Abstract
With the advent and rapid progress of the novel blue economy, the prospect
of large-scale commercial production of diverse natural bioactive compounds from
aquatic biota is likely to be realized in the near future. The biodiversity of the marine
biota represents a potentially abundant source of new biomolecules with potentially
different economical applications. Most of these biotas are able to survive under stress
conditions, as a result, they produce complex metabolites with unique biological
properties. These natural substances could be used as functional constituents in the
food sector. Moreover, they could aid in the treatment of a broad range of different
diseases, including antitumor, antioxidant, antiaging, anti-inflammatory, and
antimicrobial. The special properties of these compounds make them an attractive
group deserving increasing scientific interest. It is interesting to note that there are
some biomolecules exclusively found in marine biota, including phlorotannins and
sulfated polysaccharides. This chapter explains the bioactive molecules from different
marine biota as well as illustrates their chemical structure and highlights their new
biologically active form.