| To investigate the discipline of the penetration and metabolism of pesticides in the control objects and protected crops will help to understand the mode of action, detoxification and other toxicology problems, and it also contribute to the rational application of pesticides. Similarly, researches on the degradation of pesticides in water and soil, and the residue dynamics in harvested crops, will be helpful to evaluate the safety, to develop the standards of safe use and pesticides residue.As one of the major active ingredients of the botanical pesticide, celangulins formulated as emulsifiable concentrate and micro-emulsion, celangulin V has never been thoroughly investigated in terms of the above mentioned fields. Therefore, the penetration and metablolism of celagulin V in the insects and plants, the environmental behaviour of celangulin V in aquatic system and soil were studied in the program. The main findings are as follows:1. The 6th instar larvae of armyworm(Mythimna separata) and the 5th instar larvae of black cutworm(Agrotis ypsilon) were used as test insects. The acetone solution of celangulin V was delivered in its pronotum by the method of drip administration. In the insect hemolymph, celangulin V was not detected by HPLC-UV analysis after the treatment of 1~16h. While minimal celangulin V was detected by HPLC-MS/MS, the contents were 0.169μg·mL-1 and 0.078μg·mL-1 after the treatment of 4h, which means that penetrating from the integment into the blood cavity was difficult for the tested chemical. Feeding the tested insects with leaves discs contain poison, the contents of celangulin V in the larvae hemolymph of armyworm and black cutworm were 1.74μg·mL-1 and 1.65μg·mL-1 after treatment 1h, and it achieved peak levels after 4h, the contents were 4.54μg·mL-1 and 5.81μg·mL-1, which indicated that celangulin V ingested into digestive tract could rapidly penetrate intestinal lining into the blood cavity.2. Celangulin V ingested by oral could be rapidly metabolized via detoxification. The metabolism of celangulin V in the body of the two tested insects conformed to a negative exponential function, the equations for the 6th larvae of armyworm and the 5th larvae of black cutworm were C = 92.33e-0.0528t and C = 88.30e-0.1268t, half-life were 13.1h and 5.5h, respectively. The metabolism rate of celangulin V in black cutworm larvae was much greater than that of armyworm larvae. Difference in metabolism rate might be one of the selective toxicity mechanisms of celangulin V against two tested insects.3. After administration with a mixture of celangulin V with synergist S16 and TPP, the metabolism rate of celangulin V in armyworm and black cutworm larvae could be inhibited obviously. In the case of black cutworm larvae, the metabolism of celangulin V were inhibited 36.11% and 14.50% by S16, 46.38% and 25.56% by TPP after treatment 8h and 24h, respectively. In the case of armyworm larvae, the metabolism of celangulin V were inhibited 21.35% and 4.94% by S16, 21.14% and 11.95% by TPP after treatment 8h and 24h, respectively. The results indicated that the metabolisms of celangulin V in tested larvae were mainly catalyzed by mixed function oxidase (MFO) and carboxyl esterase.4. The results showed that celangulin V could be adsorbed by root system or leaves, and then upstream in broad bean seedling (dicotyledons). Dipping the roots in the concentration of 10μg?mL-1 aquatic system for 48h, the content of celangulin V in the plant was 1.72μg?g-1. Spraying the middle leaves with 200μg?mL-1 solutions, the content of celangulin V in the upper leaves was 0.77μg?g-1 after 48h. It indicated that the penetration into root was much easier than into leaves. In addition, celangulin V could penetrate wheat (monocot) seedling roots more easily than that of broad bean in aquatic system, the content of celangulin V in the wheat seedling was 2.72μg?g-1 after 48h. However, the intake of celangulin V by root from soil treated with the solution was difficult and it might due to celangulin V was absorbed strongly by soil.5. The stability in different pH aquatic systems of celangulin I, celangulin V, NW28 and NW53, four types of dihydroagarofuran compounds, was investigated under 54℃. The results showed that celangulin I, celangulin V and NW53 were stable at pH 4, their hydrolysis rates were 10.43%, 8.93% and 6.60% after 24h respectively, while NW28 was relatively unstable, its hydrolysis rate was 19.75%. Celangulin I, celangulin V and NW28 were stable at pH 7, their hydrolysis rates were 12.00%, 12.03% and 6.43% after 24h respectively, while NW53 was less stable, and its hydrolysis rate was 50.55%. At pH 10, celangulin I, celangulin V, NW28 and NW53 were unstable and their half-life was 1.7h, 14.1h, 7.1h and 0.9h, respectively.The structures of the major hydrolysis products of celangulin V were analyzed by MS and MS / MS technique preliminary. The results showed that all hydrolysis products were derived from 1~3 ester bonds cleavage, and they all occurred in C-1, C -2, C-8 and C-9 positions, no products were observed derived from the cleavage of ester bond at C-13. At the same time, seven hydroxyls derivative (full hydrolysis product) was also not observed.6. The results of laboratory simulation tests indicated that the degradation rate of celangulin V in different types of soil varied greatly, their order of degradation rate was Tianjin alkaline earth > Northeast black earth> Jiangxi red earth> Guanzhong loess, the dynamic equation and the half-life of degradation were: Ct = 9.613e-0.0321T, 21.59d; Ct = 10.592e-0.0219T, 31.65d; Ct = 10.261e-0.0123T, 56.35d; Ct = 11.275e-0.0118T, 58.74d. The main degradation products of celangulin V in soil were similar with that in water.In field trials, the degradation dynamic of celangulin V in cabbage was fit to the negative exponential equation Ct = 1.210e-0.0588T and half-life was 11.8d. The degradation dynamic in soil was also fit to the negative exponential equation Ct = 0.0596e- 0.0475T and half-life was 14.6d. The results of ultimate residue test showed that the content of celangulin V in cabbage was 0.067 mg·kg-1 , which was sprayed with quintuple of the recommended high dose for three times, and was harvested after 14 days of the last application. It indicated that celangulins formulation was belonging to low-residue pesticide.
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