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1.
Molecules ; 25(6)2020 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-32182987

RESUMO

The aim of this paper is to evaluate the physicochemical and microbiological properties of active thermoplastic starch-based materials. The extract obtained from grape cane waste was used as a source of stilbene bioactive components to enhance the functional properties of thermoplastic starch (TPS). The biomaterials were prepared by the compression molding technique and subjected to mechanical, thermal, antioxidant, and microbiological tests. The results showed that the addition of grape cane extract up to 15 wt% (TPS/WE15) did not significantly influence the thermal stability of obtained biomaterials, whereas mechanical resistance decreased. On the other side, among all tested pathogens, thermoplastic starch based materials showed antifungal activity toward Botrytis cinerea and antimicrobial activity toward Staphylococcus aureus, suggesting potential application in food packaging as an active biomaterial layer.


Assuntos
Embalagem de Alimentos , Extratos Vegetais/química , Plásticos/química , Amido/química , Temperatura , Vitis/química , Antioxidantes/análise , Botrytis/efeitos dos fármacos , Botrytis/crescimento & desenvolvimento , Testes de Sensibilidade Microbiana , Extratos Vegetais/farmacologia , Espectroscopia de Infravermelho com Transformada de Fourier , Staphylococcus aureus/efeitos dos fármacos , Amido/farmacologia , Termogravimetria
2.
J Sep Sci ; 40(17): 3487-3496, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28657140

RESUMO

Miniaturized sample pretreatments for the analysis of phenolic metabolites in plasma, involving protein precipitation, enzymatic deconjugation, extraction procedures, and different derivatization reactions were systematically evaluated. The analyses were conducted by gas chromatography with mass spectrometry for the evaluation of 40 diet-derived phenolic compounds. Enzyme purification was necessary for the phenolic deconjugation before extraction. Trimethylsilanization reagent and two different tetrabutylammonium salts for derivatization reactions were compared. The optimum reaction conditions were 50 µL of trimethylsilanization reagent at 90°C for 30 min, while tetrabutylammonium salts were associated with loss of sensitivity due to rapid activation of the inert gas chromatograph liner. Phenolic acids extractions from plasma were optimized. Optimal microextraction by packed sorbent performance was achieved using an octadecylsilyl packed bed and better recoveries for less polar compounds, such as methoxylated derivatives, were observed. Despite the low recovery for many analytes, repeatability using an automated extraction procedure in the gas chromatograph inlet was 2.5%. Instead, using liquid-liquid microextraction, better recoveries (80-110%) for all analytes were observed at the expense of repeatability (3.8-18.4%). The phenolic compounds in gerbil plasma samples, collected before and 4 h after the administration of a calafate extract, were analyzed with the optimized methodology.


Assuntos
Dieta , Cromatografia Gasosa-Espectrometria de Massas , Hidroxibenzoatos/sangue , Microextração em Fase Líquida , Animais , Gerbillinae
3.
Food Res Int ; 143: 110265, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33992366

RESUMO

Grape canes, also named vine shoots, are well-known viticultural byproducts containing high levels of phenolic compounds, which are associated with a broad range of health benefits. In this work, grape canes (Vitis vinifera cv. Pinot noir) were extracted in a 750 L pilot-plant reactor under the following conditions: temperature 80 °C, time 100 min, solid/liquid ratio 1:10. The comprehensive characterization of grape cane phenolic compounds was performed by liquid chromatography coupled to high-resolution/accurate mass measurement LTQ-Orbitrap mass spectrometry. A total of 44 compounds were identified and, 26 of them also quantified, consisting of phenolic acids and aldehydes (17), flavonoids (12), and stilbenoids (15). The most abundant class of phenolics were stilbenoids, among which (E)-ε-viniferin predominated. The phenolic profile of grape canes obtained using pilot plant extraction differed significantly from the results of laboratory-scale studies obtained previously. Additionally, we observed a high antioxidant capacity of grape cane pilot-plant extract measured by the radical antioxidant scavenging potential (ABTS+) (2209 ± 125 µmol TE/g DW) and oxygen radical absorbance capacity using fluorescein (ORAC-FL) (4612 ± 155 µmol TE/g DW). Grape cane pilot-plant extract for their phenolic profile may be used as a by-product for the development of novel nutraceutical and pharmaceutical products, improving the value and the sustainability of these residues.


