Abstract: The optimization of the extraction of volatile oil from Asarum forbesii Maxim with microwave assistance was studied through one-factor-at-a-time instigations followed by mathematical modeling for extraction efficiency as a response to liquid-to-solid ratio, microwave power and treatment time based on the principle of Box-Behnken experimental design and response surface analysis of model. Liquid-to-solid ratio of 8.3:1, microwave power of 309 W and treatment time of 154 s were found optimum for the extraction of volatile oil with ethyl acetate, which was selected out of four common organic solvents based on oil yield. Under these conditions, the experimental value of oil yield was 7.96%, substantially complying with the theoretical value. This indicates good reliability of the developed regression model in predicting oil yield. The volatile oil extracted by the optimized method was subjected to separation and identification on a gas chromatography-mass spectrometry (GC-MS) system. A total of 25 constituents were separated and 19 of them were identified and quantified by area normalization method. This study can provide useful references for the development and exploitation of Asarum forbesii Maxim.

Key words: microwave-assisted extraction, Asarum forbesii Maxim, volatile oil, response surface methodology, gas chromatography-mass spectrometry