SIMULTANEOUS ANALYSIS AND RETENTION BEHAVIOR OF THE GLUCURONIDE, GLUCOSIDE, AND N-ACETYLGLUCOSAMINIDE CONJUGATES OF BILE-ACIDS IN CONVENTIONAL AND INCLUSION HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHIC METHODS

Simultaneous analysis and structure-retention correlation were examine d for various glycosidic-conjugated bile acids in reversed-phase high- performance liquid chromatography (HPLC). The substrates examined incl uded the beta-glucuronide, beta-glucoside, and beta-N-acetylglucosamin ide conjugates of C-24 bile acids related to lithocholic, hyodeoxychol ic, chenodeoxycholic, ursodeoxycholic, deoxycholic, hyocholic, and cho lic acids having an O-beta-D-glycosidic linkage at the position C-3, C -6, or C-7 in the 5 beta-steroid nucleus. The bile acids as their fluo rescence-sensitive C-24 pyrenacyl ester derivatives were measured on a C-18 reversed-phase column, eluting with methanol-water mixtures in t he absence and presence of methyl-beta-cyclodextrin (Me-beta-CD). Chan ges in the retentions of these compounds depended significantly not on ly on the Me-beta-CD concentration but rather on the methanol content, implying the possible formation of solute-Me-beta-CD-methanol ternary complexes by hydrogen-bonding interactions. The combined use of conve ntional and inclusion HPLC retention data reported herewith provided i mportant information for characterizing the structures of bile acid gl ycosides as well as inclusion complexes. (C) 1998 Elsevier Science B.V .