Assuntos
Vitis , Bengala , Cromatografia Líquida , Espectrometria de Massas , Fenóis
4.
Antioxidants (Basel) ; 10(7)2021 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-34356363

RESUMO

Grape canes, the main byproducts of the viticulture industry, contain high-value bioactive phenolic compounds, whose application is limited by their instability and poorly solubility in water. Encapsulation in cyclodextrins allows these drawbacks to be overcome. In this work, a grape cane pilot-plant extract (GCPPE) was encapsulated in hydroxypropyl beta-cyclodextrin (HP-ß-CD) by a spray-drying technique and the formation of an inclusion complex was confirmed by microscopy and infrared spectroscopy. The phenolic profile of the complex was analyzed by LC-ESI-LTQ-Orbitrap-MS and the encapsulation efficiency of the phenolic compounds was determined. A total of 42 compounds were identified, including stilbenes, flavonoids, and phenolic acids, and a complex of (epi)catechin with ß-CD was detected, confirming the interaction between polyphenols and cyclodextrin. The encapsulation efficiency for the total extract was 80.5 ± 1.1%, with restrytisol showing the highest value (97.0 ± 0.6%) and (E)-resveratrol (32.7 ± 2.8%) the lowest value. The antioxidant capacity of the inclusion complex, determined by ORAC-FL, was 5300 ± 472 µmol TE/g DW, which was similar to the value obtained for the unencapsulated extract. This formulation might be used to improve the stability, solubility, and bioavailability of phenolic compounds of the GCPPE for water-soluble food and pharmaceutical applications.

5.
J Chromatogr A ; 1215(1-2): 1-7, 2008 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-19027907

RESUMO

Extraction of 2,4,6-tribromophenol (TBP), pentachlorophenol (PCP) and pentachloroanisole (PCA) from whole fat cow milk using headspace solid-phase microextraction (HS-SPME) with polyacrylate (PA) and polydimethylsiloxane (PDMS) fibers was evaluated and compared. The PA was studied to extract PCA, TBP and PCP, while PDMS was used to extract PCA and acetyl derivatives of PCP and TBP. The parameters: fiber position, matrix effect, temperature and extraction time were studied. The analysis was made by gas chromatography coupled with mass spectrometry. The results show that the distance between fiber and milk had a significant effect on the extraction kinetics. Also, the fat content in milk was a critical parameter that clearly affected the extracted mass of each compound. By using a PA fiber, the sensitivity for PCA and TBP was higher than that obtained with PDMS fiber; however, PA fiber did not allow PCP determination. The recoveries from milk were 95+/-4%, 96+/-2% and 96+/-4% for PCP, TBP and PCA, respectively, with the PDMS fiber and 94+/-3% and 95+/-1% for TBP and PCA, respectively, with PA fiber. The method using PDMS fiber was applied to real whole milk samples.


Assuntos
Anisóis/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos , Leite/química , Pentaclorofenol/análise , Fenóis/análise , Madeira , Animais , Bovinos , Padrões de Referência , Sensibilidade e Especificidade
6.
J Sep Sci ; 31(6-7): 1124-9, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18327848

RESUMO

An ultrasonic bar-assisted extraction and CE separation procedure for the determination of pentachlorophenol (PCP) and 2,4,6-tribromophenol (TBP) residues in sawdust was developed and applied. For this purpose, micellar electrokinetic capillary chromatography (MEKC) was used and compared with a GC/MS methodology. This methodology allowed the quantification of PCP and TBP in a concentration range of 2.5-12.0 mg/kg for TBP and 2.8-12.0 mg/kg for PCP. Different sample treatment processes were evaluated in order to extract these compounds from sawdust. Better results were obtained when the residues were extracted with ultrasound-assisted hexane, filtered, evaporated, dissolved in Na(2)CO(3), and injected into the CE equipment. The optimal option for GC/MS was extraction with Na(2)CO(3 )followed by a derivation using acetic anhydride and liquid-liquid extraction with hexane. This method allowed the quantification of TBP and PCP in sawdust in a concentration range of 0.19-12.00 mg/kg and 0.14-12.00 mg/kg, respectively. The CE method was compared with the GC/MS as reference method. The results were shown to be statistically similar by both methods for PCP as well as for TBP.


