title: Single-step analysis of individual conjugated bile acids in human bile using 1H NMR spectroscopy.
abstract: 1H and 13C NMR spectra of intact human bile were assigned using one-dimensional (1H and 13C) and two-dimensional (1H-1H and 1H-13C) experiments. Individual conjugated bile acids--glycocholic acid, glycodeoxycholic acid, glycochenodeoxycholic acid, taurocholic acid, taurodeoxycholic acid, and taurochenodeoxycholic acid--were identified. The bile acids were quantified accurately and individually in a single step by using distinct and characteristic amide signals. Making use of 13C NMR, the study also suggests a way to analyze unconjugated bile acids separately, if present. Chemical shift assignments and rapid single-step analysis of individual conjugated bile acids from intact bile presented herein may have immense utility in the study of bile acid metabolism and deeper understanding of hepatobiliary diseases.
authors.affiliation: Centre of Biomedical Magnetic Resonance, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow-226 014, India. gangcbmr@hotmail.com
authors.forename: G A Nagana
authors.initials: GA
authors.lastname: Gowda
authors.forename: Omkar B
authors.initials: OB
authors.lastname: Ijare
authors.forename: B S
authors.initials: BS
authors.lastname: Somashekar
authors.forename: Ajay
authors.initials: A
authors.lastname: Sharma
authors.forename: V K
authors.initials: VK
authors.lastname: Kapoor
authors.forename: C L
authors.initials: CL
authors.lastname: Khetrapal
mesh_terms: D001646:Bile / Q000737:chemistry*; D001647:Bile Acids and Salts / Q000737:chemistry*; D002635:Chenodeoxycholic Acid / Q000032:analysis; D005999:Glycochenodeoxycholic Acid / Q000032:analysis; D006000:Glycocholic Acid / Q000032:analysis; D006002:Glycodeoxycholic Acid / Q000032:analysis; D006801:Humans; D008954:Models, Biological; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D013655:Taurochenodeoxycholic Acid / Q000032:analysis; D013656:Taurocholic Acid / Q000032:analysis; D013657:Taurodeoxycholic Acid / Q000032:analysis
chemical_list: D001647:Bile Acids and Salts; D002635:Chenodeoxycholic Acid; D006002:Glycodeoxycholic Acid; D013655:Taurochenodeoxycholic Acid; D013657:Taurodeoxycholic Acid; D013656:Taurocholic Acid; D005999:Glycochenodeoxycholic Acid; D006000:Glycocholic Acid