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1.
Molecules ; 29(12)2024 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-38930972

RESUMO

Copper (II), a vital fungicide in organic viticulture, also acts as a wine oxidation catalyst. However, limited data are currently available on the impact that maximum allowed copper (II) ion doses in wine grapes at harvest can have on aged wine quality. This was the focus of the present study. We investigated the copper (II) effects by producing both white and red wines from musts containing three initial metal concentrations according to the limits set for organic farming. In detail, the influence of copper (II) on fermentation evolution, chromatic characteristics, and phenolic compounds was evaluated. Interestingly, the white wine obtained with the highest permitted copper (II) dose initially exceeded the concentration of 1.0 mg/L at fermentation completion. However, after one year of storage, the copper (II) content fell below 0.2 ± 0.01 mg/L. Conversely, red wines showed copper (II) levels below 1.0 mg/L at the end of fermentation, but the initial copper (II) level in musts significantly affected total native anthocyanins, color intensity, hue, and acetaldehyde concentration. After 12-month aging, significant differences were observed in polymeric pigments, thus suggesting a potential long-term effect of copper (II) on red wine color stability.


Assuntos
Acetaldeído , Cobre , Fermentação , Fenóis , Vitis , Vinho , Vinho/análise , Cobre/análise , Acetaldeído/análise , Fenóis/análise , Fenóis/química , Vitis/química , Cor , Antocianinas/análise , Antocianinas/química
2.
J Sci Food Agric ; 104(9): 5163-5175, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38308579

RESUMO

BACKGROUND: Climate changes have been leading to an excessive synthesis of quercetin (Q) and its glycosides (Q-Gs) in specific red grape varieties, such as Sangiovese. This has resulted in concentrations overcoming the solubility threshold of Q in wines, with the consequent formation of undesirable precipitates. This study aims at assessing the impact of various factors, including anthocyanins, temperature, nucleation seeds and time, on the precipitation of Q in red wine. RESULTS: The influence of anthocyanins on Q solubility was examined by adding a grape skin extract rich in anthocyanins to a model solution containing 89 µmol L-1 of Q. The data revealed that the solubility of both Q and Q-Gs increased as a function of the anthocyanin concentration in the model solution. In a subsequent experiment, red wines were stored at two different temperatures (2 and 20 °C), supplemented with Q nucleation seeds, and monitored over a 10-day period. Notably, after only 3 days of contact with Q seeds at 2 °C, a reduction of over 75% in Q concentration was observed in the supernatant. Among the considered factors, contact with nucleation seeds emerged as the most significant one (P < 0.0001). CONCLUSION: Q precipitation in red wines is influenced by the presence of anthocyanins in solution, although it is not the sole determinant. The data also suggested that a potential strategy for wineries to mitigate the risk of Q precipitation in bottled wine would be the acceleration of this process by promoting the formation of nucleation seeds. © 2024 Society of Chemical Industry.


Assuntos
Antocianinas , Quercetina , Sementes , Vitis , Vinho , Antocianinas/química , Antocianinas/análise , Quercetina/química , Quercetina/análise , Vinho/análise , Vitis/química , Sementes/química , Precipitação Química , Temperatura , Solubilidade , Frutas/química , Extratos Vegetais/química
3.
Molecules ; 28(21)2023 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-37959842

RESUMO

Climate change is causing a significant decrease in the total acidity of grapes and related wines. This represents a serious issue for sparkling wine production. Consequently, before the second fermentation, the acidification of base wines is often necessary. However, the impacts of the most important organic acids on the foam properties of sparkling wines are not yet well known. The impacts of the addition of tartaric, malic, citric, and lactic acid on the quality of Falanghina and Bombino sparkling wines were evaluated. Analyses were performed soon after the second fermentation and one year after aging sur lees. The addition of each different organic acid to the two base wines resulted in significant changes in the sparkling wines not only in terms of pH, titratable acidity, and buffering capacity but also in the content of total amino acids and, in some cases, in the height of the foam and its stability over time. For both grape varieties, acidified wines showed a lower content of total amino acids in comparison with the control wines. The addition of lactic acid determined a higher persistency of the foam even after one year of aging sur lees only in Falanghina wines. The results obtained herein highlight the importance of organic acids and the pH of the base wines for the content of amino acids in sparkling wines. No strict correlation between organic acid addition and the foamability of wines was observed.


