Lipid Class and Fatty Acid Compositions of Dried Sea Cucumber Apostichopus japonicus

Sea cucumber, Apostichopus japonicus, is becoming popular around the world due to its nutritional and medicinal properties. There are still no detailed chemical studies of the lipid class, glycolipids compositions of sea cucumber. This study was conducted to determine the lipid class and glycolipid compositions of dried sea cucumber, A. japonicus, and analyze fatty acid compositions of Monogalactosyl Diglycerides (MGDG), Steryl Glycosides (SG) and Sulfoquinovosyl Diglycerides (SQDG). Total lipids of sea cucumber were extracted by Bligh and Dyer method and Sep-Pak Silica plus long cartridge, and Thin Layer Chromatography (TLC) silica gel G-60 F254 was used for the separation of different lipid classes and glycolipid compositions. The composition of fatty acids was analyzed by GC. The level of total lipids in the dried sea cucumber, Apostichopus japonicus, was 4 ± 1% of dry weight (w/w) and the amount of neutral lipids, glycolipids and phospholipids was 31 ± 1%, 29 ± 1% and 40 ± 1% of the total lipids (w/w), respectively. MGDG, SG and SQDG were the major glycolipids, and the contents were 37.5 ± 0.3%, 33.8 ± 0.5% and 23.6 ± 0.7% of the total glycolipids (w/w), respectively and significantly higher than other glycolipids (p < 0.05). SQDG contained much higher Arachidonic Acid (AA), Eicosapentaenoic Acid (EPA) and MGDG contained higher Docosahexaenoic Acid (DHA) compared with SG (p < 0.05). Further investigation is required to understand the positional distribution of fatty acids and molecular species in MGDG, SG and SQDG in detail.