Contribution of mass spectrometry to the structural confirmation of components of the antibiotic GE2270 complex.
The GE2270 complex consists mainly of GE2270 A (MW 1289), a thiazolyl peptide antibiotic whose structure originates from the modification of a chain of 14 amino acids in a process which creates six thiazole rings and one pyridine. Together with the main component, a number of structurally related molecules are co-produced in small quantities by fermentation. A preparative high-performance liquid chromatrography method was developed to isolate GE2270 factors B1, B2, C1, C2a, C2b, D1, D2, E and T. Their structures, preliminarily determined by 1H-nuclear magnetic resonance spectroscopy in comparison with GE2270 A, were confirmed by low and high resolution fast-atom bombardment mass spectrometry and studies on the intact molecules and on their main hydrolysis products. Their molecular weights range from 1246 to 1306 Da. The structural differences between the factors lie in the extent of methylation and/or oxidation of thiazole rings (D and E) and asparagine, and in the aromatization of the oxazoline ring.
Colombo
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Marion Merrell Dow Research Institute, Lepetit Research Center, Gerenzano (VARESE), Italy.
Stella
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Selva
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D000900:Anti-Bacterial Agents / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D008401:Gas Chromatography-Mass Spectrometry; D006868:Hydrolysis; D008968:Molecular Conformation; D010455:Peptides; D010456:Peptides, Cyclic; D016339:Spectrometry, Mass, Fast Atom Bombardment; D013056:Spectrophotometry, Ultraviolet; D013844:Thiazoles / Q000737:chemistry
D000900:Anti-Bacterial Agents; D010455:Peptides; D010456:Peptides, Cyclic; D013844:Thiazoles; C068122:GE 2270 A