Assuntos
Vitis , Vinho , Vinho/análise , Vitis/química , Compostos Orgânicos , Aminoácidos/análise , Ácido Láctico
4.
Int J Mol Sci ; 22(11)2021 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-34073604

RESUMO

Dietary phenolic compounds possess potent bioactivity against inflammatory pathways of chronic inflammatory conditions, such as type 2 diabetes. Here, the phenolic profile and bioactivity of Italian red wines Gaglioppo, Magliocco, and Nerello Mascalese were characterized. NMR, HPLC/UV-Vis and spectrophotometric characterization showed that Magliocco was the richest wine in monomeric anthocyanins (two-fold), catechins, and low molecular weight phenolics (LMWP). A positive correlation was observed between the polyphenolic content and antioxidant capacity (p < 0.05), with Magliocco displaying the highest antioxidant capacity (p < 0.01). In vitro evidence on the endothelial cell models of insulin resistance and hyperglycemia showed the ability of Magliocco to reduce reactive oxygen species (ROS) (p < 0.01) and cytokine release (p < 0.01) and to upregulate SIRT1 and SIRT6 (p < 0.01). On the whole, the results indicated that the quantitative and qualitative phenolic profiles of red wines influence their in vitro beneficial effects on oxidative and proinflammatory milieu in endothelial cells, showing a positive modulation of SIRT1 and SIRT6, both implied in vascular aging.


Assuntos
Antioxidantes/farmacologia , Células Endoteliais/enzimologia , Fenóis/farmacologia , Sirtuína 1/metabolismo , Sirtuínas/metabolismo , Vinho , Antioxidantes/química , Linhagem Celular , Humanos , Fenóis/química
5.
Molecules ; 26(12)2021 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-34208342

RESUMO

BACKGROUND: Numerous oenological practices can cause an excess of dissolved oxygen in wine, thus determining sensory and chromatic defects in the short- to long-term. Hence, it is necessary to manage the excess of oxygen before bottling. METHODS: In this study, the management of the dissolved oxygen content by a polypropylene hollow fiber membrane contactor apparatus was performed in two wines from different grape varieties (Aglianico and Falanghina). The wines were analyzed after an 11-month aging. Anthocyanins and acetaldehyde content were evaluated by HPLC. In addition, other phenolic compounds and chromatic characteristics were analyzed by spectrophotometric methods. NMR and HR ESIMS analyses were conducted to evaluate the amount of pyranoanthocyanins and polymeric pigments. RESULTS: After 11 months of aging, in both wines a decrease of free and total SO2 with respect to initial values was detected. In the wines with the highest dissolved oxygen levels, a more remarkable loss was observed. No significant differences in terms of color parameters were detected. In red wine with the highest oxygen content, a massive formation of polymeric pigments and BSA reactive tannins was observed, as opposed to wines with lower oxygen levels. CONCLUSION: The study demonstrated that the membrane contactor can prove a successful tool to manage dissolved oxygen in wines as to prevent their oxidative spoilage.


Assuntos
Acetaldeído/química , Antocianinas/química , Oxigênio/metabolismo , Fenóis/química , Polipropilenos/química , Vitis/química , Vinho/análise , Oxirredução , Oxigênio/análise
6.
Molecules ; 26(4)2021 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-33557306