Assuntos
Cromatografia Capilar Eletrocinética Micelar/métodos , Poeira/análise , Fenóis/análise , Fenóis/química , Ultrassom , Madeira/química , Calibragem , Cromatografia Gasosa-Espectrometria de Massas
7.
J Chromatogr A ; 1536: 205-215, 2018 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-28625677

RESUMO

Grapevine canes, a pruning-derived by-product, possess a great amount of bioactive (poly)phenolic compounds belonging to different chemical classes, thus, having a good potential for further valorization. However, in order to properly design valorization strategies, the precise chemical composition of this material has to be known. Up to now, this chemical characterization has been based on analysis of different groups of components individually, due to difficulties related to their huge chemical variability. In this work, a comprehensive two-dimensional liquid chromatography-based method (LC×LC) is developed to obtain the profiles of (poly)phenolic compounds present in grapevine canes from several varieties. Three different set-ups have been tested and compared; the combination of diol and C18 columns produced the best results, allowing the characterization of the (poly)phenolic profile in around 80min. This way, 81 different components were detected in the samples; most of them could be tentatively assigned using the information provided by the DAD and MS detectors employed. Indeed, it has been possible to detect in a single run components belonging to stilbenoids, procyanidins and prodelphinidins of varying degrees of polymerization, some of them not formerly described in this natural source. The method has shown extremely good separation capabilities, and is characterized by high effective peak capacity (842) and orthogonality (A0=78%). The obtained results demonstrate that Vitis vinifera L. canes may retain a great potential to be used as an underexploited natural source of bioactive compounds, with potential applications in different fields.


Assuntos
Cromatografia Líquida , Fenóis/química , Extratos Vegetais/química , Vitis/química , Fenóis/análise , Caules de Planta/química , Proantocianidinas/análise
8.
Food Chem ; 268: 347-354, 2018 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-30064768

RESUMO

Calafate is a berry with high concentration of anthocyanins and hydroxycinnamic acids that grows in South Patagonia. To date, no metabolism studies of phenolic compounds using calafate have been carried out. A calafate extract was characterized by HPLC-DAD-ESI-MS/MS. After extract administration (300 mg/kg), a pharmacokinetic study of phenolic compounds in gerbil plasma was performed by GC-MS/MS. Sixteen phenolic acids increased after intake. Phenylacetic acid derivatives exhibit the highest concentration, while main increase of phenolic catabolites was observed 2 h post-intake. 3-hydroxyphenylacetic and phenylacetic acids increased at 4-8 h post-intake. All catabolites found in gerbil plasma exhibit concentration peaks between 0.1 and 1 µM, however no parental anthocyanins were detected. Establish in vivo plasmatic concentration ranges of phenolic compounds derived from polyphenol consumption following WHO recommendations, plays a key role to carry out future in vitro assays in order to correctly assign biological benefits of calafate berry consumption.


Assuntos
Berberis/química , Gerbillinae/metabolismo , Fenóis/farmacocinética , Animais , Frutas , Gerbillinae/sangue , Peso Molecular , Espectrometria de Massas em Tandem
9.
J Chromatogr B Analyt Technol Biomed Life Sci ; 1074-1075: 70-78, 2018 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-29331860

