Two new milbemycin derivatives from a genetically engineered strain Streptomyces bingchenggensis.

Two new milbemycin derivatives, milbemycin M (1) and milbemycin N (2), were isolated from the culture of a genetically engineered strain Streptomyces bingchenggensis BCJ60. Their structures were elucidated through the interpretation of NMR and HR-ESI-MS spectroscopic data, as well as comparison with previous reports. The acaricidal and nematicidal activities of them against Tetranychus cinnabarinus and Bursaphelenchus xylophilus were tested. The results showed that compounds 1-2 possessed potent acaricidal and nematocidal activities.