RESUMO

BACKGROUND: Three accelerated oxidation tests were proposed to simulate red wine oxidation thus providing information useful to correctly manage moderate oxygen exposure of wine during aging in regard to phenolic composition and wine color. Since the results of the tests have never been compared on wines with different initial composition, the aim of this study was to find a suitable method to simulate oxidation of any still red wine. METHODS: Aglianico, Barbera, Gaglioppo, Magliocco, and Nerello wines were treated with (1) three cycles of air saturation, (2) the addition of hydrogen peroxide, and (3) the addition of acetaldehyde. Changes in chromatic characteristics and phenolic composition were determined by spectrophotometric and HPLC methods. RESULTS: Important differences in the behavior of the different wines were detected: the highest formation of polymeric pigments was observed in Barbera and Aglianico wines. In contrast, Gaglioppo and Magliocco wines showed a lower variability before and after the oxidation probably due to the lower anthocyanin/tannin ratio. Among the accelerated oxidation tests applied, no significant differences in color parameters and phenolic composition were detected in samples treated with the addition of H2O2 and the air saturation method. CONCLUSION: The study demonstrated that H2O2 addition is a successful tool to predict the evolution of different phenolic compounds during the air saturation treatment of wines.


Assuntos
Análise de Alimentos/métodos , Vinho/análise , Acetaldeído/análise , Cor , Cinética , Oxirredução
7.
Molecules ; 25(20)2020 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-33050381

RESUMO

BACKGROUND: In the wine industry, in addition to condensed tannins of grape origin, other commercial tannins are commonly used. However, the influence of oxygen uptake related to different tannin additions during the post fermentative phase in wine has not been completely investigated. In this study, we evaluated the influence of four different commercial tannins (namely, condensed tannins, gallotannins, ellagitannins and tea tannins) during four saturation cycles. METHOD: Wine samples were added with four different tannin classes (30 g/hL) as to have 5 different experimental samples: control, gallotannins (GT), condensed tannins (CT), ellagitannins (ET), and tea tannins (TT). The chemical composition of the four commercially available tannin mixtures was defined by means of NMR and high-resolution mass spectrometry. After the addition of tannins, each wine sample was oxidized by air over four cycles of saturation. During the experiment oxygen consumption rate (OCR), sulfur dioxide consumption, acetaldehyde production, phenolic compounds, chromatic characteristics, astringency measured by the reactivity towards saliva proteins and astringency subqualities were evaluated. RESULTS: The experiment lasted 52 days. The addition of tannins influenced the oxygen consumption on the 1st day of the saturation cycles and, in the case of TT, a higher total consumption of oxygen was also detected. Acetaldehyde increased during the experiment while the native anthocyanins decreased throughout the oxidation process. CONCLUSION: Wines added with tannins featured improved color intensities with respect to the control; the addition of TT, GT and ET slightly promoted the formation of short polymeric pigments; the astringency, determined before and at the end of the experiment, decreased in all the samples, including the control wine, and mostly in the ET and GT samples.


Assuntos
Fenóis/química , Taninos/química , Vinho , Adstringentes/química , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Consumo de Oxigênio/fisiologia
8.
J Food Sci Technol ; 57(7): 2602-2611, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32549610

RESUMO

Wines produced from Sangiovese (sg) grapes, the most cultivated red grape variety in Italy and widely grown across the world, is often subjected to loss of clarity due to the formation of a deposit constituted by fine needle-shaped crystals. In this work, a qualitative study by 1H-NMR and 13C-NMR analysis of the deposit obtained by filtering cloudy sg wines showed that it was constituted by crystals of quercetin (Q). The analysis of hydro-alcoholic solutions (12% ethanol and pH 3.2.) and red wines added with increasing amounts of Q showed that, above 3 mgL-1 of Q, a deposit can be detected and, the time necessary for its formation depends on the medium. The comparison among sg and other 11 monovarietal wines showed that sg was the richest in Q and quercetin glycosides (GQ). Both Q and GQ decreased in the analyzed solutions over time and the decrease was faster for Q than for GQ. The controlled exposure to oxygen determined a decrease of Q higher than the 50% of the initial values. Data obtained in this study suggested that practices as micro-oxygenation and wood aging could help to decrease the amount of Q in sg wines.

