Teicoplanin A2-2

Teicoplanin is a glycopeptide antibiotic produced by Actinoplanes teichomyceticus. A strain improvement to increase the productivity of the major component, teicoplanin A2-2, was carried out. As the fatty moiety of teicoplanin A2-2 is derived from L-valine, L-valine analogue (valine hydroxamate)-resistant mutants were derived. One of the mutants, 98-1-227, overproduced valine and produced a higher titer of total teicoplanin with higher A2-2 content. In a pilot fermentor (7 m3), the total productivity of teicoplanin was 1,800 units/ml and the A2-2 content was 58%.

The interaction between the main components of the new glycopeptide antibiotic teicoplanin, A2-2, A2-3, A2-4, A2-5 and A3-1, and human serum albumin has been studied in vitro by equilibrium dialysis (pH 7.4, 37 degrees C). From Scatchard analysis of the data, the calculated association constants (Ka) were: A2-2, 2.47 X 10(4), A2-3, 2.86 X 10(4), A2-4, 2.95 X 10(4) and A2-5, 3.87 X 10(4) mol.l-1. The number of binding sites per albumin molecule ranged between 1.23 to 1.31. A3-1 had a lower affinity with a Ka of about 5 X 10(3) mol.l-1. Extrapolated to the in vivo situation, the data suggested that about 90-95% of A2 components will be bound to serum albumin, and about 68-72% of A3-1. The in vitro findings were confirmed by a pharmacokinetic study in volunteers given [14C] teicoplanin i.v., in whom the fraction of teicoplanin bound to serum protein ranged between 87.6 and 90.8%.

Background:Teicoplanin is a glycopeptide antibiotic used for the treatment of infections caused by Gram-positive bacteria. There is a good correlation between trough levels and clinical outcome, therefore therapeutic drug monitoring is recommended. Here we present a liquid chromatography-mass spectrometry (LC-MS) method with online extraction based on turbulent flow chromatography for the quantification of the five main components of teicoplanin, A2-1, A2-2, A2-3, A2-4, and A2-5.Methods:After online extraction, analytical chromatography was performed on a Hypersil Gold C8 column under acidic conditions. As mass spectrometer, a Q Exactive hybrid instrument was used. Samples were prepared by adding internal standard and subsequent centrifugation. Patient samples (n=125) that had previously been analyzed using a commercially available immunoassay (QMS teicoplanin) were re-analyzed by LC-MS.Results:The imprecision was <6.9%, inaccuracy between 99.6% and 109%, for both, within- and between-day analysis. The method was shown to be free of matrix effects in the relevant time ranges and was compared to a commercially available immunoassay, QMS® teicoplanin from Thermo Fisher Scientific. The LC-MS assay produced comparable results to the QMS assay, the correlation coefficient was 0.856 (95% confidence interval 0.800-0.896). LC-MS yielded lower concentrations than the immunoassay as could be demonstrated by the bias of -1.16 mg/L (95% confidence interval -1.90-0.43 mg/L) in the Bland-Altman analysis.Conclusions:This specific, automated, LC-MS assay for teicoplanin is suitable for therapeutic drug monitoring.