| It was significant for the creation of novel pesticide with our independent knowledge property right to search new insecticidal and antifungal plants , and guided by bioassay , to isolate and identify new compound from plants with up-to-date structure and particular insecticidal or antifungal activities against new targets. For this purpose, Ligusticum sinense Oliv. was selected from 20 Chinese medicinal herbs for insecticidal and antifungal activities and constituents research. Primary results were as follows:(1) Some Chinese medicinal herbs for relieving exterior syndrome, especially L. sinense were worthy of being further researched on their pesticidal activities. Screening on the antifeedant activity of 20 tested Chinese medicinal herbs for relieving exterior syndrome showed above 90% antifeedant rate and slight poison activity of L. sinense Oliv., Magnolia denudata Desr., Arctium lappa L., Saposhnikovia divaricata (Turcz.) Schischk and Notopterygium incisum Ting ex H. T. Chang against Mythimna separata Walker. Juvenile hormone analogs (JHA) activity of L. sinense against Tenebrio molitor L.was also found in the experiment.(2) The acetone extract from Ligusticum sinense Oliv. showed strong contact and fumigation activity against the 3rd instar larvae of Mythimna separata Walker and Plutella xylostella Linnaeus with 24h contact LD50 of 0.0623mg and 0.1502mg dried plant material per larva, and 12h fumigation LCsoof 24.3422mg and 10.6015 mg dried material per liter, respectively. JHA activity of acetone extract against pupae of Tenebrio molitor L. was also observed and evaluated with IDsoof 6.5157mg dried plant material per pupa. The poison symptoms of tropically treated M. separata were observed, following a similar pattern of nerve poisoning: A) excitation, B) convulsion, C) paralysis, and D)death.(3) Guided by bioassy of contact activity, four constituents were isolated from Ligusticum sinense Oliv. and respectively identified as sarisan (1-allyl-2-methoxy-4,5-methylene - dioxybenzene), butylidenephthalide, ligustilide and a glyceride compound by IR, MS, 1H and 13C NMR spectral data analysis, among which sarisan was the main insecticidal ingredient.(4) The bioassay of insecticidal activities of sarisan from Ligusticum sinense Oliv. showed contact activity of sarisan against the 4th instar larvae of M separata and Plutella xylostella Linnaeus with 12h contact LD50 of 53.75 g and 65.06 g per larva, and fumigation activity against the 4th instar larvae of M. separata and the adults of Musca domestica Linnaeus with fumigation LC50 of 16.92 l/L(12h) and 3.52ul/L(24h), respectively. The effect of sarisan on the development and hatch of the eggs and survival of hatched larvaeas well as ovicidal activity was observed and estimated.(3) Analysis method of sarisan content by GC, the optimum technical conditions of supercritical fluid extraction(SFE) of sarisan from Ligusticum sinense Oliv. and the relationship between insecticidal activity of SFE products and their content of sarisan were studied by the design of orthogonal experiment with three factors including temperature, pressure and volume of CO2 and five levels. As a result of my study,(1) a linar regression formulation (y=1.7211x+1.8356, R2=0.9653,0.5 g y 20 g) between the quantity of sarisan and the ratio of the peak area of sarisan and internal standard, octadecane was obtained under the following GC conditions: SE-30 type of capillary quartz colume(10m 0.25mm), FID, temperature of colume, injection and detection 130 , 200 and 240 , Flow velocity of carries,N2 1.5ml/min , Rang 1, ATT 32, sample quantity 1 u 1, the reserve time of asrisan and octadecane, 1.98min and 9.14min. (2) The optimun technical conditions of SFE of sarisan from L. sinense were as follows: Firstly static extract 20 minutes under 50 and 5000psi, and then turn to dynamic one under 65 ,6000psi and 30mL CO2. By this way, the ratios of obtaining extracts, sarisan and sarisan content were respectively 16.210%, 11.108%and 82.194% caculated by engineer...
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