Two New 5-Oxomilbemycins Possessing an Unusual 3,27-Epoxy Bond from the Genetically Engineered Strain Streptomyces bingchenggensis BCJ60

Two undescribed milbemycin derivatives, milbemycin P (1) and milbemycin Q (2), were isolated from a culture of the 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. Their acaricidal and nematocidal activities against Tetranychus cinnabarinus and Bursaphelenchus xylophilus were tested. The results showed that compounds 1–2 possessed potent acaricidal and nematocidal activities.