API-ionspray Tandem Mass Spectrometric Analysis of Tetrahydroprotoberberine and Protoberberine Alkaloids

API-ionspray MS and MS/MS techniques were utilized to elucidate the structures of fifteen alkaloids consisting of six tetrahydroprotoberberine and nine protoberberine alkaloids, which were isolated, identified, and derivatized previously from the roots of a variety of Thalictrum sp. (Ranunculaceae) and Coptis sp. (Ranunculaceae) and the barks of Phellodendron Wilsonii (Rutaceae), based on the UV, IR, NMR, EI-MS data, derivatization and synthesis. In this investigation, apparent protonated molecular (MH + ), along with dimeric MH + ions for the tertiary alkaloids, molecular ions (M + ) for the quaternary alkaloids in the Ql Scan MS spectra, and product ions in the MS/MS spectra for structural elucidation were observed for all studied alkaloids each in nanogram or in picrogram quantities.