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Cattle avermectins

The microorganism was classified as a new species of actinomycete. Streptomyces avermitilis. Its anthelmintic activity was shown to reside in 8 closely related macrocyclic lactones, named avermectins, which were also found to possess activity against free-living and parasitic arthropods. One of the natural components, avermectin is now being evaluated as a pesticide for the control of mites of citrus and cotton crops and control of the Red Imported Fire Ant. A chemical derivative, 22,23-dihydroavermectin or ivermectin, has been developed as an antiparasitic agent. It is being marketed for use in cattle, horses and sheep and is expected to become available for swine and dogs. [Pg.5]

Included in this group are avermectins and milbemycins, which are fermentation products possessing a 16-member cyclic lactone, a spirochetal moiety, and a disaccharide unit. Abamycin, ivermectin, doramectin, and eprinomectin are major avermectins available for anthelminthic treatment of livestock, whereas moxidectin is a milbemycin with worldwide acclaim as a cattle anthelminthic (Fig. 4.7). [Pg.141]

Metabolism studies showed that the major metabolites of the components of ivermectin in cattle, sheep, and rats were 24-hydroxymethyl compounds, whereas major metabolites in swine were 3-0-desmethyl compounds. Identification of the 24-hydroxymethyl metabolites has not been yet achieved in swine, whereas identification of Hie 3-O-desmetlryl metabolites has not been made possible in cattle or sheep (54, 55). Recent metabolism studies (56) in cattle, swine, and rats have indicated, however, diat the metabolism of avermectins was qualitatively similar for all three species. There were quantitative differences both between species and between compounds for a given species, but all three species produced... [Pg.144]

Doramectin, unlike ivermectin components, possesses a double bond between C22 and C23 and a cyclohexyl ring on C25. This novel avermectin is intended for use in cattle and sheep in the form of a single subcutaneous injection at a dosage of 0.2 mg/kg bw, or in pigs in the form of a single intramuscular injection at a dosage of 0.3 mg/kg bw (58). [Pg.145]

Eprinomectin is derived from the natural product abamectin by conversion of the 4 -hydroxy group to the 4 -cp -A-acetyl substituent. Like abamectin, eprinomectin is a mixture of two active constituents that contain more than 90% 4 -deoxy-4 -(ep/-acetylamino)avermectin B a and less than 10% 4 -deoxy-4 - epi-acetylaminojavermectin Bib. It is indicated for treatment of internal and external parasites in beef and dairy cattle at a dosage of 0.5 mg/kg bw and is applied along the midline of the animal s back (61). [Pg.146]

Three classes of anthelminthics were also monitored macrocyclic lactones, benzimidazoles, and levamisole. Samples were taken from cattle, sheep, pigs, and ostriches. Only 2 of 2613 samples contained residues above the MRL. These were for fenbendazole in a cattle sample and avermectin in a sheep sample. [Pg.478]

Immunoaffinity chromatography cleanup has also been applied as an ideal and reliable strategy for residue analysis. Immunoaffinity columns prepared by coupling the antibodies to a cyanogen bromide-activated support were used to analyze avermectin BI residues in cattle tissues (359) and ivermectin in sheep serum (376). An immunoaffinity column prepared by an alternative activation/ coupling procedure with carbonyl diimidazole was also employed to analyze ivermectin residues in swine liver (361) since the earlier-reported methods did not work well in the analysis of this matrix. This recent work demonstrated the high specificity of tire antibody-mediated cleanup, but also showed that the immunoaffinity procedures could not always or completely eliminate matrix interference of samples. Therefore, application of additional cleanup steps before or after these procedures is often inevitable. [Pg.1010]

Ivermectin is a semisynthetic analog of avermectin B which contains at least 80% of 22,23-dihydroavermectin B,a and not more than 20% of 22,23-dihydroavermectin B,b. It is a potent anthelminthic/insecticide for the control of a wide variety of arthropod parasites, including endoparasites and ectoparasites of animals such as cattle, horses, sheep, swine, and dogs. Its oral LD50 in rats is 650 mg/kg. [Pg.66]

Ivermectins B1 are derived from the avermectines Bl, the natural fermentation products of Streptomyces avermitilis. The avermectins Bl have double bonds between carbon atoms at 22 and 23, whereas the ivermectins Bl have single bonds in these positions (Fig. 2a). They have an intermediate polarity. The ivermectins Bl are a mixture of two major homologs, ivermectins Bla (>80%) and ivermectins Bib (<20%), but a crude ivermectin complex also contains various minor components. Ivermectins Bl are broad-spectrum antiparasitic agents used against Onchocerca volvulus in human medicine and for food production animals such as cattle, swine, and horses. [Pg.1457]

Ivermectins B1 are broad-spectrum antiparasitic agents widely used for food-producing animals such as cattle, swine, and horse.They are derived from avermectins Bl, the natural fermentation products of Streptomyces avermitilis. [Pg.2195]

T. J. Ridsdill-Smith, Effects of avermectin residues in cattle dung on dung beetle (Coleoptra Scarabaeidae) reproduction and survival. Vet. Para-sitoL, 1993, 48, 127-137. [Pg.411]


See other pages where Cattle avermectins is mentioned: [Pg.11]    [Pg.69]    [Pg.183]    [Pg.396]    [Pg.144]    [Pg.382]    [Pg.126]    [Pg.414]    [Pg.11]    [Pg.52]    [Pg.54]    [Pg.3955]    [Pg.193]    [Pg.193]    [Pg.78]    [Pg.115]    [Pg.282]    [Pg.203]    [Pg.159]    [Pg.160]    [Pg.179]    [Pg.414]    [Pg.83]    [Pg.58]    [Pg.267]    [Pg.389]   
See also in sourсe #XX -- [ Pg.11 ]




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