Studies On Preparation Technology Of High Quality Essential Oils From Radix Aucklandia

Radix Aucklandia, the roots of Aucklandia Lappa Decne, a plant of compositae, is an important traditional Chinese medicine and a raw material of perfume. The main active chemical part of Radix Aucklandia is its essential oil and the main active constituents are sesquiterpene lactone such as costunolide and dehydrocostuslactone, which have pharmacological functions of relaxing smooth muscle relaxation, relieving spasm, and protecting gastric mucosa and anti-ulcer and cholagogic activities. The essential oil from Radix Aucklandia is also important material in perfume industry.The purpose of this paper was to optimize preparation technology of essential oil from Radix Aucklandia. The contents of costunolide and dehydrocostuslactone as well as those of other pharmacological active and flavor ingradients were used as quality evaluation index of the essential oil from Radix Aucklandia. The contents of contunolide and dehydrocostuslactone in the essential oil from Radix Aucklandia were determined by the quantitative method of costunolide and dehydrocostuslactone in Radix Aucklandia recorded in Chinese pharmacopoeia (2010 Edition). The contents of other pharmacological active and flavor ingradients were analyzed using GC-MS.Firstly, extracting process of essential oil from Radix Aucklandia was optimized. Four extracting methods including supercritical CO2 extraction, steam distillation, reflux extraction with petroleum ether, and soak with methanol were used to extract essential oil from Radix Aucklandia. By comparing the yields and chemical compositions as well as the contents of costunolide and dehydrocostuslactone in the essential oils from different methods, the best extracting method was determined as soaking Radix Aucklandia with methanol.Next, the effects of different processing methods of raw material were investigated on chemical compositions and contents of contunolide and dehydrocostuslactone in essential oil in Radix Aucklandia.4 different methods such as frying without additional ingredients (1), stir-heating with bran (2), roasting surrounded with bran (3), and roasting wrapped in wet paper (4), steaming method (5) were used to process raw Radix Aucklandiae. Then the essential oils were extracted wtih supercritical CO2 and analyzed for chemical compostions and contents of costunolide and dehydrocostuslactone.. By comparing the yield and chemical compositions of the essential oils as well as the contents of costunolide and dehydrocostuslactone in the essential oils from Radix Aucklandia processed by different methods, it was concluded that Radix Aucklandia should be processed by roasting surrounded with wheat bran to produce raw material of perfume, wheras as a drug to treat epigastric pain, the raw drug should be processed by frying without additional ingredients.Finally, essential oil from Radix Aucklandia was refined by molecular distillation. Contents of costunolide and dehydrocostuslactone in the refined essential oil were used to evaluate purification process, The result showed that the optimum conditions as following:the distillation tempterature,150℃; sample loading speed,1.2 g/min; the operating pressure,0.13 mbar; film scraping speed,200 r/min. The total content of costunolide and dehydrocostuslactone is 72.11% in the refined essential oil from Radix Aucklandia.