RESUMO

Grape canes, the residues from the annual pruning of vines, contain high levels of inducible (E)-resveratrol and also oligomeric stilbenoids and proanthocyanidins. These two families of phenolic compounds are bioactive, but to quantify them in a single chromatographic run using only ultraviolet detection is a difficult task. To overcome this limitation, a chromatographic method was developed using a core shell column for separation, an ultraviolet-visible diode array detector (DAD) and a fluorescence (FL) detector connected in series for quantification, with an electrospray ionization interface (ESI) and a triple quadrupole mass spectrometric detector (MS/MS) added for identification of the analytes. The proanthocyanidins (+)-catechin, (-)-epicatechin, procyanidins B1, B2, and C1, an unknown dimer and trimer, two prodelphinidin dimers, and monogallate procyanidin dimers were detected in the tested grape cane samples. The stilbenoids detected were (E)-resveratrol, (E)-piceatannol, (E)-piceid, (E)-ε-viniferin, vitisin B, a glycosylated monomer, three oxidized dimers, an unknown dimer and a tetramer, pallidol, hopeaphenol, (E)-δ-viniferin, and (E)-ω-viniferin. However, this method required 60min for each analysis. A faster and more efficient method for quantitative analysis was developed based on HPLC-DAD-FL, reducing the time required to 24min for the simultaneous quantification of proanthocyanidins and stilbenoids in Cabernet Sauvignon, Pinot Noir, and Tintorera grape canes stored at controlled temperatures and relativity humidities for 134days after pruning. To the best of our knowledge, this is the first time a prodelphinidin dimer has been quantified in grape canes. The incorporation of fluorescence detection in series with DAD not only allowed the quantification of proanthocyanidins, it also improved the detectability of some minor stilbenoids present in the canes, such as (E)-piceid. The (E)-resveratrol and (E)-piceatannol levels increased significantly during cane storage, while those of (E)-ε-viniferin and ampelopsin A did not show significant increases. The relative humidity had a determining effect on the levels of (E)-resveratrol and (E)-piceatannol in the canes of all varieties studied; their concentrations were higher at a relative humidity of 60% than at 70%. This is the first time that the proanthocyanidin profiles of canes stored after pruning were monitored under controlled conditions of temperature, time and relative humidity. The concentration of (-)-epicatechin decreased during storage under both relative humidities. Furthermore, the levels of proanthocyanidin B1 and the prodelphinidin dimer also decreased to a certain extent.


Assuntos
Proantocianidinas/análise , Espectrometria de Fluorescência/métodos , Estilbenos/análise , Vitis/química , Frutas/química , Limite de Detecção , Modelos Lineares , Reprodutibilidade dos Testes
10.
Food Chem ; 265: 101-110, 2018 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-29884360

RESUMO

The following oligostilbenoids were isolated from extracts of Vitis vinifera L. Pinot Noir grape canes produced at a pilot-plant scale: (E)-ε-viniferin, (E)-resveratrol, (E)-piceatannol, ampelopsin A, vitisin B, pallidol, (E)-δ-viniferin, (E)-ω-viniferin, (E)-trans-cis-miyabenol C, isorhapontigenin, scirpusin A, and a new isomer named isoscirpusin A. The antioxidant capacity of the isolated stilbenoids was studied by three different assays, and their 50% inhibition concentration (IC50) against cancer cells was determined by MTT reduction assay. Besides (E)-resveratrol, stilbenoids have outstanding antioxidant capacity in the ORAC-FL assay. The strongest antiproliferative effect was observed for (E)-piceatannol and ampelopsin A against the bladder cancer cell line J82. (E)-Piceatannol has inhibitory effect on human lung cancer SK-MES-1 cells. Moreover, the whole extract has antiproliferative effect on all tested cell lines. In conclusion, beside (E)-resveratrol, grape cane extract contains oligostilbenoids with potential health benefits. This underexploited viticultural residue has the potential to produce valuable phytochemicals or ingredients in functional foods.


