Synthesis and insecticidal activity of 7-(1-carbonyl-piperazin-4-yl)methyl-camptothecin derivatives

With (20S)-camptothecin (CPT) as the raw material, a series of 7-(1-carbonyl-piperazin-4-yl)methyl-camptothecin derivatives (4a - 4m) were synthesized after modification of C7 of CPT. Their structures were identified by1H NMR and LC-MS. The preliminary bioassay showed that the compound 7-(1-(4-methoxybenzoyl)piperazin-4-yl) methyl-camptothecin (4g) and 7-(1-cyclopentanecarbonyl-piperazin-4-yl)methyl-camptothecin (4j) exhibited more insecticidal activity against Tetranychus cinnabarinus and Bursaphelenchu xylophilus than CPT. For T. cinnabarinus, LC50 value (24 h) of 4g was 8.10 and 9.05 mg/L. And for B. Xylophilus, LC50 (24 h) value of 4j was 6.34 and 6.68 mg/L. The results are useful for the investigation of insecticidal activity and structure-activity relationship of camptothecin derivatives.