Mass, spectrometry of steroid glucuronide conjugates. II - Electron impactfragmentation of 3-keto-4-en- and 3-keto-5 alpha-steroid-17-O-beta glucuronides and 5 alpha-steroid-3 alpha,17 beta-diol 3- and 17-glucuronides
M. Thevis et al., Mass, spectrometry of steroid glucuronide conjugates. II - Electron impactfragmentation of 3-keto-4-en- and 3-keto-5 alpha-steroid-17-O-beta glucuronides and 5 alpha-steroid-3 alpha,17 beta-diol 3- and 17-glucuronides, J MASS SPEC, 36(9), 2001, pp. 998-1012
The steroid glucuronide conjugates of 16,16,17-d(3)-testosterone, epitestos
terone, nandrolone (19-nortestosterone),16,16,17-d(3)-nortestosterone methy
ltestosterone,metenolone,mesterolone,5 alpha -androstane-3 alpha, 17 beta -
diol, 2,2,3,4,4-d(5)-5 alpha -androstane-3 alpha ,17 beta -diol, 19-nor-5 a
lpha -androstane-3 alpha ,17 beta -diol, 2,2,4,4-d(4)-19-nor-5 alpha -andro
stane-3 alpha ,17 beta -diol and 1 alpha -methyl-5 alpha -androstane-3 alph
a/beta, 17 beta -diol were synthesized by means of the Koenigs-Knorr reacti
on. Selective 3- or 17-O-conjugation of bis-hydroxylated steroids was perfo
rmed either by glucuronidation of the corresponding steroid ketole and subs
equent reduction of the keto group or via a four-step synthesis starting fr
om a mono-hydroxylated steroid including (a) protection of the hydroxy grou
p, (b) reduction of the keto group, (c) conjugation reaction and (d) remova
l of protecting groups. The mass spectra and fragmentation patterns of all
glucuronide conjugates were compared with those of the commercially availab
le testosterone glucuronide and their characterization was performed by gas
chromatography/mass spectrometry and nuclear magnetic resonance spectrosco
py. For mass spectrometry the substances were derivatized. to methyl esters
followed by trimethylsilylation of hydroxy groups and to pertrimethylsilyl
ated products using labelled and unlabelled trimethylsilylating agents. The
resulting electron ionization mass spectra obtained by GC/MS quadrupole an
d ion trap instruments, full scan and selected reaction monitoring experime
nts are discussed, common and individual fragment ions are described and th
eir origins are proposed. Copyright (C) 2001 John Wiley & Sons, Ltd.