title: New nemadectin congeners with acaricidal and nematocidal activity from Streptomyces microflavus neau3 Y-3.
abstract: Two nemadectin congeners 1 and 2 were isolated from the fermentation broth of a mutant strain (Y-3) of Streptomyces microflavus neau3. Their structures were determined on the basis of extensive spectroscopic analysis and comparison with data from the literature. Compound 2 possessed a 5-membered ring lactone that is unprecedented among known milbemycins and avermectins. Both compounds 1 and 2 exhibited potent acaricidal activity and nematocidal activity. Especially, compound 2 demonstrated impressive acaricidal activity against adult mites with an IC50 of 2.3±0.9 μg/mL and mite eggs with an IC50 of 17.5±2.1 μg/mL and nematocidal activity against Caenorhabditis elegans with an IC50 of 0.7±0.2 μg/mL, which are higher than those of nemadectin and the known commercial acaricide and nematocide milbemycin A3/A4.
authors.affiliation: School of Life Science, Northeast Agricultural University, No. 59, Mucai Street, Xiangfang District, Harbin 150030, PR China.
authors.forename: Ling-Yu
authors.initials: LY
authors.lastname: Yang
authors.forename: Ji-Dong
authors.initials: JD
authors.lastname: Wang
authors.forename: Ji
authors.initials: J
authors.lastname: Zhang
authors.forename: Chang-Yan
authors.initials: CY
authors.lastname: Xue
authors.forename: Hui
authors.initials: H
authors.lastname: Zhang
authors.forename: Xiang-Jing
authors.initials: XJ
authors.lastname: Wang
authors.forename: Wen-Sheng
authors.initials: WS
authors.lastname: Xiang
mesh_terms: D056810:Acaricides / Q000737:chemistry / Q000302:isolation & purification / Q000633:toxicity; D000818:Animals; D000969:Antinematodal Agents / Q000737:chemistry / Q000302:isolation & purification / Q000633:toxicity; D017173:Caenorhabditis elegans / Q000187:drug effects; D018942:Macrolides / Q000737:chemistry* / Q000302:isolation & purification / Q000633:toxicity; D009682:Magnetic Resonance Spectroscopy; D008925:Mites / Q000187:drug effects; D008968:Molecular Conformation; D013302:Streptomyces / Q000737:chemistry* / Q000378:metabolism
chemical_list: D056810:Acaricides; D000969:Antinematodal Agents; D018942:Macrolides; C027837:moxidectin
keywords: Acaricidal activity; Nemadectin congeners; Nematocidal activity; Streptomyces microflavus neau3