Structural Elucidation of Isoquinoline, Isoquinolone, Benzylisoquinoline, Aporphine, and Phenanthrene Alkaloids Using API-ionspray Tandem Mass Spectrometry

API-ionspray MS and MS/MS techniques were utilized to elucidate the structures of twenty-two isoquinoline alkaloids consisting of six simple isoquinolines, three isoquinolones, seven benzylisoquinolines, four aporphines, and two phenanthrenes. Most of alkaloids were isolated, identified, derivatized, and degraded previously from the roots of a variety of Thalictrum sp. (Ranucularaceae) and the barks of Phellodendron Wilsonii (Rutaceae) based on the UV, IR, NMR, EI- & CI-MS, and CD data, derivatization, degradation, and synthesis. In this investigation, apparent protonated molecular ion (MH + ), MNH 4 + , MNa + and MK + , along with some of dimeric MH + , dimeric MNH 4 + and dimeric MNa + for the secondary and tertiary alkaloids, and M + for the quaternary alkaloids, revealed in the Q1 Scan MS spectra, and in the tandem MS/MS spectra, prominent as well as diagnostic product ions were observed for structural elucidation of 22 isoquinoline alkaloids each in nanogram quantities.