Structures of new Erythrinan alkaloids and nitric oxide production inhibitors from Erythrina crista-galli.
Two new Erythrinan alkaloids, cristanines A and B (1, 2), were isolated from the bark of Erythrina crista-galli L. together with nine known Erythrinan alkaloids (3-5, 7-12) and an indole alkaloid (13). The structures of the compounds, cristanines A (1) and B (2), were elucidated by spectroscopic methods. Three of the twelve compounds isolated showed significant inhibitory activity on lipopolysaccharide induced nitric oxide (NO) production.