摘要
In this study, variations in composition and properties of polysaccharides isolated from brown algae Costaria costata were analyzed. The algae were collected from May to July of the harvest period. The carbohydrates alginate and fucoidan were extracted with selected solvents. 1H Nuclear magnetic resonance and rheology were used to investigate the monomer composition and rheological characteristics of alginate. Gas chromatography and Fourier transform-infrared spectroscopy were employed to investigate the compositional properties of purified fucoidan. The results indicated that the composition and properties of alginate and fucoidan varied during the life of this alga. The alginate from the alga harvested in May and June had a higher molecular weight, viscosity, and proportion of mannuronic acid, whereas that harvested in July had a lower molecular weight and viscosity but a higher proportion of guluroinc acid. The alginate from C. costata had a higher molecular weight and a different mannuronic acid： guluronic acid ratios compared with other algae; thus, it could be used in the chemical, food, cosmetics, and pharmaceutical industries. Fucoidan content reached the maximum in June. Substantial changes in the molecular weight distribution, monosaccharide composition, and sulfate content occurred simultaneously. The fraction of fucose in the polysaccharides decreased significantly from June to July, whereas that of mannose increased. This alga can be harvested during different growth periods to obtain fucoidans and alginates with different compositions and, therefore, with different biological properties.
In this study,variations in composition and properties of polysaccharides isolated from brown algae Costaria costata were analyzed.The algae were collected from May to July of the harvest period.The carbohydrates alginate and fucoidan were extracted with selected solvents.1 H Nuclear magnetic resonance and rheology were used to investigate the monomer composition and rheological characteristics of alginate.Gas chromatography and Fourier transform-infrared spectroscopy were employed to investigate the compositional properties of purified fucoidan.The results indicated that the composition and properties of alginate and fucoidan varied during the life of this alga.The alginate from the alga harvested in May and June had a higher molecular weight,viscosity,and proportion of mannuronic acid,whereas that harvested in July had a lower molecular weight and viscosity but a higher proportion of guluronic acid.The alginate from C.costata had a higher molecular weight and a different mannuronic acid:guluronic acid ratios compared with other algae;thus,it could be used in the chemical,food,cosmetics,and pharmaceutical industries.Fucoidan content reached the maximum in June.Substantial changes in the molecular weight distribution,monosaccharide composition,and sulfate content occurred simultaneously.The fraction of fucose in the polysaccharides decreased significantly from June to July,whereas that of mannose increased.This alga can be harvested during different growth periods to obtain fucoidans and alginates with different compositions and,therefore,with different biological properties.
基金
supported by the Key Research and Development Program in Shandong Province(No.2016GSF121034)
the National Science and Technology Pillar Program in the 12th Five Year Plan of China(No.2015BAD17B02)
Open Foundation of the State Key Laboratory of Bioactive Seaweed Substances
the Jiangsu Provincial Key R&D Project(No.BE2015335)
