title: Application of liquid chromatography-ion trap mass spectrometry to the characterization of the 16-membered ring macrolide josamycin propionate.
abstract: Coupled liquid chromatography and ion trap mass spectrometry (LC/MS) was used for the characterization of the semi-synthetic 16-membered ring macrolide josamycin propionate. On-line identification of impurities in this antibiotic complex was performed with an ion trap mass spectrometer without recourse to time-consuming isolation and purification procedures. Ion trap mass spectrometry is ideally suited to identification of impurities because it provides MSn capability, enabling multiple stages of mass spectrometry to obtain the maximum amount of structural information for a given molecule. The ion trap was used with an electrospray ionization source operated in the positive ion mode or with an atmospheric pressure chemical ionization source operated in the negative ion mode. The identity of the unknown compounds was deduced using the MS/MS and MSn collision-induced dissociation spectra of reference substances or structural analogs as interpretative templates, combined with knowledge about the nature of functional group fragmentation behavior. Given the importance attached to the identification of impurities of unknown identity in pharmaceutical substances, this study is useful for companies producing josamycin propionate. The knowledge of the fragmentation behavior is also of importance in further research on other 16-membered macrolides.
authors.affiliation: Faculteit Farmaceutische Wetenschappen, Laboratorium voor Farmaceutische Chemie en Analyse van Geneesmiddelen, Katholieke Universiteit Leuven, E. Van Evenstraat 4, B-3000 Leuven, Belgium.
authors.forename: Cindy
authors.initials: C
authors.lastname: Govaerts
authors.forename: Hezekiah Kibet
authors.initials: HK
authors.lastname: Chepkwony
authors.forename: Ann
authors.initials: A
authors.lastname: Van Schepdael
authors.forename: Erwin
authors.initials: E
authors.lastname: Adams
authors.forename: Eugène
authors.initials: E
authors.lastname: Roets
authors.forename: Jos
authors.initials: J
authors.lastname: Hoogmartens
mesh_terms: D002853:Chromatography, Liquid; D015570:Josamycin / Q000031:analogs & derivatives* / Q000032:analysis* / Q000737:chemistry*; D007933:Leucomycins / Q000032:analysis / Q000737:chemistry; D013058:Mass Spectrometry; D015394:Molecular Structure; D010100:Oxygen / Q000032:analysis / Q000737:chemistry; D012015:Reference Standards
chemical_list: D007933:Leucomycins; C043427:josamycin propionate; D015570:Josamycin; C026483:midecamycin; D010100:Oxygen