Extraction and chemical composition of soluble polysaccharide from green laver, Enteromorpha prolifera

摘要

Soluble polysaccharide (SP) from green laver, Enteromorpha prolifera was extracted 3 times with distilled water at 100 deg C for 2 hrs and fractionated with cetylpyridinium chloride (CPC) and ion exchange chromatography (DEAE Separose CL-6B). The SPamounted to 23.7 percent of the dry seaweed weight and contained 68.8 percent carbohydrate. It was mainly constituted of rhamnose, glucose, xylose, sulfate and uronic acid and was fractionated with CPC into three (CPC-S, CPC-PS, CPC-PP) fractions. The major acid fraction CPC-PS accounted for 10.2 percent of the dry algal weight. CPC-PS was further fractionated on DEAE Sepharose CL-6B into Fr-1 (8.0 percent), Fr-2 (35.8 percent), Fr-3 (23.7 percent) fractions. The Fr-3 fraction contained 2.2 percent protein, 21.4 percent sulfate, 15.3 percent uronic add, and 72.4 percent polysaccharides composed of rhamnose, xylose and glucose. The Fr-2 fraction, which was richer in uronic acid (17.5 percent) and poorer in sulfate (19.0 percent) and total sugar (68.8 percent) than the Fr-3, had a sugar composition close to that of Fr-3. The average molecular weights of Fr-2 and Fr-3 were 510,000 and 830,000 daltons, respectively. Fr-3 turned out to be homogeneous by cellulose acetate electrophoresis.