obtained by CE also evidence that the overall kinetics are governed by the hydrolysis of hexasaccharide intermediates. Finally, the effect of PEG on hyaluronidase activity was evaluated in the presence of natural or synthetic inhibitors. Our results show a significant difference of the inhibitors' affinity toward hyaluronidase in the presence of PEG. Surprisingly, the presence of the crowding agent results in a loss of the inhibition effect of small polycyclic inhibitors, while larger charged inhibitors were less affected. In this work, CE analyses confirm the importance of mimicking the cellular environment for the discovery and development of reliable inhibitors. Graphical abstract.

3.
J Nat Prod ; 83(5): 1611-1622, 2020 05 22.
Artigo em Inglês | MEDLINE | ID: mdl-32343138

RESUMO

Six new triterpenoids (1-6), two known genins (7 and 8), and five known functionalized triterpenoids (9-13) were isolated from a Quercus robur heartwood extract. The purification protocol was guided by LC-HRMS by searching for structural analogues of bartogenic acid on the basis of their putative empirical formula. The structures of the new compounds were unequivocally elucidated using HRESIMS and 1D/2D NMR experiments. Sensory analyses were performed in water and in a non-oaked white wine on the pure compounds 1-13 at 5 mg/L. All molecules were perceived as bitter in water and wine, but they were mostly reported as modifying the wine taste balance. Using LC-HRMS, compounds 1-13 were observed in oaked red wine and cognac and were semiquantified in oak wood extracts. The influence of two cooperage parameters, oak species and toasting process, on compounds 1-13 content was studied. All compounds were found in quantities significantly higher in pedunculate than in sessile oak wood. Toasting is a key step in barrel manufacture and modulates the concentration of the discussed compounds. Significantly higher quantities were observed in untoasted wood compared to medium or highly toasted wood. These findings provide new insights into the molecular origin of taste changes due to oak aging.

4.
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
5.
J Nat Prod ; 82(2): 265-275, 2019 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-30689385

RESUMO

Eight new triterpenoids (1-8), the known genin (9), and two known functionalized triterpenoids (10 and 11) were isolated from a Quercus petraea heartwood extract. The structures of the new compounds were unequivocally elucidated using HRESIMS and 1D/2D NMR experiments. Sensory analyses were performed in a non-oaked wine on the pure compounds 1-11. Except compounds 1 and 11, all molecules exhibited a sweet taste at 5 mg/L that was particularly intense for compounds 3 and 9. Using LC-HRMS, compounds 1-11 were observed in an oak wood extract and in oaked red wine and cognac. They were also semiquantified in several samples of sessile ( Q. petraea) and pedunculate ( Q. robur) oak wood extract. All compounds were found in quantities significantly higher in sessile than in pedunculate oak wood. These results support the hypothesis of their contribution to the increase in sweetness during oak aging and show that they can be used as chemical markers to identify the species of oak used for cooperage.


Assuntos
Quercus/química , Triterpenos/isolamento & purificação , Vinho/análise , Espectroscopia de Ressonância Magnética , Extratos Vegetais/análise , Paladar , Triterpenos/análise , Triterpenos/química , Madeira/química
6.
Food Chem ; 272: 388-395, 2019 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-30309559

RESUMO

This work aimed at improving knowledge about sweetness in dry wines. Following on from the empirical observations of winegrowers, we assessed the contribution of grape seeds to wine sensory properties. An inductive fractionation method guided by gustatometry was used to isolate and characterize sweet-tasting compounds from grapes. Fractionation of grape seed macerates was achieved by liquid-liquid extraction, centrifugal partition chromatography (CPC) and preparative HPLC. Then, the structures of the purified compounds were elucidated by use of FTMS and NMR. Five compounds were identified: two new compounds, 2-hydroxy-3-methylpentanoic-2-O-ß-glucopyranoside (H3MP-G) and 2-hydroxy-4-methylpentanoic-2-O-ß-glucopyranoside acids (H4MP-G), along with gallic-4-O-ß-glucopyranoside acid (AG-G), 3-indolyl-(2R)-O-ß-d-glycoside lactic acid (ILA-G) and epi-DPA-3'-O-ß-glucopyranoside acid (epi-DPA-G). These compounds exhibited various levels of sweetness in a hydro-ethanolic solution and in white and red wines. Additionally, H3MP-G, H4MP-G and epi-DPA-G were identified for the first time in grapes and wines, whereas AG-G has already been reported in white grapes but never in wine.


