Browsing by Author "Pinho, P. Guedes de"
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- Amanita phalloides poisoning: Mechanisms of toxicity and treatmentPublication . Garcia, Juliana; Costa, Vera M.; Carvalho, Alexandra T.P.; Baptista, Paula; Pinho, P. Guedes de; Bastos, Maria de Lourdes; Carvalho, FélixAmanita phalloides, also known as 'death cap', is one of the most poisonous mushrooms, being involved in the majority of human fatal cases of mushroom poisoning worldwide. This species contains three main groups of toxins: amatoxins, phallotoxins, and virotoxins. From these, amatoxins, especially α-amanitin, are the main responsible for the toxic effects in humans. It is recognized that α-amanitin inhibits RNA polymerase II, causing protein deficit and ultimately cell death, although other mechanisms are thought to be involved. The liver is the main target organ of toxicity, but other organs are also affected, especially the kidneys. Intoxication symptoms usually appear after a latent period and may include gastrointestinal disorders followed by jaundice, seizures, and coma, culminating in death. Therapy consists in supportive measures, gastric decontamination, drug therapy and, ultimately, liver transplantation if clinical condition worsens. The discovery of an effective antidote is still a major unsolved issue. The present paper examines the clinical toxicology of A. phalloides, providing the currently available information on the mechanisms of toxicityinvolved and on the current knowledge on the treatment prescribed against this type of mushrooms. Antidotal perspectives will be raised as to set the pace to new and improved therapy against these mushrooms.
- Antimicrobial activity of endophytic fungi from olive tree leavesPublication . Malhadas, Cynthia; Malheiro, Ricardo; Pereira, J.A.; Pinho, P. Guedes de; Baptista, PaulaIn 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.]
- Aroma compounds in eleven edible mushroom species: relationship between volatile profile and sensorial characteristicsPublication . Pinho, P. Guedes de; Ribeiro, Bárbara; Gonçalves, Rui; Baptista, Paula; Valentão, Patrícia; Seabra, Rosa M.; Andrade, Paula B.Wild edible mushrooms are consumed a lot in many countries, being cooked or eaten in salads. Their culinary and commercial value is mainly due to their organoleptic properties, namely aroma and flavour. In addition, the aroma is very characteristic for each mushroom species, which determines the distinction between them. Despite the high consumption of mushrooms, little work is available concerning their volatile composition. Trás-os-Montes region (north-eastern Portugal) is known for the variety of its soils and diversity of climate conditions. This variability assumes an important role in mushroom production, which is why this region is recognised as one of the richest regions in wild edible species. In this work eleven wild edible mushrooms collected in this region were studied: Suillus bellini, Suillus luteus, Suillus granulatus, Tricholomopsis rutilans, Hygrophorus agathosmus, Amanita rubescens, Russula cyanoxantha, Boletus edulis, Tricholoma equestre, Fistulina hepatica and Cantharellus cibarius. With the exception of B. edulis, F. hepatica, C. cibarius and S. luteus, there is no knowledge of volatile characterisation of these species. The volatile and semi-volatile constituents were determined by headspace solid-phase microextraction (HS-SPME) and by liquid extraction combined with gas chromatographymass spectrometry (GC-MS). A total of 49 volatiles and 17 semi-volatile components were identified. Using sensorial analysis, the descriptors “mushroom-like”, “farmfeed-like”, “floral”, “honey-like”, “hay-herb” and “nutty” were obtained. The multivariate analysis (principal component analysis and agglomerative hierarchic cluster analysis) of sensorial and chemical data revealed a correlation between sensory descriptors and volatiles. The studied mushroom species can be divided in three groups: one rich in C8 derivatives, like 3-octanol, 1-octen-3-ol, trans-2-octen-1-ol, 3-octanone and 1-octen-3-one; another with high amounts of terpenic volatile compounds; and a third one rich in methional. The presence and contents of these compounds gives a considerable contribution to their sensory characteristics.
- Aroma compounds in eleven edible mushroom species: relationship between volatile profile and sensorial characteristicsPublication . Pinho, P. Guedes de; Ribeiro, Bárbara; Gonçalves, Rui; Baptista, Paula; Valentão, Patrícia; Seabra, Rosa M.; Andrade, Paula B.Wild edible mushrooms, are consumed a lot in many countries, being cooked or eaten in salads. Their culinary and commercial value is mainly due to their organoleptic properties, namely aroma and flavour. In addition, the aroma is very characteristic for each mushroom species, which determines the distinction between them (1, 2). Despite the high consumption of mushrooms, little work is available concerning· their volatile composition. Tras-os-Montes region (north-east.em Portugal) is known for the variety of its soils and diversity of climate conditions.
