Two new 13-hydroxylated milbemycin metabolites from the genetically engineered strain Streptomyces avermitilis AVE-H39

Abstract

Two new milbemycin metabolites, 13α-hydroxymilbemycin β₁₃ (1) and 26-methyl-13α-hydroxymilbemycin β₁₃ (2), were isolated from the fermentation broth of a genetically engineered strain Streptomyces avermitilis AVE-H39. Their structures were determined by the comprehensive spectroscopic data, including 1 D, 2 D NMR, MS spectral analysis and the comparison with data from the literature. Compounds 1 and 2 not only exhibited potent acaricidal activities against Tetranychus cinnabarinus, but also had nematocidal activity against Bursaphelenchus xylophilus.

Graphical abstract

Keywords:

• Genetically engineered strain
• new milbemycins
• structure elucidation
• acaricidal activity
• nematocidal activity

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This research was financially supported by the Key Research and Development Programs of Zhejiang Province (Grant No: 2020C02028), (Grant No: 2019C02030), (Grant No: 2019C02024) and the Zhejiang Provincial Natural Science Foundation of China (HX2019069, HX2019078).