Extracting Process of Essential Oil from Chrysanthemum indicum by Solvent-free Microwave Extraction and Its Components Analysis

Solvent-free microwave extraction (SFME) was used to extract essential oil from fresh and dried flowers of Chrysanthemum indicum. The extraction process was optimized. The chemical constituents of the two essential oils were analyzed by GC-MS, the relative content of each component was calculated by peak area normalization method. The results showed that the optimum condition of extracting essential oil from fresh flowers was that: extracting time 50 min, microwave power 540 W, and the yield of essential oil was 0.1129% of fresh flowers weight. The optimum condition of extracting essential oil from dried flowers was: material-liquid ratio 1:5 g/mL, soaking time 3 h, extracting time 60 min, the microwave power 540 W, and the yield of essential oil was 0.1926% of dried flowers weight. The main chemical constituents of fresh flower essential oil extracted by SFME were monoterpene and monoterpene oxygenated compounds, and the main compounds with relative content were trans-sabinyl acetate (13.20%), (−)-alpha-thujone (11.10%), cis-sabinol (9.70%), cis-chrysanthenol (5.06%), (+)-alpha-phellandrene (3.87%), cubebene (3.78%), 1, 8-cineole (3.61%), 3-thujol (3.37%), 2-thujene (3.36%). The main chemical constituents of dried flower essential oil were monoterpene oxygenates and sesquiterpenes, and the main compounds with relative content were cis-chrysanthenol(8.59%), trans-caryophyllene (7.63%), germacrened (7.06%), alpha-farnesene(5.86%), (−)-alpha-thujone (4.85%), trans-sabinyl acetate (4.34%), (+)-cis-chrysanthenyl acetate (3.45%), (+)-camphor (3.35%). The content of essential oil in fresh flowers of Chrysanthemum indicum was higher than that in dried flowers, and the relative content of monoterpenoids was higher than that in dried flowers. So the essential oil from fresh flowers of Chrysanthemum indicum had more application value.