Compounds from the bark of Illicium tsaii and their anti-inflammatory activity
Illicium tsaii is a Chinese native species growing in northwest China. The bark of I. tsaii, has been applied for the treatment of rheumatoid arthritis. Phytochemical investigation on this species resulted in the isolation and characterization of 28 compounds from the stem bark of I. tsaii. Structure determination was accomplished by means of spectroscopic data interpretation. The biological activity of the isolated compounds was evaluated toward multiple targets related to inflammation such as NAG-1, NF-κB, iNOS and ROS. Sesquilignans showed significant activity, among which dunnianol, macranthol and isodunnianol increased NAG-1 activity 1.5 – 3.0 fold and decreased cellular oxidative stress by 40 – 65%. These three compounds showed substantial activity against iNOS, while only macranthol showed activity against NF-κB. This is the first study on the constituents of I. tsaii and evaluation of their biological activity.