The milbemycins are a group of

macrolide The Macrolides are a class of natural products that consist of a large macrocyclic lactone ring to which one or more deoxy sugars, usually cladinose and desosamine, may be attached. The lactone rings are usually 14-, 15-, or 16-membered. M ...

s chemically related to the avermectins and were first isolated in 1972 from ''

Streptomyces hygroscopicus ''Streptomyces hygroscopicus'' is a bacterial species in the genus ''Streptomyces''. It was first described by Hans Laurits Jensen in 1931. Biochemistry Cultures of different strains of ''S. hygroscopicus'' can be used to produce a number of ...

''. They are used in veterinary medicine as

antiparasitic Antiparasitics are a class of medications which are indicated for the treatment of parasitic diseases, such as those caused by helminths, amoeba, ectoparasites, parasitic fungi, and protozoa, among others. Antiparasitics target the parasitic ag ...

agents against worms, ticks and fleas.The 2nd International Electronic Conference on Synthetic Organic Chemistry: Insecticides

Mechanism of action

Like avermectins, milbemycins are products of fermentation by ''

Streptomyces ''Streptomyces'' is the largest genus of Actinomycetota and the type genus of the family Streptomycetaceae. Over 500 species of ''Streptomyces'' bacteria have been described. As with the other Actinomycetota, streptomycetes are gram-positive, ...

'' species. They have a similar mechanism of action, but a longer half-life than the avermectins. They open

glutamate Glutamic acid (symbol Glu or E; the ionic form is known as glutamate) is an α-amino acid that is used by almost all living beings in the biosynthesis of proteins. It is a non-essential nutrient for humans, meaning that the human body can syn ...

-sensitive

chloride channel Chloride channels are a superfamily of poorly understood ion channels specific for chloride. These channels may conduct many different ions, but are named for chloride because its concentration ''in vivo'' is much higher than other anions. Several ...

s in

neuron A neuron, neurone, or nerve cell is an membrane potential#Cell excitability, electrically excitable cell (biology), cell that communicates with other cells via specialized connections called synapses. The neuron is the main component of nervous ...

s and

myocyte A muscle cell is also known as a myocyte when referring to either a cardiac muscle cell (cardiomyocyte), or a smooth muscle cell as these are both small cells. A skeletal muscle cell is long and threadlike with many nuclei and is called a m ...

s of

invertebrate Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chordate ...

s, leading to hyperpolarisation of these cells and blocking of signal transfer.

Examples

References

Anthelmintics Insecticides {{antiinfective-drug-stub