Assuntos
Antineoplásicos/isolamento & purificação , Antineoplásicos/farmacologia , Antioxidantes/isolamento & purificação , Antioxidantes/farmacologia , Estilbenos/isolamento & purificação , Estilbenos/farmacologia , Vitis/química , Antineoplásicos/química , Antioxidantes/química , Linhagem Celular Tumoral , Citoproteção/efeitos dos fármacos , Humanos , Estilbenos/química
11.
J Agric Food Chem ; 65(13): 2793-2804, 2017 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-28274120

RESUMO

A novel 'Red Globe' (RG)-derived grape variety, 'Pink Globe' (PG), was described and registered as a new genotype, with earlier ripening and sweeter taste than those of RG. Microsatellite analysis revealed that PG and RG are undifferentiable; however, the PG VvmybA1c contains six single-nucleotide polymorphisms within the coding and noncoding region, possibly related to the reduced VvmybA1 expression levels. Conversely, HPLC-DAD-ESI-MS/MS analysis showed significantly lower anthocyanin content in PG skin than in RG skin, and PG had no detectable trihydroxylated anthocyanins. Total flavonols did not differ between the variants, although some quercetin derivate concentrations were lower in PG. HPLC-FLD analysis revealed slightly higher concentrations of epicatechin and a procyanidin dimer in PG seeds, although the antioxidant capacity of crude extracts from either variety did not differ significantly. These differences, particularly in monomeric anthocyanin content, can be attributed to altered activity of a MYB-type transcription factor, reducing Vvufgt expression.


Assuntos
Fenóis/química , Proteínas de Plantas/genética , Vitis/química , Vitis/genética , Frutas/química , Frutas/genética , Frutas/metabolismo , Fenóis/metabolismo , Proteínas de Plantas/metabolismo , Sementes/química , Sementes/genética , Sementes/metabolismo , Espectrometria de Massas em Tandem , Vitis/metabolismo
12.
Chemosphere ; 62(6): 1011-20, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16084564

RESUMO

Formaldehyde, acetaldehyde, acetone, propanal, butanal, 2-butenal, 3-methylbutanal, hexanal, benzaldehyde, 2-methylbenzaldehyde, and 2,5-dimethylbenzaldehyde were measured during six spring days at downtown Santiago de Chile. Measurements were performed 24h/day and averaged over three hour periods. The averages of the maxima (ppbv) were, formaldehyde: 3.9+/-1.4; butanal: 3.3+/-3.4; acetaldehyde: 3.0+/-0.9; acetone: 2.4+/-1.0; 2-butenal: 0.56+/-0.52; propanal: 0.46+/-0.21; benzaldehyde: 0.34+/-0.3; 3-butanal: 0.11+/-0.05; hexanal: 0.11+/-0.08; 2-methylbenzaldehyde: 0.08+/-0.05; 2,5-dimethylbenzaldehyde: 0.05+/-0.03. Aliphatic aldehydes (C1-C3) are strongly correlated among them and weakly with primary (toluene) and secondary (ozone plus nitrogen dioxide or PAN) pollutants. In particular, the correlation between acetaldehyde and propanal values remains even if diurnal and nocturnal data are considered separately, indicating similar sources. All these aldehydes present maxima values in the morning (9-12h) and minima at night (0-3h). The best correlation is observed when butanal and 2-butenal data are considered (r=0.99, butanal/2-butenal=6.2). These compounds present maxima values during the 3-6h period, with minima values in the 0-3h period. These data imply a strong pre-dawn emission. Other aldehydes show different daily profiles, suggesting unrelated origins. Formaldehyde is the aldehyde whose concentration values best correlate with the levels of oxidants. The contribution of primary emissions and photochemical processes to formaldehyde concentrations were estimated by using a multiple regression. This treatment indicates that (32+/-16)% of measured values arise from direct emissions, while (79+/-23)% is attributable to secondary formation.


