Brown algae is an important source of marine bioactive substances

and fucoidans is a kind of water-soluble heteropolysaccharide mainly in the cell wall matrix of brown algae

which has been proved to have a variety of biological activities

including anti-oxidation

anticoagulant

anti-inflammation

anti-viral

anti-tumor

immune regulation

hyperglycemic

and other activities. However

the structure of algal polysaccharide sulfate in brown algae is complex and diverse

presenting the diversity of physiological activity. Natural fucoidan has a large molecular weight

complex structure

and the research on the structural analysis and structure-effect relationship of diversity is not deep enough

so that the research progress is slow

with low international recognition

and the application and popularization are severely restricted. Therefore

it is an indispensable key step in drug development to deduce the functional structure of fucoidan by integrating the existing research results and systematical research and investigation. Based on these considerations above

the research status of structures

analytical methods of structures

structural modification

and structure-activity relationship were reviewed through CNKI

Pubmed

ScienceDirect databases

and the deep research on structure-activity relationship was prospected

aiming to provide a reference for the further study in functional structures and action mechanism of fucoidan structure

as well as for development of medicine and health care product.