title: Characterization of impurities in commercial spectinomycin by liquid chromatography with electrospray ionization tandem mass spectrometry.
abstract: Analysis of commercial spectinomycin samples with ion-pairing reversed-phase LC coupled with electrospray ionization tandem MS (LC/ESI-MS/MS) indicates that eight additional compounds are present, including actinamine, (4R)-dihydrospectinomycin, (4S)-dihydrospectinomycin and dihydroxyspectinomycin, as well as four new impurities reported, to our knowledge, for the first time. The structures of these compounds were elucidated by comparing their fragmentation patterns with known structures, and NMR was employed to characterize and distinguish (4R)-dihydrospectinomycin and (4S)-dihydrospectinomycin. Identification of dihydrospectinomycin isomers is necessary because (4R)-dihydrospectinomycin is a minor active pharmaceutical ingredient of spectinomycin, whereas (4S)-dihydrospectinomycin is considered to be an impurity (impurity C) by the European Pharmacopoeia (Ph. Eur.).
authors.affiliation: National Institutes for Food and Drug Control, Department of Antibiotics, Beijing, People's Republic of China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Wang
authors.affiliation: National Institutes for Food and Drug Control, Department of Antibiotics, Beijing, People's Republic of China.
authors.forename: Mingjuan
authors.initials: M
authors.lastname: Wang
authors.affiliation: National Institutes for Food and Drug Control, Department of Antibiotics, Beijing, People's Republic of China.
authors.forename: Jin
authors.initials: J
authors.lastname: Li
authors.affiliation: National Institutes for Food and Drug Control, Department of Antibiotics, Beijing, People's Republic of China.
authors.forename: Shangchen
authors.initials: S
authors.lastname: Yao
authors.affiliation: National Institutes for Food and Drug Control, Department of Antibiotics, Beijing, People's Republic of China.
authors.forename: Jing
authors.initials: J
authors.lastname: Xue
authors.affiliation: National Institutes for Food and Drug Control, Department of Antibiotics, Beijing, People's Republic of China.
authors.forename: Wenbo
authors.initials: W
authors.lastname: Zou
authors.affiliation: National Institutes for Food and Drug Control, Department of Antibiotics, Beijing, People's Republic of China.
authors.forename: Changqin
authors.initials: C
authors.lastname: Hu
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry*; D002853:Chromatography, Liquid / Q000379:methods; D004340:Drug Contamination; D000198:Spectinomycin / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods; D053719:Tandem Mass Spectrometry / Q000379:methods
chemical_list: D000900:Anti-Bacterial Agents; D000198:Spectinomycin