Novel mass spectral fragmentation of heptafluorobutyryl derivatives of acyl analogues of platelet-activating factor

• Published in: Journal of the American Society for Mass Spectrometry 1991-12, Vol.2 (6), p.476-482
• Main Authors: T.Weintraub, Susan, Neal Pinckard, R., Heath, Timothy G., Gage, Douglas A.
• Format: Article
• Language: English
• Subjects: Analytical, structural and metabolic biochemistry; Biological and medical sciences; Fundamental and applied biological sciences. Psychology; Protein hormones. Growth factors. Cytokines; Proteins
• ISSN: 1044-0305; 1879-1123
• DOI: 10.1016/1044-0305(91)80034-5

Direct derivatization of the acyl analogue of platelet-activating factor (acyl-PAF) with heptafluorobutyric anhydride results in replacement of the phosphocholine moiety with a heptafluorobutyryl (HFB) group. Electron capture (EC) mass spectrometric analysis of this compound that makes use of negative ion detection along with subsequent accurate mass measurement and tandem mass spectrometry studies revealed that in addition to expected fragmentation due to losses of elements of HF, ketene, and/or acetic acid, there is a rearrangement reaction between the HFB group and the substituent on carbon-2 of the glycerol backbone. For 2-acetyl isomers, this fragmentation yields a characteristic ion at m/z 237; for 1-acetyl isomers, the analogous ion is observed at [M-135] −, along with a corresponding carboxylate anion. The use of the HFB derivative is invaluable for analysis of PAF homologues and analogues because it provides detailed structural information in combination with the high sensitivity of a gas chromatography combined with EC-mass spectrometry assay.