Preparation and structural elucidation of the picolinyl ester of aldosterone for liquid chromatography-electrospray ionization tandem mass spectrometry.
Treatment of aldosterone with 35% HCl in EtOH or in MeOH followed by the picolinyl derivatization gave the picolinyl derivative of aldosterone-ethyl ether, 8, or methyl ether, 9, as a single and well-shaped liquid chromatographic peak. Picolinyl derivatization of aldosterone produced 21-picolinyl derivative of 18,20-anhydro-hemiacetal derivatives, 6, with poor chromatographic peak with wide half-width. Further conversion of 6 to 8 required long reaction time (>4 h). Structure of each picolinyl or alkyl ether-picolinyl derivative, was carefully elucidated by nuclear magnetic resonance spectroscopy, electron ionization mass spectrometry and liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS). Enhancement of sensitivity (approximately 10-fold) in positive-LC-ESI-MS/MS of aldosterone was confirmed by the use of the alkyl ether-picolinyl derivatization when compared to the underivatized molecule.
Faculty of Pharmaceutical Science, Tohoku Pharmaceutical University, Sendai, Miyagi, Japan. kyama@tohoku-pharm.ac.jp
Kouwa
K
Yamashita
Yumiko
Y
Tadokoro
Madoka
M
Takahashi
Mitsuteru
M
Numazawa
D000450:Aldosterone / Q000737:chemistry* / Q000302:isolation & purification; D002853:Chromatography, Liquid; D004952:Esters; D010848:Picolinic Acids / Q000737:chemistry* / Q000302:isolation & purification; D012015:Reference Standards; D012996:Solutions; D021241:Spectrometry, Mass, Electrospray Ionization; D053719:Tandem Mass Spectrometry
D004952:Esters; D010848:Picolinic Acids; D012996:Solutions; D000450:Aldosterone; C030614:picolinic acid