Anti-Helicobacter pylori and thrombin inhibitory components from Chinese dragon's blood, Dracaena cochinchinensis

Chemical studies on the constituents of Dracaena cochinchinensis led to the discovery of eight new flavonoid derivatives ( 1- 8) along with 14 known compounds ( 9- 22). The identification and structural elucidation of these isolates were based on spectral analyses. All isolates were tested for antibacterial activities against Helicobacter pylori (ATCC43504) and thrombin inhibitory effects. As a result, new flavonoid derivatives 6 and 7 and (2 S)-4',7-dihydroxy-8-methylflavan ( 11) were found to be most efficacious against H. pylori (ATCC43504) with MIC values of 29.5, 29.5, and 31.3 microM, respectively, and the seven new flavonoid derivatives ( 1- 7) and one known biflavonoid ( 9) were observed to exhibit moderate thrombin inhibitory activity.