- Aroma compounds in eleven edible mushroom species: relationship between volatile profile and sensorial characteristicsPublication . Pinho, P. Guedes de; Ribeiro, Bárbara; Gonçalves, Rui; Baptista, Paula; Valentão, Patrícia; Seabra, Rosa M.; Andrade, Paula B.Volatile and semi-volatile components of 11 wild edible mushrooms, Suillus bellini, Suillus luteus, Suillus granulatus, Tricholomopsis rutilans, Hygrophorus agathosmus, Amanita rubescens, Russula cyanoxantha, Boletus edulis, Tricholoma equestre, Fistulina hepatica and Cantharellus cibarius, were determined by headspace solidphase microextraction and by liquid extraction combined with gas chromatographymass spectrometry.
- Changes in volatile compounds of Dittrichia viscosa caused by the attack of the gall-forming dipteran Myopites stylatusPublication . Santos, Sónia A.P.; Mota, Luís; Malheiro, Ricardo; Silva, Franceli; Campos, Mercedes; Pinho, P. Guedes de; Pereira, J.A.The false yellowhead Dittrichia viscosa (L.) Aiton (Asteraceae) is a spontaneous plant occurring in south-ern Europe. A tritrophic relationship is observed in the aerial parts of this plant since flowers are attackedby the gall-forming dipteran Myopites stylatus (Fabricius) which, in turn, is parasitized by hymenopteranspecies. This relationship may be mediated by volatile organic compounds (VOCs) released by the aerialparts of the plant. Thus, VOCs exhaled by leaves, flowers and flower galls of D. viscosa were characterizedby headspace solid-phase microextraction (HS-SPME) and gas chromatography-ion trap-mass spectrom-etry (GC-IT-MS). A total of 46 compounds were identified, including alcohols, aldehydes, esters, ketones,phenol derivatives, terpenes and sesquiterpenes. Volatile fractions registered from the different aerialparts of D. viscosa were quantitative and qualitatively different. Leaves were composed by 31 volatile com-pounds, flowers by 34 and galls by 29. Sesquiterpenes represented about 76.8% of the volatiles exhaledfrom leaves; flowers were composed mainly by sesquiterpenes (49.1%) and terpenes (34.6%) such as -pinene, limonene and -pinene and flower galls exhaled phenol derivatives (68.7%) such as anethol andestragole, and terpenes (25.1%) such as eucalyptol and limonene. Several sesquiterpene like compoundswere exclusive from leaves, while esters (e.g. methyl-2-propylhexanoate) were exclusive from flowersand the terpene eucalyptol from flower galls. The potential effect of volatiles exhaled by the differentaerial parts of D. viscosa on the behaviour of insects implicated in the relationship with D. viscosa isdiscussed.
- Chemical assessment and in vitro antioxidant capacity of Ficus carica latexPublication . Oliveira, Andreia P.; Silva, Luís R.; Ferreres, Frederico; Pinho, P. Guedes de; Valentão, Patrícia; Silva, Branca M.; Pereira, J.A.; Andrade, Paula B.Ficus species possess latex-like material within their vasculatures, affording protection and selfhealing from physical attacks. In this work, metabolite profiling was performed on Ficus carica latex. Volatiles profile was determined by HS-SPME/GC-IT-MS, with 34 compounds being identified, distributed by distinct chemical classes: 5 aldehydes, 7 alcohols, 1 ketone, 9 monoterpenes, 9 sesquiterpenes and 3 other compounds. Sesquiterpenes constituted the most abundant class in latex (ca. 91% of total identified compounds). Organic acids composition was also characterized, by HPLC-UV, and oxalic, citric, malic, quinic, shikimic and fumaric acids were determined. Malic and shikimic acids were present in higher amounts (ca. 26%, each). The antioxidant potential of this material was checked by distinct in vitro chemical assays. A concentration-dependent activity was noticed against DPPH, nitric oxide and superoxide radicals. Additionally, acetylcholinesterase inhibitory capacity was evaluated, but a weak effect was found.
