Microbial oxidation of milbemycin A4 at the C-25 ethyl group was performed. Milbemycin A4 was converted to 31- and 32-hydroxy derivatives by Cirdnella umbellata SANK 44272 along with 24- and 30-hydroxy derivatives. Related compounds, 5-ketomilbemycin A4 5-oxime and 13β-fluoromilbemycin A4 were similarly converted to the hydroxylated compounds by this microorganism. Absidia cylindrospora SANK 31472 converted milbemycin A4 to the corresponding 32-oic acid, 24-hydroxy derivative and a few oxygenated compounds including at the C-25 ethyl group.
微
生物氧化了米普霉素A4的C-25乙基基团。米普霉素A4被Cirdnella umbellata
SANK 44272转化为31-和32-羟基衍
生物,同时生成了24-和30-羟基衍
生物。相关的化合物5-酮米普霉素A4 5-
肟和13β-
氟米普霉素A4也被该微
生物转化为羟基化合物。Absidia cylindrospora
SANK 31472将米普霉素A4转化为相应的32-酸、2
4-羟基衍
生物以及一些包括C-25乙基基团的氧化化合物。