Bacitracin analysis

Fig. 6. A Chromatogram of a mixture containing the print molecule (oxacillin), two other p-lactam-antibiotics (penicillin G and penicillin V) and a non- 3-lactam-antibiotic (bacitracin) on an oxacillin imprinted MIP containing 4-vinylpyridine residues, cross-linked with TRIM. The analysis was performed in organic mobile phase (ACN/AcOH,99 l).B Same conditions but using the respective non-imprinted control polymer. C Structures of penicillin V, penicillin G, and oxacillin. Reprinted with permission from Skudar K, Briiggemann O, Wittelsberger A, Ramstrom O (1999) Anal Commun 36 327. Copyright 1999 The Royal Society of Chemistry...

Kang, J. W., De Reymaeker, G., Van Schepdael, A., Roets, E., and Hoogmartens, J. (2001). Analysis of bacitracin by micellar electrokinetic capillary chromatography with mixed micelle in acidic solution. Electrophoresis 22, 1356-1362. 

An IPC-ESI-MS/MS method allowed the simultaneous determination of neomycin and bacitracin in human and rabbit sera [79] and the analysis of aminoglycoside antibiotics in human plasma [80]. IPC was recently validated for the estimation of bulk and formulated gatifloxacin [81]. The IPC determination of norfloxacin in diverse matrices worked as a stability indicating method [82], A CI2 stationary phase with embedded polar group successfully achieved IPC baseline tetracycline separation simply by using a phosphate as the IPR [83], A practical IPC method for the quality control of fosfomycin calcium and its related substances was recently suggested [84],... 

Fig. 3 Chromatograms obtained by pH zone-refining CCC. (A) Separation of CBZ(Z) dipeptides. Experimental conditions are as follows apparatus type-J multilayer CPC (PC Inc., Potomac, MD, USA) with a 10-cm revolution radius column multilayer coil, 1.6-mm ID, 325 mL capacity solvent system methyl tert-h xiy ether/acetonitrile/water (2 2 3), 16 mM TEA in organic phase (pH 1.83), and 5.5 mM NH3 in aqueous phase (pH 10.62) sample eight CBZ(carbobenzyloxy) dipeptides as indicated in the chromatogram, each 100 mg in 50 mL of solvent (25 mL in each phase) flow rate 3.3 mL/hr in head-to-tail elution mode detection 206 nm revolution 800 rpm retention of stationary phase 65.1%. (B) Separation of bacitracin complex. High-performance liquid chromatography (HPLC) analysis indicated that two major components, bacitracins A and B, were isolated in peaks 3 and 5, respectively. Experimental conditions are as follows apparatus and column same as above solvent system methyl r -butyl ether/ acetonitrile/water (4 1 5), 40 mM triethylamine, 10% DEHPA in the organic stationary phase, and 20 mM HCl in aqueous mobile phase flow rate 3 mL/min sample 5 g of bacitracin dissolved in 40 mL of solvent (20 mL in each phase) revolution 800 rpm detection 280 nm.

After the experiment, fractions from the foam and liquid outlets are collected and analyzed. The elution curve of bacitracin components from the foam outlet shows three major peaks, and the one from the liquid outlet. The HPLC analysis of fractions clearly indicate that the bacitracin components are separated in the order of hydrophobicity of the molecule in the foam fractions and in increasing order of their hydrophiUcity in the liquid fractions. 

A more detailed analysis of the action of antibiotics demonstrated in fact that many of these compounds may be of significance in the physiology of the producer organism, like bacitracin A in the transport of ions, and gramicidin S in the inhibition of spore outgrowth, cf. Table 63, rather than in ecology. Knowledge in this field is, however, still scarce. 

Bacitracin has little or no optical activity (43). It is particularly resistant to acid hydrolysis, i.e., after 18 hours in 6 AT HCl, some peptide still remains (43,79). However, its approximate amino acid analysis (43,143) shows the following for each 100 g. of bacitracin, 11 g. of phenylalanine, 9 g. of leucine, 22 g. of isoleucine, 10 g. of glutamic acid, 17 g. of aspartic acid, 9 g. of lysine, 10 g. of histidine, 14 g. of cystine, and 1.5 g. of ammonia. Perhaps bacitracin also contains ornithine or hydroxylysine. The comparison of the bacitracin composition with that of subtilin is of interest, since both are products of B. svbtilis. 

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