Chlorinated Alkaloids in Menispermum dauricum DC. Root Culture

• Published in: Journal of organic chemistry 2001-05, Vol.66 (10), p.3299-3302
• Main Authors: Sugimoto, Yukihiro, Babiker, Hind A. A., Saisho, Tomoki, Furumoto, Toshio, Inanaga, Shinobu, Kato, Masako
• Format: Article
• Language: English
• Subjects: Alkaloids - analysis; Alkaloids - metabolism; Chlorine - metabolism; Crystallography, X-Ray; Molecular Structure; Plant Roots - chemistry; Plant Roots - cytology; Plant Roots - metabolism; Plants, Medicinal - chemistry; Plants, Medicinal - cytology; Plants, Medicinal - metabolism; Radioisotopes; Spectrum Analysis; Spiro Compounds - analysis; Spiro Compounds - metabolism
• ISSN: 0022-3263; 1520-6904
• DOI: 10.1021/jo001494l

Feeding experiments using 36Cl showed that Menispermum dauricum root culture produces four alkaloids containing chlorine. They included the novel alkaloids dauricumine and dauricumidine as well as the known alkaloids acutumine and acutumidine. The structures of novel alkaloids were established by spectroscopic, crystallographic, and chemical methods. These four alkaloids were labeled with 36Cl, isolated, and fed independently to root cultures. Mutual conversion between acutumine and acutumidine, and between dauricumine and dauricumidine by N-methylation and N-demethylation, was demonstrated. Moreover, dauricumine was converted to acutumine and acutumidine. Epimerization of acutumidine to dauricumidine or vice versa was not observed. These results suggest that dauricumine is the first chlorinated alkaloid formed in cultured M. dauricum roots. Skewed distribution of radioactivity derived from labeled dauricumine is proof that epimerization at C-1 proceeds at a lower rate than N-demethylation.