2023 Volume 40 Pages 46-51
Oysters contain various nutritional and functional components, such as zinc, glycogen, and taurine. Therefore, oyster extract containing extracted and concentrated nutritional and functional components are marketed. However, the effective use of oyster extract by-products (OEBP) needs to be realized. A previous study revealed that several types of mollusc bivalves characteristically contain ceramide aminoethyl phosphonate (CAEP), a sphingophosphonolipid, that improves skin barrier function. In this study, we analyzed the chemical structure of CAEP in OEBP to differentiate it from other marine CAEP. CAEP was purified by alkali and acid treatments, followed by three types of column chromatography for Pacific oyster by-products. To analyze the chemical structure of CAEP, fatty acid composition analysis via methyl esterification and long-chain base composition analysis via trimethylsilyl derivatization were performed. The results showed that 26% of OEBP-derived phospholipids were CAEP. Chemical structural analysis indicated that the fatty acid composition of the OEBP-derived CAEP was C16:0 (68%), C17:0 (5%), and C18:0 (27%). Furthermore, the long-chain base composition of OEBP-derived CAEP was d16:1 (24%), d18:1 (13%), d18:2 (39%), d20:1 (4%), and d20:2 (12%). These results indicate that most of the long-chain bases of marine CAEP reported to date have carbon numbers of ≤19, whereas Pacific oyster-derived CAEP characteristically contains long-chain bases with carbon numbers of 20.
