TY - JOUR
T1 - Identification of a novel conjugate in human urine
T2 - Bile acid acyl galactosides
AU - Goto, Takaaki
AU - Shibata, Akihiro
AU - Sasaki, Daisuke
AU - Suzuki, Naoto
AU - Hishinuma, Takanori
AU - Kakiyama, Genta
AU - Iida, Takashi
AU - Mano, Nariyasu
AU - Goto, Junichi
N1 - Funding Information:
This work was supported in part by a grant from the Ministry of Education, Culture, Sports, Science and Technology.
PY - 2005/3
Y1 - 2005/3
N2 - We report a novel conjugate, bile acid acyl galactosides, which exist in the urine of healthy volunteers. To identify the two unknown peaks obtained in urine specimens from healthy subjects, the specimens were subjected to solid phase extraction and then to liquid chromatographic separation. The eluate corresponding to the unknown peaks on the chromatogram was collected. Following alkaline hydrolysis and liquid chromatography (LC)/electrospray ionization (ESI)-mass spectrometric (MS) analysis, cholic acid (CA) and deoxycholic acid (DCA) were identified as liberated bile acids. When a portion of the alkaline hydrolyzate was subjected to a derivatization reaction with 1-phenyl-3-methyl-5- pyrazolone, a derivative of galactose was detected by LC/ESI-MS. Finally, the liquid chromatographic and mass spectrometric properties of these unknown compounds in urine specimens were compared to those of authentic specimens and the structures were confirmed as CA 24-galactoside and DCA 24-galactoside. These results strongly imply that bile acid 24-galactosides, a novel conjugate, were synthesized in the human body.
AB - We report a novel conjugate, bile acid acyl galactosides, which exist in the urine of healthy volunteers. To identify the two unknown peaks obtained in urine specimens from healthy subjects, the specimens were subjected to solid phase extraction and then to liquid chromatographic separation. The eluate corresponding to the unknown peaks on the chromatogram was collected. Following alkaline hydrolysis and liquid chromatography (LC)/electrospray ionization (ESI)-mass spectrometric (MS) analysis, cholic acid (CA) and deoxycholic acid (DCA) were identified as liberated bile acids. When a portion of the alkaline hydrolyzate was subjected to a derivatization reaction with 1-phenyl-3-methyl-5- pyrazolone, a derivative of galactose was detected by LC/ESI-MS. Finally, the liquid chromatographic and mass spectrometric properties of these unknown compounds in urine specimens were compared to those of authentic specimens and the structures were confirmed as CA 24-galactoside and DCA 24-galactoside. These results strongly imply that bile acid 24-galactosides, a novel conjugate, were synthesized in the human body.
KW - Atmospheric pressure chemical ionisation
KW - Bile acid
KW - Electrospray ionisation
KW - Galactose
KW - Glycoside
KW - Liquid chromatography/mass spectrometry
KW - Tandem mass spectrometry
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U2 - 10.1016/j.steroids.2004.12.006
DO - 10.1016/j.steroids.2004.12.006
M3 - Article
C2 - 15763597
AN - SCOPUS:14844320834
SN - 0039-128X
VL - 70
SP - 185
EP - 192
JO - Steroids
JF - Steroids
IS - 3
ER -
