title: HPLC/ELSD analysis of amidated bile acids: an effective and rapid way to assist continuous flow chemistry processes.
abstract: The employment of the flow N-acyl amidation of natural bile acids (BAs) required the in-line connection with suitable analytical tools enabling the determination of reaction yields as well as of the purity grade of the synthesized glyco- and tauro-conjugated derivatives. In this framework, a unique HPLC method was successfully established and validated for ursodeoxycholic (UDCA), chenodeoxycholic (CDCA), deoxycholic (DCA) and cholic (CA) acids, as well as the corresponding glyco- and tauro-conjugated forms. Because of the shared absence of relevant chromophoric moieties in the sample structure, an evaporative light scattering detector (ELSD) was profitably utilized for the analysis of such steroidal species. For each of the investigated compounds, all the runs were contemporarily carried out on the acidic free and the two relative conjugated variants. The different ELSD response of the free and the corresponding conjugated BAs, imposed to build-up separate calibration curves. In all the cases, very good precision (RSD% values ranging from 1.04 to 6.40% in the long-period) and accuracy (Recovery% values ranging from 96.03 to 111.14% in the long-period) values along with appreciably low LOD and LOQ values (the former being within the range 1-27 ng mL(-1) and the latter within the range 2-44 ng mL(-1)) turned out.
authors.affiliation: Dipartimento di Chimica e Tecnologia del Farmaco, Università degli Studi di Perugia, Perugia, Italy.
authors.forename: Roccaldo
authors.initials: R
authors.lastname: Sardella
authors.forename: Antimo
authors.initials: A
authors.lastname: Gioiello
authors.forename: Federica
authors.initials: F
authors.lastname: Ianni
authors.forename: Francesco
authors.initials: F
authors.lastname: Venturoni
authors.forename: Benedetto
authors.initials: B
authors.lastname: Natalini
mesh_terms: D001647:Bile Acids and Salts / Q000032:analysis* / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D056148:Chromatography, Reverse-Phase; D006027:Glycosides / Q000737:chemistry; D006801:Humans; D008027:Light; D016014:Linear Models; D015203:Reproducibility of Results; D012542:Scattering, Radiation; D013656:Taurocholic Acid / Q000737:chemistry; D013997:Time Factors
chemical_list: D001647:Bile Acids and Salts; D006027:Glycosides; D013656:Taurocholic Acid