Bioactive polysaccharide from Caulerpa lentillifera

Caulerpa lentillifera (sea grape) is an edible green marine macroalgae, consisting of polysaccharides as major component. They can grow locally in many places in Thailand. Extracted polysaccharide from C. lentillifera has been applied in medical fields, such as antioxidant activity, immunostimulatory and anticoagulant activity. This study focused on the effect of C. lentillifera material types for polysaccharide extraction and the efficacy of reused ethanol in precipitate process.  Polysaccharide extraction was performed at 50^oC and 90^oC for 2 hours.  After residue removal, polysaccharide solution was precipitated by ethanol. The result revealed that dried sea grapes gave the higher yield than fresh materials for polysaccharide extraction.  However, total sugar, protein and sulfate in polysaccharide extracts (dry weight basis) were 2-3 times higher in fresh material than dried material. Significantly, total phenolic contents were also higher in fresh C. lentillifera extracts (1.53 - 2.11 mg GAE/g extract) than that of the dried materials (0.41-0.52 mg GAE/g extract) with high potential property for ABTS and DPPH radical scavenging at IC₅₀ values at 5.75-7.54 mg/mL and 35.46-74.79 mg/mL, respectively. For ethanol precipitation, the results showed that reused ethanol with > 90% alcohol can recover more than 75% polysaccharide while reused ethanol with < 90% alcohol, the efficacy of the precipitation was lower than 20%.  These results revealed that fresh materials of C. lentillifera can directly applied for polysaccharide extraction with reused ethanol for bioactive compounds.