Focus on the development of botanical insecticides such as polyphenols may represent an alternative method to chemical control. In the present study, total glutathione concentration and its related antioxidant enzymes in foregut, midgut, hindgut and fat body homogenates of the desert locust Schistocerca gregaria are examined. Glutathione S‐transferase (GST) activity exhibits a significantly higher value in fat bodies compared with other tissues. A simple and reproducible procedure for the purification of S. gregaria fat body GST is established and the purified enzyme is shown to be homogenous. The purified GST displays a typical Michaelis behaviour with respect to its substrates. Characterization of the GST, including optimum pH, substrate specificity and inhibitor effects, is carried out. The ability of some flavonoids to inhibit S. gregaria fat body GST activity is examined. High‐performance liquid chromatography analysis indicates that the major components in Glycyrrhiza glabra roots are 18α‐glycyrrhetinic acid, quercetin and rutin, and the major components in Hibiscus sabdariffa calyx are cyanidin 3‐O‐glucoside chloride and delphinidin. Quercetin and delphinidin chloride exhibit strong GST inhibition and the inhibition type is determined for both. Rutin shows a smaller inhibitory effect, whereas 18α‐glycyrrhetinic acid and cyanidin have no effect. Inhibition of S. gregaria fat body GST activity would be expected to prevent, or at least delay, the development of resistance to chemical pesticides. Among the examined levels of the antioxidant enzymes, total glutathione concentration and its related enzymes in foregut, midgut, hindgut and fat body crude homogenates of S. gregaria GST activity exhibit a significantly higher value in fat bodies compared with other tissues. Some flavonoids that are detected in H. sabdariffa calyx and G. glabra root extracts are the most effective inhibitors of the purified S. gregaria fat body GST activity. Inhibition of S. gregaria fat body GST activity by quercetin and delphinidin (major compounds detected by HPLC) would be expected to prevent, or at least delay, the development of resistance to chemical pesticides.

中文翻译：

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从沙漠蝗虫 Schistocerca gregaria 中纯化脂肪体谷胱甘肽 S 转移酶：研究黄酮类化合物对酶活性的抑制作用

专注于开发多酚等植物性杀虫剂可能是化学防治的替代方法。在本研究中，研究了沙漠蝗 Schistocerca gregaria 的前肠、中肠、后肠和脂肪体匀浆中的总谷胱甘肽浓度及其相关的抗氧化酶。与其他组织相比，脂肪体中的谷胱甘肽 S-转移酶 (GST) 活性显示出更高的值。建立了一种用于纯化 S. gregaria 脂肪体 GST 的简单且可重复的程序，并且表明纯化的酶是同质的。纯化的 GST 相对于其底物显示出典型的 Michaelis 行为。进行了 GST 的表征，包括最佳 pH、底物特异性和抑制剂作用。一些黄酮类化合物抑制 S. 检查 gregaria 脂肪体 GST 活性。高效液相色谱分析表明，光果甘草根中的主要成分为18α-甘草次酸、槲皮素和芦丁，木槿花萼中的主要成分为花青素3-O-葡萄糖苷氯化物和飞燕草素。槲皮素和翠雀素氯化物表现出强烈的 GST 抑制作用，并确定了两者的抑制类型。芦丁显示出较小的抑制作用，而 18α-甘草次酸和花青素则没有作用。预计抑制 S. gregaria 脂肪体 GST 活性将防止或至少延迟对化学杀虫剂的抗性的发展。在所检测的抗氧化酶水平中，前肠、中肠、后肠和脂肪体粗匀浆中的总谷胱甘肽浓度及其相关酶。与其他组织相比，gregaria GST 活性在脂肪体中表现出显着更高的值。在 H. sabdariffa 花萼和 G. glabra 根提取物中检测到的一些类黄酮是纯化的 S. gregaria 脂肪体 GST 活性的最有效抑制剂。槲皮素和飞燕草素（HPLC 检测到的主要化合物）抑制 S. gregaria 脂肪体 GST 活性有望防止或至少延迟对化学杀虫剂的抗性的发展。