Assuntos
Compostos Orgânicos/química , Compostos Orgânicos/isolamento & purificação , Sementes/química , Paladar/efeitos dos fármacos , Vitis/química , Vinho/análise , Antioxidantes/análise , Cromatografia Líquida de Alta Pressão , Compostos Orgânicos/farmacologia
7.
Nutrients ; 10(11)2018 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-30400351

RESUMO

BACKGROUND: Recent studies showed that trans-ε-viniferin (ε-viniferin), a trans-resveratrol dehydrodimer, has anti-inflammatory and anti-obesity effects in rodents. The main purpose of this work was to assess the tissue distribution study of ε-viniferin and its metabolites after intraperitoneal (IP) administration in rat. METHODS: After IP injection of 50 mg/kg, ε-viniferin and its metabolites were identified and quantified in plasma, liver, kidneys, adipose tissues, urine, and faeces by Liquid Chromatography-High Resolution Mass Spectrometry (LC-HRMS). RESULTS: ε-Viniferin underwent a rapid hepatic metabolism mostly to glucuronides but also to a lesser extent to sulphate derivatives. The highest glucuronide concentrations were found in liver followed by plasma and kidneys whereas only traces amounts were found in adipose tissues. In contrast the highest ε-viniferin areas under concentration (AUC) and mean residence times (MRT) values were found in white adipose tissues. Finally, much lower levels of ε-viniferin or its metabolites were found in urine than in faeces, suggesting that biliary excretion is the main elimination pathway. CONCLUSION: A rapid and large metabolism of ε-viniferin and a high bioaccumulation in white adipose tissues were observed. Thus, these tissues could be a reservoir of the native form of ε-viniferin that could allow its slow release and a sustained presence within the organism.


Assuntos
Benzofuranos/farmacocinética , Estilbenos/farmacocinética , Adiposidade , Animais , Benzofuranos/administração & dosagem , Cromatografia Líquida , Relação Dose-Resposta a Droga , Fezes/química , Glucuronídeos/metabolismo , Injeções Intraperitoneais , Rim/metabolismo , Fígado/metabolismo , Masculino , Ratos , Ratos Wistar , Estilbenos/administração & dosagem
8.
Appl Microbiol Biotechnol ; 102(9): 3995-4007, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29552694

RESUMO

The concept of wine complexity has gained considerable interest in recent years, both for wine consumers and wine scientists. As a consequence, some research programs concentrate on the factors that could improve the perceived complexity of a wine. Notably, the possible influence of microbiological factors is particularly investigated. However, wine complexity is a multicomponent concept not easily defined. In this review, we first describe the actual knowledge regarding wine complexity, its perception, and wine chemical composition. In particular, we emphasize that, contrary to expectations, the perception of wine complexity is not related to wine chemical complexity. Then, we review the impact of wine microorganisms on wine complexity, with a specific focus on publications including sensory analyses. While microorganisms definitively can impact wine complexity, the underlying mechanisms and molecules are far from being deciphered. Finally, we discuss some prospective research fields that will help improving our understanding of wine complexity, including perceptive interactions, microbial interactions, and other challenging phenomena.


