Rearrangement and Fragmentation of Estrogen Ether Ions: New Aspects Found with Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

Abstract

Electrospray ionization mass spectra of several di- and tri-hydroxy-estratriene-ethers, as well as estradiol and estriol, have been investigated by high-resolution mass spectrometry. The fragmentation mechanisms leading to the loss of water molecules from the protonated molecular ion have been rationalized by using protecting groups as well as mass spectrometric means such as collision-induced dissociation and infrared multi-photon dissociation. The unexpected observation of a simultaneous loss of two water molecules from the protonated estradiol ethers and of three water molecules from the protonated estriol ethers has been discussed with respect to varying reaction mechanisms and rearrangements. Results and conclusions derived from them were obtained by adequate deuterated ethers.