Nor-isoprenoids profile during port wine ageing—influence of some technological parameters

Nor-isoprenoid compounds, such as β-damascenone, β-ionone, 2,2,6-trimethylcyclohexanone (TCH), 1,1,6-trimethyl-1,2-dihydronaphthalene (TDN) and vitispirane were determined in 14 young port wines and 45 old port wines. As between the two groups of wines levels of these compounds are quite different, an experimental protocol was performed in order to determine which technological parameter (dissolved O2, free SO2 levels, pH and time/temperature) was related with the formation/consumption of these molecules. The five nor-isoprenoids were equally affected by the selected parameters and a similar profile with time was observed. The synergistic effects of increasing temperature and lowering pH had the largest impact. For samples treated with high oxygen regimes (saturation), the levels of all considered nor-isoprenoids decreased after a certain concentration of oxygen consumed (e.g. 10 mg l−1). Nevertheless, during barrel port wine ageing, corresponding to the 45 wines, two different behaviours can be observed: TDN, vitispirane and TCH increase significantly whilst a decrease of levels of β-ionone and β-damascenone with port barrel ageing was observed. It was also calculated that “over 40 year” old port wines have, respectively, 15, 5 and 3 times higher levels of TDN, vitispirane and TCH than the young ports. For these three compounds the respective rates of formation are higher than those of degradation, which suggests a higher number or higher concentration of precursors than those involved for the megastigame C13 nor-isoprenoids β-damascenone and β-ionone

Toxicometabolomics: small molecules to answer big toxicological questions

Given the high biological impact of classical and emerging toxicants, a sensitive and comprehensive assessment of the hazards and risks of these substances to organisms is urgently needed. In this sense, toxicometabolomics emerged as a new and growing field in life sciences, which use metabolomics to provide new sets of susceptibility, exposure, and/or effects biomarkers; and to characterize in detail the metabolic responses and altered biological pathways that various stressful stimuli cause in many organisms. The present review focuses on the analytical platforms and the typical workflow employed in toxicometabolomic studies, and gives an overview of recent exploratory research that applied metabolomics in various areas of toxicology.info:eu-repo/semantics/publishedVersio

Fatty acid composition of wild edible mushrooms species: a comparative study

A comparative study was developed on the total fatty acids composition of twelve wild edible mushroom species (Suillus bellini, Suillus luteus, Suillus granulatus, Hygrophorus agathosmus, Amanita rubescens, Russula cyanoxantha, Boletus edulis, Tricholoma equestre, Fistulina hepatica, Cantharellus cibarius, Amanita caesarea and Hydnum rufescens). In order to define qualitative and quantitative profiles, combined fatty acids were hydrolyzed with potassium hydroxide/methanol and all free compounds were derived to their methyl ester forms with methanolic boron trifluoride, followed by analysis by GC-MS. Thirty fatty acids were determined. As far as we know, the fatty acid profiles of A. caesarea and H. rufescens are described for the first time. As for the remaining species, a high number of new compounds were identified, which much improved the knowledge about their fatty acids profiles. In general, oleic, linoleic, palmitic and stearic acids were present in highest contents. Polyunsaturated and monounsaturated fatty acids, valuable healthy compounds for humans, predominated over saturated fatty acids for all the studied mushroom species. R. cyanoxantha presented the highest fatty acids amounts, while B. edulis was the poorest species. By Agglomerative Hierarchic Cluster Analysis the studied species were gathered in 5 groups, based in their fatty acid patternsFundação para a Ciência e a Tecnologia (FCT) for a grant (SFRH/BD/22108/2005)

Study of major aromatic compounds in port wines from carotenoid degradation

The carotenoids degradation and the formation of volatiles were examined by simulating Port wine aging. A two year old red Port wine was saturated with oxygen, supplemented with lutein and b-carotene and kept at 60ºC during 87 h. A similar study was performed in a model wine solution. Results showed that the percentage decrease in lutein levels was, respectively, 79% and 95%, in the wine model solution and in the Port wine, and 55% and 10% for b-carotene, indicating that lutein was more sensitive to degradation than b-carotene. Two other unknown degradation carotenoid compounds were identified by HPLC/DAD (reverse phase λmax: 422; 445; 475 and 422; 445; 472) in the lutein supplemented wine. Levels of b-ionone and b-cyclocitral increased (2.5 times) in both, wine and wine model solution, supplemented with b-carotene. Along with these compounds, the same behaviour was observed in b-damascenone in the supplemented lutein wine and wine model solution. New insights were provided into the understanding of aroma modifications occurring during Port wine aging. The relationship between carotenoid molecules (b-carotene and lutein) and some volatiles has also been provided

