Polysaccharides characterize structurally with long chains of residue of sugar/monosaccharide, unlike oligosaccharide that possess 3-10 units’ simple sugars. This reveals structural complexity that exists in macromolecular polysaccharide. They may be linear or branched structural form.
1.1.2. Polysaccharide Sources and Chemical Structural Units
Generally, polysaccharide displayed great diversity in both source and chemical structure (Table 1.1.). Higher organisms such as animals (marine), plants, algae, fungi, and bacteria inherently produce polysaccharide (Shi, 2016). Thus, sources of polysaccharide are very numerous and globally found available. Cellulose, chitin, chitosan, and starch are the dominant polysaccharide biomacromolecules in nature.
Table 1.1: Polysaccharide Various Sources and Structural Units
Name Source Classification Structural Unit/Composition Chain type Bond (Glycoside) Ref.
Plant e.g. cereals, root and tubers, legumes etc
Neutral or nonionic polysaccharide
Mostly D-(1:4) and Limited D-(1:6) on branched side
(Lovegrove et al., 2017)
Neutral D-glucopyranose ring
Plant e.g. fruit and vegetables
D-glucan, D-xylose, and D-galactose in Xyloglucan
D-(1:4), D-(1:6) linked to D-(1:2)
(Liu et al., 2015; Lovegrove et al., 2017)
Animal e.g. marine crustaceans
(Abdel-Rahman et al., 2015)
Plant e.g. Root and tubers
Glucose, galactose, mannose, arabinose etc
Branch D-(1:2) and D-(1:6) on branched side chains, and D-(1:4) on glucan backbone
(Nayak and Pal, 2018)
Plant e.g. fruit and vegetable
Fig.1.1. Structural repeats units of some major polysaccharides