SEPARATION AND CHARACTERIZATION OF URSODEOXYCHOLATE 7-N-ACETYLGLUCOSAMINIDES IN HUMAN URINE BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY WITH FLUORESCENCE DETECTION

The separation and characterization of unconjugated, glycine- and taur ine-conjugated ursodeoxycholate 7-N-acetylglucosaminides in human urin e without prior deconjugation have been carried out by high-performanc e liquid chromatography (HPLC) on a reversed phase column. The bile ac id fraction was obtained from a urine specimen by the combined use of a Sep-Pak C18 cartridge for solid phase extraction and lipophilic gel, piperidinohydroxypropyl Sephadex LH-20 (PHP-LH-20), for ion-exchange chromatography. Bile acid N-acetylglucosaminides were derivatized quan titatively into the corresponding fluorescent esters through the inher ent primary hydroxyl group by treatment with 9-anthroyl cyanide. The d erivatives were separated into unconjugated, glycine- and taurine-conj ugated fractions on PHP-LH-20. Subsequent resolution into individual N -acetylglucosaminides was attained by HPLC with fluorescence detection on a Cosmosil 5C18 column using 0.3% potassium phosphate buffer-metha nol as a mobile phase. Unconjugated, glycine- and taurine-conjugated u rsodeoxycholate 7-N-acetylglucosaminides in human urine from a patient with primary biliary cirrhosis were unambiguously identified on the b asis of their chromatographic behavior using mobile phases of differen t pHs and organic modifiers. It has proved that ursodeoxycholate 7-N-a cetylglucosaminides in urine were dominantly conjugated with glycine, while any 3-N-acetylglucosaminides of ursodeoxycholates as well as oth er common bile acids were not present.