Extraction, Separation And Identification Of AA Essential Oil With Repellent And Fumigant Activity

Plant essential oil is a kind of oily liquid, it can volatilize under normal atmospheric temperature. Because it has very strong bioactivity, studied on essential oil has already become the focus. The essential oil of some plants can repellent and fumigant to the stored-product insect pest, it is hopeful to become substitute products of the fumigant used now. This research was focus on the extraction, separation and identification of AA oil with repellent and fumigant bioactivity. The research confirmed the optimum craft of extracting essential oil, separated and identified the chemical components. The intention was to find the really effective component in the essential oil, and identify the activity monomer finally. This research can offer the theoretical foundation for development of the new-type fumigant.1. Using the method of steam distillation to extract AA oil, the optimum craft is: petroleum ether for extract solvent, distillation for 120 min. Extraction rates is 0.32%. Using the method of simultaneous distillation-extraction to extract AA oil, the optimum craft is: petroleum ether for extract solvent, distillation for 240 min. Extraction rates is 0.52%. We also compared the repellent and fumigant activity of the essential oil by extraction of two kinds of method. In the all, we can conclude that the essential oil of two kinds of extracting method had not distinction basically. But the method of simultaneous distillation-extraction had the high extraction rates. We confirmed that the method of simultaneous distillation-extraction is the optimum extraction method. So we used this extracting method.2. We used the method of filter-paper arena and bottle to assay the bioactivity of essential oil. Essential oil was separated through chemical method and column chromatography. In the same time we carried on the bioactivity and test different component pats separated. Separating through chemistry, we get six kinds of different component parts: alkaline component I, strong acid component II, weak acid component III, weak acid component IV, neutral component V, aldehyde and ketone component VI. Through assaying the six component parts the bioactivity, we concluded that bioactivity of neutral component V is the strongest. Neutral component V of essential oil had a strong repellent activity to Tribolium castaneum adults at 20μ1/ml in a filet-paper arena test. Mean repellency is 97.76%. Repellency class reached V class. Neutral component Vof essential oil also had high-fumigant activity against T. castaneum adults. At 20μ/ L air, exposure for 48 hours, mortality of adults reached 68.52%. So we collected the neutral component parts to separate further. Through the column chromatographic of silica gel, we get six kinds of components: A, B, C, D, E, and F. Assaying the bioactivity of six component parts, we concluded that bioactivity of component B is the strongest. The component B was eluted by petroleum ether and acetate of ethyl mixed in 10:1. It had strong repellent activity to T. castaneum adults. Mean repellency is 94.44% at 20μl/ml. Repellency class reached V class. It also had high-fumigant activity against T.castaneum adults. At 20μl/L air, exposure for 48 hours, mortality of adults reached 88.78%.We collected the component B to separate further. Through the column chromatographic of silica gel again, we get four kinds of components: B-1, B-2, B-3, B-4. Assaying the bioactivity of four component pats, we concluded that bioactivity of component B-2 is the strongest. The component B-2 was eluted by petroleum ether and diethyl ether mixed in 10:1. It had strong repellent activity to T. castaneum adults. Mean repellency is 96.76% at 20μl/ml. Repellency class had reach V class. It also had high-fumigant activity against T. castaneum adults. At 20μl/L air, exposure for 48 hours, mortality of adults reached 89.92%.3. Utilize GC and GC-MS to analyse the component B-2 which had the strongest bioactivity, we confirmed the effective composition is among them. Twenty kinds of compositions were examined altogether, and sixteen kinds of compositions among of them had been identified, accounting for 98.76% of total amount examined. The main constituents are eucalyptol, 61.21%; Bornyl acetate, 6.29%; Borneol, 5.73%; 3-carene, 4.79%; Carane, 4,5-epoxy-trans, 3.78%; Camphor, 3.5%.4. Assaying the repellent and fumigant activity of monomer eucalyptol, we confirmed the one kinds of monomer. When eucalyptol concentration is 6μl/ml and 8μl/ml, it had strong repellent activity to T. castaneum adults. Mean repellency is 96.67% and 98.88% at 20μl/ml. Repellency class also reachedⅤclass. It also had high-fumigant activity against T.castaneum adults. At 20μl/L air and 25μl/L air, exposure for 48 hours, mortality of adults reached 86.46% and 93.26%. So we can conclude that eucalyptol may be the one kind of active composition of this essential oil.