Design, synthesis, photophysical properties and insecticidal activities of coumarin compound for the photocontrolled release of dinotefuran

In order to improve the efficacy of dinotefuran, the coumarin-caged dinotefuran (COU-DIN), was designed and synthesized by coupling dinotefuran with the coumarin photoremovable protecting group 7-diethylamino coumarin (COU). The structure of COU-DIN was characterized by nuclear magnetic resonance spectroscopy (NMR) and high resolution mass spectrometry (HRMS). Then its photophysical properties, insecticidal activities against 3 pests including Aphis craccivora, Aedes albopictus and Mythimna separate, and stability to water were evaluated under 420 nm blue light and sunlight. The results showed that COU-DIN could be controlled by 420 nm blue light and sunlignt to release dinotefuran with a release rate of 90% efficiently, regularly and quantitatively, and COU-DIN was satble in water. In addition, the insecticidal activity of COU-DIN was singnificant different before and after illumination. And COU-DIN after illumination had equivalent potencies against the 3 pests above comparied to dinotefuran. These results demonstrated that COU-DIN had the potential as a novel photocontrolled delivery device for dinotefuran.