title: Design, synthesis, and biological activities of milbemycin analogues.
abstract: Milbemycins have received considerable interest in agricultural chemistry due to a special action mode, extremely high activity against arachnoide pests, low toxicity to mammals, and environmentally benign characteristics. Two series of novel milbemycin analogues (4Ia-6IIc) containing alkyl and aryl groups at the 4'- and 13-positions were designed and synthesized by five schemes. These analogues were identified by (1)H NMR, (13)C NMR, and elemental analysis (or HRMS). Their insecticidal activities against carmine spider mite, oriental armyworm, and black bean aphid were evaluated. The results showed that all of the title compounds had low acaricidal activity against carmine spider mite. However, most of them exhibited good insecticidal activities against oriental armyworm and black bean aphid at a concentration of 200 mg L(-1). The most potent substituents of 2,2-dimethylbutanoyl (4Ib), phenylacetyl (4IIm), and (Z)-1-(methoxyimino)-1-phenylacetyl (4IIn) exhibited the highest larvicidal activities, and its insecticidal LC(50) values against oriental armyworm were 0.250, 0.204, and 0.350 mg L(-1), while its insecticidal LC(50) values against black bean aphid were 0.150, 0.070, and 0.120 mg L(-1), respectively. These substituents provided some hints for further investigation on structure modification.
authors: Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Pesticide and Environmental Toxicology, Zhejiang University, Hangzhou, People's Republic of China.
authors: Jin-Hao
authors: JH
authors: Zhao
authors: Xiao-Jun
authors: XJ
authors: Xu
authors: Ming-Hua
authors: MH
authors: Ji
authors: Jing-Li
authors: JL
authors: Cheng
authors: Guo-Nian
authors: GN
authors: Zhu
mesh_terms: D000818:Animals; D001042:Aphids / Q000187:drug effects; D015195:Drug Design; D007306:Insecticides / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D007814:Larva / Q000187:drug effects; D018942:Macrolides / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D015394:Molecular Structure; D009036:Moths / Q000187:drug effects; D013329:Structure-Activity Relationship; D040102:Tetranychidae / Q000187:drug effects
chemical_list: D007306:Insecticides; D018942:Macrolides; C027837:moxidectin