High performance liquid chromatography and fast atom bombardment mass spectrometry of unusual branched and unsaturated phospholipid molecular species.

The unusual symmetrical molecular species 1,2-di-3,7,11,15-tetramethylhexadecanoyl-sn-glycero-3-phosphoglyce rol, 1,2-di-5,8,11,14-docosatetraenoyl-sn-glycero-3-phosphocholine, 1,2-di-5,9,19-octacosatrienoyl-sn-glycero-3-phosphoethanolamine, and 1,2-di-5,9,23-triacontatrienoyl-sn-glycero-3-phosphoethanolamine were isolated from the marine sponges Axinella verrucosa, Higginsia tethyoides, Tethya aurantia and Aplysina fistularis by HPLC and studied by fast atom bombardment (FAB) mass spectrometry. In addition to molecular weights, branching and double bonds were located in the fatty acyl chains of the intact phospholipid molecules, using FAB either in a positive or negative mode. Some mass spectral results were obtained on enriched phospholipid fractions rather than pure molecular species using MS/MS.