The Regular Patterns of Mass Spectrometry of Sterols and Related Derivatives(Ⅳ).Studies on the Mass Spectrometry of 5-En-steryl Acetates with Common Saturated Side Chain and with Cyclopropane-containing Side Chain

In this paper, the mass spectrometric fragmentation typicalities of 5-en-steryl ac-etates with common saturated side chain and with cycloropane-containing side chain are reported. The diagnostic peaks at m/z (M+ -HOAc and terminal alkyl group) ; (M+ -168,fission of ring B) ; 255 and 213 display the structure of terminal alkyl group; of side chain ;of steryl mucleus,respectively. They are typical of 5-en-steryl acetates with com-mon saturated side chain. The characteristic peaks at m/z (M+ -HOAc and terminal alkyl group) ; (M+ - HOAc and fission of cyclopropane ring) ; 255 and 213 show the structure of terminal alkyl group ;of side chain containing a cyclopropane ring ;of steryl nucleus,respectively. They are typical of 5-en-steryl acetates with cyclopropane-contain-ing side chain.