Chemical Composition of the Brown Alga Padina pavonia ( L . ) Gaill . from the Adriatic Sea

The brown alga Padina pavonia (L.) Gaill. is widespread in the Adriatic Sea. It belongs to the family Dictyotaceae, order Dictyotales, subclass Isogeneratae, class Phaeophyceae. There are limited data on the chemical composition of the algae from the genus Padina. Fatty acids, containing 14–22 carbon atoms have been identified in different Padina species (Qasim 1986, Karawya et al. 1987, Kanias et al. 1992, Wahbeh 1997). Significant differences in the sterol composition were found within the different Padina species. Fucosterol predominated in Padina gymnospora (Kütz.) Sond. and no cholesterol was found (Al Easa et al. 1995). Fucosterol was also the main sterol in Padina crassa Yamada (Enoloh et al. 1981). In Padina vickersiae (Kütz.) Sond. (Combaut et al. 1985, Aknin et al. 1992) from Senegal waters and in Padina pavonia from the Aegean Sea (Kanias et al. 1992) the main sterol was cholesterol.The biogenetic precursor of fucosterol, 24-methylene cholesterol, was found in significant amounts in Padina vickersiae (Aknin et al. 1992) and in Padina gymnospora from the Qatar coast (Al Easa et al. 1995). In the Mediterranean Padina pavonia (Iatrides et al. 1983) the main sterol appeared to be fucosterol instead of cholesterol. Several oxidised sterol derivatives have been found in some Padina species, 24-hydroperoxy-24vinyl-cholesterol in Padina pavonia (Ktari and Guyot 1999), 7-ketocholesterol in Padina tetrastromatica Hauck. (Parameswaran et al. 1994) and 7α-hydroxyfucosterol in Padina crassa (Tan et al. 1992). Few terpenoids have been found in Padina species. Halogenated terpenoids were identified in Padina tetrastromatica (Parameswaran et al. 1994, 1996). Loliolide was identified in P. tetrastromatica (Rao and Pullaiah 1982) and in P. crassa (Tan et al. 1992). Hexahydrofarnesylacetone was found in P. tetrastromatica (Rao and Pullaiah 1982). Dimethylsulfide and dimethyl-β-propiothetin were identified in Padina arborescens Holmes (Iida et al. 1985). Pigments were investigated in Padina pavonia by Hegazi et al. (1998). The characteristic brown algal polysaccharides (alginates and laminarans) were found in Padina pavonia (Khafaji 1986) and P. tetrastromatica (Rao et al. 1984). In P. tetrastromatica two new sulphated heteropolysaccharides, containing sugar and protein residues were also found (Rao et al. 1984). Galactol was identified in P. tetrastromatica (Parameswaran et al. 1996). We concentrated our efforts on the analysis of fatty acids from lipids, sterols, volatile compounds and the polar fraction from P. pavonia. Sterols and lipids are important constituents of the cell membranes and are responsible for many of the cell functions. Due to their significant concentrations in living organisms they might have a practical application. Volatile compounds often contain biologically active compounds, some of them with allopathic activity. Polar fractions, extracted with n-butanol, are very complex and there are limited data on their composition. They often contain biologically active compounds and their investigation with modern methods Chemical Composition of the Brown Alga Padina pavonia (L.) Gaill. from the Adriatic Sea