Phlorotannins and phenols of brown algae (Phaeophyceae)

Abstract

Phlorotannins and their derivatives, as well as other phenolic substances are abundant in brown algae. These substances present highly diversified structures and broad biological activity spectrum. Their high concentration in a number of species demonstrates relevant physiological and ecological roles in marine environments. This fact contributes to the important survival of brown algae in these environments. Presently, 105 such metabolites are known from 49 species belonging to different classes of brown algae. These compounds are: 1 phloroglucino1, 4 fucols, 8 phorethols, 30 fucophlorethols, 17 fuhalols, 14 ecols, 4 alkyl-phenols, 13 acyl-phenols, 2 ha1o-phloroglucino1s, 3 halo-ph1orethols, 2 halo-eco1s, 3 benzyl_a1cohols, 2 prenyl_toluols and 2 sulphated derivatives. These metabolites were arranged according to their biogenetic pathways originated from the phorog1ucinol precursor. The large distribution of these pheno1ic compounds in brown algae suggests their use as possible markers for taxonomic and phy1ogenetic studies. They can also furnish important support to clarify the taxonomic limits of these algae.