Assuntos
Poluentes Atmosféricos/análise , Aldeídos/análise , Oxidantes Fotoquímicos/análise , Acetona/análise , Chile , Cidades , Monitoramento Ambiental , Dióxido de Nitrogênio/análise , Ozônio/análise , Ácido Peracético/análogos & derivados , Ácido Peracético/análise , Tolueno/análise
13.
Food Chem ; 194: 908-19, 2016 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-26471634

RESUMO

The Chilean raspberry Rubus geoides Sm. (Rosaceae) is a native species occurring in the Patagonia. Five R. geoides samples were assessed for phenolic content and composition, antioxidant activity, effect on total reduced glutathione (GSH) synthesis and protective effect against H2O2 and methylglyoxal (MGO)-induced stress in epithelial gastric AGS cells. The HPLC-DAD/ESI-MS profiles allowed the tentative identification of 39 phenolics including flavonol glycosides and tannins. R. geoides presented higher total phenolic and flavonoid content than Rubus idaeus. Two out of the five phenolic enriched R. geoides extracts (PEEs) exhibited better antioxidant activity than R. idaeus in the DPPH, FRAP and TEAC assays. A significant cytoprotective activity was observed when AGS cells were pre-incubated with extracts and subsequently challenged with H2O2 or MGO. Treatment with the PEEs increased the intracellular GSH content. R. geoides fruit extracts may induce the activation of intracellular protection mechanisms against oxidative and dicarbonyl-induced stress.


Assuntos
Peróxido de Hidrogênio/química , Fenóis/análise , Extratos Vegetais/química , Receptores de Peptídeos/química , Rubus/química , Antioxidantes/farmacologia , Chile , Flavonoides/análise , Estresse Oxidativo , Substâncias Protetoras , Aldeído Pirúvico
14.
J Chromatogr A ; 1085(2): 285-92, 2005 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-16106710

RESUMO

Two capillary zone electrophoretic (CZE) methods for determination of shikimic acid in Chilean red wine were developed and compared with a HPLC method. Both electrophoretic methods were carried out by using a reversed electroosmotic flow induced by trimethyl(tetradecyl)ammoniumbromide (TTAB) with indirect detection at 260 nm using p-aminobenzoic acid as a UV-absorbing co-ion or by direct detection at 213 nm. In both cases, the separation was carried out in a 50 microm I.D. uncoated capillary with an effective length of 48 cm, a negative power supply of 30 kV, using a buffer based on bis[2-hydroxyethyl]imino-tris[hydroxymethyl]methane (Bis-Tris), pH 7.0 or 7.5 and hydrodynamic injection. The chromatographic separations were carried out on a C-18 reversed phase column followed by a sulfonyl-styrene-divinylbenzene (S-DVB) ion exclusion column at 70 degrees C with H2SO4 0.02 M as isocratic mobile phase and a flow rate of 0.5 mL min(-1). The three methods allowed the quantification of shikimic acid with quantification limits between 1.0 and 12.0 mg L(-1) and precision between 7.3 and 10.1%, however, only the concentrations obtained by CZE with direct detection were statistically similar to those of HPLC. This parameter was evaluated as analytical tool to verify varietal authenticity of red wines. In all cases, the Cabernet Sauvignon wines presented higher concentrations of shikimic acid, compared with Merlot or Carmenère wines.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Eletroforese Capilar/métodos , Ácido Chiquímico/análise , Vinho/análise , Padrões de Referência , Ácido Chiquímico/normas
15.
Food Chem ; 167: 84-90, 2015 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-25148963

RESUMO

Diverse edible berries are native to the Patagonian region of Southern Chile. These berries are underused because their nutritional properties are relatively unknown. In this work, the profiles and concentrations of hydroxycinnamic acid derivatives and flavonols, and the antioxidant capacity of the berry extracts, were studied using HPLC-DAD-ESI-MS/MS and CUPRAC assays, respectively. In total, 46 compounds were identified, including 17 hydroxycinnamic acid derivatives and 26 flavonols. Caffeoylquinic acid isomers were the most abundant compounds, and quercetin and myricetin derivatives were the main flavonols found. The berries from Ribes genera showed a high diversity and concentration of these 2 families of compounds and contained 3-caffeoylquinic acid and quercetin-3-rutinoside at the highest concentrations. The Patagonian berries, especially the berries of Rubus and Ribes genera, had high cupric reducing antioxidant capacity, comparable with that described for berries from the Northern hemisphere. These results contribute to promote the nutritional study of these fruits.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Ácidos Cumáricos/química , Flavonóis/análise , Frutas/química , Espectrometria de Massas em Tandem/métodos , Antioxidantes , Chile
16.
J Agric Food Chem ; 51(21): 6261-7, 2003 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-14518953

