Neuroinflammation mediated by microglia cells plays a critical role in the development of Alzheimer's disease. To identify novel natural neuroinflammation inhibitors, a bioactivity-guided phytochemical research was performed on the traditional Chinese medicine "Awei", that exhibited a significant inhibitory effect on nitric oxide production in over-activated microglia cells. The research identified sixteen bioactive sesquiterpene coumarins (two new and fourteen known ones) in the effective extract of