LIPID-COMPOSITION OF THE BROWN-ALGAE FUCUS-VESICULOSUS AND ASCOPHYLLUM-NODOSUM

The lipid composition of the two brown marine algae, Fucus vesiculosus and Ascopyllum nodosum, was very similar. The major acyl lipids were monogalactosyldiacylglycerol, digalactosyldiacylglycerol, sulphoquinovosyldiacylglycerol and trimethyl-beta-alaninediacylglycerol. The major phospholipid was phosphatidylethanolamine but this represented less than 10% of the total acyl lipids. Monogalactosyldiacylglycerol was the most unsaturated lipid, with high proportions of eicosapentaenoic and octadecatetraenoic acids and sulphoquinovosyldiacylglycerol was the most saturated glycolipid with high proportions of palmitate and oleate. The phospholipids phosphatidylcholine and phosphatidylethanolamine had very similar fatty acid patterns, with around 60% of their acyl chains being arachidonic acid. In Fucus vesiculosus the galactosyldiacylglycerides had most of the 16C acyl chains esterified at the sn-I position. Alpha-Linolenic acid and eicosapentaenoic acid were also mostly esterified to the sn-I position while octadecatetraenoic acid was concentrated at the sn-2 position. Both sulphoquinovosyldiacylglycerol and phosphatidylglycerol showed typically prokaryotic positional distribution of fatty acids with 16C chains concentrated at the sn-2 position. Of these, trans-DELTA3-hexadecenoic acid was exclusively esterified to the sn-2 position of phosphatidylglycerol.