Compostos fenólicos e atividade antioxidante de Leiothrix flavescens (Bong.) Ruhland (Eriocaulaceae)

This paper describes a chemical investigation (by high-speed counter-current chromatography) of an extract in methanol of the capitula (flower-heads) of the endemic Brazilian herb Leiothrix flavescens (Bong.) Ruhland (Eriocaulaceae). Fractionation of this extract by preparative chromatography and identification of the isolated compounds by spectrometric methods (IR, UV, ESI-MS, NMR) led to the identification of flavones (apigenin, luteolin and 6-methoxyluteolin) and 1,3-di-O-feruloyl glycerol. The antioxidant activity of the extract was determined by DPPH reduction and the total phenolic content by the Folin-Ciocalteau assay. It was found that the methanolic extract of L. flavescens possesses strong antioxidant activity. Additionally, the chemical profile provided useful data for a discussion of the taxonomy of the Eriocaulaceae.

Níveis constitutivos de compostos fenólicos podem estar relacionados à resistência da cana-de-açúcar à cigarrinha-das-raízes

The interaction of the leafhopper-of-roots with the sugar cane is still poorly marked and there is little information on resistant varieties. The phenolic compounds are involved in resistance mechanisms of the antibiosis type, but few studies are devoted to the studying role of these compounds in the interaction of plants with sucking insects. The study was conducted to determine how the sugar cane responded to the infestation of Mahanarva fimbriolata in terms of accumulation of phenolic compounds. An experiment was carried out under controlled conditions in a randomized design in a factorial schedule 3 x 2 x 4, with 3 genotypes and sugar cane, 2 levels of nymphs infestation of M. fimbriolata and sampling 4 times, with 4 repetitions. The genotypes SP80-1816 and RB72454 showed higher levels of total phenols when subjected to an infestation of the pest, but the duration of the nymphal stage and mortality of sharpshooters were significantly lower in those varieties, indicating that the increase in the concentration of phenolic compounds may had been caused by death and decay of the roots. It was not observed variation in levels of total phenols in the variety SP83- 5073 subject to an infestation of M. fimbriolata. However, the mortality of the leafhopperof- roots and duration of the stage of nymphs were significantly higher in genotype, indicating the existence of resistance-type antibiosis. Analysis of correlation showed that higher initial levels of phenolic compounds resulting in mortality of the pest can increase the duration of the nymph stage.

Compostos fenólicos e atividade antioxidante em Salvia officinalis L. micropropagada

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Yacon (Smallanthus sonchifolius): compostos fenólicos totais e efeitos sobre a glicemia e estresse oxidativo em ratos diabéticos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Efeitos da concentração dos compostos fenólicos no mosto da fermentação alcoólica

Pós-graduação em Agronomia (Energia na Agricultura) - FCA

Atividade antioxidante, compostos fenólicos totais e cor em abacate ‘hass’ submetido a diferentes tratamentos físicos

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Compostos fenólicos de Paepalanthus geniculatus (Eriocaulaceae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Efeito da hidrotermica em abacate ‘Hass’ sobre a capacidade antioxidante, compostos fenólicos e coloração

This study aimed to determine the antioxidant activity, total phenolic compounds and color in avocado 'Hass' hydrothermally treated. The fruits were hydrothermally treated at 45 degrees C for 5, 10, 15 and 20 min. After treatment, fruit were stored at room temperature (21 +/- 1 degrees C and 70 +/- 5% relative humidity) and cold (10 degrees C +/- 1 and 90 +/- 5% relative humidity). The fruits were analyzed for their antioxidant capacity by DPPH method and phenolic compounds at 0, 3, 9 and 12 days. The fruits color was measured at 0, 3, 6, 9, 12 and 15 days. The control fruits had higher antioxidant capacity and content of phenolic compounds during the storage period, compared to the fruits hydrothermally treated. The hydrothermally treatment altered the behavior as for the maintenance of the antioxidant activity in relation to the fruits control. In spite of superior values of antioxidant activity for the fruits maintained at 21 +/- 1 degrees C and 70 +/- 5% relative humidity, those refrigerated presented better aspect for commercialization. The refrigerated fruits presented better aspect for commercialization in relation to the maintained under room temperature. The brightness, color a * and b * values decreased with the storage days. Values color superiors were observed for the fruits control and those maintained under refrigeration. As it increased the irradiation dose reduced the fruits antioxidant activity and coloration.

