Reversed-Phase Liquid Chromatography-Quadrupole-Time-of-Flight Mass Spectrometry for High-Throughput Molecular Profiling of Sea Cucumber Cerebrosides.

Usually, the chemical structures of cerebrosides in sea creatures are more complicated than those from terrestrial plants and animals. Very little is known about the method for high-throughput molecular profiling of cerebrosides in sea cucumbers. In this study, cerebrosides from four species of edible sea cucumbers, specifically, Apostichopus japonicas, Thelenota ananas, Acaudina molpadioides and Bohadschia marmorata, were rapidly identified using reversed-phase liquid chromatography-quadrupole-time-of-flight mass spectrometry (RPLC-QToF-MS). [M + H](+) in positive electrospray ionization (ESI) mode were used to obtain the product ion spectra. The cerebroside molecules were selected according to the neutral loss fragments of 180 Da and then identified according to pairs of specific products of long-chain bases (LCB) and their precursor ions. A typical predominant LCB was 2-amino-1,3-dihydroxy-4-heptadecene (d17:1), which was acylated to form saturated and monounsaturated non-hydroxy and monohydroxy fatty acids with 17-25 carbon atoms. Simultaneously, the occurrence of 2-hydroxy-tricosenoic acid (C23:1h) was characteristic of sea cucumber cerebrosides, whereas this molecule was rarely discovered in plants, mammals, or fungi. The profiles of LCB and fatty acids (FA) distribution might be related to the genera of sea cucumber. These data will be useful for identification of cerebrosides using RPLC-QToF-MS.