The Study On Separation, Purifacition And Functionality Of Polysaccharide From Sporophyll Of Undaria Pinnatifida Suringar

Sporophyll of Undaria pinnatifida Suringar is rich in nutrients. Its fucoidan has significantly physiological functions in anti-clotting, lowering blood pressure, improving immunity and other biological activity. To develop and utilize of Undaria pinnatifida Suringar polysaccharide has an important significance.In this article. Fucoidans were extracted and purified from the Sporophyll of Undaria pinnatifida Suringar. The physicochemical properties, structure and antioxidant properties in vitro of fucoidan, moisture absorption and moisture retention were studied. The results showed as following:(1) Extraction of funoidans:Water extraction and ultrasonic extraction were used and compared. The optimal conditions of water extraction were:extraction time4h, extraction temperature90℃, ratio of solution to algae power40; The optimal conditions of ultrasonic extraction were:ultrasonic frequency400W, ultrasonic time15min, ratio of solution to algae power25. And ultrasonic wave assisted method indicates:As the effect of ultrasonic auxilaiary is not obvious. The water extraction is still the best method.(2) Isolation and purification:fucoindan was isolated and purified by DEAE-Sepharose Fast Flow, three fucoindans were collected, named F1, F2, F3. Their purity was identified by agarose gel electrophoresis and UV methods. The results indicate:F1and F3were pure.(3) Physicochemical properties, composition and structure:The solution fucoidan was weakly acidic, PH6.60, without starch. SO42-was14.7%determined by Turbidimetry; Uronic acid was7.53%determined by carbazole-sulfuric acid. The TLC results indicate: fucoidans and F1were both made up of L-fucose、D-Galactose and an unknown monosaccharide. The IR shows F1were pyranose of β-glycosides mainly, sulfate groups lie to C2or C3; F3were pyranose of α-glycosides mainly, sulfate groups lied to C4of fucose.(4) Antioxidation, moisture absorption and moisture retention:The experiments of fucoidan in vitro antioxidant show that the antioxidant effect of fucoidan is not obvious. The clearance rate of O2·-can reached12.07%. The result showed that moisture absorption of fucoidan was moderate and the moisture retention was more perdurable than sorbitol especially in dried circumstance, although the moisture absorption was lower than glycerol. In high humidity, the moisture retention of fucoidan was better than glycerol and sorbitol.