Lipids of different parts of the lamina of Laminaria japonica Aresch.

Fatty acid and lipid composition of different parts of the lamina of the brown alga Laminaria japonica have been examined. Significant differences were found in the amount of polyunsaturated fatty acids (PUFAs) of n-3 and n-6 series as well as in the content of the oleic acid in the lower, middle and upper parts of algal blades. The lower parts of the lamina were rich in n-6 PUFAs, while upper parts were rich in n-3 PUFAs. The highest content of oleic acid as well as that of neutral lipids was found in the middle of the fronds. Phospholipids concentrated mostly in lower parts of the blades, while glycolipids concentrated in the upper zones of the lamina. Examination of the glycolipid composition showed the presence of monogalactosyldiacylglycerol, digalactosyldiacylglycerol and sulphoquinovosyldiacylglycerol. The main phospholipids proved to be phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol and phosphatidylhydroxyethylglycine. The relationships between these compounds varied in different parts of the lamina.