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This paper studies from the neem seed kernel extract azadirachtin A variety of extraction process, improve its purification method to study the impact of the stability factor, design more stable neem Formulation, and validate its efficacy. Detailed study of the the Azadirachtin A variety of solvent extraction process, were investigated kernel crushing way, the amount of solvent, extraction temperature, extraction time, post-processing technology, such as the rate of extraction of azadirachtin A. Soaked pulverization technology for the first time, the pulverization, extraction combined to solve the problems of the lipid-containing species kernel pulverizing difficult, and the use of a hydrocarbon solvent sedimentation technique, so that after the processing can be simplified, the extraction rate is significantly improved. Trial found the ideal extraction conditions: liquid ratio 1:2, extraction time 4 × 4hr, extraction temperature 20oC. Under optimal conditions, the lipid-containing seeds, defatted seeds as raw material, the extraction rate of azadirachtin A: methanol -0.5385% 0.2941% ethanol -0.4578% 0.2783% ethyl acetate -0.2867 %, 0.1667%, ethanol / petroleum ether (3/1) -0.3260% -0.2140%, acetone, acetonitrile -0.1011% -0.0920% methyl tert-butyl ether. Highest methanol extraction rate; ethyl acetate rate is relatively low, but the process is simple, and high product purity. Quantitatively analyzed by HPLC azadirachtin A content of the main ingredient in the neem extract was determined using the HPLC-MS method. Ultrasonic technology for the first time will be applied to the process of extraction of azadirachtin A study by orthogonal experiment found that the ultrasonic assisted extraction than ideal conditions: liquid ratio 2:1, ultrasonic power 200W, ultrasonic time with the solvent, methanol-15min, ethanol-20min, ethyl acetate-10min. Under optimal conditions, lipid-containing seeds, defatted seeds as raw materials extraction, the extraction rate of azadirachtin A: methanol -0.5623% 0.3786% ethanol -0.4578% 0.3658% ethyl acetate -0.3123 % 0.2462%. The extraction rate is higher than the solvent extraction. By orthogonal experiments found better conditions for the supercritical fluid extraction of azadirachtin A: extraction temperature 32 ° C, extraction pressure 32MPa, carbon dioxide the flow 10kg/hr, Entrainer / materials (liquid to solid ratio) (v: m) : 1, respectively in the extraction conditions to the lipid-containing seed kernels and defatted seed kernels for the extraction of raw materials, the extraction rate of the azadirachtin A, respectively 0.2501% and 0.2084%. The system studied azadirachtin A three purification process. After solvent allocation purification, the purity of azadirachtin A increased by 35.87% to 63.45%; adsorption by silica gel column mixed solvent gradient elution the azadirachtin A purity increased from 35.87% to 50% -60%; this product again subjected to silica gel column chromatography to a purity of 68% azadirachtin A; first be applied to the purification process of the azadirachtin A macroporous resin XAD-1180. The examine the XAD-1180 for the Azadirachtin the static and dynamic adsorption, found better adsorption conditions were as follows: the concentration of azadirachtin A 2mg/mL 30% aqueous methanol as the adsorption solution, the flow rate of 1BV/hr. Respectively 50% and 60% aqueous methanol gradient desorption flow rate was 1BV/hr and 0.5BV/hr. After XAD-1180 once macroporous resin purification, azadirachtin A purity lt; WP = 4 gt; 35.87% to 85.15%. After secondary purification purity of 93.18%. The process is a simple operation, processing a large amount of purified product azadirachtin A high purity, the resin can be reused, etc.. Factors affecting the thermal stability of azadirachtin A system. Aflatoxin and reduce water by activated carbon removal, the stability of azadirachtin A significant improvement; presence of various emulsifiers accelerated degradation of azadirachtin A, which Twain -20 and CH400 pair of azadirachtin A degradation less affected; better the stabilizing effect of the stabilizer epoxidized soybean oil, the amount increases to 5% of the azadirachtin A good stabilizing effect. The experimental study of the main factors to affect the stability of the light through the glass film. Found emulsifier Tween -20, CH400 beneficial azadirachtin light stabilizers, stabilizers aminobenzoate and phenyl salicylate can better improve the light stability of the azadirachtin A, azadirachtin A in the ultraviolet light under the decomposition rate is far greater than the rate of decomposition under the sun. Designed on the basis of the stability studies, a reasonable proportion to filter out the ideal 0.5% of azadirachtin and wettable powder formulations of neem EC formulations and WP. EC ratio: azadirachtin A 0.3-0.8%, 2-6% p-aminobenzoic acid, epoxidized soybean oil 3-10%, CH400 (or Tween 20), 3-8%, methanol, 25 - 40% dimethyl sulfoxide, 15-20%, xylene padded 100%; wettable formulations: on azadirachtin A0.3-0.8%, 2-6% p-aminobenzoic acid, epoxidized soybean oil 3 - 10% sodium dodecyl sulfate 1-5%, NNO2-5%, 3-6% of white carbon black, kaolin filled to 100%. 0.5% of azadirachtin and 0.5% WP diluted 600 times and 800 times the diamondback moth prevention 94-97% and 0.5% of azadirachtin prevention of Liriomyza sativae the field pharmacodynamic field efficacy trials found: test, seven days after application control efficiency of 81.32% -84.05%.
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