Milbemycine

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Structure of the milbemycins

Milbemycins are a group of macrolides that are chemically similar to avermectins . The first representatives were isolated for the first time in 1972 from the bacterium Streptomyces hygroscopicus , later artificially produced derivatives were added to this group. Meanwhile 13 natural milbemycins are known (Milbemycin α 1 .. α 10 and β 1 .. β 3 ). Some milbemycins are used in veterinary medicine as anti-parasitic agents. Chemically, they are aglycones of the avermectins with a very similar macrocyclic lactone ring without disaccharide side chains.

Mechanism of action

Milbemycins, like avermectins, are fermentation products of ray fungi ( Streptomyces spp.) And have a similar mechanism of action, but a significantly longer effectiveness. Milbemycin oxime is obtained from Streptomyces hygroscopicus aureolacrimosus. In invertebrates, it increases 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 a blockage of the conduction of excitation . Milbemycin-D is used outside Europe for the treatment of gastrointestinal nematodes in dogs and for the prophylaxis of heartworm disease. However, its therapeutic breadth is small.

Examples

Surname = R 1 = R 2 -R 3 CAS
Milbemectins -H, (β) -OH -H, -H -CH 3  : -CH 2 CH 3 = 3: 7 51596-10-2 +
51596-11-3
Milbemycin oxime = NOH -H, -H -CH 3  : -CH 2 CH 3 = 3: 7 129496-10-2
Moxidectin -H, (β) -OH = STILL 3 ( Z ) -C (CH 3 ) = CH-CH (CH 3 ) 2 113507-06-5
Nemadectin -H, (β) -OH -H, (α) -OH ( Z ) -C (CH 3 ) = CH-CH (CH 3 ) 2 102130-84-7
Milbemycin-D -OH -H -CH- (CH 3 ) 2 77855-81-3

Individual evidence

  1. ↑ a b Wolfgang Krämer, Ulrich Schirmer, Peter Jeschke, Matthias Witschel: Modern Crop Protection Compounds . Wiley-VCH, 2011, ISBN 978-3-527-32965-6 , pp. 1312 ff . ( limited preview in Google Book search).
  2. ↑ a b c The 2nd International Electronic Conference on Synthetic Organic Chemistry: Insecticides  ( page no longer available , search in web archives )  Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice.@1@ 2Template: Dead Link / www.sciforum.net  
  3. ↑ a b Wolfgang Löscher, Fritz Rupert Ungemach, Reinhard Kroker: Pharmacotherapy in domestic and farm animals . Parey bei Mvs, 2006, ISBN 978-3-8304-4160-1 , pp. 302 f . ( limited preview in Google Book search).
  4. ↑ Milbemectin data sheet
  5. ↑ Milbemycin oxime data sheet
  6. ↑ Milbemycin-D