Low-molecular-weight fucoidan: Chemical modification, synthesis of its oligomeric fragments and mimetics

Fucoidan is a unique polysaccharide that has various biological activities partly owing to its capability to act as mimetics of natural ligands of protein receptors. However, its use is limited due to a number of reasons including those associated with molecular weight and composition variation in relation to an algae type and habitat, raw material collection time, extraction method and duration. The main problem which limits its application in therapy is high molecular weight and seasonal composition. To expand the scope of its application, it is necessary to develop a validated procedure of high-molecular-weight fucoidan depolymerization or synthesis of its oligomeric elements . Therefore, there is a need for the synthesis of polysaccharideoligomeric components and/or polymer mimetics which allow for the creation of chains with a certain degree of sulfation, molecular weight and yield. This paper presents the most commonly used methods of fucoidan homopolysaccharide and heteropolysaccharide fragments synthesis as well as problems associated with their synthesis, including fucoidan analogues available in the form of glycopolymers that are obtained by using different methods of radical polymerization. These fucoidan mimetic glycopolymers have a biological activity similar to that of native fucoidans with high yield, which allows for their use as potential agents in the pharmaceutical industry.