Design, Synthesis, and Bioactivity of Spiro Derivatives Containing a Pyridine Moiety.

We designed and synthesized a series of pyridine spiro derivatives and evaluated their insecticidal and antiviral activities. Some compounds exhibited good insecticidal and antiviral activities. Notably, the E series of compounds displayed good insecticidal activity against Tetranychus urticae. Compounds E20 (EC50 = 63.68 mg/L) and F4 (EC50 = 47.81 mg/L) exhibited inactivation activities against the tobacco mosaic virus (TMV), which were similar to that of Ningnanmycin (EC50 = 58.01 mg/L). Molecular docking showed that compounds E20 and F4 exhibited satisfactory affinities for the TMV coat protein (TMV-CP), with binding energies (-6.7 and -6.4 kcal/mol, respectively) slightly lower than that of Ningnanmycin (-6.3 kcal/mol). Further, molecular dynamics analysis revealed that compounds E20 and F4 exhibited better binding stability values than Ningnanmycin. Microscale thermophoresis showed that compounds E20 (Kd = 0.053 ± 0.016 µM) and F4 (Kd = 0.045 ± 0.022 µM) bound more strongly to TMV-CP than Ningnanmycin (Kd = 0.10 ± 0.029 µM). The results of transmission electron microscopy showed that these two compounds hindered the self-assembly and growth of TMV. In summary, we showed that these pyridine spiro derivatives could be used as a basis for the research and development of novel pesticides.

Spiro Derivatives in the Discovery of New Pesticides: A Research Review.

Spiro compounds are biologically active organic compounds with unique structures, found in a wide variety of natural products and drugs. They do not readily lead to drug resistance due to their unique mechanisms of action and have, therefore, attracted considerable attention regarding pesticide development. Analyzing structure-activity relationships (SARs) and summarizing the characteristics of spiro compounds with high activity are crucial steps in the design and development of new pesticides. This review mainly summarizes spiro compounds with insecticidal, bactericidal, fungicidal, herbicidal, antiviral, and plant growth regulating functions to provide insight for the creation of new spiro compound pesticides.