[Synthesis and characterization of 9-O-alkyl substituted palmatine derivatives].

For the establishment of chemical library of protoberberines provided for the bio-activity screening, the target compounds were synthesized by thermal degradation and nucleophilic substitution reactions with the bio-active alkaloid, palmatine (1), as the raw material, and their structures were identified and conformed by 1H-NMR and MS spectra. Among them, 13 compounds were new.