Antimicrobial activity of endophytic fungi from olive tree leaves

In this study, the antimicrobial potential of three fungal endophytes from leaves of Olea europaea L. was evaluated and the host plant extract effect in the antimicrobial activity was examined. The volatile compounds produced by endophytes were identified by GC/MS and further correlated with the antimicrobial activity. In potato dextrose agar, both Penicillium commune and Penicillium canescens were the most effective inhibiting Gram-positive and -negative bacteria (up to 2.7-fold compared to 30 µg/mL chloramphenicol), whereas Alternaria alternata was most effective inhibiting yeasts (up to 8.0-fold compared to 25 μg/mL fluconazole). The presence of aqueous leaf extract in culture medium showed to induce or repress the antimicrobial activity, depending on the endophytic species. In the next step, various organic extracts from both A. alternata mycelium and cultured broth we re prepared; being ethyl acetate extracts displayed the widest spectrum of anti-microorganisms at a minimum inhibitory concentration ≤0.095 mg/mL. The volatile composition of the fungi that displayed the highest (A. alternata) and the lowest (P. canescens) antimicrobial activity against yeasts revealed the presence of six volatiles, being the most abundant components (3-methyl-1-butanol and phenylethyl alcohol) ascribed with antimicrobial potentialities. Overall the results highlighted for the first time the antimicrobial potential of endophytic fungi from O. europaea and the possibility to be exploited for their antimicrobial agents. Graphical Abstract: [Figure not available: see fulltext.]This work is funded by FEDER funds through COMPETE (Programa Operacional Factores de Competitividade) and by national funds by FCT (Fundação para a Ciência e a Tecnologia) in the framework of the project “EndoBio—Isolation and screening of endophytic fungi for biological control of olive against Colletotrichum acutatum and Verticillium dahliae” (PTDC/ AGR-PRO/4354/2012).info:eu-repo/semantics/publishedVersio

Metabolomic analysis of the toxicity pathways elicited by subtoxic concentrations of methylone in primary mouse hepatocytes

info:eu-repo/semantics/publishedVersio

Interaction between two co-occurring fungi present in chestnut orchards

Hypholoma fasciculare is a wood-decaying basidiomycete with a worldwide distribution, including tropical, temperate and boreal forest ecosystems. In Trás-os-Montes region (Northeast of Portugal) this species is commonly present in soils of several habitats, including chestnut and oak tree forests. The ectomycorrhizal fungus Pisolithus tinctorius is another species with high occurrence in those ecosystems. The present work intends to study the in vitro interaction between H. fasciculare and P. tinctorius through evaluation of fungal growth, changes on hyphae morphology, the production of volatile compounds and Iytic enzymes. The results obtained showed that H. fasciculare inhibited significantly the growth of P. tinctorius in 49%, long before hyphal contact of their colonies. This inhibition could be result from the liberation from H. fasciculare of volatile compounds and/or diffusible inhibitory substances, such as extracellular enzymes. Alteration in the production of volatile compounds, distributed in several chemical classes (alcohols, ketones, aldehydes, terpenes, among others) was detected over the time course of interaction. In addition, amylase, cellulase, laccase and lipase were produced by H. fasciculare. The possible role of these compounds during interaction will be discussed.This work is supported by FCT I&D grant PTDC/ AGR-AAM/099556/200

Interaction between Hypholoma fasciculare and the ectomycorrhizal fungus Pisolithus tinctorius

In the past few years, cord-forming basidiomycetes have received considerable attention in their growth strategies in the presence of other fungi (saprotrophic and pathogenic). In the present study, the in vitro interaction between the cord-forming basidiomycete Hypholoma fasciculare and the ectomycorrhizal fungus Pisolithus tinctorius was studied. Dual-cultures were established and the radial fungal growth, hyphae morphology and production of volatile compounds were evaluated during interaction. Growth of P. tinctorius is severely inhibited by H. fasciculare even before mycelia contact, suggesting a mechanism of antagonism at a distance. Following contact with H. fasciculare mycelia, P. tinctorius displayed distinctive hyphal interference with collapsed or atypical hyphae. Alteration in the production of volatile compounds, distributed in several chemical classes (alcohols, ketones, aldehydes, terpenes, among others) was also detected over the time course of interaction. Sesquiterpenes compounds with putative antifungal properties were the most abundant before fungal contact and their possible role during interaction will be discussed