9.
Environ Sci Technol ; 50(2): 1023-30, 2016 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-26655059

RESUMO

Anecdotal reports exist of aquarium hobbyists that experienced severe respiratory distress and/or skin injury following cleaning operation of home aquaria containing Palythoa sp. soft corals. Hundreds of cases of respiratory illness and/or dermatitis have been recorded in proximity to the sea concomitantly with algal blooms of Ostreopsis spp. in the Mediterranean area. Both Palythoa spp. and Ostreopsis spp. contain congeners of palytoxin, a highly potent toxin whose inhalation hazard is however unknown. In this study, we demonstrate the presence of high levels of palytoxins (palytoxin and hydroxypalytoxin) in both soft coral and seawater from a home marine aquarium involved in the poisoning of a whole family. Due to the high toxin levels found in seawater, a procedure for a rapid and efficient determination of palytoxin in seawater was setup. A comparison of symptoms of Palythoa- and Ostreopsis-related inhalatory poisonings showed many similarities including fever, respiratory distress, nausea, and flu-like symptoms. From the chemical and symptomatological data reported herein it is reasonable to hold palytoxins responsible for respiratory disorders following inhalation. Although the exact mechanism through which palytoxin congeners exert their inhalatory toxicity is still unknown, this represents a step toward demonstrating that palytoxin congeners exert toxic effects through inhalation both in natural environments and in the surroundings of private and public aquaria.


Assuntos
Acrilamidas/análise , Acrilamidas/intoxicação , Antozoários/química , Dinoflagellida/química , Acrilamidas/administração & dosagem , Administração por Inalação , Adolescente , Adulto , Animais , Venenos de Cnidários/análise , Venenos de Cnidários/intoxicação , Exposição Ambiental/efeitos adversos , Humanos , Piranos/análise , Piranos/intoxicação , Água do Mar/química , Extração em Fase Sólida
10.
Environ Sci Technol ; 50(3): 1544-51, 2016 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-26714047

RESUMO

This study provides the first evaluation of the cytotoxic effects of the recently identified palytoxin (PLTX) analog, ovatoxin-a (OVTX-a), the major toxin produced by Ostreopsis cf. ovata in the Mediterranean Sea. Its increasing detection during Ostreopsis blooms and in seafood highlights the need to characterize its toxic effects and to set up appropriate detection methods. OVTX-a is about 100 fold less potent than PLTX in reducing HaCaT cells viability (EC50 = 1.1 × 10(-9) M vs 1.8 × 10(-11) M, MTT test) in agreement with a reduced binding affinity (Kd = 1.2 × 10(-9) vs 2.7 × 10(-11) M, saturation experiments on intact cells). Similarly, OVTX-a hemolytic effect is lower than that of the reference PLTX compound. Ost-D shows the lowest cytotoxicity toward HaCaT keratinocytes, suggesting the lack of a hydroxyl group at C44 as a critical feature for PLTXs cytotoxic effects. A sandwich ELISA developed for PLTX detects also OVTX-a in a sensitive (LOD = 4.2 and LOQ = 5.6 ng/mL) and accurate manner (Bias = 0.3%), also in O. cf. ovata extracts and contaminated mussels. Although in vitro OVTX-a appears less toxic than PLTX, its cytotoxicity at nanomolar concentrations after short exposure time rises some concern for human health. The sandwich ELISA can be a viable screening method for OVTXs detection in monitoring program.


Assuntos
Dinoflagellida/química , Toxinas Marinhas/toxicidade , Acrilamidas , Animais , Bivalves/química , Linhagem Celular , Venenos de Cnidários , Ensaio de Imunoadsorção Enzimática , Humanos , Toxinas Marinhas/isolamento & purificação , Mar Mediterrâneo , Alimentos Marinhos , Frutos do Mar , Testes de Toxicidade
11.
Anal Bioanal Chem ; 408(3): 915-32, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26608282

