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Metabolism of [ 14 C]niflumic acid isolation and identification of metabolites from human urine
Author(s) -
Cohen Allen I.,
Weliky Irving,
Lan ShihJung,
Levine Seymour D.
Publication year - 1974
Publication title -
biomedical mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 121
eISSN - 1096-9888
pISSN - 0306-042X
DOI - 10.1002/bms.1200010103
Subject(s) - niflumic acid , chemistry , urine , derivative (finance) , metabolism , mass spectrometry , phenylacetic acid , chromatography , biochemistry , stereochemistry , financial economics , economics
The two major metabolites of [ 14 C]niflumic acid, 2‐(3′‐[ 14 C] trifluoromethylanilino)nicotinic acid have been isolated from human urine. Low and high resolution mass spectrometry indicate that both metabolites (M2a and M2b) are monohydroxylated derivatives of niflumic acid. The 100 MHz proton magnetic resonance spectrum of M2b demonstrates it to be 5‐hydroxyniflumic acid, whereas M2a is either the 4′‐ or 6′‐hydroxy derivative. The synthesis of 6′‐methoxyniflumic acid methyl ester and comparison of its spectral data and melting point with that of the corresponding derivative of M2a reveal their non‐identity. The structure of M2a is, therefore, 4′‐hydroxyniflumic acid.