RESUMO

Vitisin A was prepared from malvidin 3-glucoside and pyruvic acid in model wine medium, isolated by countercurrent chromatography, and purified by preparative high-performance liquid chromatography (HPLC). The synthesized compound was used as a reference standard to quantify vitisin A in Chilean wines from Vitis vinifera cv. Cabernet Sauvignon, including a vertical row of wines from the same vineyard over 16 years. Maximum vitisin A content was reached within the first year of storage. Importantly, up to half of the initial amount of vitisin A in young wines was still present in 15 year old wines. Although vitisin A was found to be much more stable as compared to other monomeric C-4 underivatized anthocyanins, it also slowly degrades after reaching its peak concentration. The "color activity concept" was applied to vitisin A, malvidin 3-glucoside, malvidin 3-(6' '-acetylglucoside), and polymeric pigments isolated by countercurrent chromatography in order to estimate their contribution toward the overall color expression of wines. It was found that vitisin A is only a minor contributor to the visually perceived color of aged red wines (color contribution approximately 5%). The major contributor is the polymeric fraction (color contribution approximately 70-90%).


Assuntos
Benzofuranos/análise , Fenóis/análise , Pigmentação , Vitis/química , Vinho/análise , Chile , Frutas/química , Concentração de Íons de Hidrogênio , Pigmentos Biológicos/análise , Polímeros/análise , Fatores de Tempo
17.
J Forensic Leg Med ; 23: 37-43, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24661704

RESUMO

In the field of forensic toxicology, femoral blood is the most useful sample for the determination and quantification of drugs; however, cases in which blood is unavailable are common. In such cases, validated methodologies for drug determination in alternative matrices can be decisive in the investigation of a case. In particular, when femoral blood is unavailable for analysis for the presence of systemic exposure to cocaine and its principal metabolite, benzoylecgonine, validated methodologies from matrices other than blood that can be obtained in the autopsy room would be useful to the forensic toxicologist in the evaluation of a specific forensic case. To address this issue, we implemented and compared in our study the systematic evaluation of extraction, chromatographic separation, and quantification of cocaine and benzoylecgonine in different biological matrices (right and left cardiac blood, femoral arterial and venous blood, urine, vitreous humor, cerebrospinal fluid, brain accumbens nucleus, brain ventral tegmental area, and liver). The studied matrices were those most likely to be obtained from different autopsy rooms at the time of forensic testing in deceased individuals who are presumed of antemortem drug consumption. Solid phase extraction of analytes from the different matrices was performed using C-8/SCX mixed-phase columns, and gas chromatographic mass spectrometry separation was performed using detection in single-ion monitoring mode. The methodological validation was performed for all the studied matrices, and the results showed similar sensitivity and recoveries without statistical differences between the studied matrices. The methods were applied to evaluate a thanatological case using all the study matrices, showing unequal postmortem distribution of cocaine and benzoylecgonine throughout the different matrices tested. The present work opens the option of applying appropriate methodologies in the analysis of matrices, other than the usual blood, to obtain reliable results that may help clarify a forensic case. In addition, we present findings from different studies. This work affirms not only the potentiality of obtaining reliable data but also reaffirms the challenge of applying these data and taking into account the complexity of interpreting results in matrices other than blood.


Assuntos
Cocaína/análogos & derivados , Cocaína/análise , Detecção do Abuso de Substâncias/métodos , Adulto , Autopsia , Cocaína/sangue , Toxicologia Forense , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Masculino , Extração em Fase Sólida
18.
Food Chem ; 155: 256-63, 2014 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-24594183

RESUMO

Increasing evidence for the health benefits of E-resveratrol has triggered interest in stilbenoids in grapes, wine and by-products. Less attention has been paid to stilbenoid levels in viticulture residues. However, grape canes are a promising source of stilbenoids and have economic potential because they are a source of high-value phytochemicals. The objective of this research was to determine the effect of post-pruning storage on stilbenoid levels in grape canes. In most samples, the predominant stilbenoid was (E)-resveratrol, followed by (E)-ε-viniferin. In Pinot Noir canes stored after pruning at room temperature, the stilbenoid levels increased significantly after 8 months. The concentration was increased by up to fivefold, reaching 4,777 mg kg(-1)dw (dry weight). This effect did not occur in frozen, lyophilised or milled material. Branches collected directly from the plants after grape vintage and those remaining on the plant after pruning showed only a small increase in stilbenoid levels.