RESUMO

Blooms of benthic dinoflagellates of the genus Ostreopsis (mainly O. cf. ovata and occasionally O. cf. siamensis) represent a serious concern for humans in the Mediterranean area, due to production of palytoxin-like compounds listed among the most potent marine toxins known. In this work, six strains of Ostreopsis sp. from Cyprus Island were analyzed through an integrated approach based on molecular, chemical, and eco-toxicological methods. Cypriot Ostreopsis sp. was found to be a species distinct from O. cf. ovata and O. cf. siamensis, belonging to the Atlantic/Mediterranean Ostreopsis spp. clade. Some variability in toxin profiles emerged: three strains produced ovatoxin-a (OVTX-a), OVTX-d, OVTX-e, and isobaric palytoxin, so far found only in O. cf. ovata; the other three strains produced only new palytoxin-like compounds, which we named ovatoxin-i, ovatoxin-j1, ovatoxin-j2, and ovatoxin-k. The new ovatoxins present the same carbon skeleton as ovatoxin-a, differing primarily in an additional C2H2O2 moiety and an unsaturation in the region C49-C52. Other minor structural differences were found, including the presence of a hydroxyl group at C44 (in OVTX-j1 and OVTX-k) and the lack of a hydroxyl group in the region C53-C78 (in OVTX-i and OVTX-j1). The toxin content of the analyzed Ostreopsis sp. strains was in the range 0.06-2.8 pg cell(-1), definitely lower than that of a Ligurian O. cf. ovata strain cultured under the same conditions. Accordingly, an eco-toxicological test on Artemia salina nauplii demonstrated that Ostreopsis sp. presents a very low toxicity compared to O. cf. ovata. The whole of these data suggest that Ostreopsis sp. from Cyprus Island poses a relatively low risk to humans.


Assuntos
Dinoflagellida/química , Toxinas Marinhas/química , Toxinas Marinhas/toxicidade , Animais , Artemia/efeitos dos fármacos , Cromatografia Líquida , Dinoflagellida/classificação , Dinoflagellida/metabolismo , Ilhas , Toxinas Marinhas/metabolismo , Espectrometria de Massas , Estrutura Molecular
12.
J Nat Prod ; 79(3): 590-7, 2016 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-26918635

RESUMO

Humulus lupulus (hop plant) has long been used in traditional medicine as a sedative and antimicrobial agent. More recently, attention has been devoted to the phytoestrogenic activity of the plant extracts as well as to the anti-inflammatory and chemopreventive properties of the prenylated chalcones present. In this study, an Italian sample of H. lupulus cv. "Cascade" has been investigated and three new compounds [4-hydroxycolupulone (6), humudifucol (7) and cascadone (8)] have been purified and identified by means of NMR spectroscopy along with four known metabolites. Notably, humudifucol (7) is the first prenylated dimeric phlorotannin discovered in nature. Because structurally related phloroglucinols from natural sources were found previously to inhibit microsomal prostaglandin E2 synthase (mPGES)-1 and 5-lipoxygenase (5-LO), the isolated compounds were evaluated for their bioactivity against these pro-inflammatory target proteins. The prenylated chalcone xanthohumol inhibited both enzymes at low µM concentrations.


Assuntos
Chalconas/isolamento & purificação , Chalconas/farmacologia , Humulus/química , Fitoestrógenos/isolamento & purificação , Fitoestrógenos/farmacologia , Plantas Medicinais/química , Polifenóis/isolamento & purificação , Polifenóis/farmacologia , Araquidonato 5-Lipoxigenase , Chalconas/química , Flavonoides , Oxirredutases Intramoleculares/antagonistas & inibidores , Itália , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Fitoestrógenos/química , Extratos Vegetais/química , Polifenóis/química , Prenilação , Propiofenonas , Prostaglandina-E Sintases
13.
Anal Bioanal Chem ; 407(5): 1463-73, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25486923

