Chlorinated alkaloids in Menispermum dauricum DC. Root culture

Feeding experiments using Cl-36 showed that Melzispermum,dauricum root cult ure produces four alkaloids containing chlorine. They included the novel al kaloids dauricumine and dauricumidine as well as the known alkaloids acutum ine and acutumidine. The structures of novel alkaloids were established by spectroscopic, crystallographic, and chemical methods. These four alkaloids were labeled with Cl-36, isolated, and fed independently to root cultures. Mutual conversion between acutumine and acutumidine, and between dauricumi ne and dauricumidine by N-methylation and N-demethylation, was demonstrated . Moreover, dauricumine was converted to acutumine and acutumidine. Epimeri zation of acutumidine to dauricumidine or vice versa was not observed. Thes e results suggest that dauricumine is the first chlorinated alkaloid formed in cultured M. dauricum roots. Skewed distribution of radioactivity derive d from labeled dauricumine is proof that epimerization at C-l proceeds at a lower rate than N-demethylation.