Assuntos
Microbiologia de Alimentos , Vinho/microbiologia , Pesquisa/tendências
9.
Molecules ; 24(1)2018 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-30598007

RESUMO

During barrel aging, spirits undergo organoleptic changes caused by the release of aroma and taste compounds. Recently, studies have revealed the bitter properties of oak wood lignans, such as (±)-lyoniresinol, and their contribution to wine taste. To evaluate the impact of lignans in spirits, a targeted screening of 11 compounds was set up and served to validate their presence in this matrix, implying their release by oak wood during aging. After development and validation of a quantification method, the most abundant and the bitterest lignan, (±)-lyoniresinol, was assayed by liquid chromatography⁻high resolution mass spectrometry (LC-HRMS) in spirits. Its gustatory detection threshold was established at 2.6 mg/L in spirits. A large number of samples quantified were above this detection threshold, which suggests its effect of increased bitterness in spirit taste. Significant variations were observed in commercial spirits, with concentrations ranging from 0.2 to 11.8 mg/L, which could be related to differences in barrel aging processes. In "eaux-de-vie" of cognac, concentrations of (±)-lyoniresinol were observed in the range from 1.6 mg/L to 12 mg/L. Lower concentrations were measured for older vintages.


Assuntos
Bebidas Alcoólicas/análise , Lignanas/análise , Lignanas/química , Anisóis/análise , Cromatografia Líquida , Espectrometria de Massas , Estrutura Molecular , Naftalenos/análise , Odorantes/análise , Quercus/química , Paladar , Madeira/química
10.
Food Chem ; 239: 252-259, 2018 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-28873567

RESUMO

This research investigated the influence of lactic acid bacteria (LAB) strains on ester levels in Bordeaux red wines. These wines were made in five Bordeaux areas in two vintages, using three yeast strains. Malolactic fermentation (MLF) was carried out using industrial starters or indigenous strains, each in triplicate. Ester concentrations were determined by liquid-liquid-extraction- or HS-SPME-GC/MS at various stages in the winemaking process. The levels of most compounds were slightly impacted by LAB, depending on grape variety. Nevertheless, branched hydroxylated esters, such as ethyl 2-hydroxy-3-methylbutanoate and ethyl 2-hydroxy-4-methylpentanoate were the only compounds to be strongly influenced by the bacteria strain, regardless of matrix composition or the yeasts used for alcoholic fermentation. Moreover, the effect observed after MLF persisted over time, for at least 12months. These esters are apparently important markers of LAB esterase activity. To our knowledge, this was the first time they had been identified in this role.


Assuntos
Ácido Láctico/metabolismo , Fermentação , Valeratos , Vitis , Vinho
11.
Phytochemistry ; 146: 47-55, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29223063

RESUMO

A phytochemical investigation of the trunk bark ethyl acetate extract of Citharexylum spinosum L. has led to the isolation of four previously undescribed iridoid glycosides, tunispinosides A-D, and five known phenylethanoid glycosides, verbascoside, leucosceptoside A, martynoside, isoverbascoside and plantainoside C, together with 4-hydroxy-2,6-dimethoxyphenyl 6'-O-vanilloyl-ß-D-glucopyranoside, two 8,3'-neolignan glycosides, plucheosides D1-D2, coniferyl aldehyde, vanillic acid, syringic acid, ferulic acid and tyrosol. All compounds were isolated for the first time from C. spinosum. Their isolation was carried out using silica gel column and high performance liquid chromatography (HPLC). Structures were established by spectroscopic means including 1D and 2D NMR experiments, and spectrometric ESI-HRMS analysis.


Assuntos
Glicosídeos Iridoides/isolamento & purificação , Compostos Fitoquímicos/isolamento & purificação , Casca de Planta/química , Verbenaceae/química , Glicosídeos Iridoides/química , Estrutura Molecular , Compostos Fitoquímicos/química , Tunísia
12.
J Agric Food Chem ; 65(37): 8154-8161, 2017 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-28871789

RESUMO

Hsp12 is a small heat shock protein produced in many organisms, including the yeast Saccharomyces cerevisiae. It has been described as an indicator of yeast stress rate and has also been linked to the sweetness sensation of wine. To obtain a sufficient amount of protein, we produced and purified Hsp12 without tag in Escherichia coli. A simple fast two-step process was developed using a microplate approach and a design of experiments. A capture step on an anion-exchange salt-tolerant resin was followed by size exclusion chromatography for polishing, leading to a purity of 97%. Thereafter, specific anti-Hsp12 antibodies were obtained by rabbit immunization. An ELISA was developed to quantify Hsp12 in various strains of Saccharomyces cerevisiae. The antibodies showed high specificity and allowed the quantitation of Hsp12 in the yeast. The quantities of Hsp12 measured in the strains differed in direct proportion to the level of expression found in previous studies.