RESUMO

Palytoxins from Ostreopsis cf. ovata (a putative palytoxin and ovatoxins) are emerging toxins in the Mediterranean basin and are not yet regulated, although there is evidence that they can accumulate in seafood and thus enter the human food chain. This poses serious concerns for human health, because palytoxin itself is among the most potent marine toxins known. In 2009, the European Food Safety Authority (EFSA) announced the need for optimization of efficient analytical methods for detecting palytoxins and for preparing standards. Herein, we propose a procedure including a one-step extraction, solid-phase-extraction (SPE) clean-up, and liquid chromatography-high resolution mass spectrometry (LC-HRMS) detection of individual palytoxins in mussels. The method enabled efficient chromatographic separation of individual compounds, including structural isomers, with good sensitivity, reproducibility, and linearity in a large dynamic range (14-1000 ng mL(-1) in matrix). As a result, the putative palytoxin from Ostreopsis cf. ovata was identified as an isomer of palytoxin itself and re-named isobaric palytoxin. The whole procedure (sample preparation and LC-HRMS analysis) proved able to detect palytoxins in both spiked and natural mussel samples at levels as low as 70 µg kg(-1) in crude mussel extracts and 15 µg kg(-1) after SPE clean-up. Although full validation of the method is currently prevented by the unavailability of palytoxin(s) certified standards and reference material, this study constitutes a first step towards achieving this.


Assuntos
Acrilamidas/análise , Bivalves/química , Cromatografia Líquida/métodos , Toxinas Marinhas/análise , Espectrometria de Massas/métodos , Frutos do Mar/análise , Animais , Venenos de Cnidários , Contaminação de Alimentos/análise , Inocuidade dos Alimentos
14.
Anal Bioanal Chem ; 407(4): 1191-204, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25492088

RESUMO

Blooms of the benthic dinoflagellate Ostreopsis cf. ovata are a concern in the Mediterranean Sea, since this species produces a wide range of palytoxin-like compounds listed among the most potent marine toxins. This study focused on two analogs of palytoxin found in cultures of six strains of O. cf. ovata isolated from the south of Catalonia (NW Mediterranean Sea). In addition to some already known ovatoxins, our strains produced two minor compounds, ovatoxin-g and the so far called putative palytoxin, whose structures had not been elucidated before. Insufficient quantity of these compounds impeded a full nuclear magnetic resonance (NMR)-based structural elucidation; thus, we studied their structure in crude algal extracts through liquid chromatography-electrospray ionization high-resolution mass spectrometry(n) (LC-ESI-HRMS(n)) in positive ion mode. Under the used MS conditions, the molecules underwent fragmentation at many sites of their backbone and a large number of diagnostic fragment ions were identified. As a result, tentative structures were assigned to both ovatoxin-g and the putative palytoxin, the latter being identified as a palytoxin isomer and re-named as  isobaric palytoxin.


Assuntos
Acrilamidas/isolamento & purificação , Cromatografia Líquida de Alta Pressão/métodos , Dinoflagellida/química , Éteres Cíclicos/isolamento & purificação , Água do Mar , Espectrometria de Massas por Ionização por Electrospray/métodos , Venenos de Cnidários , Mar Mediterrâneo , Estrutura Molecular , Água do Mar/análise , Água do Mar/microbiologia
15.
J Org Chem ; 79(1): 72-9, 2014 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-24328268

RESUMO

More than 40 years after its isolation, the understanding of how palytoxin interacts with biological systems has yet to be fully determined. The Na(+),K(+)-ATPase pump constitutes a molecular receptor for palytoxin that is able to convert the pump into an open channel, with consequent loss of cellular K(+) and remarkable rise of cytosolic Na(+) levels. In addition, a slight permeability to Ca(2+) is detected when palytoxin binds to the pump. It has been demonstrated that the increase of cytosolic free Ca(2+) concentration gives rise to downstream events ultimately leading to cell death. The widely accepted recognition of the dependence of important cellular events on calcium ion concentration propelled us to investigate the occurrence of palytoxin-Ca(2+) complex in aqueous solution by NMR- and molecular modeling-based approach. We identified two specific regions of palytoxin where Ca(2+) is preferentially coordinated. This study constitutes the first characterization of a calcium complex with palytoxin and, as such, is expected to support the investigation of the toxin molecular bioactivity.


