COMPARATIVE-STUDY OF THE ENDEMIC FRESH-WATER FAUNA OF LAKE BAIKAL .4. PHOSPHOLIPID AND FATTY-ACID COMPOSITIONS OF 2 GASTROPOD MOLLUSKS OF THE GENUS VALVATA

Lipid and phospholipid compositions of endemic freshwater molluscs, belonging to the class Gastropoda Valvata baicalensis and Valvata piligera were investigated. Distribution of phospholipids was studied by qualitative and quantitative micro-thin-layer chromatography. Only major phospholipid classes, phosphatidylethanolamine and phosphatidylcholine, were found to contain plasmalogen forms. The fatty acids composition of total lipids, neutral, glyco- and phospholipid fraction was investigated by capillary gas chromatography-mass spectrometry. Ninety-five fatty acids were identified: 23 saturated (both iso- and anteiso-), 28 monoenoic, 14 dienoic and 30 polyenoic. Among polyenoic acids were identified a high percentage of tree main acids 18:3n-3, 18:3n-6 and 20:4n-6 in phospholipid and glycolipid fractions; among saturated acids were found a high percentage of iso-(3.56-4.25%) and anteiso-(2.02 and 2.75%) acids in neutral fractions. A number of unusual polyunsaturated fatty acids, such as 18:5n-3, 24:4n-6, 24:5n-6, 24:6n-3 and furanoid acids, were found.