Structural tailoring of fucoidan backbones for maximizing their benefits: Enzymatic, chemical, and physical strategies.

Fucoidans are a heterogenous class of sulfated, fucose-rich, and high molecular weight polysaccharides derived mainly from brown seaweeds. They have attracted particular interest in different scientific and industrial fields. Nevertheless, their applications are affected by various chemical properties, including molecular weight, sulfation pattern, and degree of sulphation. For instance, most of the reported bioactivities (e.g., immunomodulatory and cytotoxic activities) have been enhanced with more sulfated and low molecular weight fractions, in contrast to the anticoagulant effect. Additionally, high molecular weight fucoidans are unsuitable for nanomedicine formulation, oral absorption, and distribution to various body organs. Hence, different strategies have been developed as a subsequent stage of processing to modify the native fucoidans in order to produce more bioactive and efficiently formulated products. The current article highlights the various enzymatic (e.g., fucoidanase and fucoidan sulfatase), chemical, and other strategies used for structural modifications of native fucoidans accompanied by varied bioactivities. Interestingly, the enzymatic method has proved to be more specific and selective retaining the native sulfated chemical backbone efficiently. Hence, this review may help in tayloring new fucoidan derivatives for targeted homogenous production and maximized applications of fucoidans in the medical and pharmaceutical fields. [ABSTRACT FROM AUTHOR]