Optimization of Extraction-purification Process and Quantitative Detection for Chrysolaminarin from Marine Diatoms

Abstract:

Chrysolaminarin is a kind of β-1,3-glucan possessing many functions such as anti-oxidative, anti-tumor, hypoglycemic, hypolipidemic and immunomodulatory activities. Marine diatoms are rich in chrysolaminarin, but extraction-purification process and accurate quantitative determination method are the bottlenecks of current research and development. In this study, the extraction-purification process for the intracellular chrysolaminarin from marine diatom Phaeodactylum tricornutum was optimized, and the optimal conditions were established as follows: The freeze-dried algal powder was extracted four times with the Tris-EDTA buffer, and the protein was removed using trichloroacetic acid (TCA; final concentration 10%) before the polysaccharide was recovered via alcohol precipitation. The aniline blue fluorescence method, phenol-sulfuric acid method and gel chromatography method were used to compare systematically the determined contents. The results showed that the aniline blue fluorescence method had the optimal detection range of 1~40 μg/mL and the lowest detection limit (4.12 μg/mL), the highest precision (relative standard deviation (RSD) 1.27%), the best reproducibility (RSD 2.49%) and high average recovery rate in spiked samples (100.85%), thereby being superior to other two methods. The optimized process and new detection method established in this study provide technical support for the development and utilization of chrysolaminarin.