title: Study of the electrospray ionization tandem mass spectrometry of sildenafil derivatives.
abstract: A detailed analysis of the product ion spectrum generated from the protonated molecule of sildenafil (Viagra(R)) under multiple tandem mass spectrometry (ESI-MS(n)) conditions using an ion-trap mass spectrometer is reported. Molecular composition data of the fragment ions were obtained with the aid of comparisons of the multiple tandem mass spectra of eight sildenafil derivatives in two series, the structures of which are identical except for some substituted alkyl groups. Attempts have been made to provide rational pathways for the formation of the fragment ions from these protonated sildenafil derivatives. The structure-fragmentation relationships will facilitate the characterization of the structures of other sildenafil analogs.
authors.affiliation: Laboratory of Drug Metabolism and Pharmacokinetics, Shenyang Pharmaceutical University, China. zhongdf@ihw.com.cn
authors.forename: Dafang
authors.initials: D
authors.lastname: Zhong
authors.forename: Jie
authors.initials: J
authors.lastname: Xing
authors.forename: Shuqiu
authors.initials: S
authors.lastname: Zhang
authors.forename: Lu
authors.initials: L
authors.lastname: Sun
mesh_terms: D010879:Piperazines / Q000032:analysis*; D011687:Purines; D000068677:Sildenafil Citrate; D021241:Spectrometry, Mass, Electrospray Ionization; D013450:Sulfones; D009626:Terminology as Topic
chemical_list: D010879:Piperazines; D011687:Purines; D013450:Sulfones; D000068677:Sildenafil Citrate