Liquid chromatographic investigation of quinoxaline antibiotics and their analogues by means of ultraviolet diode-array detection

Alfredson, Thomas V.; Maki, August H.; Adaskaveg, Marye e.; Excoffier, Jean-Louis; Waring, Michael J.

doi:10.1016/s0021-9673(01)84205-9

Cited by 11 publications

(5 citation statements)

References 25 publications

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“…The presence of two discrete conformers of triostin A in slow exchange, which may be separated chromatographically, has been reported. [23] 1 H NMR spectra in CDCl 3 of the two compounds were consistent with previously reported data, [24,25] where the NMe-Val adopts a trans conformation and the presence of the two conformers is a result of the isomerization cis/trans of the NMe groups of Cys. The in vitro activity of the two conformers of triostin A was evaluated in three tumour cell lines (MDA-MB-231, A549, HT29).…”

supporting

confidence: 89%

Protection by Conformationally Restricted Mobility: First Solid‐Phase Synthesis of Triostin A

Tulla‐Puche¹,

Marcucci²,

Fermin³

et al. 2008

Chemistry A European J

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Conformationally restricted mobility: The application of an efficient solid‐phase strategy based on protection by conformationally restricted mobility (see scheme) has allowed, for the first time, the synthesis and determination of the biological activity of the two triostin A conformers, which result from the isomerization cis/trans of the N‐methyl group of Cys. The most polar conformer showed the greatest inhibitory effect on cell growth.

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supporting

confidence: 89%

Protection by Conformationally Restricted Mobility: First Solid‐Phase Synthesis of Triostin A

Tulla‐Puche¹,

Marcucci²,

Fermin³

et al. 2008

Chemistry A European J

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“…All spectroscopic measurements were made in a low ionic strength aqueous buffer containing 2 mM phosphate, 10 mM NaCI and 0.01 mM EDTA at pH 7.0 (L PSE buffe디. Sample concentrations were determined spectrophotometrically using previously reported extinction coefficients for the peptides [12] and polynucleotides [8].…”

Section: Sample Preparationmentioning

confidence: 99%

“…1QN and 2QN s없nples were prepared by directed biosynthesis methods as described by Gauvreau 때d Waring [1 이 . Both 1QN and 2QN peptides were further purified by HPLC methods described pr해ously[12] prior to spectroscopic investigations. Triostin A samples were generously provided by Drs.…”

mentioning

confidence: 99%

Application of ODMR to the study of DNA complexes of bisintercalating antibiotics and their biosynthesized derivatives

et al. 1991

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Th e DNA complexes of triostin A, echinomycin, and the monoquinoline (ION) and bisquinoline (20N) biosynthesized derivatives of echinomycin were investigated by optic띠 detection of triplet-state magnetic resonance (ODMR) spectroscopy, with the quinox따ine and q띠noline moieties of the DNA-binding peptides used as intrinsic probes. Plots of zero-field splitting (zfs) D parameter versus monitored wavelength revealed heterogeneity in the phosphorescence emission of echinomycin, triostin A, and 20N ascribed to the occurren,:e of m혀or and minor forms of the peptides in aqueous solution. ODMR results, in co띠unctIOn with findings from phosphorescence studies, indicate that the quinox외ine and quinoline chromophores of the major forms of the peptides are involved in aromatic stacking interactions in complexes with the natural DNAs from Micrococcus ωodeiktic따; Escherichia coli, and calf thymus as evidenced by red shifts in the phosphorescence 0,0 bands of the drugs, reductions in the phosphorescence lifetimes and zfs D and E parameters, and p이arity reversal of the ODMR slow passage signals upon drug complexation. The reversal in ODMR signal pol따ity of echinomycin 뻐d 20N is a consequence of changes in the triplet-state sublevel decay constants upon peptide binding to the natural DNAs. Th e extent of reduction of the D parameter for the major form of echinomycin, 20N, and the quinoline moiety of ION upon complexation with polymeric DNAs was found to correlate with the binding a떠nities measured for these targets [1], but no correlation was found for the quinox외ine moiety of ION. Preliminary studies of triostin A-DNA complexes also revealed no correlation between the reduction in zfs D-value upon complexation and binding affinity, although the largest reductions in D-value among the peptides investigated in this report were exhibited by the poly(dG-dC) ' poly(dGdC) and natural DNA complexes of triostin A.

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“…The amount of time spent comparing visually is dependant upon the complexity of the sample matrix. The literature contains many examples of the utilization of the three-dimensional data to resolve overlapping peaks, [1][2][3][4][5][6][7][8][9] determine peak purity, 10 -13 facilitate librar y searches, 10 and allow comparison between LC-DAD and LC-MS (liquid chrom atography-m ass spectrom etr y). 1 4 These methods are of limited value when comparing highly similar samples.…”

Section: Introductionmentioning

confidence: 99%

Determining Sample Differences in a Sample Series of Complex Liquid Chromatography—Diode Array Detector Data Using Chemometrics

2003

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In analytical laboratories, one often has to deal with sample series that have minor differences between them. For example, different batches of the same material may cause manufacturing problems, and quality control is an important issue. Another example is decomposition studies, where changes may or may not occur in a sample. To extract the differences between such highly related samples from LC-DAD (liquid chromatography-diode array detector) data is a time-consuming and subjective task. This paper describes an algorithm that efficiently extracts such differences.

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Liquid chromatographic investigation of quinoxaline antibiotics and their analogues by means of ultraviolet diode-array detection

Cited by 11 publications

References 25 publications

Protection by Conformationally Restricted Mobility: First Solid‐Phase Synthesis of Triostin A

Protection by Conformationally Restricted Mobility: First Solid‐Phase Synthesis of Triostin A

Application of ODMR to the study of DNA complexes of bisintercalating antibiotics and their biosynthesized derivatives

Determining Sample Differences in a Sample Series of Complex Liquid Chromatography—Diode Array Detector Data Using Chemometrics

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