Synthesis And Insecticidal Activity Of Camptothecin Derivatives

To search for new insecticidal substances from natural products has gradually become one effective way of exploring new insecticides. It was found out that Camptothecin(CPT) has multiple insecticidal and antibacterial activity, and it has the potential of becoming botanical pesticides. Under the influence of its own structure, it has low water soluble, so the insecticidal activity is affected. In order to explore camptothecin derivatives with high solubility and good insecticidal activity, according to analogue synthesis and sub-structure method of connecting, we used CPT as the raw material to modify CPT 7-C and CPT 20-OH respectively, and got 49 camptothecin derivatives, and all the structures of target compound were identified by 1H NMR and LC-MS; With Tetranychus cinnabarinus and Bursaphelenchu xylophilus as insects, the indoor insecticidal activity of synthetic compunds was tested.1. After substitution and amidation, amide piperazine and sulfonamide piperazine was added to 7-C,then 34 camptothecin derivatives were obtained; after the modification of 20-OH, different groups of amino acid were added, and 16 camptothecin derivatives were obtained. All the dericatives were identified by 1H NMR and LC-MS.2. With Bursaphelenchus xylophilus and Tetranychus cinnabarinus as the insects, the indoor activity of synthesized derivatives were tested by the impregnation method and slide dipmethod. The results showed that after adding the amide piperazine, the insecticidal activity of CPT7-C against Bursaphelenchus xylophilus and Tetranychus cinnabarinus was enhanced; while after adding the sulfonamide piperazine to CPT 7-C, the insecticidal activity was not evident; while after adding amino acids to CPT 20-OH, the water-solubility was increased, and the insecticidal activity was enhanced.For Bursaphelenchu xylophilus, LC50(24h) of 7-(1-(4-methoxybenzoyl)piperazin-4-yl)-methyl-camptothecin(4g) and 7-(1-(2-methoxybenzoyl)piperazin-4-yl) methyl-camptothecin(4f) was6.34 mg/L and 6.53mg/L representatively, and it is increased evidently than 18.84 mg/L. For Tetranychus cinnabarinus, LC50(24h) of 4g and 7-(1-cyclopentanecarbonyl-piperazin-4-yl)methyl-camptothecin(4j) was 8.10mg/L and 9.05mg/L respectively, and it is increased obviously than 27.25mg/L.