title: Separation of WAP-8294A components, a novel anti-methicillin-resistant staphylococcus aureus antibiotic, using high-speed counter-current chromatography.
abstract: The WAP-8294A complex was isolated from the fermentation broth of Lysobacter sp. WAP-8294, whose major component, WAP-8294A2, showed a strong activity against Gram-positive bacteria including methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococci in vitro, and also exhibited a potent activity against MRSA in vivo. The previous separation procedure using the conventional chromatographic methods was laborious and time-consuming, and the recovery of the desired compound was often unsatisfactory. In the present study, high-speed counter-current chromatography (HSCCC) was applied to the separation of the main components of the WAP-8294A complex. Due to the high polarity of the target compounds, we selected a hydrophilic two-phase solvent system composed of n-butanol-ethyl acetate-aqueous 0.005 M trifluoroacetic acid (1.25:3.75:5, v/v/v) which provided a suitable range of partition coefficient values for these compounds. Although the settling time of this solvent system was much longer than the optimum range, suggesting a low retention of the stationary phase under the standard experimental conditions, the separation was successfully performed at the low flow-rate of 0.5 ml/min. A sample size of 25 mg yielded pure fractions of three components (1-6 mg). The identification of each component was carried out by HPLC and fast atom bombardment mass spectrometry. The method will contribute to the clinical development of WAP-8294A2 as an anti-MRSA agent.
authors.affiliation: Faculty of Phannacy, Meijo University, Nagoya, Japan. kiharada@meijo-u.ac.jp
authors.forename: K I
authors.initials: KI
authors.lastname: Harad
authors.forename: M
authors.initials: M
authors.lastname: Suzuki
authors.forename: A
authors.initials: A
authors.lastname: Kato
authors.forename: K
authors.initials: K
authors.lastname: Fujii
authors.forename: H
authors.initials: H
authors.lastname: Oka
authors.forename: Y
authors.initials: Y
authors.lastname: Ito
mesh_terms: D003377:Countercurrent Distribution / Q000379:methods*; D047630:Depsipeptides; D016106:Methicillin Resistance; D010456:Peptides, Cyclic / Q000737:chemistry / Q000302:isolation & purification*; D016339:Spectrometry, Mass, Fast Atom Bombardment; D013211:Staphylococcus aureus / Q000737:chemistry*
chemical_list: D047630:Depsipeptides; D010456:Peptides, Cyclic; C116834:lotilibcin