Human urinary metabolites of 3-(2',4',5'-triethoxybenzoyl)propionic acid, a new biliary smooth muscle relaxant with choleretic activity.
Biotransformation of 3-(2',4',5'-triethoxybenzoyl)propionic acid (tri-, ethoxybenzoylpropionate) was studied in man using isotopic cluster technique. From the 24 h urine of a male volunteer given an equimolar mixture of non-labelled and pentadeuterium-labelled triethoxybenzoylpropionate (1 mg/kg) orally, the parent drug, 3-(2',5'-diethoxy-4'-hydroxybenzoyl)propionic acid (4'-phenol) and 3-(2',4'-diethoxy-5'-hydroxybenzoyl)propionic acid (5'-phenol) were isolated and identified by g.l.c.-mass spectrometry. 2. Urinary components were also quantified by mass chromatography: the parent drug (67.4% of dose) and 4'- and 5'-phenols in a mixture (20.3%). More than 80% of urinary triethoxybenzoylpropionate was present as its glucuronic acid ester, as evidenced by using beta-glucuronidase and saccharo-1,4-lactone, a specific inhibitor of the enzyme. Almost all of 4'- and 5'-phenols appeared as conjugates with glucuronic acid and/or sulphuric acid. These findings indicated that in man triethoxybenzoylpropionate was largely conjugated with glucuronic acid and in part underwent deethylation followed by conjugation for elimination mainly in urine.
D001565:Benzoates / Q000652:urine; D001711:Biotransformation; D002756:Cholagogues and Choleretics / Q000652:urine*; D002849:Chromatography, Gas; D005965:Glucuronates / Q000652:urine; D006801:Humans; D008297:Male; D013058:Mass Spectrometry; D008722:Methods; D011422:Propionates / Q000652:urine*
D001565:Benzoates; D002756:Cholagogues and Choleretics; D005965:Glucuronates; D011422:Propionates; C014258:3-(2',4',5'-triethoxybenzoyl)propionic acid