GC-MS Analysis of Chemical Constituents Extracted from Ligusticum chuanxiong Hort. by Ultrasonic Extraction

Ligusticum chuanxiong Hort.is a kind of traditional Chinese herb.Its effective substances are mainly lactones,which can not be extracted completely when using simple methods because some lactones are hiden in the cell wall.In this paper,we use ultrasound to break cell wall and then immerse in organic solvent at 63 ℃ in order to extract latones completely.The extracts were analyzed by GC-MS.Two kinds of lactones named 3-methyl-phthalide and 2(1,3H)-1-isobenzofuranone,3-butadiene-4,5-dihydro-,are discovered,whose mass fraction are 0.36 % and 0.31 % in total contents of lactones.To our knowledge,they have not been reported yet.Three solvents were used to extract Ligusticum chuanxiong Hort in this experiment,they were chloroform,petroleum ether and the mixture of ethyl alcohol and water(V/V 80/20,pH = 1).When volatile constituents are extracted,chloroform and petroleum ether have higher extraction efficiency.On the other hand,when fatty acids are extracted the mixture alcohol and water is more effective.Using any of the above solvents,the main constituents in Ligusticum chuanxiong Hort.are lactones,terpenes and fatty acids are the second.