Analysis of Phospholipids, Lysophospholipids, and Their Linked Fatty Acyl Chains in Yellow Lupin Seeds (Lupinus luteus L.) by Liquid Chromatography and Tandem Mass Spectrometry.

ABSTRACT

Hydrophilic interaction liquid chromatography (HILIC) and electrospray ionization (ESI) coupled to either Fourier-transform (FT) orbital-trap or linear ion-trap tandem mass spectrometry (LIT-MS/MS) was used to characterize the phospholipidome of yellow lupin (Lupinus luteus) seeds. Phosphatidylcholines (PC) were the most abundant species (41 ± 6%), which were followed by lyso-forms LPC (30 ± 11%), phosphatidylethanolamines (PE, 13 ± 4%), phosphatidylglycerols (PG, 5.1 ± 1.7%), phosphatidic acids (PA, 4.9 ± 1.8%), phosphatidylinositols (PI, 4.7 ± 1.1%), and LPE (1.2 ± 0.5%). The occurrence of both isomeric forms of several LPC and LPE was inferred by a well-defined fragmentation pattern observed in negative ion mode. An unprecedented characterization of more than 200 polar lipids including 52 PC, 42 PE, 42 PA, 35 PG, 16 LPC, 13 LPE, and 10 PI, is reported. The most abundant fatty acids (FA) as esterified acyl chains in PL were 181 (oleic), 182 (linoleic), 160 (palmitic), and 183 (linolenic) with relatively high contents of long fatty acyl chains such as 220 (behenic), 240 (lignoceric), 201 (gondoic), and 221 (erucic). Their occurrence was confirmed by reversed-phase (RP) LC-ESI-FTMS analysis of a chemically hydrolyzed sample extract in acid conditions at 100 °C for 45 min.