Canarosine: A new guanidine alkaloid from Canavalia rosea with inhibitory activity on dopamine D1 receptors

Abstract

A new acyclic guanidine alkaloid, canarosine (1), together with five known compounds, β-sitosterol (2), stigmasterol (3), daucosterol (4), epi-inositol 6-O-methyl ether (5), and rutin (6), were isolated from the aerial parts of Canavalia rosea. Their structures were established on the basis of their spectroscopic data. In the radioligand receptor binding assay, canarosine (1), at a concentration of 100 μg/ml, caused 91% inhibition of the dopamine D1 receptor binding with an IC₅₀ value of 39.4 ± 5.8 μM.

Keywords:

• Canavalia rosea DC
• Fabaceae
• guanidine alkaloid
• dopamine D1 receptors

Acknowledgements

This work was supported in part by a 90th anniversary grant from Chulalongkorn University (Ratchadaphiseksomphot Endowment Fund) and a grant from the National Research Council of Thailand.