Isolation, Identification And Biological Activity Of The Insecticidal Components From Artemisia Hedinii Ostenf. Et Pauls Against Mythimna Separata (Walker)

By comparison of the insecticidal activities Artemisia Linn hedinii Ostenf. et Pauls.has been screened from 16 species of poisonous plants in Tianzhu Inartificial Meadow,. Through extracting Artemisia Linn hedinii Ostenf. et Pauls. with various organic solvents and different extraction methods, Identified the best extraction solvents and method Through Analysis of active ingredients of the each part of Artemisia Linn hedinii Ostenf. et Pauls..defined the major active components of the site. The experiment results were as follows:1. The indoor bioactivities of 16 species of plant materials acetone extracts were delermined with Mythimna seperata Walker as test insect,the results showed that 9 species of plant materials acetone extracts possessed some anti-feeding activity at 48 hours after treatment. 8 species of plant materials acetone extracts possessed some contact toxicity activities at 72h 6 species of plant materials acetone extracts possessed some stomach toxicity activities after 48h. Compared with the insecticidal activities of 16 plant extracts to Mythimna seperata Walker, Artemisia Linn hedinii Ostenf. et Pauls. extracts got better.2. 10 extracts were got by extracting whole plant of Artemisia Linn hedinii Ostenf. et Pauls. with 5 different polar organic solvents such as petroleum ether, n-Hexane, chloroform, ethyl acetate and methanol by the methods of shaking incubator with constant temperature and soxhlet extraction. The output ratio by soxhlet extraction was better. For the used solvents, the output ratio with methanol and Ethyl Acetate were better, 12.1% and 10.2% respectively.3. Determination of biological activities of 10 Artemisia Linn hedinii Ostenf. et Pauls. extracts showed that 10 extracts all possessed some biological activities. There were significant difference between different extracts activities. The extracts activities with methanol by soxhlet extraction was the most outstanding, and its main functions were antifeedant, growth inhibition as well as some contact and stomach toxicity effects. In the anti-feeding experiment, anti-feeding rate of 24 hr was 96.1% and of 48 hr was 96.2%. In the contact toxicity activities, mortality of 48 hours was 66.67% by dip method. Mortality due to the stomach poison was 30% after 48 hours. The growth inhibition to Mythimna seperata Walker was 80.82%. The average pupal weight and the pupation rate remarkably decreased and the rate of growth and development were both delayed to the contrast. The insecticidal activity of the Artemisia Linn hedinii Ostenf. et Pauls.'s aerial part was higher than the underground part.4. By liquid-liquid extraction for methanol extract of Artemisia Linn hedinii Ostenf. et Pauls., water has the highest extraction rate, others were in sequence of chloroform, ethyl acetate, butanol and petroleum ether. Study on the activities of 5 types of extraction to Mythimna seperata Walker showed that chloroform extracts have the best effect because the anti-feeding rate after treating 48h was 89.6%, contact toxicity by dip method was 60%. The best stomach toxicity effect was by water, whose mortality was 66.67% after 72hr treatment.5. Extracting whole plant of Artemisia Linn hedinii Ostenf. et Pauls. by using the mixture of methanol and n-hexane was followed by Column Chromatographic Separation to the extracts. 3 Fractions of nonpolar, weak polar and polar were got and then analyzed by GC-MS to measure their composition. It was found that nonpolar fraction was alkane which was from wax of the plant, weak polar fraction was sterides and polar ftraction was organic acid.