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Abstract(s)
O presente trabalho teve como principal objetivo avaliar a capacidade antioxidante e antimicrobiana de nove algas castanhas (Ascophyllus nodosum, Himanthalia elongata, Undaria pinnatifida, Pelvetia canaliculata, Saccharina latíssima, Bifurcaria bifurcata, Laminaria ochroleuca, Sargassum muticum e Fucus spiralis), recolhidas na costa norte da Península Ibérica. Demonstrou-se que os vários extratos brutos das algas castanhas apresentam propriedades biológicas e químicas, nomeadamente atividade antimicrobiana e antioxidante. Neste trabalho, analisou-se o efeito de cinco solventes de extração (etanol, clorofórmio, hexano, acetona e acetato de etilo) no rendimento da extração, n conteúdo em compostos fenólicos e flavonoides, na capacidade antioxidante e na atividade antimicrobiana. O conteúdo fenólico e a capacidade antioxidante dos extratos brutos obtidos foram avaliados por diferentes métodos: conteúdo fenólico total (TPC), atividade de eliminação de radicais (DPPH● -RSA) e poder antioxidante redutor férrico (FRAP). Além disso, a atividade antimicrobiana de cada extrato foi estudada com seis microrganismos: Staphylococcus aureus (ATCC 25923); Staphylococcus epidermidis (NCTC 11047); Bacillus cereus (ATCC 14579); Pseudomonas aeruginosa (ATCC 10145); Salmonella enteritidis (ATCC 13676) e Escherichia coli (NCTC 9001). O maior rendimento de extração das macroalgas foi obtido quando o etanol foi usado como solvente extrator. Porém, quanto aos valores de TPC, DPPH● -RSA e FRAP, o acetato de etilo foi o solvente que possibilitou os maiores teores fenólicos e capacidades antioxidantes. No que diz respeito à capacidade antioxidante dos extratos das espécies das algas, os maiores valores de TPC e FRAP foram encontrados na espécie Ascophyllus nodosum, enquanto os maiores valores de DPPH● -RSA foram alcançados nos extratos de Fucus spiralis. As atividades antimicrobianas dos extratos de alga variaram em relação ao solvente utilizado, reforçando a ideia de que esta característica é dependente do solvente e deve ser otimizada para cada caso. Saccharina latissima e Bifurcaria bifurcata foram as algas mais promissoras considerando o seu potencial como agentes antimicrobianos.
The main objective of the present work was to evaluate the antioxidant and antimicrobial capacity of nine brown algae, collected from the north coast of the Iberian Peninsula. It has been shown that crude and composite extracts of brown algae have useful properties, namely antimicrobial and antioxidant activity. In the present work, it was analyzed the effect of five different extraction solvents (ethanol, chloroform, hexane, acetone and ethyl acetate) on the extraction yield, phenolic content, antioxidant capacity and antimicrobial activity of nine species of brown macroalgae (Ascophyllus nodosum, Himanthalia elongata, Undaria pinnatifida, Pelvetia canaliculata, Saccharina latissimus, Bifurcaria bifurcata, Laminaria ochroleuca, Sargassum muticum and Fucus spiralis). The phenolic content and antioxidant capacity of the crude extracts were recovered by different methods: total phenolic content (TPC), radical scavenging activity (DPPH● -RSA) and ferric reducing antioxidant power (FRAP). In addition, the antimicrobial activity of each extract was studied against six different microorganisms: Staphylococcus aureus (ATCC 25923); Staphylococcus epidermidis (NCTC 11047); Bacillus cereus (ATCC 14579); Pseudomonas aeruginosa (ATCC 10145); Salmonella enteritidis (ATCC 13676) and Escherichia coli (NCTC 9001). The highest extraction yield was obtained when the ethanol was used as an extracting solvent. However, regarding the values of TPC, DPPH● -RSA and FRAP, ethyl acetate was the solvent that provided the greatest antioxidant capabilities. Regarding the composition of algae species, the highest values of TPC and FRAP were found in Ascophyllus nodosum, while the highest values of DPPH● -RSA were found in Fucus spiralis. The antimicrobial activities of algae extracts were variable regarding the solvent, reinforcing the idea that this characteristic is solvent dependent and must be optimized for each case. Saccharina latissimi and Bifurcaria bifurcata were the most promising algae, considering their potential as antimicrobial agents.
The main objective of the present work was to evaluate the antioxidant and antimicrobial capacity of nine brown algae, collected from the north coast of the Iberian Peninsula. It has been shown that crude and composite extracts of brown algae have useful properties, namely antimicrobial and antioxidant activity. In the present work, it was analyzed the effect of five different extraction solvents (ethanol, chloroform, hexane, acetone and ethyl acetate) on the extraction yield, phenolic content, antioxidant capacity and antimicrobial activity of nine species of brown macroalgae (Ascophyllus nodosum, Himanthalia elongata, Undaria pinnatifida, Pelvetia canaliculata, Saccharina latissimus, Bifurcaria bifurcata, Laminaria ochroleuca, Sargassum muticum and Fucus spiralis). The phenolic content and antioxidant capacity of the crude extracts were recovered by different methods: total phenolic content (TPC), radical scavenging activity (DPPH● -RSA) and ferric reducing antioxidant power (FRAP). In addition, the antimicrobial activity of each extract was studied against six different microorganisms: Staphylococcus aureus (ATCC 25923); Staphylococcus epidermidis (NCTC 11047); Bacillus cereus (ATCC 14579); Pseudomonas aeruginosa (ATCC 10145); Salmonella enteritidis (ATCC 13676) and Escherichia coli (NCTC 9001). The highest extraction yield was obtained when the ethanol was used as an extracting solvent. However, regarding the values of TPC, DPPH● -RSA and FRAP, ethyl acetate was the solvent that provided the greatest antioxidant capabilities. Regarding the composition of algae species, the highest values of TPC and FRAP were found in Ascophyllus nodosum, while the highest values of DPPH● -RSA were found in Fucus spiralis. The antimicrobial activities of algae extracts were variable regarding the solvent, reinforcing the idea that this characteristic is solvent dependent and must be optimized for each case. Saccharina latissimi and Bifurcaria bifurcata were the most promising algae, considering their potential as antimicrobial agents.
Description
Keywords
Macroalgas Algas castanhas Conteúdo fenólico Capacidade antioxidantes Compostos bioativos Atividade antimicrobiana Macroalgae Brown algae Phenolic content Antioxidant capacity Bioactive Compounds Antimicrobial activity