title: Identification of AJ-2615 and its S-oxidized metabolites in rat plasma by use of tandem-mass spectrometry.
abstract: The structural elucidation of the metabolites of a new calcium entry blocker, AJ-2615 (AJ), in rat plasma is described. Metabolites in a crude plasma extract from spontaneously hypertensive rats were identified without chromatographic separation by fast atom bombardment tandem mass spectrometry. When the plasma extract was examined by using parent ion scans, the presence of the oxidized metabolites of AJ was suggested. These metabolites were identified as the S-oxide and the S,S-dioxide by comparing their daughter ion spectra with those of authentic samples. The presence of the two diastereomeric S-oxides of AJ in the plasma extract was ascertained by high-performance liquid chromatography. Their relative configurations were determined by infrared and proton nuclear magnetic resonance spectra.
authors.affiliation: Research Laboratories, Dainippon Pharmaceutical Co. Ltd, Osaka, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Kurono
authors.forename: A
authors.initials: A
authors.lastname: Itogawa
authors.forename: K
authors.initials: K
authors.lastname: Yoshida
authors.forename: S
authors.initials: S
authors.lastname: Naruto
authors.forename: P
authors.initials: P
authors.lastname: Rudewicz
authors.forename: M
authors.initials: M
authors.lastname: Kanai
mesh_terms: D000818:Animals; D002121:Calcium Channel Blockers / Q000097:blood*; D002851:Chromatography, High Pressure Liquid; D003988:Dibenzothiepins / Q000097:blood*; D004563:Electrochemistry; D008297:Male; D008968:Molecular Conformation; D010084:Oxidation-Reduction; D010879:Piperazines / Q000097:blood; D051381:Rats; D011918:Rats, Inbred SHR; D016339:Spectrometry, Mass, Fast Atom Bombardment
chemical_list: D002121:Calcium Channel Blockers; D003988:Dibenzothiepins; D010879:Piperazines; C067818:monatepil