利用液相色谱-四极杆-飞行时间串联质谱法(LC—Q—TOFMS/MS)分析美国红参(Parastichopus californi-cus)脑苷脂的分子种组成。以氯仿-甲醇(2:1,v/v)溶液提取,经皂化和固相萃取柱(SPE)净化后,在正离子模式下。通过自动二级质谱方式同时获取样品脑苷脂分子的一级和二级质谱图。筛取含180Da中性丢失碎片的分子,再结合二级质谱中的长链碱和脂肪酸碎片,确定每种脑苷脂分子的结构。通过该法一次性共分析出123种美国红参脑苷脂分子种;含有的长链碱共18种,其中植物鞘氨醇型与鞘氨醇型长链碱的相对含量比为1:2;脂肪酸为18~25碳的饱和或单不饱和脂肪酸,以24碳脂肪酸为主,2-羟基脂肪酸占58.62%,饱和与单不饱和脂肪酸的相对含量比约为1:3。LC—Q—TOFMS/MS法分析海参脑苷脂分子种的灵敏度高,准确,简便,为海参脑苷脂的构效关系研究及功能食品开发提供理论依据。
Cerebrosides from sea cucumber Parastichopus californicus were identified by using liquid chromatography-quadrupole-time-of-flight mass spectrometry (LC-Q-TOF MS/ MS). The samples were extracted with chloroform-methanol (2: l, v/v) solution and purified by a SPE cartridge. In positive ion mode electrospray ionization (ESI), the precursor ion scan mass spectra and product ion scan mass spectra were obtained through the automatic MS/MS mode. Cerebroside molecules were selected according to the neutral loss fragments of 180 Da, and then were identified according to long-chain base (LCB) fragments and fatty acid (FA) fragments. One hundred and twenty-three cerebroside molecular species were identified. There are 18 species of LCB, and the relative content ratio of phytosphingosines and sphingosines is 1 : 2. The carbon numbers of fatty acids are mainly 18 - 25, of which 24 carbon fatty acids are predominant. The relative content ratio of saturated fatty acids and monounsaturated fatty acid is about 1 : 3, and the presence of 2-hydroxy fatty acids is about 58.52%. LC-Q-TOF MS/MS method is sensitive, accurate and simple. At the same time, this study provided a theoretical basis for structure-activity relationship studies and functional food development of Parasticho- pus californicus as well.