10 research outputs found
Isolamento e anĂĄlise quĂmica parcial de exopolissacarĂdeos da diatomĂĄcea marinha cultivada Coscinodiscus wailesii (Coscinodiscales, Bacillariophyta)
The marine diatom Coscinodiscus wailesii has attracted ecological interest because their blooms affect fishing areas. The aim of this work was the isolation, extraction and partial chemical characterization of soluble exopolysaccharide and bound exopolysaccharide from C. wailesii. Cultures were grown in Guillards f/2 medium under controlled conditions of temperature, aeration, photoperiod and light intensity. Percentage of carbohydrate, uronic acids, sulfates groups and cellular lipids was determined. Ion exchange chromatography of exopolysaccharides produced three fractions whose partial chemical structures were disclosed using 13C NMR and methylation techniques
Chemical Assessment and Antimicrobial and Antioxidant Activities of Endophytic Fungi Extracts Isolated from Costus spiralis (Jacq.) Roscoe (Costaceae)
Costus spiralis (Costaceae) is a species native to the Amazon region and is used in traditional medicine. The endophytic fungi used in this study were obtained from leaves of this plant. 13 strains were selected to obtain hydroethanolic extracts and were submitted to hydroalcoholic extraction and evaluated for antioxidant activity by DPPH (2,2-difenil-1-picrilhidrazil) and FRAP (ferric reducing antioxidant power), and all of the fungi had positive results. The antimicrobial action of crude extracts had a good range of activities. All extracts had inhibitory activities against the yeasts of Candida albicans and C. parapsilosis, with 125 to 500 g/mL MIC. Eight extracts had antimicrobial activities against Bacillus subtilis (MIC from 62.4 to 125 g/mL), 5 against Pseudomonas aeruginosa (MIC from 125 to 500 g/mL), 2 against Salmonella enterica (MIC from 125 to 62.5 g/mL), and 2 against Enterococcus faecalis (MIC from 500 to 125 g/mL). The presence of secondary metabolites, including coumarins, was observed during chemical evaluation by thin layer chromatography. Total phenol content was estimated, and a strong positive correlation to antioxidant activity was observed, according to its Pearson coefficient. This is the first report of the bioactive potential of endophytic fungi isolated from the Costaceae family in Brazilian ecosystems
ConteĂșdo fenĂłlico e atividade antioxidante de diferentes cultivares de ipomoea batatas (l.) lam. obtidas por melhoramento genĂ©tico para produção industrial de etanol
A batata-doce (Ipomoea batatas (L.) Lam.) Ă© um vegetal
nativo da América Tropical, com destaque no cenårio
da agricultura mundial. A principal finalidade do
cultivo desta planta concentra-se na obtenção de raĂzes
para alimentação humana, de animais domésticos e
produção de etanol. A preferĂȘncia de consumo de I.
batatas concentra-se nas raĂzes, consequentemente
a parte aérea, na maioria das vezes, é descartada ou
fornecida como alimento para animais. Este trabalho
teve como objetivo determinar o conteĂșdo fenĂłlico
total, o perfil cromatogrĂĄfico e o potencial antioxidante
das folhas de 10 cultivares de I. batatas provenientes de
melhoramento genético convencional direcionado para
a produção industrial de etanol. Extratos etanólicos
das folhas de plantas adultas foram avaliados quanto
ao conteĂșdo fenĂłlico pelo mĂ©todo Folin-Ciocalteu, que
variou entre 54,72 ± 4,35 e 112,29 ± 3,65 mg EAT/g,
flavonoides por complexação com cloreto de alumĂnio
(29,15 ± 3,72 a 97,36 ± 2,13 mg ER/g), atividade
antioxidante in vitro pelos métodos DPPH, FRAP e
atividade quelante. Adicionalmente, foram investigados
os componentes fenĂłlicos por cromatografia em
camada delgada (CCD) e cromatografia lĂquida
de alta eficiĂȘncia (CLAE), que revelaram matrizes
complexas de compostos, constituĂdas por ĂĄcido elĂĄgico
e vĂĄrios flavonoides. Constatou-se um elevado potencial
antioxidante correlacionado satisfatoriamente pelo
coeficiente de Pearson com teor de fenĂłis e flavonoides
totais. Os resultados demonstraram grande potencial
de agregação de valor ao cultivo de I. batatas, pela
integração das pråticas agroenergéticas que utilizam
suas raĂzes, com a obtenção de outros produtos de base
orgĂąnica presentes nas folhas desta planta