- Co-ingestion of amatoxins and isoxazoles-containing mushrooms and successful treatment: A case reportPublication . Garcia, Juliana; Costa, Vera M.; Costa, Ana Elisa; Andrade, Sérgio; Carneiro, Ana Cristina; Conceição, Filipe; Paiva, José Artur; Pinho, P. Guedes de; Baptista, Paula; Bastos, Maria de Lourdes; Carvalho, FélixMushroom poisonings occur when ingestion of wild mushrooms containing toxins takes place, placing the consumers at life-threatening risk. In the present case report, an unusual multiple poisoning with isoxazoles- and amatoxins-containing mushrooms in a context of altered mental state and poorly controlled hypertension is presented. A 68-year-old female was presented to São João hospital (Portugal) with complaints of extreme dizziness, hallucinations, vertigo and imbalance, 3 h after consuming a stew of wild mushrooms. The first observations revealed altered mental state and elevated blood pressure. The examination of cooked mushroom fragments allowed a preliminary identification of Amanita pantherina. Gas chromatography-mass spectrometry (GC-MS) showed the presence of muscimol in urine. Moreover, through high-performance liquid chromatography-ultraviolet detection (HPLC-UV) analysis of the gastric juice, the presence of α-amanitin was found, showing that amatoxins-containing mushrooms were also included in the stew. After 4 days of supportive treatment, activated charcoal, silybin and N-acetylcysteine, the patient recovered being discharged 10 days post-ingestion with no organ complications. The prompt and appropriate therapy protocol for life-threatening amatoxins toxicity probably saved the patient's life as oral absorption was decreased and also supportive care was immediately started.
- Correlation between the pattern volatiles and the overall aroma of wild edible mushroomsPublication . Pinho, P. Guedes de; Ribeiro, Bárbara; Gonçalves, Rui; Baptista, Paula; Valentão, Patrícia; Seabra, Rosa M.; Andrade, Paula B.Volatile and semivolatile components of 11 wild edible mushrooms, Suillus bellini, Suillus luteus, Suillus granulatus, Tricholomopsis rutilans, Hygrophorus agathosmus, Amanita rubescens, Russula cyanoxantha, Boletus edulis, Tricholoma equestre, Fistulina hepatica, and Cantharellus cibarius, were determined by headspace solid-phase microextraction (HS-SPME) and by liquid extraction combined with gas chromatography–mass spectrometry (GC-MS). Fifty volatiles and nonvolatiles components were formally identified and 13 others were tentatively identified. Using sensorial analysis, the descriptors “mushroomlike”, “farm-feed”, “floral”, “honeylike”, “hay-herb”, and “nutty” were obtained. A correlation between sensory descriptors and volatiles was observed by applying multivariate analysis (principal component analysis and agglomerative hierarchic cluster analysis) to the sensorial and chemical data. The studied edible mushrooms can be divided in three groups. One of them is rich in C8 derivatives, such as 3-octanol, 1-octen-3-ol, trans-2-octen-1-ol, 3-octanone, and 1-octen-3-one; another one is rich in terpenic volatile compounds; and the last one is rich in methional. The presence and contents of these compounds give a considerable contribution to the sensory characteristics of the analyzed species
- Determination of amatoxins and phallotoxins in Amanita phalloides mushrooms from northeastern Portugal by HPLC-DAD-MSPublication . Garcia, Juliana; Oliveira, Ana Paula Leandro; Pinho, P. Guedes de; Freitas, Victor; Carvalho, Alexandra T.P.; Baptista, Paula; Pereira, Eric Carvalho; Bastos, Maria de Lourdes; Carvalho, FélixAmanita phalloides is a toxic mushroom responsible for the majority of deaths occurring after mushrooms ingestion, mainly due to amatoxins. In the present study the contents and distribution of the major amatoxins and phallotoxins in different tissues of A. phalloides from two different sites of Portugal were analyzed by liquid chromatography (LC) coupled to diode array (DAD) and mass spectrometry (MS) detection. The main toxins were separated by LC and its chemical structures confirmed by MS. a-Amanitin contents in caps, stipe and volva tissues were quantified by RP-HPLC. The results show that caps have the highest content of amatoxins, whereas the volva was richest in phallotoxins. Moreover variability in the toxins composition from different geographic sites was also observed. This study provides for the first time the content of toxins in A. phalloides from Portugal.