Structures of [M–44]+ ions in the electron impact and fast atom bombardment mass spectra of the β-blocker nipradilol with a nitrate ester group

✍ Scribed by Michiaki Yoneda; Kazuo Tsujimoto; Mamoru Ohashi; Masami Shiratsuchi; Yasushi Ohkawa

• Publisher: John Wiley and Sons
• Year: 1990
• Tongue: English
• Weight: 348 KB
• Volume: 25
• Category: Article
• ISSN: 1076-5174
• DOI: 10.1002/oms.1210250305

✦ Synopsis

Both electron impact (EI) and fast atom bombardment (liquid secondary ion mass spectrometry) (FAB(LS1MS)) spectra of the antibypertensive drug nipradilol (3,4-dihydro-&(2-hydroxy-3-isopropylamino)propoxy-~nitroxy-ZH-1-benzopyran) and it analogues exhibit intense [M -44]+ peaks. However, high-resolution measurements and tandem mass spectrometric techniques clarified that the composition of the ion produced by El is [M -C2H,01+, whereas that of the ion produced by FAB(LS1MS) is [M -NO, + 2HI'. FAB collisionactivated dissociation-tandem mass spectrometry revealed that the structure of the latter ion corresponds to the MH' of the hydrolysis product of the nitrate ester group.