Abstract
One new, 10, 11-dioxo-6,7 alpha-erythraline epoxide (1) and four known erythrinan alkaloids 10, 11-dioxoerythraline (2), erysodine (3), 8-oxo-erythraline ( 4) and erythraline (5) were isolated from the 70% methanolic extract of stems of E. Corallodendron (Fabaceae). The isolated compounds were elucidated by exploiting 1D/2D NMR, and HR-ESI-MS analysis. The absolute configuration of 1 was determined by electronic circular dichroism (ECD). Mono Amine Oxidase inhibitory activity of the isolated alkaloids was investigated in vitro using kynuramine deamination assay on recombinant human MAO-A and B enzymes. The binding modes were predicted by molecular docking and the structure activity relationships of erythrinans were then evaluated. All isolated alkaloids demonstrated preferential activity against MAO-B. 1 displayed the highest potency and selectivity against MAO-B with IC50 of 25.18 mu M, ( SI >3.97). The selective inhibition exhibited by erythrinan alkaloids against MAO-B is in line with the expected biological impact of Erythrina in the treatment of neurodegenerative diseases and presents this chemical class as promising leads for managing AD and PD diseases.