An Effective and Promising Strategy for Plant Protection: Synthesis of -Carvone-Based Thiazolinone-Hydrazone/Nanochitosan Complexes with Antifungal Activity and Sustained Releasing Performance.

The development of novel natural product-derived nano-pesticide systems with loading capacity and sustained releasing performance of bioactive compounds is considered an effective and promising plant protection strategy. In this work, 25 -carvone-based thiazolinone-hydrazone compounds ~ were synthesized by the multi-step modification of -carvone and structurally confirmed. Compound was found to show favorable and broad-spectrum antifungal activity through the in vitro antifungal activity evaluation of compounds ~ against eight phytopathogenic fungi. Thus, it could serve as a leading compound for new antifungal agents in agriculture. Moreover, the -carvone-based nanochitosan carrier bearing the 1,3,4-thiadiazole-amide group was rationally designed for the loading and sustained releasing applications of compound , synthesized, and characterized. It was proven that carrier had good thermal stability below 200 °C, dispersed well in the aqueous phase to form numerous nanoparticles with a size of~20 nm, and exhibited an unconsolidated and multi-aperture micro-structure. Finally, -carvone-based thiazolinone-hydrazone/nanochitosan complexes were fabricated and investigated for their sustained releasing behaviors. Among them, complex with a well-distributed, compact, and columnar micro-structure displayed the highest encapsulation efficiency and desirable sustained releasing property for compound and thus showed great potential as an antifungal nano-pesticide for further studies.