Isolation and Structural Characterization of Polymyxin B Components

J Chromatogr A. 2001 Apr 6;912(2):369-73. doi: 10.1016/s0021-9673(01)00585-4.

Abstract

Polymyxin B is a peptide antibiotic complex present as sulphate. The components were separated preparatively on a poly(styrene-divinylbenzene) (PLRP-S), 1000 A, 8 microm, 250 x 12.5 mm I.D. stationary phase maintained at 60 degrees C and using 215 nm detection. Elution was carried out with acetonitrile-sodium sulphate solution (0.7%, m/v; pH adjusted to 2.5 with trifluoroacetic acid)-water (18:50:32, v/v) at a flow-rate of 4.0 ml/min. Seven polymyxin B components were isolated and characterized using 1H and 13C NMR. The molecular masses were confirmed by mass spectrometry. The structures of two components were determined for the first time. Polymyxins B5 and B6 were identified as having the same composition as polymyxin B1 except that the fatty acid moiety was nonanoic acid and 3-hydroxy-6-methyloctanoic acid, respectively.

MeSH terms

  • Chromatography, Liquid / methods
  • Magnetic Resonance Spectroscopy
  • Mass Spectrometry
  • Molecular Weight
  • Polymyxin B / chemistry*
  • Protein Conformation
  • Spectrophotometry, Ultraviolet

Substances

  • Polymyxin B