本文選題：手性農(nóng)藥 + 對(duì)映體選擇性作用�。� 參考：《浙江大學(xué)》2015年碩士論文

【摘要】：研究背景：手性農(nóng)藥的廣泛使用,使其不可避免的進(jìn)入到各種環(huán)境系統(tǒng),進(jìn)而可通過各種介質(zhì)和途徑進(jìn)入生物體內(nèi),造成傷害。同一手性農(nóng)藥的不同對(duì)映體,由于生化特性的不同,進(jìn)入環(huán)境后往往具有不同的環(huán)境行為,其對(duì)生物及人體的生理作用也具有對(duì)映體選擇性差異,從而導(dǎo)致一系列截然不同急慢性毒性作用。但長(zhǎng)期以來(lái),外消旋的手性農(nóng)藥都被當(dāng)作一種化合物來(lái)研究其環(huán)境行為和生態(tài)毒性效應(yīng)。近年來(lái)有關(guān)手性農(nóng)藥對(duì)映體選擇性環(huán)境毒性的研究已經(jīng)引起了人們的熱切關(guān)注。另外,由于不同物種對(duì)進(jìn)入其體內(nèi)的手性化合物的對(duì)映體選擇性降解存在明顯的種間差異,導(dǎo)致其在不同物種體內(nèi)呈現(xiàn)不同的濃度和ER值,從而造成的急慢性毒性效應(yīng)也會(huì)存在種間差異。當(dāng)前的研究已經(jīng)關(guān)注到這一現(xiàn)象,但沒有深入探討,關(guān)于手性農(nóng)藥對(duì)映體選擇性種間代謝差異的原因,也未見報(bào)道。研究方法：實(shí)驗(yàn)選取目前世界上使用最為廣泛,且能代表殺蟲、除草和殺菌三種主要類型的手性農(nóng)藥：氟蟲腈、禾草靈和甲霜靈為研究對(duì)象,以人肝癌細(xì)胞系(HepG2)、大鼠肝癌細(xì)胞系(H4IIE)、雞肝癌細(xì)胞系(LMH)和草魚肝臟細(xì)胞系(L8824)這幾種能代表高等脊椎動(dòng)物的細(xì)胞系為研究模型。分別研究這三種手性農(nóng)藥在上述物種細(xì)胞內(nèi)代謝時(shí)主要的CYP450酶的誘導(dǎo)情況,看是否存在明顯的種間差異。進(jìn)而以甲霜靈為例,用UPLC-MS/MS測(cè)定其經(jīng)過這四種細(xì)胞代謝24h后的殘留及ER值的變化情況,比較其對(duì)映體選擇性種間代謝差異,和上述酶活實(shí)驗(yàn)結(jié)果的種間差異性相互映證。并通過添加不同的CYP450的特異性抑制劑,來(lái)進(jìn)一步驗(yàn)證上述對(duì)映體選擇性種間代謝差異的產(chǎn)生與特定的CYP450酶被誘導(dǎo)之間的關(guān)系。研究結(jié)果：酶活實(shí)驗(yàn)中,不同的手性農(nóng)藥在同種物種細(xì)胞內(nèi)代謝時(shí),細(xì)胞內(nèi)主要的CYP450酶的誘導(dǎo)情況是不一樣的,且同種手性農(nóng)藥在不同物種細(xì)胞體內(nèi)代謝時(shí),誘導(dǎo)的CYP450酶的種類也存在種間差異,添加特異性的CYP450抑制劑后,這些誘導(dǎo)的酶活可以得到相應(yīng)的抑制。分析實(shí)驗(yàn)中,甲霜靈經(jīng)四種物種細(xì)胞代謝后,兩種對(duì)映異構(gòu)體的殘留和ER值的情況變化存在明顯的種間差異。HepG2、H4IIE和LMH細(xì)胞選擇性代謝S-甲霜靈,L8824細(xì)胞選擇性代謝R-甲霜靈。并且,添加上述酶活實(shí)驗(yàn)中被誘導(dǎo)的CYP450酶的特異性抑制劑后,這些差異和變化都得到了相應(yīng)的抑制。研究結(jié)論：本研究表明,手性農(nóng)藥在不同物種細(xì)胞內(nèi)代謝時(shí)存在明顯的對(duì)映體選擇性種間代謝差異,經(jīng)過不同物種細(xì)胞代謝后,手性農(nóng)藥會(huì)呈現(xiàn)不同的ER值；并且種間代謝差異的產(chǎn)生與特定的CYP450酶被誘導(dǎo)有關(guān),抑制相應(yīng)的CYP450酶活后,這些對(duì)映體選擇性種間代謝差異情況也會(huì)得到抑制。說明這些手性農(nóng)藥在不同物種體內(nèi)可能是由不同的CYP450酶來(lái)進(jìn)行對(duì)映體選擇性代謝的。由于不同的物種細(xì)胞對(duì)手性農(nóng)藥存在對(duì)映選擇性種間代謝差異,使得手性農(nóng)藥在不同物種體內(nèi)呈現(xiàn)不同的濃度和ER值,進(jìn)而可能對(duì)這些物種細(xì)胞造成不同的毒性作用,所以在評(píng)價(jià)手性農(nóng)藥的生態(tài)風(fēng)險(xiǎn)時(shí)應(yīng)充分考慮對(duì)映異構(gòu)體的種間代謝差異。
[Abstract]:Research background: the wide use of chiral pesticides makes it inevitable to enter various environmental systems, and can then enter organisms through various mediums and ways, causing injury. The different enantiomers of the same chiral pesticide have different environmental behavior after entering the environment because of the different biochemical characteristics. The physiological action also has the selectivity difference in enantiomers, which leads to a series of distinct acute and chronic toxicity. But for a long time, the chiral pesticides in raceme have been used as a compound to study their environmental behavior and ecotoxicity. In recent years, the study of the environmental toxicity of chiral pesticides enantiomers has been caused by people. In addition, there are significant differences in the selective degradation of enantiomers of chiral compounds entering their bodies, resulting in different concentrations and ER values in different species, and there are interspecies differences in acute and chronic toxic effects. But there is no in-depth discussion on the reasons for the differences in the interspecific metabolic difference between chiral pesticides enantiomers. Research