Derivatives of 1-benzyl-2-methylbenzimidazoles (BMBIs) were synthesized to evaluate their biological activities against Bombyx mori, a lepidopteran model insect. Synthesized BMBIs exhibited two different biological activities: inhibition of development and acute lethality. From a structural perspective, the activity varied with the position of the substitutions on the 1-benzyl moiety; BMBIs with substitutions on the 2 and/or 4 positions had comparatively high activity in comparison with those with substitutions on the 3-position. There was more activity for the inhibition of development with low doses, and more for acute lethality with high doses. The activity was also affected by the applied stage, that is, application in the 4th instar mostly interfered the larval molting or pupation, whereas that in the 3rd instar caused more acute mortality. Taken together, these results suggest that BMBIs have multiple modes of action.

合成了 1-苄基-2-甲基苯并咪唑 (BMBI) 衍生物，以评估其对鳞翅目模式昆虫Bombyx mori的生物活性。合成的 BMBI 表现出两种不同的生物活性：抑制发育和急性致死。从结构角度来看，活性随1-苄基部分上的取代位置而变化；与3位取代的BMBI相比，2位和/或4位取代的BMBI具有相对较高的活性。低剂量时抑制发育的活性更强，高剂量时急性致死的活性更强。活性还受施用阶段的影响，即4龄施用主要干扰幼虫蜕皮或化蛹，而3龄施用则引起更严重的死亡率。综上所述，这些结果表明 BMBI 具有多种作用模式。