Study On The Extraction Of Essential Oil From Yunnan Tobacco And The Purification Process Of Neophytadiene

In this paper,Yunnan typical primary flue-cured tobacco leaves were used as raw materials,taking yields of essential oils as the objective,the process conditions of supercritical CO₂ extraction of essential oils from tobacco leaves were optimized.The extraction rates and contents of volatile oils from fresh tobacco leaves planted in different regions were also compared.Ultrasound-assisted,cable-type,and solvent extraction methods were used to extract the active ingredients in the flue-cured tobacco leaves,and the composition of the initial extracts of the four extraction methods under optimal conditions was analyzed and compared.Then,with nicotine and neophytadiene as target,using the primary extracts as raw materials,a simple and efficient method for separating and purifying nicotine and neophytadiene was studied.The main research contents are as follows:1.Supercritical CO₂ fliud was used to extract volatile oils from the primary flue-cured tobacco leaves,and taking the volatile oil yield as an index,the best extraction process was selected as:extraction pressure was 25MPa,tempe rature 50?,CO₂ flow 20g/min,extraction time 2 hours.And the influence fact or intensity sequence was:temperature>time>pressure>CO ₂ flow rate.Under this condition,the average oil yield was 3.18%.The components of the volatile oil extracted under the optimal extraction conditions were analyzed by GC-MS.The analysis results showed that the main effective components were nico tine,neophytadiene,(Z,Z,Z)-9,12,15-octadecadienoic acid,n-hexadecanoic acid,vitamin E and 1,5,9-trimethyl-12-(1-methylethyl)-4,8,13-cyclododecatriene-1,3-diol,etc.2.Drawing on the optimal extraction conditions of the first flue-cured tobacco leaves,supercritical CO₂ extraction was performed on different parts of fresh tobacco leaves planted in Yunnan different regions,and the yields were compared.The results showed that the yield was higher for the middle parts of fresh tobacco leaves from Tonghai area,and the color of the extract was partial yellow.The yields of other regions were lower and the colors were relatively light.The results of GC-MS analysis showed that the main components of the extracts were nicotine,5-hydroxy-2,4-di-tert-butylphenyl valerate and 2-hexyl-1-decanol,etc.It was quite different from the main components of extracts from the first flue-cured tobacco leaf.3.Ultrasonic-assisted extraction,Soxhlet extraction,and solvent extraction were used to extract components of the primary flue-cured tobacco leaves,and the yields and main components of the extracts were compared when different concentrations of ethanol aqueous solution were used as extractants.When the solvent or entrainer was100%ethanol,the yield of the initial extract was the highest under Soxhlet extraction.The comparison of the yields of the four extraction processes was Soxhlet extraction>Ultrasonic assisted extraction>Solvent extraction>Supercritical CO₂ extraction.4.Based on nicotine and neophytadiene,exploring the analysis conditions of gas chromatography-mass spectrometry(GC-MS).5.Taking nicotine and neophytadiene as target isolates,the appropriate extraction method was selected.Here,using the initial extracts obtained by above extraction methods as raw materials,solvent reverse extraction and column chromatography were used to separate and purifie nicotine and neophytadiene.The results showed that through organic solvent back extraction,the content of neophytadiene in the product reached 97.99%,and the yield was 21.34%with the supercritical primary extract as raw materials,the nicotine content of 63.24%,neophytadiene content of 33.53%,and the total product yield of 17.76%in purified product by using the ultrasonic-assisted primary extract as raw materials,and the purity of neophytadiene in the final product was 67.34%,the yield was 8.76%with solvent extract as raw materials.When column chromatography was used to elute the supercritical initial extract,the content of neophytadiene in the product reached75.11%,and the yield was 25.1%.