Assuntos
Escherichia coli/genética , Proteínas de Choque Térmico/genética , Proteínas de Choque Térmico/isolamento & purificação , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/isolamento & purificação , Saccharomyces cerevisiae/genética , Cromatografia por Troca Iônica , Escherichia coli/metabolismo , Expressão Gênica , Proteínas de Choque Térmico/metabolismo , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo
13.
J Agric Food Chem ; 65(5): 1058-1069, 2017 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-28064486

RESUMO

Chardonnay wines impart a unique complex aroma characterized by its buttery, yellow stone fruit, melon, bready, and woody notes. Among the terms used in the sensory analysis of these wines, this study investigated hazelnut-like attributes. Multidimensional gas chromatography coupled to olfactometry identified five pyrroles reminiscent of hazelnut: 1-ethylpyrrole-2-carboxaldehyde, 1H-pyrrole, 2-acetyl-1H-pyrrole (first identification in wine), 1-methylpyrrole-2-carboxaldehyde, and 1H-pyrrole-2-carboxaldehyde. Quantitative analyses demonstrated their significantly higher abundance in Chardonnay wines. However, they proved irrelevant in sensory terms, given the low amounts measured in wine compared to their olfactory detection threshold. Nevertheless, the presence of methanethiol derivatives from these pyrroles was investigated in wine. 1-Methylpyrrole-2-methanethiol and 1-ethylpyrrole-2-methanethiol were identified and exhibited hazelnut-like aroma. These compounds, which have not been observed in natural products to date, are potent volatile compounds with detection thresholds of 0.7 and 1.4 ng/L, respectively, in model wine. These findings open up promising perspectives concerning the interpretation of the typical aromatic nuances of some Chardonnay wines.


Assuntos
Corylus/química , Compostos Orgânicos Voláteis/química , Vinho/análise , Cromatografia Gasosa , Humanos , Odorantes/análise , Olfatometria , Olfato , Paladar , Volatilização
14.
J Nat Prod ; 79(10): 2432-2438, 2016 10 28.
Artigo em Inglês | MEDLINE | ID: mdl-27684096

RESUMO

Quercoresinosides A and B (1 and 2), two new lignans, were isolated from a toasted Quercus petraea heartwood extract along with a known compound, 3-methoxy-4-hydroxyphenol 1-O-ß-d-(6'-O-galloyl)glucopyranoside (3). The purification protocol was based on a taste-guided approach that sought to reveal new bitter compounds released from oak wood into wines and spirits. HRMS and NMR data were used to establish that compounds 1 and 2 are lignan derivatives bearing a glucosyl unit and a galloyl unit at the same positions. Hydrolysis of these compounds showed that they could be distinguished by the absolute configuration of their respective lyoniresinol genin as determined by chiral LC-HRMS in comparison with (+)- and (-)-lyoniresinol standards. Sensory analyses were performed in a non-oaked wine on the pure compounds 1-3. The three molecules exhibited a bitter taste at 2 mg/L that was particularly intense for compounds 2 and 3. Finally, LC-HRMS demonstrated the occurrence of compounds 1-3 in oaked wine and brandy, which supports the hypothesis of their contributions to the increase in bitterness during oak aging.


