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
The 1,2,3-thiadiazole-carboxylate moiety was reported to be an important pharmacophore of plant activators.In this study,a series of novel plant activators based on thieno[2,3-d]-1,2,3-thiadiazole-6-carboxylate were designed and synthesized and their biological activity as plant activators was studied.The structures of the novel compounds were identifed by1H NMR,19F NMR and HRMS.The in vivo bioassay showed that these novel compounds had good effcacy against seven plant diseases.Especially,compounds 1a and 1c were more potent than the commercialized plant activator BTH.Almost no fungicidal activity was observed for the active compounds in the in vitro assay,which matched the requirements as plant activators.
A series of novel anthranilic diamides with benzyl sulfide scaffold were synthesized,in which N-pyridylpyrazole moiety generally regarded as key pharmacophore was abandoned.The target compounds were characterized by ~1H NMR,^(13)C NMR,^(19)F NMR and HRMS.The preliminary bioassays indicated that half of the title compounds were endowed with good insecticidal activities against armyworm(Mythimna sepatara) at the concentration of 500 mg/L,Exhilaratingly,the synthesized compound 3a was also active against Tetranychus cinnabarinus at 100 mg/L.The difference in activities between the target compounds was influenced by the substituents,which provided some hints for further investigation on structure modifications.
Yin-Bo ChenJi-Ling LiXu-Sheng ShaoXiao-Yong XuZhong Li
Compared with traditional structure-based approaches for the identification of species-specific ligands, the ab initio approach, based on large-scale protein sequences from different species, has been used to locate specific sites that may be important to the molecular selectivity of species. Statistically significant differences in the distribution of residues in different species and differences in the physicochemical properties of residue-specific sites may largely account for species selectivity. The nicotinic acetylcholine receptor (nAChR), an important neuro-receptor with significantly different ligand selectivity in different species, was used to test our method. Because of the lack of nAChR structural information, the mechanism of ligand discrimination is unclear which hinders attempts at novel molecular design. In this study, the specific site residues 186 and 189 in the principal subunits and residues 34, 55, 56, 57, 106 and 112 in complementary subunits of nAChR were identified by applying our method with stringent statistical cutoffs. These sites were predicted to contribute to ligand selectivity and this result coincides well with the known experimental data.
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