Analytical applications of circular dichroism

Purdie, Neil; Swallows, Kathy A.; Murphy, Laura H.; Purdie, Robin

doi:10.1016/0731-7085(89)80160-8

Cited by 28 publications

(25 citation statements)

References 9 publications

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“…The near-UV CD spectrum can be sensitive to small changes in tertiary structure due to protein-protein interactions and ⁄ or changes in solvent conditions (15). The signal strength in the near-UV CD region is much weaker than that in the far-UV CD region.…”

Section: Protein Analysesmentioning

confidence: 99%

Circular Dichroism Techniques: Biomolecular and Nanostructural Analyses‐ A Review

2009

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This paper reviews the best known techniques using circular dichroism spectroscopy such as conventional circular dichroism (i.e. electronic circular dichroism), magnetic circular dichroisms (magnetic vibrational circular dichroism, x-ray magnetic circular dichroism), fluorescence detected circular dichroism, near-infrared circular dichroism, vibrational circular dichroism, Fourier transform infrared circular dichroism, high pressure liquid chromatography circular dichroism, stopped-flow circular dichroism, and synchrotron radiation circular dichroism. Also, we have described here the most important applications of circular dichroism spectroscopy in structural biochemistry and nanoscience.

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Section: Protein Analysesmentioning

confidence: 99%

Circular Dichroism Techniques: Biomolecular and Nanostructural Analyses‐ A Review

2009

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“…This is why it is important that determination of AMP species should be carried out by methods that are capable of providing information on the enantiomeric purity and chirality. However, the amphetamine molecule has not, according to our knowledge, been chirally examined, except by electronic circular dichroism (CD), which showed that the AMP-CD signal was too weak to be conclusive [7]. Therefore, the following study can be considered as the first of its kind on the AMP molecules.…”

Section: Introductionmentioning

confidence: 99%

Raman Optical Activity and Raman Spectra of Amphetamine Species—Quantum Chemical Model Calculations and Experiments

Berg¹,

Shim²,

White³

et al. 2012

AJAC

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Theoretical calculations and preliminary measurements of vibrational Raman optical activity (ROA) spectra of different species of amphetamine (amphetamine and amphetamine-H + ) are reported for the first time. The quantum chemical calculations were carried out as hybrid ab initio DFT-molecular orbital calculations by use of the Gaussian 03W program, based on complete geometry minimizations of the conformational energy of the S-(+)-amphetamine molecule, the S-(+)-amphetamine-H + ion, and the R-(-)-amphetamine molecule. Following this, harmonic frequency calculations have been made, providing information about the cation vibrational bands, expected in salts of single anions (chlorides) as well as in salts of anions with internal bonds (sulfates, hydrogen phosphates, etc.). It shows that the kind of anion should be given better attention, as so far it has often not been the case, when the spectra are employed for identification purposes. The DFT calculations show that the most stable conformations are those allowing for close contact between the aromatic ring and the amine hydrogen atoms. The internal rotational barrier within the same amphetamine enantiomer has a considerable influence on the Raman and ROA spectra. As predicted the experimental ROA spectra were found to depend on the chirality. Two street samples, provided by the London Police, were also measured and compared to the calculated ROA spectra. The street samples were found to contain different enantiomers of the protonated amphetamine-H + sulfate. According to the present study the AMPH + ion in aqueous sulfate solution seems to adopt a conformation in which the phenyl and ammonium groups are in transpositions, similar to what has been found in the solid state.

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“…Moreover, pretreatment of biological samples usually requires specific polar solvents incompatible with normal phase . Usually, the complexity of an enantioseparation problem can be simplified by the use of circular dichroism detectors .…”

Section: Introductionmentioning

confidence: 99%

Scope of partial least‐squares regression applied to the enantiomeric composition determination of ketoprofen from strongly overlapped chromatographic profiles

Padró

Osorio-Grisales

Arancibia

et al. 2015

J of Separation Science

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Valuable quantitative information could be obtained from strongly overlapped chromatographic profiles of two enantiomers by using proper chemometric methods.Complete separation profiles where the peaks are fully resolved are difficult to achieve in chiral separation methods, and this becomes a particularly severe problem in case that the analyst need to measure the chiral purity, i.e., when one of the enantiomers is present in the sample in very low concentrations. In this report, we explore the scope of a multivariate chemometric technique based on unfolded partial least-squares regression, as a mathematical tool to solve this quite frequent difficulty. This technique was applied to obtain quantitative results from partially overlapped chromatographic profiles of R-and S-ketoprofen, with different values of enantioresolution factors (from 0.81 down to less than 0.2 resolution units), and also at several different S:R enantiomeric ratios. Enantiomeric purity below 1% was determined with excellent precision even from almost completely overlapped signals. All these assays were tested on the most demanding condition, i.e., when the minor peak elutes immediately after the main peak. The results were validated using univariate calibration of completely resolved profiles and the method applied to the determination of enantiomeric purity of commercial pharmaceuticals.

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Analytical applications of circular dichroism

Cited by 28 publications

References 9 publications

Circular Dichroism Techniques: Biomolecular and Nanostructural Analyses‐ A Review

Circular Dichroism Techniques: Biomolecular and Nanostructural Analyses‐ A Review

Raman Optical Activity and Raman Spectra of Amphetamine Species—Quantum Chemical Model Calculations and Experiments

Scope of partial least‐squares regression applied to the enantiomeric composition determination of ketoprofen from strongly overlapped chromatographic profiles

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