Acridone Alkaloids. VII. Constituents of Citrus sinensis OSBECK var. brasiliensis TANAKA. Isolation and Characterization of Three New Acridone Alkaloids, and a New Coumarin

Abstract

Fractionation and chromatography of the acetone extract of the root bark of Citrus sinensis OSBECK var. brasiliensis TANAKA (Rutaceae) afforded three new acridone alkaloids namely citrusinie-I, -II and citbrasine and a new coumarin, ethylsuberenol. The structures of citrusinine-I, -II, and citbrasine, and ethylasuberenol were characterized as 1a, 2a, 3, and 6, respectively. Citracridone-I (4), suberenol (7), suberosin (8), crenulatin (9), xanthoxyletin (10), xanthyletin (11), nordentatin (12), elemol (13), and p-hydroquinone were also isolated.