Chloramphenicol commercially available

Few medicines based on boron are known, in general boric acid or a boronic acid serve to esterify an a-diol or an ortho-diphenol. This is the case for the emetic antimony borotartrates of the ancient pharmacopoieas, for the injectable catecholamine solutions, for tolboxane " , that is close to meprobamate and that was commercially available as a tranquilhzer some decades ago, or also for the phenylbo-ronic esters of chloramphenicol. " Boromycine was the first natural product containing boron isolated. " It is a complex between boric acid and a polyhydroxylated tet-radentate macrocycle. " Another natural product is aplas-momycin with antibiotic properties. " " ... 

S, S)-2-Amino-1-phenyl-1,3-propanediol (8) is commercially available and is a byproduct of the technical synthesis of the antibiotic chloramphenicol. It is comparatively inexpensive, so there is no need for laboratory synthesis. It is readily converted to dihydrooxazoles which are themselves useful auxiliaries. The synthesis of (72)-phenylalaninol from this aminodiol via a dihydrooxa-zole has been cited (Section 2.3.1.). Hydrolysis of the intermediate dihydrooxazole leads to an amino alcohol 9 methylated at oxygen which is used as a more convenient starting material for the preparation of dihydroxazoles used in enolatc reactions (Sections D. 1.3.1.4., B.2.). 

Various ELISA kits are commercially available for the detection of antibiotics in foods of animal origin. There at least four kits on the market for the detection of chloramphenicol (which is banned for use in food-producing species in the EU and many other countries) in tissue, honey, milk, and aquaculture products and five kits... 

The bacterial CAT enzyme catalyzes the transfer of acetyl groups to chloramphenicol from acetyl coenzyme A (acetyl CoA). In a typical assay, this reaction is monitored with relabeled chloramphenicol After separation by thin-layer chromatography (TLC), the acetylated and nonacetylated forms can be distinguished by autoradiography, and quantitation is achieved by isolating the forms and measuring their radioactivity in a scintillation counter. Quantitative CAT assays have been performed on Drosophila tissue culture and dissociated cell extracts (Di Nocera and Dawid 1983 Benyajati and Dray 1984 Thummel et al. 1988 Krasnow et al. 1989 Ye et al. 1997). CAT can also be detected with commercially available antibodies. In addition, a nonradioactive CAT assay exists that utilizes a fluorescent chloramphenicol derivative (Molecular Probes). 

Results showed a total of 2.8% of the samples (n 2972) to be inhibitor positive by the Delvotest SP test further examination identified 1.7% as -lactam antibiotics, and 1.1 % as sulfonamides and dapsone. The percentage of chloramphenicol suspicious samples determined by the Charm II test was amazingly high however, tests for confirmation were not available and contamination of the samples by residues of the chloramphenicol-based preservative azidiol could not be excluded with certainty. Low concentrations of streptomycins were also detected in 5.7% of the samples (n 1221), but the MRL was not exceeded. Macrolide and tetracycline residues were not found in significant levels. Model trials with commercially applied yoghurt cultures confirmed how important the compliance to MRLs can be to dairy industry compared to antibiotic-free milk, a pH of 5.0 was reached with a delay of 15 min in the case of contamination with cloxacillin 30 min in the case of penicillin, spiramycin, and tylosin and 45 min in the case of oxytetracycline contamination. 

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