Dimethylisopropylsilyl ether derivatives in gas chromatography-mass spectrometry of some prostanoids. Application to the microdetermination of 15-ketoprostaglandin F2 alpha formed by enzymatic conversion of PGF2 alpha in vitro.
Treatment of 15-ketoprostaglandin F2 alpha (15-keto-PGF2 alpha) with ethereal diazomethane at -78 degrees C provided only the expected methyl ester (ME), without the formation of the pyrazoline adduct. The electron-ionization mass spectrum of the dimethylisopropylsilyl (DMiPS) ether derivative of 15-keto-PGF2 alpha ME showed the molecular ion, and the characteristic fragment ion of [M-43]+ was of high abundance. The appearance of these ions in the high-mass region made it possible to determine trace amounts of 15-keto-PGF2 alpha in biological specimens without any interference from endogenous substances. The detection limit for the DMiPS ether derivatives of 15-keto-PGF2 alpha ME was 12 pg (signal-to-noise ratio = 10). The method was applied to the analysis of 15-keto-PGF2 alpha obtained by the enzymatic conversion of PGF2 alpha with 15-hydroxyprostaglandin dehydrogenase in vitro.
Yamashita
K
K
Research Laboratory, Nippon Kayaku Co. Ltd., Tokyo, Japan.
Watanabe
K
K
Ishibashi
M
M
Katori
M
M
Miyazaki
H
H
D015237:Dinoprost / Q000031:analogs & derivatives; D004987:Ethers; D008401:Gas Chromatography-Mass Spectrometry; D007202:Indicators and Reagents; D011460:Prostaglandins F / Q000032:analysis* / Q000378:metabolism*; D012821:Silanes
D004987:Ethers; D007202:Indicators and Reagents; D011460:Prostaglandins F; D012821:Silanes; C026528:15-ketoprostaglandin F2alpha; D015237:Dinoprost