Spirotetramat metabolizes to its active enol form in the plant. We described here a photocaged pesticide delivery system that can release insecticidal spirotetramat enol form upon light irradiation. Covalently linking spirotetramat-enol with photoresponsive coumarin generated the caged insecticide. The photophysical and photochemical properties, deprotection photolysis and insecticidal activities of the caged spirotetramat enol were studied. This light-triggered system can undergo cleavage to release free spirotetramat enol form at the presence of blue light （420 nm） or sunlight, Bioassays indicated that the triggered molecule has no obvious insecticidal activity against Aphis craccivora Koch at dark and could be activated by light to release the insecticidal ingredients, which provides precise control over insecticide delivery.
Phenalenone is a kind of defensive compound biosynthesized inside plants in response to the outside attack such as fungus and nematodes.A set of derivatives encompassing structural modifications on the privileged phenalenone scaffold were synthesized through introduction of phenyl and hydroxy!substitutes at 9-positon and 2-position and assessed their insecticidal activities against armyworm（Mythimna separata Walker） and cowpea aphids[Aphis craccivora）.No obvious insecticidal activities of the synthesized compounds were observed against armyworm.Some of the 9-phenyl and 2-hydroxy substituted phenalenone analogues showed potential activities against cowpea aphids with 33%-41%mortality at 500 mg/L.
Spiro heterocycles frequently occur in bioactive molecules. In the pursuit of neonicotinoids with spiro hererocycles, three types of novel neonicotinoids with spirobenzofuranone, spirooxindole or spiroacenaphythylenone framework were designed and synthesized. Insecticidal evaluation showed that some of spirobenzofuranone containing neonicotinoids exhibited moderate activity against cowpea aphid, armyworm or brown planthopper.
Nan-Yang ChenLi-Ping RenMin-Ming ZouZhi-Ping XuXu-Sheng ShaoXiao-Yong XuZhong Li
A series of novel tetrahydroimidazo[1,2-a]pyridine-5（1H）-one derivatives containing a electronegative pharmacophore（=CNO_2） were synthesized via practical aza-ene reaction and characterized by ~1H NMR,^（13）C NMR,^（19）F NMR and HRMS. Preliminary bioassays showed that some of the target compounds exhibited good insecticidal activity against brown planthopper（Nilaparvata lugens） and cowpea aphids（Aphis craccivora） at 500 mg L^（-1）. Among them, compound 11 h was active against brown planthopper at100 mg L^（-1）. The insecticidal activities varied significantly depending on the types and patterns of the substituents, which provided guidance for further investigation on structure modifications.
Xuan-Qi LiuYa-Qin LiuXu-Sheng ShaoZhi-Ping XuXiao-Yong XuZhong Li