Assuntos
Lignanas/isolamento & purificação , Quercus/química , Vinho , Anisóis , Cromatografia Líquida de Alta Pressão/métodos , Humanos , Lignanas/química , Estrutura Molecular , Naftalenos , Ressonância Magnética Nuclear Biomolecular , Paladar , Madeira/química
15.
Anal Bioanal Chem ; 408(14): 3789-99, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-27000563

RESUMO

Wine taste balance evolves during oak aging by the release of volatile and non-volatile compounds from wood. Among them, an enantiomer of lyoniresinol, (+)-lyoniresinol, has been shown to exhibit bitterness. To evaluate the impact of (+)-lyoniresinol on wine taste, a two-step quantitation method was developed and validated. First, (±)-lyoniresinol was assayed in wines, spirits, and oak wood macerates by C-18 liquid chromatography-high resolution mass spectrometry (LC-HRMS). Then, the lyoniresinol enantiomeric ratio was determined by chiral LC-HRMS in order to calculate the (+)-lyoniresinol content. In red and white wines, the average concentrations of (+)-lyoniresinol were 1.9 and 0.8 mg/L, respectively. The enantiomer proportions were not affected by bottle aging, and lyoniresinol appeared to remain stable over time. The sensory study of (+)-lyoniresinol established its perception threshold at 0.46 mg/L in wine. All the commercial wines quantitated were above this perception threshold, demonstrating its impact on wine taste by an increase in bitterness. In spirits, (+)-lyoniresinol ranged from 2.0 to 10.0 mg/L and was found to be released continuously during oak aging. Finally, neither botanical origin nor toasting was found to significantly affect the (+)-lyoniresinol content of oak wood. Graphical abstract From oak wood to wine: evaluation of the influence of (+)-lyoniresinol on the bitterness of wines and spirits.


Assuntos
Bebidas Alcoólicas/análise , Anisóis/análise , Cromatografia Líquida/métodos , Espectrometria de Massas/métodos , Naftalenos/análise , Quercus/química , Vinho/análise , Madeira/química , Estereoisomerismo
16.
J Agric Food Chem ; 64(3): 618-26, 2016 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-26719914

RESUMO

Oak aging is a crucial step in winemaking during which the organoleptic properties of wine are modified. Various parameters affect the chemical composition of oak wood including botanical origin, which has been previously shown to be a determinant factor. This study focused on the development of a LC-HRMS method to assay four recently discovered taste-active triterpenes (three sweet and one bitter). The method was applied to evaluate the effect of oak species (Quercus petraea and Quercus robur) on the concentration of these molecules in wood. The results showed that sessile oak was richer in sweet triterpenes and poorer in the bitter one than pedunculate oak, with high interindividual variations within species. Furthermore, a triterpenoid index was calculated to reveal the triterpenoid composition of oak wood. This index appears to be a promising tool for the unambiguous discrimination of oak species and could offer new insights into oak wood selection by coopers and the monitoring of oak aging by winemakers.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Espectrometria de Massas/métodos , Quercus/química , Triterpenos/química , Madeira/química , Análise Discriminante , Quercus/classificação , Madeira/classificação
17.
Anal Chim Acta ; 888: 191-8, 2015 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-26320975

RESUMO

Wine expresses its beauty by sending a sensory message to the taster through molecules coming from grapes, yeast metabolism or oak wood. Among the compounds released during barrel aging, lyoniresinol has been recently reported as a relevant contributor to wine bitterness. As this lignan contains three stereogenic carbons, this work aimed at investigating the influence of stereochemistry on wine taste by combining analytical and sensorial techniques. First, an oak wood extract was screened by Liquid Chromatography-High Resolution Mass Spectrometry to target isomers separable in a symmetric environment and a diastereoisomer called epi-lyoniresinol was isolated for the first time. Then, an original racemic resolution based on natural xylose-derivatives was carried out to obtain lyoniresinol enantiomers. Chiroptical spectroscopic measurements associated with theoretical calculations allowed the unambiguous determination of their absolute configuration. The taste properties of all these stereoisomers revealed that only one lyoniresinol enantiomer is strongly bitter whereas the other one is tasteless and the diastereoisomer is slightly sweet. The presence of these three compounds was established in an oaked Bordeaux wine by chiral and non-chiral chromatography, suggesting the significant influence of stereochemistry on wine taste.


