RESUMO
Enzymatic hydrolysate of the crude polysaccharide (SFP) extracted from Sargassum fusiforme was purified by column DEAE-52 and Sephadex G-100 to yield four components, namely, ESFP1, ESFP2, ESFP3 and ESFP4. These components were characterized by chemical composition assay, GC/MS, HPGPC, UV and FT-IR techniques. The inâ vitro antioxidant activities of the four purified fractions were investigated by measuring their radical scavenging activity and reducing power. The results suggested that all the four components possess good antioxidant activities. Among them, ESFP1 was found to possess the strongest 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and hydroxyl radical-scavenging activity, and the greatest ferric reducing power. The immunomodulatory effect of these four polysaccharides was demonstrated by their ability to promote proliferation, and to enhance both phagocytic activity and NO release in a macrophage RAW264.7 model. The results revealed that the bioactivities of the polysaccharides are related to their molecular weight, and the uronic acid and sulfate contents.
Assuntos
Antioxidantes/farmacologia , Polissacarídeos/farmacologia , Sargassum/química , Animais , Antioxidantes/química , Antioxidantes/isolamento & purificação , Compostos de Bifenilo/antagonistas & inibidores , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Relação Dose-Resposta a Droga , Lipopolissacarídeos/antagonistas & inibidores , Lipopolissacarídeos/farmacologia , Camundongos , Estrutura Molecular , Peso Molecular , Óxido Nítrico/antagonistas & inibidores , Óxido Nítrico/biossíntese , Picratos/antagonistas & inibidores , Polissacarídeos/química , Polissacarídeos/isolamento & purificação , Células RAW 264.7 , Sargassum/metabolismo , Estereoisomerismo , Relação Estrutura-AtividadeRESUMO
Polysaccharides are a structurally diverse class of biomolecules with a wide variety of bioactivities. Natural polysaccharides isolated from plants and fungi are used as raw materials in food and pharmaceutical industries due to their therapeutic properties, non-toxicity, and negligible side effects, but many natural polysaccharides possess low bioactivities when compared to synthetic medicines due to their structure and physicochemical properties. Literature studies revealed that carboxymethylation of polysaccharides enhances the bioactivities and water solubility of native polysaccharides significantly, and provide structural diversity and even the addition of new bioactivities. This review article mainly focuses on the recent research on carboxymethylation of polysaccharides including preparation, characterization, and bioactivities. This article also throws light on future directions and scope to develop new carboxymethylated polysaccharide derivatives for many industries such as food processing, cosmetics, nutraceuticals, and pharmaceutical industry.