Análise do teor de compostos fenólicos e de ligninas em diferentes órgãos vegetativos de espécies arbóreas nativas de diferentes grupos sucessionais

O sucesso do desenvolvimento da dinâmica das formações vegetais depende das relações estabelecidas entre as espécies vegetais com outros organismos e com o meio físico. Tais relações estão sujeitas a situações de estresse, podendo esse ser de caráter abiótico, como condições elevadas de radiação solar e temperatura e déficit hídrico ou de caráter biótico, como a herbivoria e o ataque de patógenos. Dessa maneira, em virtude à necessidade de um sistema de defesa, as plantas utilizam compostos químicos, como compostos fenólicos e ligninas, para se desenvolverem com proteção. Os compostos fenólicos são compostos oriundos do metabolismo secundário vegetal e ocorrem na parede celular dos tecidos vegetais, constituindo assim uma rápida linha de defesa vegetal a lesões e infecções e funcionando como substrato para atuação de enzimas de defesa como peroxidases e polifenoloxidases. Junto com a atuação dos compostos fenólicos, as ligninas fornecem à planta maior resistência mecânica e impermeabilidade suficiente aos vasos condutores do xilema, proporcionando, assim, desde um fundamental auxílio aos vegetais na conquista do ambiente terrestre até o estabelecimento de uma barreira protetora eficiente contra o ataque de microorganismos. Assim, por meio da extração e análise dos teores de compostos fenólicos e de ligninas de porção de raiz, caule, ápice caulinar e folhas maduras e imaturas de indivíduos de Erythrina speciosa Andrews, Eugenia uniflora L., Hevea brasiliensis M. Arg., Hymenaea courbaril L. var. stilbocarpa (Hayne) Lee et Lang, Joannesia princeps Vell., Lecythis pisonis Cambess, Licania tomentosa (Benth.) Fritsch, Pachira aquatica Aubl. e Psidium guajava L., classificou-se como espécies pioneiras Erythrina speciosa Andrews, Hymenaea courbaril L. var. stilbocarpa (Hayne) Lee et Lang, Joannesia princeps Vell., Pachira aquatica Aubl... (Resumo completo, clicar acesso eletrônico abaixo)

Compostos fenólicos de 10 variedades de uva

Phenolic compounds represent one of the main groups of secondary metabolites. Due to their chemical diversity, they have a variety of functions in plants, such as protection against ultraviolet radiation, herbivores and pathogens, and attraction of pollinators or dispersers of fruits and seeds. For human, the phenolic compounds are used like food colorings and flavors and, due to their pharmacological properties, mainly to antioxidant activity, they are associated with several health benefits, such as delay senility, prevention and therapy of cardiovascular diseases and of some cancers. The grapes are considered one of the main source of phenolic compounds and the fruit and its products are consumed in Brazil and worldwide. Considering the phenolic compounds diversity and their different distribution in the grape parts, this work had like aims the extraction, identification and quantification of the main classes of phenolic compounds of 10 grape varieties. The content of total phenols, flavanols and anthocyanins were determined, respectively, according to the Folin-Ciocalteu, DMACA and comparison of pH spectrophotometric methods. The content of total phenols varied from 142.75 + 1.86 to 483.39 + 5.90 mg.L-1 in the peel and from 86.50 + 0.54 to 146.32 + 9.97 mg.L-1 in the pulp. The amount of total flavanols varied from 3.68 + 0.03 to 6.92 + 0.26 mg.L-1 in the peel and from 0.90 + 0.00 to 1.36 + 0.00 mg.L-1 in the pulp. The content of total anthocyanins varied from 7.00 + 0.99 to 406.56 + 39.50 mg.L-1 in the peel and from 2.88 + 0.28 to 46.36 + 1.89 mg.L-1 in the pulp. The phenolic compounds concentration was higher in the peel than in the pulp. The total phenols and anthocyanins varied a lot while the total flavanols were more constant. The flavanols represent the smaller portion of phenolic compounds

Propriedade antioxidante de compostos fenólicos: importância na dieta e na conservação de alimentos

