Fast atom bombardment (tandem) mass spectrometric analysis of intact polar ether lipids extractable from the extremely halophilic archaebacteriumHalobacterium cutirubrum

Abstract

Fast atom bombardment (FAB) mass spectrometric analyses of the three major polar ether lipids extracted from Halobacterium cutirubrum produced simple positive and negative ion mass spectra which contained ions with masses which corresponded to cationized or deprotonated lipid molecules. Structural information was obtained on individual components of polar lipid mixtures by discrete selection of ion masses when the instrument was operated in the tandem mass spectrometric mode. Tandem mass spectra contained abundant ions at masses which indicated collision-induced cleavage of phosphate (di)ester, sulphate ester or glycosidic linkages. This study showed that FAB (tandem) mass spectrometry can be used to analyse intact polar ether lipids present at microgram concentrations in crude lipid mixtures and these analyses can indicate the presence of structural features (i.e. O-methylation and the presence of cyclic isoprenoidyl chains) which are difficult to determine with other analytical methods.