Macroalgae-derived Rare Sugars: Applications and Catalytic Synthesis

Abstract Rare sugars have attracted much attention since they are highly beneficial for health as alternative sweeteners and full of potential economic value in industry. The limited availability of rare sugars in nature has promoted efforts on the conversion of sugars obtained from terrestrial plants into rare sugars, either via biological or chemo-catalytic approaches. However, the processes are generally complicated and consist of multiple steps. Macroalgae or seaweeds have been industrially used as a natural source of phycocolloids. These water-soluble polysaccharides contain monomeric sugars with unique chemical structures and are categorized as rare. In this review, the potency of macroalgae as a sustainable source of rare sugars and the recent progress on their catalytic conversion, either via biological or chemo-catalytical process, are summarized and discussed. Especially, the depolymerization of macroalgae for the production of rare sugars is presented. It is expected to enrich our knowledge in the development of sustainable production of rare sugars from macroalgae.