3,768 research outputs found

    An efficient one-pot synthesis of polyphenolic amino acids and evaluation of their radical-scavenging activity

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    A simple and efficient procedure for the synthesis of N-acyl 4-hydroxy, 4-hydroxy-3-methoxy and 3,4-dihydroxy phenylglycine amides by a strategy based on the multicomponent Ugi reaction is proposed. Hydroxybenzaldehyde derivatives were reacted with 4-methoxybenzylamine, cyclohexyl isocyanide and benzoic acid or 2-naphthylacetic acid to give Ugi adducts that were treated with trifluoroacetic acid yielding N-acyl hydroxyphenylglycine amides in good yields. The same procedure using as acid component protocatechuic acid or hydrocaffeic acid gave N-catechoyl 3,4-dihydroxyphenylglycine amides. The use of N-benzyloxycarbonylglycine as acid component allowed the preparation of a 3,4-dihydroxyphenylglycyl dipeptide derivative. Radical-scavenging activity studies of the polyphenolic amino acid derivatives showed a sharp increase in activity with the increase in number of hydroxyl or catechol groups present. Cyclic voltammetry experiments established a correlation between oxidation peak potentials and the radical-scavenging activity.This work received financial support from the Foundation for Science and Technology (FCT, Portugal), through projects PTDC/QUIQOR/29015/2017, UID/QUI/00686/2016 (CQUM) and UID/QUI/50006/2013-POCI-01-0145-FEDER-007265, co-financed by European Union (FEDER under the Partnership Agreement PT2020), and from North of Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF) (project NORTE-010145-FEDER-24). We also acknowledge the Doctoral grant SFRH/BD/100889/2014. We are thankful to Laboratory for Structural Elucidation of the Materials Centre of the University of Porto CEMUP for MS/NMR analysis and able technical support

    Vanadate oligomers: in vivo effects in hepatic vanadium accumulation and stress markers

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    The formation of vanadate oligomeric species is often disregarded in studies on vanadate effects in biological systems, particularly in vivo, even though they may interact with high affinity with many proteins. We report the effects in fish hepatic tissue of an acute intravenous exposure (12, 24 h and 7 days) to two vanadium(V) solutions, metavanadate and decavanadate, containing different vanadate oligomers administered at sub-lethal concentration (5 mM; 1 mg/kg). Decavanadate solution promotes a 5-fold increase (0.135 ± 0.053 lg V 1 dry tissues) in the vanadium content of the mitochondrial fraction 7 days after exposition, whereas no effects were observed after metavanadate solution administration. Reduced glutathione (GSH) levels did not change and the overall reactive oxygen species (ROS) production was decreased by 30% 24 h after decavanadate administration, while for metavanadate, GSH levels increased 35%, the overall ROS production was depressed by 40% and mitochondrial superoxide anion production decreased 45%. Decavanadate intoxication did not induce changes in the rate of lipid peroxidation till 12 h, but later increased 80%, which is similar to the increase observed for metavanadate after 24 h. Decameric vanadate administration clearly induces different effects than the other vanadate oligomeric species, pointing out the importance of taking into account the different vanadate oligomers in the evaluation of vanadium(V) effects in biological systems

    Enhanced sweet taste perception in obesity: joint analysis of gustatory data from multiple studies

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    Copyright © 2022 Ribeiro, Torres, Fernandes, Camacho, Branco, Martins, Raimundo and Oliveira-Maia. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.Introduction: While sweet taste perception is a potential determinant of feeding behavior in obesity, the supporting evidence is inconsistent and is typically associated with methodological limitations. Notably, possible associations between sweet taste perception and measures of food reward remain undetermined. Materials and methods: We conducted a cross-sectional analysis comparing 246 individuals with severe obesity and 174 healthy volunteers using a validated method for taste perception assessment. We included gustatory variables, namely intensity and pleasantness ratings of sour, salt, sweet, and bitter tastants, and taste thresholds assessed by electrogustometry. Reward-related feeding behavior, including hedonic hunger, food addiction, feeding behavior traits, and acceptance of foods and alcohol, was evaluated using self-rated scales for comparison with gustatory measures. Result: In logistic regressions adjusted for age, gender, educational level, and research center, we found that a greater likelihood of belonging to the obesity group was associated with higher sweet intensity ratings (OR = 1.4, P = 0.01), hedonic hunger, food addiction symptoms, restrained and emotional eating (1.7 < OR ≤ 4.6, all P ≤ 0.001), and lower alcohol acceptance (OR = 0.6, P = 0.0002). Using principal component analysis, we found that while hedonic hunger, food addiction, and emotional eating were strongly interrelated, they were not associated with sweet intensity perception that, in turn, had a closer relationship with alcohol acceptance and restrained eating. Conclusion: We found that individuals with obesity report higher sweet taste intensity ratings than healthy controls. Furthermore, while psychological measures of reward-related feeding behavior assess a common construct, sweet intensity perception may represent a different obesity-related dimension.AJO-M was supported by grants from the BIAL Foundation (176/10), from Fundação para a Ciência e Tecnologia (FCT), through a Junior Research and Career Development Award from the Harvard Medical Portugal Program (HMSP/ICJ/0020/2011), and by a Starting Grant from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement No. 950357). ST was funded by the Center for Psychology at the University of Porto (FCT UIDB/00050/2020). AF was funded by a postdoctoral fellowship from FCT (SFRH/BPD/880972/2012). GR was funded by doctoral fellowships from Universidade de Lisboa (BD/2015Call) and FCT (SFRH/BD/128783/2017).info:eu-repo/semantics/publishedVersio

