Isolation of alkaloidal constituents of Zanthoxylum usambarense and Zanthoxylum chalybeum using ion-pair HPLC

Quaternary alkaloids of two Kenyan medicinal plants belonging to the genus Zanthoxylum, Z. usambarense and Z. chalybeum, were examined using ion-pair HPLC. Both plants contained similar alkaloids, but colored protoberberines were found only in Z. chalybeum. From the stems of Z. usambarense a new alkaloid named usambanoline (1) was isolated and characterized.