Abstract: Zedoary turmeric oil from crude extract of Rhizoma Curcuma has been used as an anti-cancer agent in Traditional Chinese Medicine.Germacrone is a natural compound isolated from zedoary turmeric oil.In this study,we optimized the extraction process of germacrone from zedoary turmeric oil by central composite design and response surface methodology.The process was carried out with the content of germacrone as dependent variable,soaking time,extraction time and the amount of water as independent variables which was based on single factor tests,and each level of independent variables was made by multiple linear regression and binomial fitting.Response surface methodology was used to optimized extraction process conditions and carry on predictive analysis.The HPLC method was used to test the determination of germacrone.The results showed that average content of germacrone was 8.13% with a small deviation compared with the predicted value when optimized extraction conditions were applied with soaking time of 2.36 h,extraction time of 8.19 h and 9.98 times water.This optimized extraction process was simple and reasonable with a good predictability and can provide reference for extraction of germacrone．

Key words: zedoary turmeric oil, germacrone, response surface methodology, extraction technology, content determination