穿心莲内酯衍生物对粘虫3种保护酶活力的影响

【目的】比较4种穿心莲内酯衍生物（A2、A4b、A4d、A4e）与羟基马桑毒素（Tutin）对粘虫生理代谢影响的差异，为探索新型植物源杀虫剂提供依据。【方法】粘虫3龄幼虫采用Tutin和A2、A4b、A4d、A4e经活体和离体2种方法处理后制备粗酶液，用比色法测定试虫超氧化物歧化酶（SOD）、过氧化氢酶（CAT）和过氧化物酶（POD）3种保护酶的活力，通过酶比活力对比分析活体处理不同时间酶活力的变化及2种处理方法酶活力水平的一致性。【结果】活体试验结果表明，Tutin、A2、A4b、A4d、A4e对粘虫体内POD、CAT活力有抑制作用，而对SOD活力有促进作用；在5种化合物中，整体而言，A4b和A4e对3种保护酶的影响较大。离体测定结果表明，粘虫体内POD、CAT和SOD活力的变化趋势与活体测定结果相似。【结论】A2、A4b、A4d、A4e和Tutin通过对粘虫幼虫3种保护酶活性的干扰，削弱了其对氧自由基和H₂O₂的解毒代谢功能，表明4种穿心莲内酯衍生物可以作为新型植物源杀虫剂。采用活体与离体2种方法对粘虫比活力的测定结果一致。

Effects of andrographolide derivatives on three kinds of protection enzymes activities in Mythimna separata

【Objective】 The study was done in order to investigate the effects of four andrographolide derivatives(compounds A2,A4b,A4d,A4e) with Tutin on the physiological metabolism of Mythimna separata Walker(Lepidoptera:Noctuidae),and to provide basis to explore the new plant source pesticides.【Method】 The enzyme activities of peroxidase(POD),catalase(CAT) and superoxide dismutase(SOD) in 3rd instar larvae of M.separata treated by in vivo and vitro were determined by colorimetry method,and analysis of the enzyme’s energy in vivo at different treat time and in vitro was performed.【Result】 The in vivo results indicated that the compounds Tutin,A2,A4b,A4d and A4e inhibited the activities of POD and CAT but promoted the SOD activity in the tested larvae.A2 and A4d were the optimal compounds to inhibit POD,CAT activities and promote the SOD activity,compared with the other two andrographolide derivatives.And the in vitro results were similar to in vivo.【Conclusion】 Tutin,A2,A4b,A4d and A4e inhibited the effects of detoxifcation metabolism on oxygen free radicals and H2O2 by interfering with POD,CAT and SOD activities in the tested larvae.It shows that A2,A4b,A4d,A4e can be used as a new plant source pesticides.The enzymatic energy tested in vivo was consistent with that in vitro.