Enantiomeric separation of racemic 1-benzyl-N-methyltetrahydroisoquinolines on chiral columns and chiral purity determinations of the O-methylated metabolites in plant cell cultures by HPLC-CD on-line coupling in combination with HPLC-MS.

Effective enantiomeric separations of 1-benzyl-N-methyltetrahydroisoquinolines were achieved using commercially available Chiralcel OD-H and OJ-H columns. Online LC-CD analysis allowed for the establishment of a correlation between the absolute configuration of the separated enantiomers and their characteristic CD transitions. LC-MS combined with LC-CD analysis permitted chiral purity determinations of O-methylated metabolites of nine phenolic 1-benzyl-N-methyltetrahydroisoquinolines in cell cultures of Corydalis, Macleaya, and Nandina species.

Online structural elucidation of alkaloids and other constituents in crude extracts and cultured cells of Nandina domestica by combination of LC-MS/MS, LC-NMR, and LC-CD analyses.

The combination of NMR, MS, and CD data permitted the structural elucidation including the absolute configuration of the known alkaloids and unknown components in the extract matrix solution of Nandina domestica without isolation and sample purification prior to the coupling experiments. Unstable natural stereoisomers were identified by LC-NMR and LC-MS. Five known alkaloids, (S)-isoboldine, (S)-domesticine, (S)-nantenine, sinoacutine, and menispermine, were identified from N.