    Enhanced sweet taste perception in obesity: joint analysis of gustatory data from multiple studies

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    Copyright © 2022 Ribeiro, Torres, Fernandes, Camacho, Branco, Martins, Raimundo and Oliveira-Maia. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.Introduction: While sweet taste perception is a potential determinant of feeding behavior in obesity, the supporting evidence is inconsistent and is typically associated with methodological limitations. Notably, possible associations between sweet taste perception and measures of food reward remain undetermined. Materials and methods: We conducted a cross-sectional analysis comparing 246 individuals with severe obesity and 174 healthy volunteers using a validated method for taste perception assessment. We included gustatory variables, namely intensity and pleasantness ratings of sour, salt, sweet, and bitter tastants, and taste thresholds assessed by electrogustometry. Reward-related feeding behavior, including hedonic hunger, food addiction, feeding behavior traits, and acceptance of foods and alcohol, was evaluated using self-rated scales for comparison with gustatory measures. Result: In logistic regressions adjusted for age, gender, educational level, and research center, we found that a greater likelihood of belonging to the obesity group was associated with higher sweet intensity ratings (OR = 1.4, P = 0.01), hedonic hunger, food addiction symptoms, restrained and emotional eating (1.7 < OR ≤ 4.6, all P ≤ 0.001), and lower alcohol acceptance (OR = 0.6, P = 0.0002). Using principal component analysis, we found that while hedonic hunger, food addiction, and emotional eating were strongly interrelated, they were not associated with sweet intensity perception that, in turn, had a closer relationship with alcohol acceptance and restrained eating. Conclusion: We found that individuals with obesity report higher sweet taste intensity ratings than healthy controls. Furthermore, while psychological measures of reward-related feeding behavior assess a common construct, sweet intensity perception may represent a different obesity-related dimension.AJO-M was supported by grants from the BIAL Foundation (176/10), from Fundação para a Ciência e Tecnologia (FCT), through a Junior Research and Career Development Award from the Harvard Medical Portugal Program (HMSP/ICJ/0020/2011), and by a Starting Grant from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement No. 950357). ST was funded by the Center for Psychology at the University of Porto (FCT UIDB/00050/2020). AF was funded by a postdoctoral fellowship from FCT (SFRH/BPD/880972/2012). GR was funded by doctoral fellowships from Universidade de Lisboa (BD/2015Call) and FCT (SFRH/BD/128783/2017).info:eu-repo/semantics/publishedVersio

    Escala de Competências de Estudo: resultados de um estudo de validação no Instituto Politécnico de Leiria

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    Descreve-se um estudo exploratório de construção e validação de uma escala voltada para a avaliação das competências de estudo e abordagens à aprendizagem por parte de alunos do Ensino Superior Politécnico. Uma amostra de 264 alunos foi considerada neste estudo, tendo-se recorrido à Escala de Competências de Estudo (ECE – Almeida & Joly, em preparação). Os resultados, longe de confirmarem as dimensões iniciais propostas pelos autores, parecem identificar duas formas de auto-regulação nos alunos: uma mais centrada nos comportamentos e condutas quotidianas (organização do estudo) e outra mais dirigida por aspectos motivacionais e cognitivos. São apresentados os resultados centrados na delimitação das duas dimensões, assim como a sua associação a níveis de rendimento escolar (disciplinas em atraso e médias obtidas) e diferenciação segundo o género, idade e tipo de curso frequentado pelos alunos. As correlações com o rendimento são mais elevadas tomando a dimensão mais comportamental da autoregulação, sendo que as alunas apresentam médias mais elevadas nas duas dimensões e os alunos mais velhos apresentam níveis mais elevados de auto-regulação em termos motivacionais e cognitivos

    Assessment of sediment contamination in an impacted estuary: differential effects and adaptations of sentinel organisms and implications for biomonitoring

