Algal Research-Biomass Biofuels and Bioproducts | 2019
Influence of molecular weight on the properties of Sargassum muticum fucoidan
Abstract
Abstract The crude fucoidan extracted during hydrothermal treatment of Sargassum muticum was fractionated in a sequence of membranes (100 to 5\u202fkDa) operating at a volume concentration ratio (VCR) of 5. The retentates and final permeate were further characterised for molecular weight, oligosaccharide content, sulfate and phenolic content, as well as for radical scavenging properties, expressed as Trolox equivalent antioxidant capacity (TEAC). The 50–100\u202fkDa fraction contained 25% of solubles in the hydrolysates. The highest oligosaccharide content (69.34\u202fg\u202f100\u202fg−1) was found in the 50–100\u202fkDa fraction, whereas the maximal sulfate (12.30\u202fg\u202f100\u202fg−1) and phenolic (6.63\u202fg\u202f100\u202fg−1) content occurred in the >100\u202fkDa fraction, which also presented the highest antiradical potency, 47\u202fg\u202fTrolox-eq\u202f100\u202fg−1. However, the 10–30\u202fkDa fraction was the most cytotoxic against cervix cancer HeLa 229 cells (EC50\u202f=\u202f44\u202fμg\u202fmL−1). As a consequence, the membrane fractionation of the liquid phase obtained by autohydrolysis could provide fucoidans with different composition, molecular weight and properties.