Caracterización química y evaluación de la actividad biológica de diferentes extractos de Sargassum spp

Sargassum algae is of interest in modern agriculture, since it has growth regulators, micro and macronutrients that increase crop yields. Its extracts are considered biofertilizers for organic agriculture due to their safety and biodegradability. The objective of this work was the obtaining, characterization and evaluation of the biological activity of some Sargassum extracts. To prepare the extracts, Sargassum was collected from the coasts of Guanabo and washed several times. Two forms of preparation were studied, from the fresh material and from the milled powder using water and ethanol as solvents. A physical-chemical characterization was carried out on the extracts and the content of phenolic compounds, soluble proteins, flavonoids, soluble carbohydrates and pigments was also determined. To determine the biological activity of the extracts, a germination test of tomato seeds cv. Elbite from their imbibition for 2 h in different concentrations (1, 2, 5 and 10%) of the extracts. The chemical characterization showed that there are notable differences between extracts made from dried and ground algae and the extract made from fresh algae, the latter being the one with the lowest metabolite content. Regarding biological activity, although all extracts generally significantly influenced germination and growth rates evaluated, the hydroalcoholic extract was the most effective in stimulating, with the lowest concentration, almost all the indicators evaluated. A alga Sargassum é de interesse na agricultura moderna, pois possui reguladores de crescimento, micro e macronutrientes que aumentam o rendimento das culturas. Seus extratos são considerados biofertilizantes para a agricultura orgânica devido à sua segurança e biodegradabilidade. O objetivo deste trabalho foi a obtenção, caracterização e avaliação da atividade biológica de alguns extratos de Sargassum. Para preparar os extratos, o sargaço foi coletado na costa de Guanabo e lavado diversas vezes. Foram estudadas duas formas de preparo, a partir do material fresco e do pó moído utilizando água e etanol como solventes. Foi realizada caracterização físico-química dos extratos e determinado também o teor de compostos fenólicos, proteínas solúveis, flavonóides, carboidratos solúveis e pigmentos. Para determinar a atividade biológica dos extratos foi realizado um teste de germinação de sementes de tomate cv. Elbita a partir de sua embebição por 2 h em diferentes concentrações (1, 2, 5 e 10%) dos extratos. A cara