A guanidine compound was isolated and identified from Buthus martensii Karsch. Based on its characteristic structure, we used it as a lead compound to carry out structural optimization and subsequent fungicidal evaluation. Here 18 guanidine derivatives were designed and synthesized by a facile method, and their structures were characterized by 1H, 13C NMR, and HRMS. Biological assay indicated that most of the title compounds possess potential fungicidal activities against Alternaria altanata, and Penicillium digitatum. Especially, 5a, 5d, and 5i showed inhibition rates (IR) of 41.9, 41.9, and 44.2% respectively against P. digitatum at a concentration of 25 mg/L, whose activities surpassed that of hymexazol. This is the first report on the active derivatives from B. martensii in application of plant protection, providing scientific references for the development and utilization of active ingredients from scorpions.
Zhu, T., Li, K., Huang, D. et al. Structural Optimization, Fungicidal Activities Evaluation and Structure-activity Relationship of Guanidine Derivatives from Buthus martensii Karsch. Russ J Org Chem 59 (Suppl 1), S101–S110 (2023). https://doi.org/10.1134/S1070428023130109