Extraction, Purification And Partial Characterizations Of Polysaccharides From Gracilaria Lemaneiformis

In the present study, the crude polysaccharides were extracted from the microalgae Gracilaria lemaneiformis with ultrasonic-assisted extraction method and purified by DEAE-52 cellulose chromatography and Sephadex G-100 size-exclusion chromatography in that order. Two main fractions, GPC-1 and GPC-2, were obtained through the extraction and purification steps. Then partial characterizations, such as chemical composition, ultraviolet (UV) spectrum and infrared (IR) spectrum of the two fractions were analyzed in this study. The results indicated that the total sugar contents of GPC-1 and GPC-2 were 89.32% and 88.79%, and the protein contents of these two fractions were only 0.35% and 0.76%, compared with that of crude polysaccharides of 75.49% and 1.92%, respectively. Moreover, both the UV spectrum and the IR. spectrum demonstrated that the two fractions were typical purified polysaccharides. As a consequence, these investigated characterizations could be considered as a favorable evidence for the identification of polysaccharides from Gracilaria lemaneiformis.