17] Quantitative analysis of platelet-activating factor by gas chromatography-negative-ion chemical ionization mass spectrometry

Abstract

Publisher Summary The chapter presents a study on quantitative analysis of platelet-activating factor (PAF) by gas chromatography-negative-ion chemical ionization mass spectrometry (GC-NCI-MS). One of the most promising of these PAF derivatives is the pentafluorobenzoyl (PFB)-diglyceride. It is conveniently derived from PAF by the phospholipase C (PLC)-catalyzed hydrolysis to the diglyceride which is, in turn, esterified with pentafluarobenzoyl chloride. The PFB-diglyceride provides a highly sensitive and molecular species-selective method of PAF analysis. Analysis of PAF as the PFB-diglyceride is highly sensitive and molecular species selective method applicable to a wide variety of biological samples. The sensitivity is derived from the efficiency of ionization and the stability of the molecular anion. The method offers sensitivity and in some cases, selectivity over existing physicochemical methods of PAF analysis. Furthermore, this method is also more sensitive than bioassays for PAF, but more importantly, it obviates two important problems associated with PAF bioassays, they are as follows: (1) the differential response to various molecular species, and (2) copurification of inhibitors with PAF, which may interfere with the bioassay. The chapter discusses several procedures, including synthesis of deuterium-labeled PAF, enzymatic hydrolysis to 1-O-hexadecyl-2-acetylglycerol, synthesis of pentafluorobenzoyl derivatives, analysis of PAF precursors and metabolites, and so on.