Assuntos
Acrilamidas/química , Cálcio/química , Cátions/química , ATPase Trocadora de Sódio-Potássio/química , Venenos de Cnidários , Espectroscopia de Ressonância Magnética , Modelos Moleculares , ATPase Trocadora de Sódio-Potássio/metabolismo
16.
Environ Sci Technol ; 48(6): 3532-40, 2014 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-24564517

RESUMO

Since the late 1990s, a respiratory syndrome has been repetitively observed in humans concomitant with Ostreopsis spp. blooms (mainly O. cf. ovata) in the Mediterranean area. Previous studies have demonstrated that O. cf. ovata produces analogues of palytoxin (ovatoxins and a putative palytoxin), one of the most potent marine toxins. On the basis of the observed association between O. cf. ovata blooms, respiratory illness in people, and detection of palytoxin complex in algal samples, toxic aerosols, containing Ostreopsis cells and/or the toxins they produce, were postulated to be the cause of human illness. A small scale monitoring study of marine aerosol carried out along the Tuscan coasts (Italy) in 2009 and 2010 is reported. Aerosols were collected concomitantly with O. cf. ovata blooms, and they were analyzed by both PCR assays and LC-HRMS. The results, besides confirming the presence of O. cf. ovata cells, demonstrated for the first time the occurrence of ovatoxins in the aerosol at levels of 2.4 pg of ovatoxins per liter of air. Given the lack of toxicological data on palytoxins by inhalation exposure, our results are only a first step toward a more comprehensive understanding of the Ostreopsis-related respiratory syndrome.


Assuntos
Dinoflagellida/química , Monitoramento Ambiental/métodos , Toxinas Marinhas/análise , Acrilamidas/análise , Acrilamidas/química , Aerossóis/análise , Venenos de Cnidários , Dinoflagellida/genética , Dinoflagellida/isolamento & purificação , Itália , Biologia Marinha , Toxinas Marinhas/química , Água do Mar
17.
J Nat Prod ; 77(2): 351-7, 2014 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-24512352

RESUMO

Palytoxin ranks among the most potent marine biotoxins. Its lethality was well known to native Hawaiians that used to smear a "moss" containing the toxin on their spears to cause instant death to their victims. Human intoxications due to exposure to palytoxin and to its many congeners have been reported worldwide. Currently, palytoxins constitute the main threat to public health across the Mediterranean Sea. In the present work we report on the isolation and stereostructural determination of a new palytoxin analogue from a Hawaiian Palythoa tuberculosa sample. This new toxin is a stereoisomer of 42-hydroxypalytoxin isolated from Palythoa toxica. The whole absolute configuration of this latter toxin is also reported in the paper. Interestingly, the two 42-hydroxypalytoxins do not share the same biological activity. The stereoisomer from P. tuberculosa showed cytotoxicity toward skin HaCaT keratinocytes approximately 1 order of magnitude lower than that of 42-hydroxypalytoxin from P. toxica and about 2 orders of magnitude lower than that of palytoxin itself. This finding holds the prospect of interesting structure-activity relationship evaluations in the future.


Assuntos
Acrilamidas/farmacologia , Antozoários/química , Toxinas Marinhas/química , Acrilamidas/química , Animais , Cromatografia Líquida de Alta Pressão , Venenos de Cnidários/química , Venenos de Cnidários/farmacologia , Havaí , Humanos , Queratinócitos/efeitos dos fármacos , Toxinas Marinhas/toxicidade , Mar Mediterrâneo , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Piranos/química , Piranos/farmacologia , Estereoisomerismo , Relação Estrutura-Atividade
18.
Mar Drugs ; 12(10): 5258-76, 2014 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-25341029

