Milbemycin R, a novel spiro-heterocycle milbemycin, was obtained from the metabolites produced by the mutant strain S. bingchenggensis BCJ60B11. Its structure was determined by spectroscopic and spectrometric analyses including 1 D, 2 D NMR, IR, HR-ESI-MS data. The acaricidal and nematicidal activities of milbemycin R against Tetranychus cinnabarinus and Bursaphelenchus xylophilus were tested. Milbemycin R possessed better acaricidal activity than milbemycins A3/A4.
Keywords: Genetically engineered strain; Streptomyces bingchenggensis BCJ60B11; acaricidal and nematocidal activities; milbemycin derivative.