title: Characterization of impurities in the bulk drug lisinopril by liquid chromatography/ion trap spectrometry.
abstract: Two trace impurities in the bulk drug lisinopril were detected by means of high-performance liquid chromatography coupled with mass spectrometry (HPLC/MS) with a simple and sensitive method suitable for HPLC/MSn analysis. The fragmentation behavior of lisinopril and the impurities was investigated, and two unknown impurities were elucidated as 2-(6-amino-1-(1-carboxyethylamino)-1-oxohexan-2-ylamino)-4-phenylbutanoic acid and 6-amino-2-(1-carboxy-3-phenylpro-pylamino)-hexanoic acid on the basis of the multi-stage mass spectrometry and exact mass evidence. The proposed structures of the two unknown impurities were further confirmed by nuclear magnetic resonance (NMR) experiments after preparative isolation.
authors.affiliation: Department of Chemistry, Zhejiang University, Hangzhou 310027, China.
authors.forename: Pei-xi
authors.initials: PX
authors.lastname: Zhu
authors.forename: Dan-hua
authors.initials: DH
authors.lastname: Wang
authors.forename: Cui-rong
authors.initials: CR
authors.lastname: Sun
authors.forename: Zhi-quan
authors.initials: ZQ
authors.lastname: Shen
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004340:Drug Contamination; D017706:Lisinopril / Q000032:analysis*; D009682:Magnetic Resonance Spectroscopy; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
chemical_list: D017706:Lisinopril