Chemical Compounds from Seaweeds on the Tropical Coast of Brazil

Seaweeds have been explored by humans for thousands of years as a source of chemical compounds. This study describes the content of minerals, ash, carbohydrates, protein, lipids, and main metabolites of dichloromethane / methanol extracts of the seaweed Ulva lactuca, Padina gymnospora, Palisada perforata and Gelidiella acerosa from sandstone reefs on the Brazilian tropical coast (Pernambuco, Northeastern of Brazil). The content (% dry weight) of carbohydrates ranged from 14.35-48.52, proteins 7.49-14.98, total lipids 0.40-8.92, and ash 18.51-37.02. The concentration (mg kg dry algae⁻¹) of Ca (900-3468), Mg (1655-4902), K (810-1707), Na (1062-4580), Mn (19-4462), and Cu (3.6-6.4) were maximum in Palisada and minimum in Padina. In turn, the lowest and highest contents (mg kg dry algae⁻¹) of Fe (100-2312), Zn (18-43), and Cr (0.08-0.93) were recorded in Gelidiella and Ulva, respectively. Neophytadiene was the major compound. Phytol and palmitic acid were found in all seaweeds, although in low quantities. Palisada had the highest contents (% dry weight) of metabolites (neophytadiene: 23.89, phytol: 8.29; palmitic acid: 8.32), while Ulva had the lowest, except phytone, which was present only in this species. Our findings highlight the potential of these macroalgae from the coastal reefs as a source of chemical compounds.

Keywords:
benthic seaweeds; lipid metabolites; sandstone reefs; tropical coast