Investigation Of Chemical Composition And Biological Activities Of Polysaccharides From Bryopsidales

Bryopsis plumosa and Codium fragile which belong to Bryopsidaceae of Chlorophyceae are common green algae distributing in Qingdao coast. This work determined chemical composition of two samples and investigated the properties of the polysaccharides from them.Chemical analysis indicated that carbohydrate, minerals and crude protein were chief constituents of Bryopsis plumose and Codium fragile. Especially, the content of crude protein of Bryopsis plumose is over 30.0%. Among the founded amino acids, Glutamic and Aspartic acid were present in the highest quantity. Essential amino acids accounted for 45.3% and 46.0% of total amino acids. Bryopsis plumose and Codium fragile have low fat, but unsaturated fatty acids represented 67.0% and 43.65% of total fatty acids, respectively. Bryopsis plumose and Codium fragile might be good healthy food materials, which can provide high protein,low fat and calorie.Polysaccharides which extracted from Bryopsis plumose with hot water, sulfuric acid and sodium hydroxide were named B1, B2 and B3, respectively. Polysaccharide which extracted from Codium fragile with hot water was named C. The isolation and purification of the polysaccharides were performed on a DEAE-Sepharose FF anion-exchange column. Anion-exchange chromatography indicated that, C had three sub-fractions(CF1, CF2 and CF3), and B1 had one sub-fractions(BF). Neutral monosaccharide constitutions of the polysaccharides were analyzed by HPLC. All of the polysaccharide samples from Bryopsis plumose are mainly composed of galactose, arabinose, glucose and so on, but the main sugar unit is different because of different extraction methods. The main sugar units of C and its sub-fractions(CF1, CF2 and CF3) are galactose, arabinose, mannose and so on, but the residues'ratio is different among samples. Structure features of BF and CF3 were analyzed by FTIR and NMR. Infrared spectroscopy analysis indicated that all the samples showed typical peaks of polysaccharide. The characteristic peaks assigned to rhamnose and uronic acid residues appear on all NMR spectra. According to FTIR and NMR, polysaccharides from Bryopsis plumose are mainlyα-configuration , while polysaccharides from Codium fragile areα-configuration as well asβ-configuration.The in vitro scavenging activities on superoxide radical, hydroxyl radical and DPPH, and reduction power of samples were investigated. All fractions showed certain antioxidant activities, especially B3. The properties of moisture absorption and moisture retention of samples were investigated by controlling the relative humidity and compared with glycerol and hyaluronic acid. CF3 had similar properties with HA. It is concluded that polysaccharides from Bryopsis plumose or Codium fragile can be developed as natural moisturizer, because of its richness of raw material, easy preparation and strong activities. The anticoagulant activities of polysaccharides which extracted from Bryopsis plumose with different extraction methods were investigated. Available data obtained with in vitro models suggested that B1, B2, B3 showed significant anticoagulant activity.