Living organisms are constantly subjected to the action of free radicals, which are one of the causes of oxidation reactions, because they have on free electron, what makes it very reactive. They are products of organism reactions or they are produced by exogenous factors, such as tobacco. Fatty acids are the most vulnerable target, and may suffer lipid peroxidation, what affects the cell structure. Cardiovascular diseases, cancer and diseases of aging are occurrence of these reactions in the organism related. The aliments are also subjected to suffer oxidation reactions, what make them unfit for consumption and decreasing the useful life. Synthetics antioxidants are used as aliments preservatives, but they present some toxicity for the organism. Studies for the utilization of natural antioxidants have gained more importance in recent decades, due to the conservation potential and low toxicity. Phenolics compounds are largely present at the vegetable kingdom and they present high antioxidant potential due to the neutralization and kidnapping of free radicals capacity. These compounds are used by the industry at the aliments conservation, specially the phenolics acids. The consumption of aliments rich in phenolic compounds, such as teas, wines and fruits are low incidence of degenerative diseases related. This study consists in a bibliographic revision that covers these compounds importance in diet and at the food conservation, and the methodologies and difficulties in the extraction process due to variety of molecules of this group.

Compostos fenólicos e capacidade antioxidante em frutos de tomateiros mutantes fotomorfogenéticos

Phenolic compounds and antioxidant capacity are defense mechanisms of plants against the oxidative stress damage. Phenolic compounds are synthesized through the phenylpropanoid pathway, where the enzyme phenylalanine-ammonia-lyase plays a key role and it is influenced by light and photoreceptors such as phytochromes. The present research aims to evaluate the phenolic compounds content and antioxidant capacity of the wild Micro-Tom (MT) cultivar tomato fruits and its photomorphogenic mutant tomato plants high pigment 1 (hp1), super responsive to events mediated by light, and aurea (au), quantitative phytochrome deficient. Twenty mature fruits of each genotype (MT, hp1, au) were used in triplicate for analyses. To quantify the total phenolic compounds the Folin-Ciocalteu method was used and the antioxidant capacity was analyzed by Ferric Reducing Antioxidant Power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) methods. The hp1 mutant presented the highest total phenolic compounds content and higher antioxidant capacity than wild cultivar (MT) and au mutant, which did not differ significantly from MT cultivar.

Avaliação da influência da fermentação fúngica em estado sólido na obtenção de compostos fenólicos a partir de resíduos de café

Pós-graduação em Engenharia e Ciência de Alimentos - IBILCE

Efeito da fermentação fúngica no teor de compostos fenólicos em casca de café robusta

Coffee husk is an abundant by-product generated by the coffee industry and it can be used for the production of-value-added phenolic compounds. Currently, this residue has no commercial use due to the presence of anti-nutritional compounds and it is returned to the soil or burned. The aim of this study was to evaluate the content of phenolic compounds in Robusta coffee husk, the adequacy of this residue as substrate for fermentation processes, as well as evaluating the influence of fungal solid state fermentation to obtain phenolic compounds from this residue. In the present study, the use of different solvents for the extraction of polyphenols was evaluated and the content was found to be in the range of 96.9-159.5 mg of galic acid (GA).g(-1) substrate, depending on the solvent used. The best solvent was acetone, therefore it was selected for extraction. Studies were carried out to evaluate the effect of solid-state fermentation in the release of phenolic compounds, using the filamentous fungi Penicillium purpurogenum. The total phenolic content increased from 159.5 up to 243.2 mg GA.g(-1) substrate as a result the solid-state fermentation.

Relação entre a concentração dos compostos fenólicos do mosto e a eficiência da fermentação alcoólica por subprodutos em processo contínuo

The objective of this work was to evaluate the relationship between phenolic compounds and alcoholic fermentation efficiency. The yield of sugarcanebyproducts (glycerol, acidity, and biomass) was determined in a continuous process at SaoManoel Sugarcane Mill, (Sao Paulo, Brazil) during the 2011/2012 harvest period. The Saccharomyces cerevisiae strain used as inoculum was the CAT-1. During the harvest, the endogenous yeast outcompeted the selected strain, hence eliminating it from the process. This research consists of a case of study on the ethanol production facility. FolinCiocauteau and methylene blue method was used to assess phenolic compounds. The efficiencyof the byproducts generated during the fermentation processwas calculated. Statistics analyses were carried out using Pearson correlation and its significance, by thet-test. We concluded that the phenolic compounds within the must could not be correlated to the byproducts’fermentation efficiency calculated during a continuous fermentation process.