Assuntos
Anisóis/análise , Naftalenos/análise , Extratos Vegetais/química , Quercus/química , Percepção Gustatória , Vinho/análise , Madeira/química , Anisóis/química , Cromatografia Líquida , Distribuição Contracorrente , Humanos , Espectrometria de Massas , Naftalenos/química , Estereoisomerismo , Paladar
18.
Bioorg Med Chem Lett ; 25(18): 3825-30, 2015 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-26248805

RESUMO

A phytochemical investigation of the roots of Ononis angustissima L. (Fabaceae) offered to the bio-guided isolation of new isoflavone 3-(4-(glucopyranosyloxy)-5-hydroxy-2-methoxyphenyl)-7-hydroxy-4H-chromen-4-one 1, together with nine known compounds, ononin 2, formononetin 3, (+)-puerol A-2'-O-ß-D-glucose 4, (-)-puerol B-2'-O-ß-D-glucopyranose ((-)-sophoraside A) 5, (+)-puerol A 6, (-)-trifolirhizin 7, (-)-trifolirhizin-6'-O-malonate 8, (-)-maackiain 9 and (-)-medicarpin 10. Compounds 2-10 were isolated and identified for the first time in Ononis angustissima. We investigated antioxidant capacities of isolated molecules and results showed that compound 6 exhibited the highest antioxidant activity with IC50 values of 19.53 µg/mL, 28.29 µg/mL and 38.53 µg/mL by DPPH radical, ABTS radical cation and reducing power assay, respectively, and an interesting IC50 (20.45 µg/mL) of 1 against DPPH. In addition, the neuroprotective activity of six isolated molecules (4-7, 9, 10) were evaluated. Following the exposure of PC12 cells to Aß25-35, compounds 9 and 10 triggered a significant increase of cell viability and in a dose dependent manner.


Assuntos
Antioxidantes/farmacologia , Ononis/química , Extratos Vegetais/farmacologia , Raízes de Plantas/química , Animais , Antioxidantes/química , Antioxidantes/isolamento & purificação , Benzotiazóis/antagonistas & inibidores , Compostos de Bifenilo/antagonistas & inibidores , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Radicais Livres/antagonistas & inibidores , Estrutura Molecular , Células PC12 , Picratos/antagonistas & inibidores , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Ratos , Relação Estrutura-Atividade , Ácidos Sulfônicos/antagonistas & inibidores , Tunísia
20.
Anal Chim Acta ; 853: 425-434, 2015 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-25467487

RESUMO

Volatile and non-volatile molecules are directly responsible for the thrill and excitement provided by wine-tasting. Their elucidation requires powerful analytical techniques and innovative methodologies. In a recent work, two novel sweet compounds called quercotriterpenosides (QTT) were identified in oak wood used for wine-ageing. The aim of the present study is to discover structural analogs of such natural sweeteners in oak wood. For this purpose, an analytical approach was developed as an alternative to chemical synthesis. Orbitrap mass spectrometry proved to be a crucial technique both to demonstrate the presence of QTT analogs in oak wood by targeted screening and to guide the purification pathway of these molecules using complementary chromatographic tools. Four compounds were isolated and identified for the first time: two isomers, one glucosyl derivative and one galloyl derivative of QTT. Their tasting showed that only the two new isomers were sweet, thus demonstrating both the pertinence of the strategy and the influence of functional groups on gustatory properties. Finally, this paper presents some developments involving multistage Fourier transform mass spectrometry (FTMS) to provide solid structural information on these functional groups prior to any purification of compounds. Such analytical developments could be particularly useful for research on taste-active or bio-active products.


Assuntos
Produtos Biológicos/química , Análise de Fourier , Espectrometria de Massas/métodos , Quercus/química , Edulcorantes/química , Vinho , Madeira/química , Produtos Biológicos/análise , Produtos Biológicos/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Descoberta de Drogas , Isomerismo , Edulcorantes/análise , Edulcorantes/isolamento & purificação
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