RESUMO

The dinoflagellate Alexandrium minutum is known for the production of potent neurotoxins affecting the health of human seafood consumers via paralytic shellfish poisoning (PSP). The aim of this study was to investigate the relationship between the toxin content and the expression level of the genes involved in paralytic shellfish toxin (PST) production. The algal cultures were grown both in standard f/2 medium and in phosphorus/nitrogen limitation. In our study, LC-HRMS analyses of PST profile and content in different Mediterranean A. minutum strains confirmed that this species was able to synthesize mainly the saxitoxin analogues Gonyautoxin-1 (GTX1) and Gonyautoxin-4 (GTX4). The average cellular toxin content varied among different strains, and between growth phases, highlighting a decreasing trend from exponential to stationary phase in all culture conditions tested. The absolute quantities of intracellular sxtA1 and sxtG mRNA were not correlated with the amount of intracellular toxins in the analysed A. minutum suggesting that the production of toxins may be regulated by post-transcriptional mechanisms and/or by the concerted actions of alternative genes belonging to the PST biosynthesis gene cluster. Therefore, it is likely that the sxtA1 and sxtG gene expression could not reflect the PST accumulation in the Mediterranean A. minutum populations under the examined standard and nutrient limiting conditions.


Assuntos
Dinoflagellida/genética , Expressão Gênica/genética , Saxitoxina/análogos & derivados , Saxitoxina/genética , Dinoflagellida/metabolismo , Família Multigênica/genética , Neurotoxinas/genética , Neurotoxinas/metabolismo , RNA Mensageiro/genética , Saxitoxina/metabolismo , Intoxicação por Frutos do Mar/genética , Intoxicação por Frutos do Mar/metabolismo
19.
Food Chem ; 426: 136556, 2023 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-37343411

RESUMO

Acetaldehyde plays a key role in determining some wine properties. Interesting is the reaction of acetaldehyde with flavonoids, as the ensuing products can alter wine color, astringency, colloidal stability. Many studies reported on the formation of ethylidene-bridged flavan-3-ols as products of the reaction between acetaldehyde and either (+)-catechin or (-)-epicatechin. In white wines after one year of incubation with acetaldehyde only vinyl-(+)-catechin and vinyl-(-)-epicatechin were observed, while no ethylidene linked oligomers were detected. This observation prompted us to study the reaction of (+)-catechin with acetaldehyde in wine model solution through an experimental and theoretical approach, with the purpose of exploring the nature of the species involved along with the mechanisms leading to them. The products of the reaction were observed over 38 days. The results showed that ethylidene-bridged catechins are the first products to be formed but over time the dissociation of these dimers causes vinyl-catechins to accumulate.


Assuntos
Catequina , Vinho , Catequina/análise , Acetaldeído , Flavonoides/análise , Vinho/análise , Modelos Teóricos
20.
Front Plant Sci ; 14: 1250208, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37780525

RESUMO

The cultivated grapevine, Vitis vinifera subsp. vinifera, possesses a rich biodiversity with numerous varieties. Each variety adapts differently to varying pedoclimatic conditions, which greatly influence the terroir expression of wine regions. These conditions impact vine growth, physiology, and berry composition, ultimately shaping the unique characteristics and typicity of the wines produced. Nowadays, the potential of the different adaptation capacities of grape varieties has not yet been thoroughly investigated. We addressed this issue by studying two grape varieties, Aglianico and Cabernet Sauvignon, in two different pedoclimatic conditions of Southern Italy. We evaluated and compared the effect of different pedoclimatic conditions on plant physiology, the microbial quality of grapes using Next-Generation Sequencing (NGS) technology, the expression trends of key genes in ripe berries and the concentration of phenolic compounds in grapes and wines by HPLC-MS, HPLC-DAD, NMR and spectrophotometric analyses. Metabolomic and microbiome data were integrated with quantitative gene expression analyses to examine varietal differences and plasticity of genes involved in important oenological pathways. The data collected showed that the phenotypic response of studied grapes in terms of vigor, production, and fruit quality is strongly influenced by the pedoclimatic conditions and, in particular, by soil physical properties. Furthermore, Aglianico grape variety was more influenced than the Cabernet Sauvignon by environmental conditions. In conclusion, the obtained findings not only reinforce the terroir concept and our comprehension of grape's ability to adapt to climate variations but can also have implications for the future usage of grape genetic resources.

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