Study On Extraction And Separation Of Effective Component From The Bark Of Melia Azedarach L. And Its Bioactivity

The extraction and separation of effective component from the bark of Melia azedarach L.and its bioactivity have been studied in this dissertation. The effecting factors of different extraction methods, including supercritical carbon dioxide extraction, ultrasonic extraction, microwave assistant extraction and traditional solvent extraction, and the optimum extraction conditions were investigated. Study on antifeeding and toxic effects of extractives and effective component from the bark of Melia azedarach L. against forest pest Abraxas mirandu Butler as well as the study on extractives obtained from extraction with different solvents from Melia azedarach bark and fruit against fungi have been carried out. The main results were as follows:Extraction methods of toosendanin from the bark of Melia azedarach L. were systematically investigated in this dissertation, and several extraction methods, including supercritical carbon dioxide extraction, ultrasonic extraction, microwave assistant extraction and traditional solvent extraction, were compared in detail. The results indicated that the ultrasonic extraction method was preferred among the discussed methods. In the case of ultrasonic extraction, the optimum conditions were as the follows: 60% ethanol as solvent, the ratio of feedstock to liquor 1:9, extraction time 30 min, temperature 40°C, and ultrasonic power 200W. Under the optimum conditions, the yield of toosendanin was 0.715 %.Antifeeding and toxic effects of extractives from the bark of Melia azedarach L. against forest pest Abraxas mirandu Butler were investigated . Methanol and chloroform extractives from the bark have stronger antifeeding and higher toxic effect. For fourth instar larvae of Abraxas mirandu Butler, the antifeeding rate was 80% after 24 h of treatment and adjusted mortality rate was 93% after 72h of treatment at concentration of 400 ppm. The results revealed that chloroform extractive mostly,contain pesticide activity component, antifeeding and toxic effect of chloroform extractive was almost the same as that of toosendanin component. Chloroform extractive was directly used for botanical pesticide in practical application.Investigation on bacteriostatic activity of extractives from Melia...