methods: the experiment selected three main types of chiral pesticides in the world, which are the most widely used in the world, which represent insecticidal, herbicidal and germicidal types: fluonitrile, grasses and metalaxyl, and human hepatoma cells. Line (HepG2), rat hepatoma cell line (H4IIE), chicken liver cancer cell line (LMH) and grass carp liver cell line (L8824), the cell lines that can represent higher vertebrates, are the research models. The induction of the main CYP450 enzyme in the intracellular metabolism of these three chiral pesticides in the above species is examined to see whether there is an obvious interspecific difference. Taking formalin as an example, the changes in the residual and ER values of these four cells after 24h metabolism were measured by UPLC-MS/MS, and the differences in the interspecific metabolic difference between the enantiomers and the results of the above enzyme activity were compared. And the specific inhibitors of different CYP450 were added to further verify the enantiomers. The relationship between the production of selective interspecific metabolic differences and the induction of specific CYP450 enzymes. Results: in the enzyme activity experiment, the main CYP450 enzyme induction in the cell is different when different chiral pesticides are metabolized in the same species cell, and the same chiral pesticides are induced in the cells of different species in the cells of CYP450. There are also interspecies differences in the species of enzymes. After adding specific CYP450 inhibitors, these induced enzyme activities can be suppressed accordingly. In the analysis of experiments, after the metabolism of four species of metalaxyl, there are obvious interspecific differences in the changes of the residual and ER values of the enantiomers, and the selective metabolism of S- in H4IIE and LMH cells, S-. Metalaxyl, L8824 cells selectively metabolize R- metalaxyl. And these differences and changes have been suppressed after the addition of the specific inhibitors of the CYP450 enzyme induced in the above enzyme activity experiments. Conclusions: This study shows that there is an obvious enantioselective metabolism of enantiomeric pesticides in the intracellular metabolites of different species. The difference is that after the cell metabolism of different species, the chiral pesticides present different ER values; and the production of interspecific metabolic differences is related to the induction of specific CYP450 enzymes. After inhibiting the corresponding CYP450 enzyme activity, these enantioselective interspecific metabolic differences in the enantiomers will also be suppressed. Selective metabolism of enantiomers is carried out by different CYP450 enzymes. Due to the differences in the enantioselective metabolism of the chiral pesticides in different species, the chiral pesticides present different concentrations and ER values in different species, and may cause different toxic effects on these species, so the chiral agriculture is evaluated. The interspecific metabolic differences of enantiomers should be fully considered in the ecological risk of drugs.
【學(xué)位授予單位】：浙江大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：X592

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本文編號(hào)：1903434