Milbemycin
Milbemycins are a group of chemically similar to the macrolides avermectins. The first representatives were 1972 first isolated from the bacterium Streptomyces hygroscopicus, later still artificially produced derivatives were added to this group. There are now 13 known natural Milbemycins ( milbemycin α10 and β1 α1 .. .. β3 ). Some Milbemycins be used in veterinary medicine as a remedy for parasites. Chemically, it is to aglycones of avermectins with a very similar macrocyclic lactone ring without Disaccharidseitenketten.
Mechanism of action
Milbemycins are as avermectins fermentation products of Actinomyces ( Streptomyces spp.) And have a similar mechanism of action, but a significantly longer effective. Milbemycin oxime is obtained from Streptomyces hygroscopicus aureolacrimosus. It increases in invertebrates, the membrane permeability of the nerve or muscle cells for chloride ions by binding to glutamate and GABA -activated chloride channels. This leads to hyperpolarization of the cell membrane and to a blocking of the excitation transition. Milbemycin D is used outside of Europe for the treatment of dogs against gastrointestinal nematodes and for the prevention of heartworm disease. Its therapeutic range is small.