Liquid chromatographic investigation of quinoxaline antibiotics and their analogues by means of ultraviolet diode-array detection
| Autor: | Jean-Louis Excoffier, Michael J. Waring, Marye e. Adaskaveg, Thomas V. Alfredson, August H. Maki |
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| Rok vydání: | 1990 |
| Předmět: |
Chromatography
Tandem Ultraviolet Rays Organic Chemistry General Medicine Activation energy Echinomycin medicine.disease_cause Biochemistry Diode array Arrhenius plot Analytical Chemistry Anti-Bacterial Agents chemistry.chemical_compound Quinoxaline chemistry Quinoxalines medicine Ultraviolet Chromatography High Pressure Liquid Spectral purity |
| Zdroj: | Journal of chromatography. 507 |
| Popis: | Numerical formats for evaluation of spectral purity and for spectral comparison of ultraviolet diode-array detector data, together with library search routines, were applied to the liquid chromatographic analysis of echinomycin, triostin A and their synthetic and biosynthetic analogues. Samples of monoquinoline and bisquinoline analogues of echinomycin were found to contain echinomycin and the other respective analogue. Triostin A and its undermethylated synthetic analogues, des-N-tetramethyltriostin A (TANDEM) and [MeCys3,MeCys7]-TANDEM, were each composed of two or more components. Triostin A primarily consisted of a major chromatographic component and a minor component with very similar ultraviolet spectral features. TANDEM exhibited three chromatographic components with nearly identical ultraviolet spectral characteristics. Apparent conformational interconversion of at least two forms of the [MeCys3,MeCys7]-TANDEM analogue was observed by reversed-phase liquid chromatography. An activation energy of 15 kcal/mol was estimated for the interconversion based upon an Arrhenius plot of the data. |
| Databáze: | OpenAIRE |
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