为了发现新型的基于天然产物的农药,我们通过鬼臼毒素的结构修饰制备了一系列2'(2',6')-(Di)chloropicropodophyllotoxins肟肟衍生物。它们的结构通过质子核磁共振(1 H NMR),高分辨率质谱(HRMS),旋光度和熔点得到很好的表征。此外,通过单晶X射线衍射明确地确定了化合物5f的关键空间结构。此外,针对典型的鳞翅目害虫东方粘虫(Mythimna separata Walker)的三龄前幼虫,其杀虫活性被评估为1 mg / mL 。在所有衍生物中,化合物4c,5c和与前体鬼臼毒素和阳性对照太生丹宁相比,5d表现出更有希望的杀虫活性,最终死亡率大于60%。结果表明,在鬼臼毒素的E环的C-2'或C-2',6'位置引入氯原子或鬼臼毒素的肟磺酸酯衍生物对杀虫活性和卤素(例如氟)的引入都很重要。 2'(2',6')-(di)chloropicropodophyllon
为了发现新型的基于天然产物的农药,我们通过鬼臼毒素的结构修饰制备了一系列2'(2',6')-(Di)chloropicropodophyllotoxins肟肟衍生物。它们的结构通过质子核磁共振(1 H NMR),高分辨率质谱(HRMS),旋光度和熔点得到很好的表征。此外,通过单晶X射线衍射明确地确定了化合物5f的关键空间结构。此外,针对典型的鳞翅目害虫东方粘虫(Mythimna separata Walker)的三龄前幼虫,其杀虫活性被评估为1 mg / mL 。在所有衍生物中,化合物4c,5c和与前体鬼臼毒素和阳性对照太生丹宁相比,5d表现出更有希望的杀虫活性,最终死亡率大于60%。结果表明,在鬼臼毒素的E环的C-2'或C-2',6'位置引入氯原子或鬼臼毒素的肟磺酸酯衍生物对杀虫活性和卤素(例如氟)的引入都很重要。 2'(2',6')-(di)chloropicropodophyllon
Insight into dihalogenation of E-ring of podophyllotoxins, and their acyloxyation derivatives at the C4 position as insecticidal agents
作者:Zhiping Che、Xiang Yu、Lingling Fan、Hui Xu
DOI:10.1016/j.bmcl.2013.08.044
日期:2013.10
Unexpected sequential E-ring dihalogenation of podophyllotoxin analogues is reported. It demonstrated that a chlorine/bromine atom was prior introduced at the C2' position of podophyllotoxin, and the corresponding free rotation of E-ring around the C1-C1' bond of 2'-chloro or 2'-bromopodophyllotoxin was restricted. When 2'-chloro or 2'-bromopodophyllotoxin reacted with N-chlorosuccinimide (NCS), the chlorine atom was regioselectively introduced at their C6' position on the E-ring. Whereas 2'-chloro or 2'-bromopodophyllotoxin reacted with NBS, the bromine atom was regioselectively introduced at their C5 position on the B-ring. When 2'-chloropodophyllotoxin reacted with different carboxylic acids in the presence of BF3 center dot Et2O, the steric effect of its E-ring for stereoselective synthesis of 4 beta-acyloxy-2'-chloropodophyllotoxin derivatives was observed. The insecticidal activity of 2'(2',6')-(di)halogen-substituted podophyllotoxin derivatives were evaluated with Mythimna separata Walker. (C) 2013 Elsevier Ltd. All rights reserved.