利用QqQ-MS碰撞能量自动优化功能确定磷脂脂肪酰基位置  

Characterization of Fatty Acyl Location in Phospholipids by Triple Quadrupole Tandem Mass Spectrometry Using the Function of Collision Energy Automatic Optimization

作　　者：苏小玲[1] 徐继林[1] 陈娟娟[1] 赵鹏[1] 严小军[1] 

机构地区：[1]宁波大学,应用海洋生物技术教育部重点实验室,浙江宁波315211

出　　处：《质谱学报》2011年第4期200-206,共7页Journal of Chinese Mass Spectrometry Society

基　　金：教育部长江学者与创新团队项目(IRT0734);浙江省公益性项目(2010C32G2070011);浙江省自然科学基金(Y3100534);宁波市自然科学基金(2009A610117)资助

摘　　要：利用三重四极杆质谱碰撞能量自动优化功能,在正、负离子检测模式下,对磷脂标准品(包括PA,PC,PE,PS,PG,PI)不同碰撞能量下子离子的裂解规律进行研究。实验发现:在负离子模式下,各类磷脂的子离子[M-H-R2COOH]-强度总是高于[M-H-R1COOH]-强度,而[M-H-R’2CH=CO]-丰度总是高于[M-H-R’1CH=CO]-丰度,这个规律可以用于确定左右磷脂的酰基位置。另外,在负离子模式下,PA和PS母离子裂解产生的羧酸阴离子丰度比均为R1COO-高于R2COO-,PC则为R1COO-低于R2COO-;在正离子模式下,PS裂解产生的酰基阳离子R1CO+丰度总是低于R2CO+,PA和PC在低碰撞能量下,sn-1脂肪酰基基团作为烯酮的中性丢失而产生离子丰度总是低于sn-2位上产生的对应离子;而PE和PG的sn-1位脂肪酰基基团作为羧酸的中性丢失而产生的离子在低碰撞能量下的丰度高于sn-2位上产生的离子。这些规律可用于辅助确定磷脂脂肪酰基的位置。Utilizing the function of collision energy automatic optimization,the fragmentation patterns of the phospholipids standards,including classes of glycerophosphatidic acid（PA）,glycerophosphocholine（PC）,glycerophosphoethanolamine（PE）,glycerophosphoserine（PS）,glycerophosphoglycerol（PG） and glycerophosphoinositol（PI） were studied both in negative and positive modes by triple quadrupole tandem mass spectrometry.It could be inferred that,for all classes of phospholipids,the intensities of the ions arising from neutral loss of the sn-2 substituent as a free fatty acid（[M-H-R2COOH]-） or ketene（[M-H-R2CH=CO]-） are stronger than those of corresponding ions generated by loss of the sn-1 substituent.According to this rule,it was readily to confirm the position of acyl group.In addition,it was easy to elimination of carboxylate substituent from sn-2 position for PC,which meant that the intensity of R2COO-was higher than that of R1COO-.While for PA and PS,the phenomena were totally opposite to that of PC and the intensity of R2COO-was weaker than that of R1COO-.When in the positive ion mode,the intensity of acylium ion from the sn-1 position was weaker than the acylium ion from the sn-2 position for PS.Moreover,at low collision energy,for PA and PC species it could be found that the intensities of the ions arising from neutral loss of the sn-2 substituent as a ketene（[M-H-R＇2CH=CO]-） were greater than those of ions reflecting corresponding losses of the sn-1 substituent at low collision energy.However,for PE and PG,the intensity of the ion by loss of R1CO2H was stronger than that of ion by elimination of R2CO2H.These fragmentation rules could be used to determine the position of the fatty-acyl substituent of glycerol backbone.

关 键 词：三重四极杆质谱 磷脂 脂肪酰基位置 

分 类 号：O657.63[理学—分析化学]