Isoquinoline Alkaloids from the Rhizoma of Coptis chinensis

AIM:To study isoquinoline alkaloids of the rhizoma of Coptis chinensis. METHODS: Column chromatographic techniques were used for the isolation and purification of chemical constituents of the plant. The structures were elucidated by spectroscopic methods. RESULTS: Seven isoquinoline alkaloids, 8-oxyberberine (1) , 8-oxocoptisine (2) , 8-oxo-epiberberine (3), 6-([1,3]dioxolo[4,5-g]isoquinoline-5-carbonyl)-2,3-dimethoxy-benzoic acid methyl ester (4), corydaldine (5), noroxyhydrastineine (6) and 6,7-methylenedioxy-1(2H)-isoquinolinone (7) were isolated from this plant. CONCLUSION: Compounds 1～7 were isolated from this plant for the first time.