Halofuginone

Molecular formula CieH BrCINsOs Molecular weight 414.69 CAS Registry No 55837-20-2 Merck Index 13,4611 

Sample preparation Condition a 1 mL Bond Elut C8 SPE cartridge with 2 mL MeOH and 8 mL water adjusted to pH 4.3 with acetic acid. Mix 4 mL serum with 8 mL 10% acetic acid, add to the SPE cartridge, wash with 5 mL water adjusted to pH 4.3 with acetic acid, wash with 1 mL MeOH water 35 65 adjusted to pH 4.3 with acetic acid, wash with 1 mL water adjusted to pH 4.3 with acetic acid, elute with 1 mL MeCN water acetic acid 20 79.9 0.1 containing 2.104 -L/mL decylamine (pH ca. 4.3), inject a 50 m-L aliquot of the eluate. (Use silanized glassware.) 

Mobile phase MeCN buffer water 22 15 63 containing 210.4 LL/L decylamine, pH ca. 4.75 (The buffer was 250 mM pH 4.3 ammonium acetate.) 

Abd El-Aziz Nasr, M.I. Elissalde, M.H. Stanker, L.H. Extraction and HPLC analysis of halofuginone in chicken serum, J.Liq.Chromatogr., 1994,17, 2961-2970. 

Mobile phase MeOH water acetic acid 40 59.5 0.5 Flow rate 1 Injection volume 25 

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Results from a feeding trial in which chickens were fed a commercial feed containing 3 ppm halofuginone showed that liver could contain about 0.2 ppm, kidney 0.15 ppm, whereas muscle and fat residue levels lower than 0.02 ppm. 

ANTICOCCIDIAL AND OTHER ANTIPROTOZOAL DRUGS Halofuginone Halofuginone Bovine... 

In a similar fashion, dietary intake estimates can be made for lasalocid and halofuginone, two drugs that have disparate MRLs in the United States and Canada (51). The data presented in Table 12.6 predict that use of the US MRLs will not result in residues above the ADI established by Canada, and, conversely that use of the Canadian MRLs will not result in dietary exposure to residues above the US ADI. Aldiough some of the percentages in Table 12.6 appear substantial, it should be taken into account that the estimates would have been much smaller had less conservative factors been included in the calculations. Based on these... 

Table 12.6 Testing of Equivalence of US and Canada MRLs for Halofuginone and...

In the period 1992-1994, the drugs and groups of drugs screened by the National Residue Program included antibiotics, sulfonamides, ivermectin, halofuginone, levamisole, and morantel tartrate. The microbial assays applied by FSIS for monitoring antibiotics could detect chiortetracyciine, oxytetracycline, tetracy-... 

Table 13.5 National Residue Monitoring Program Results for Sulfonamides and Halofuginone over the Period 1992-1994 in the United States...

Halofuginone Synthetic Anticoccidial CieHj/BrCINsOs 415 MeOH, DMF... 

Halofuginone Chicken serum Bond-Elut Cg HgO/HOAc, MeOH- HgO/ACN/HOAc 315... 

Other anticoccidials for which immunoassays have been developed include the polyethers salinomycin and lasalocid, and the quinazoline drug halofuginone. Concern over the potential toxicity of salinomycin has led to development of two competitive ELISAs for detecting and measuring salinomycin residues in poultry tissues. In the first ELISA (96), 16 monoclonal antibodies were prepared and evaluated for their ability to produce a rapid and low-cost screening procedure for residues of salinomycin in poultry liver. In the second (97), the antibodies produced showed cross-reactivity with narasin but not with lasalocid, madura-... 

Halofuginone can be also analyzed in chicken serum by a competitive ELISA developed on the basis of monoclonal antibodies (99). In this study, a serum matrix effect that afforded a higher sensitivity for the detection of halofuginone in chicken serum than in assay buffer or in highly diluted serum was observed. The sensitivity of the ELISA improved when used in more concentrated serum. 

Halofuginone Eggs Na2CO3/Na2SO4 addn, EtOAc extn, Celite column cleanup... 

The most potent coccidiostat commercially available to date is halofuginone (stenorol) (67) with a feed inclusion rate of 3 p.p.m. The mode of action of this agent is unknown at present. 

There are no effective agents in use at present but the coccidiostat, halofuginone (67), is active in laboratory tests against T. parva and T. annulata. 

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