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    Conferência realizada em Lisboa, de 6-9 November de 2013Estuarine pollution is reflected in the concentration of toxicants in sediments, depending on their geochemical properties, since sediments trap substances from the water column, either dissolved or bound to suspended matter. However, determining risk of sediment contaminants to biota has many constraints. For such reason, integrative approaches are keystone. Taking the Sado estuary (SW Portugal) as a case study, contrasted to a reference estuary (the Mira) within the same geographical location, the present study aimed at integrating sediment contamination with the effects and responses to pollutants in distinct benthic organisms with commercial and ecological value

    Vanadium distribution, lipid peroxidation and oxidative stress markers upon decavanadate in vivo administration

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    The contribution of decameric vanadate species to vanadate toxic effects in cardiac muscle was studied following an intravenous administration of a decavanadate solution (1 mM total vanadium) in Sparus aurata. Although decameric vanadate is unstable in the assay medium, it decomposes with a half-life time of 16 allowing studying its effects not only in vitro but also in vivo. After 1, 6 and 12 h upon decavanadate administration the increase of vanadium in blood plasma, red blood cells and in cardiac mitochondria and cytosol is not affected in comparison to the administration of a metavanadate solution containing labile oxovanadates. Cardiac tissue lipid peroxidation increases up to 20%, 1, 6 and 12 h after metavanadate administration, whilst for decavanadate no effects were observed except 1 h after treatment (+20%). Metavanadate administration clearly differs from decavanadate by enhancing, 12 h after exposure, mitochondrial superoxide dismutase (SOD) activity (+115%) and not affecting catalase (CAT) activity whereas decavanadate increases SOD activity by 20% and decreases ( 55%) mitochondrial CAT activity. At early times of exposure, 1 and 6 h, the only effect observed upon decavanadate administration was the increase by 20% of SOD activity. In conclusion, decavanadate has a different response pattern of lipid peroxidation and oxidative stress markers, in spite of the same vanadium distribution in cardiac cells observed after decavanadate and metavanadate administration. It is suggested that once formed decameric vanadate species has a different reactivity than vanadate, thus, pointing out that the differential contribution of vanadium oligomers should be taken into account to rationalize in vivo vanadate toxicity

    A dataset on skeletal muscle mass index, body composition and strength to determinate sarcopenia in bariatric patients

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    © 2023 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)Bariatric surgery is the treatment for severe obesity, with proven efficacy in reducing weight. Weight loss associated with bariatric surgery is greatly associated with a significant reduction of skeletal muscle and bone mineral mass, which leads us to induce that after bariatric surgery, patients incur an increased risk of sarcopenia. Prophylactic programs that prevent sarcopenia in bariatric surgery patients seems to be one of the crucial points for the long-term surgical success of bariatric and metabolic surgery. This article presents a initial data set of skeletal muscle mass index, body composition and strength to determinate sarcopenia in bariatric patients. The data were collected in a Central Hospital and in the University. In total, is necessary to recruit 46 patients waiting for bariatric surgery, between 18 and 60 years, men, and woman, without contradiction for exercise. The patients are randomized in two groups, for exercise group and control group. The evaluation is made on five points of timeline, before the surgery, after the surgery, after de exercise program, six months, and twelve months after the exercise program.This work is funded by national funds through the Foundation for Science and Technology, under the project UIDP/04923/2020.info:eu-repo/semantics/publishedVersio

    Synthesis and preliminary biological evaluation of new phenolic and catecholic dehydroamino acid derivatives

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    A library of N-phenolic and N-catecholic dehydroamino acid derivatives was prepared using an innovative synthetic strategy that involves mild reaction conditions and simple work-up procedures. The method comprises coupling of phenolic or catecholic acids with β-hydroxyamino acids followed by tert-butyloxycarbonylation of all hydroxyl groups using tert-butyldicarbonate and 4-dimethylaminopyridine as catalyst. Treatment of these amino acids with N,N,N’,N’-tetramethylguanidine affords the corresponding O-tert-butyloxycarbonyldehydro-amino acid derivative. Deprotection of the aromatic hydroxyl groups is carried out with trifluoroacetic acid. This synthetic strategy can be applied in a one-pot procedure and yields compounds that can be easily inserted into peptides or other biomolecules after cleavage of the C-protecting group. Preliminary studies of cell viability show that these new compounds display very low or no toxicity. These dehydroamino acids with a phenolic or catecholic moiety can have intrinsic biological activity or used to prepare new hydrogels that mimic mussel adhesive proteins.This work received financial support from the Foundation for Science and Technology (FCT, Portugal), through projects UID/QUI/00686/2013, UID/QUI/00686/2016 (CQUM) and UID/QUI/50006/2013-POCI-01-0145-FEDER-007265, co-financed by European Union (FEDER under the Partnership Agreement PT2020), and from Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF) (project NORTE-010145-FEDER-24).info:eu-repo/semantics/publishedVersio
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