High performance liquid structure confirmation

Both purified laccase as well as the crude enzyme from the WRF Cerrena unicolor were used to convert the dyes in aqueous solution. Biotransformation of the dyes was followed spectrophotometrically and confirmed by high performance liquid chromatography. The results indicate that the decolorization mechanism follows MichaeliseMenten kinetic and that the initial rate of decolorization depends both on the structure of the dye and on the concentration of the dye. Surprisingly, one recalcitrant azo dye (AR 27) was decolorized merely by purified laccase in the absence of any redox mediator [46],... 

From grilled sun-dried sardines, two mutagenic fractions were obtained with high performance liquid chromatography using pBondapak Cie. Their structures were determined, by 270 MHz 1H-NMR and low- and high-resolution mass spectra, to be 2-amino-3-methylimidazo[4,5-/]quinoline (IQ) and 2-amino-3,4-dimethyl-imidazo[4,5-/]quinoline (MelQ) (12,13,14). The structures of these new compounds were confirmed by chemical synthesis. 

Human insulin was the first commercial health care product produced by recombinant DNA technology ZjEliJLilly,.the producer of this synthetic insulin, often relied on HPLC to confirm the structure and to determine the potency of synthetic human insulin. The story behind Lilly s recombinant DNA-produced insulin is described in an article in Science (1) High performance liquid chromatography (HPLC) techniques developed at Lilly can detect proteins that differ by a single amino acid, and HPLC tests show human insulin (recombinant DNA) is identical to pancreatic human insu-... 

Dendrimer structure is often confirmed with a variety of techniques, including H- and C-NMR, mass spectrometry, size-exclusion chromatography, high performance liquid chromatography, electrophoresis, elemental analysis, and thermal analysis. ... 

The dimethylarsinoyl derivative of sulfated ribitol (see Fig. 2, compound 15) was isolated from the red alga Chondria crassicaulis (38). It had been observed as a major arsenical in C. crassicaulis by high performance liquid chroma-tography-inductively coupled plasma mass spectrometry (HPLC-ICPMS), and was initially reported as an unknown because it did not match any available standard (39). Subsequently, the compound was isolated and a chemical structure was proposed chiefly on nuclear magnetic resonance (NMR) data chemical synthesis of authentic material confirmed the proposed structure (38). This com-... 

Second, structure of the transformed OPA derivatives (containing two OPA molecules) and the reaction mechanism leading to the transformation are determined by online high-performance liquid chromatography (HPLC)-UV-MS evidences. It has been confirmed that the common characteristics of the presumably less stable OPA derivatives are associated with their original molecular structure they contain the NH2-CH2-R moiety, and all of them furnish more than one OPA derivative. In the light of the common structure of the multiple OPA derivatives providing compounds, a plausible reaction pathway has been introduced, fully supported by... 

It seems that unless the test material is relatively pure (from a preceding purification step if needed) NMR will be used in more of a structure confirmation role than for first identification. Two relatively new applications of chromatographic techniques. Capillary Zone Electrophoresis (CZE) and High Performance Liquid Chromatography (HPLC), to the analysis of CW materials generated great interest. 

Optical rotation and refractometric detectors were combined to characterize a series of dextrins by gel permeation chromatography and high performance liquid chromatography (HPLC). Gel permeation fractionates according to the hydrodynamic volume when adsorption is avoided/ and for this reason separates isomaltodextrins from linear maltodextrins. Specific rotation power [a] is directly obtained and confirms the chemical structure. Elution of cyclodextrins is also tested and discussed. HPLC reverse phase chromatography separates the anomers as shown by optical rotation and allows good resolution in the range of low DP. 

The product (45), by warming with phosphorus pentachloride, afforded the corresponding sulfonyl chloride and the structures of both products were confirmed by NMR spectroscopy. Acenaphthene-5-sulfonyl chloride and the corresponding hydrazide are valuable fluorescence derivatization reagents for amines, amino acids and carbonyl compounds respectively in high performance liquid chromatography. ... 

---