Prparative Separation Of Bioactive Compounds From Essential Oil Of Flaveria Bibidentis(L.) Kuntze

In this article, the essential oil from Flaveria bidentis (L.) Kuntze wascomprehensive investigated, including extraction techniques, compositionidentification, content determination, separation of bioactivity compounds,and research of biological activity, which provided a theoretical basis and datasupport for Flaveria bidentis (L.) Kuntze to be used well.This thesis viewed extraction rate of essential oil from Flaveria bidentis(L.) Kuntze as the detection index. First of all, optimized the best extractionprocess for the essential oil through the single factor and orthogonal design ofexperiment. And the optimum extraction condition is as follows: solid toliquid ratio is1:20, the soak time is6h, oil bath temperature is145℃,extraction time is27h. The essential oil was analysed by GC-MS, there were37compounds extracted and separated.And29compounds were identified,which accounts for more than90%of the total essential oil. It contained olefin(48.11%), thiophene (13.98%), ketones (7.23%), and another esters, alcoholsand acids, etc. with a small amount. High performance liquid chromatography (HPLC) is an analysis methodswith a wide range applications in the separation scientific. The optimumgradient analysis condition of essential oil is as follows (mobile phase:water-A and acetonitrile-B): acetonitrile:0-15min, keep70%;15-25min,keep90%;25.01-30min, keep90%. UV monitored at214nm.High-speed countercurrent chromatography (HSCCC), being asupport-free liquid-liquid partition chromatograph method, eliminatesirreversible adsorption, sample variability, and has been widely used inpreparative separation of natural products. Different solvent systemproportions of hexane-acetonitrile–ethanol with reverse elution has beenstudy in this experimental. The two phase solvent system of HSCCCcomposed of hexane-acetonitrile–ethanol=5:4:3(v/v), which has beenselected by semi-preparative HSCCC with1.5mL/min of mobile flow.3.2mgof caryophyllene oxide at a purity of92.6%,10.4mg of7,11-dimethyl-3-methylene-1,6,10-dodecatriene at a purity of99.1%and5.7mg of caryophyllene at a purity of98.8%were obtained from200mgessential oil of Flaveria bidentis (L.) Kuntze. And when was eluted withforward, f=0.8mL/min of mobile flow.4.8mg of caryophyllene oxide at apurity of98.6%was obtained from about200mg essential oil of Flaveriabidentis (L.) Kuntze. The two phase solvent system of HSCCC composed ofHexane-dichloromethane-acetonitrile=10:3:7(v/v/v), which has been selectedby semi-preparative HSCCC with reverse elution,1.5mL/min of mobile flow. 9.9mg of7,11-dimethyl-3-methylene-1,6,10-dodecatriene at a purity of99.3%and5.3mg of caryophyllene at a purity of98.7%were obtained fromabout200mg essential oil of Flaveria bidentis (L.) Kuntze.The test result of biological activity of the essential oil from Flaveriabidentis (L.) Kuntze show that there is high herbicidal activity on Amaranthusretroflexus while on Mustard with a low herbicidal activity. It should beconsidered further screening.