Assuntos
Fenóis/química , Extratos Vegetais/química , Caules de Planta/química , Vitis/química , Frutas/química , Frutas/crescimento & desenvolvimento , Caules de Planta/crescimento & desenvolvimento , Vitis/classificação , Vitis/crescimento & desenvolvimento
19.
J Agric Food Chem ; 62(51): 12407-17, 2014 Dec 24.
Artigo em Inglês | MEDLINE | ID: mdl-25495577

RESUMO

There are 20 species of the Berberidaceae family described in Chile, whose fruits are edible and show high anthocyanin and hydroxycinnamic acid levels. Berberis microphylla G. Forst, commonly known as calafate, is the most extensively distributed. Flavonols and alkaloids in seed, pulp, skin, and whole calafate berry extracts and other Berberis were studied using HPLC-DAD-ESI-MS/MS and HPLC with fluorescence detector. Berry samples from different locations in Chilean Patagonia, including different phenological stages, were systematically addressed. Results were compared with other organs of the plant and with other Berberis species. Total flavonol concentration in calafate (n = 65) was 1.33 ± 0.54 µmol/g. Glycosyl metabolites of quercetin and isorhamnetin were the most abundant. Similar profiles were observed in calafate from distinct locations, but important differences were observed for the other edible Berberis species. Calafate pulp and skin have higher flavonol concentrations than seeds, and the maturation process reduced its levels. TEACCUPRAC and TEACABTS of whole calafate extracts and fractions are also explored. Finally, only berberine was detected in the fruit (0.001%), mainly in seeds. Results contribute to the promotion of this berry as a superfruit from Patagonia.


Assuntos
Alcaloides/análise , Antioxidantes/análise , Berberidaceae/química , Flavonóis/análise , Extratos Vegetais/análise , Berberidaceae/classificação , Berberis/química , Chile , Plantas Comestíveis/química
20.
J Agric Food Chem ; 62(29): 6918-25, 2014 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-24697704

RESUMO

Calafate (Berberis microphylla G. Forst) is an edible wild berry growing in South Patagonia that is very rich in anthocyanins and hydroxycinnamic acid derivatives. Calafate contains unusual phenolic compounds compared to other berries, such as anthocyanidin dihexosides, different from the common 3,5-diglucosides, and isomeric esters of caffeic acid with hexaric acids. After isolation, their structures have been elucidated by UV-vis, MS/MS, and NMR spectroscopies. The anthocyanidin dihexosides constitute the complete series of 3,7-ß-O-diglucosides of the five anthocyanidins usually found in calafate, the structures of which were completely elucidated in the cases of delphinidin, petunidin, and malvidin derivatives and tentatively suggested in the cases of cyanidin and peonidin, and their occurrence seems to be characteristic of calafate among other wild berries from South Patagonia. With regard to caffeoyl-hexaric acids, two of four isomers have been assigned as 3- and 4-trans-caffeoyl-glucaric acids, but the determination of the linkage position for each isomer was not possible. A third isomer was also isolated, but it easily degraded and was suggested to be the 2- or 5-trans-caffeoyl-glucaric acid. The caffeoyl-glucaric acids account for around half of the pool of hydroxycinnamic acid derivatives in calafate.


Assuntos
Antocianinas/isolamento & purificação , Frutas/química , Glucosídeos/isolamento & purificação , Antocianinas/química , Glucosídeos/química , Espectroscopia de Ressonância Magnética , Espectrofotometria Ultravioleta , Espectrometria de Massas em Tandem
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