Chemistry of seaweeds
Seaweeds are reported to contain innumerable minerals and bioactive molecules such as carbohydrates, proteins (15), and a lesser degree of lipid along with small molecules such as alkaloids, saponins, pigments, and peptides (16). Alginate is an example of polysaccharides composed of unbranched chain made of (1- 53 4)-β-D-mannuronic acid residues and (1-4)-α-L-guluronic acid residues (17). These polyuronans exist in seaweeds as salts of more than 50 different metals frequently in the form of sodium and calcium (17). Structure of some bioactive compounds are known; Figure 1 presents structure of bioactive compounds from seaweeds available in the WIO.
Figure 1 : Structure of bioactive compounds from seaweeds available in the WIO