Dimethylisopropylsilyl ether derivative in gas chromatography/mass spectrometry of 11-dehydrothromboxane B2.

Abstract

The mass spectrum exhibited a series of ions characteristic of the expected 11-dehydrothromboxane B2 (11-dehydro-TXB2) derivative. Many of the fragmentation products could be explained in terms of simple bond fission mechanisms. A further series of fragmentations proceeded via a six-membered ring transition state or by formation of the cyclic dimethylsilylene ring system. These produced ions in the low mass region containing silicon atoms, characteristic of the protected C-11 carboxylic and moiety. The appearance of these ions may be used for the identification of 11-dehydro-TXB2 and its metabolites having a lactone ring. Six homologue and analogue derivatives were prepared for investigation of the fragmentation mechanism. The proposed fragmentation mechanisms have been supported by accurate mass measurement and mass analyzed ion kinetic energy mass spectrometry.