Bioactive constituents from the rhizomes of Curcuma zedoaria

Curcuma zedoaria (Christm.) Rosc. (Zingiberaceae) is a perennial rhizomatous herb that is indigenous to Bangladesh, Sri Lanka and India, and is also widely cultivated in China, Japan, Brazil, Nepal, and Thailand. C. zedoaria, commonly called “White Turmeric”, has been used traditionally for the treatment of stomach disorders, dyspepsia, vomiting, menstrual disorders and for cancer. In our studies on the anti-platelet aggregation constituents of Formosan plants and Chinese herbs, many species have been screened for in vitro anti-platelet aggregation activity, and C. zedoaria has been found to be one of the active species. Investigation on EtOAc-soluble fraction of the rhizomes of C. zedoaria has led to the isolation of two new sesquiterpenoids, 13-hydroxycurzerenone (1) and 1-oxocurzerenone (2), and 11 known compounds (3-13). The structures of new compounds 1 and 2 was determined through spectral analyses including extensive 2D NMR deta. Among the isolated compounds, 13-hydroxycurzerenone (1), 1-oxocurzerenone (2), curzerenone (3), germacrone (4), curcolone (5), procurcumenol (6), and mixture of stigmast-4-en-3,6-dione (12) and stigmasta-4,22-dien-3,6-dione (13) exhibited inhibition (with inhibition % in the range of 21.28˜46.11%) against collagen-induced platelet aggregation at 100µM.

Keywords: Curcuma zedoaria, Zingiberaceae, sesquiterpenoids, anti-platelet aggregation activity.