Dichroism, circular, detection

Mancini, F., Fiori, J., Bertucci, C., Cavrini, V., Bragieri, M., Zanotti, M.C., Liverani, A., Borzatta, V., Andrisano, V. (2004). Stereoselective determination of allethrin by two-dimensional achiral/chiral liquid chromatography with ultraviolet/circular dichroism detection. J. Chromatogr. A 1046, 67-73. 

P. Salvadori, C. Bertucci, and C. Rosini, Circular dichroism detection in HPLC, Chirality, 5 376-385 (1991). 

C. Bertucci, E. Domenici, and P. Salvadori, Circular dichroism detection in HPLC Evaluation of the anistropy factor, J. Pharm. Biomed. Anal., 5 843-846 (1990). 

O Connor DB. (1994) Pulse radiolysis with circular dichroism detection. Radiat Phys Chem 44 371-376. 

Purdie, N. Province, D.W. Johnson, E.A. Tripeptide discriminations using circular dichroism detection. J. Pharm. Sci. 1999, 88, 715-721. 

Circular Dichroism and Magnetic Circular Dichroic Spectra.—There have been two papers concerned with the theory of c.d. one concerned with vibronic coupling,187 the other with radiationless decay.188 Circular dichroism detected 78 80 81 84 88... 

Yamamoto, A., Akiba, N., Kodama, S., Matsunaga, A., Kato, K., and Nakazawa, H., Enantiomeric purity determination of malic acid in apple juices by multibeam circular dichroism detection, J. Chromatogr. A, 928, 139, 2001. 

A. Ozdemir, L. K. Lednev, and S. A. Asher, Comparison between UV Raman and circular dichroism detection of short helices in bomboUtin in, Biochemistry 41, 1893-1896 (2002). 

Beaufour, M., Morin, P., Ribet, J.-P. and Maurizot, J.-C. FIPLC quantitation of the four stereoisomers of benzoxathiepin derivatives with cellulose phenyl type chiral stationary phase and circular dichroism detection. J. Pharm. Biomed. Anal 41 544, 2006. 

Zougagh, M., Aranda, R, Castaneda, G. and Rios, A. Supercritical fluid extraction-achiral liquid chromatography with circular dichroism detection for the determination of menthone enantiomers in natural peppermint oil samples. Talanta 79(2) 284, 2009. 

Williams, R. C., Edwards, J. R, Joshi, A. S. and Aubry, A.-F. Chiral analysis of drug substance in clinical plasma extracts using achiral HPLC with circular dichroism detection. /. Pharm. Biomed. Anal 25 501, 2001. 

Miller, M. T., Ge, Z. and Mao, B. Development of a nonchiral HPLC method with circular dichroism detection for chiral analysis of molybdenum-catalyzed enantioselective synthesis products. Chirality 14 659, 2002. 

The unmodified and complementary oligonucleotides were also synthesized, in order to detect thermodynamic and spectroscopic differences between the double helices. Circular dichroism spectra revealed that the covalently bound anthracene does not stack in the centre of the DNA double helix. Mutagenic activity by intercalative binding of the anthracene residue is thus unlikely. Only in vitro and in vivo replication experiments with site-specifically modified... 

Circular dichroism employs standard dispersive or interferometric instmmentation, but uses a thermal source that is rapidly modulated between circular polari2ation states using a photoelastic or electro-optic modulator. Using phase-sensitive detection, a difference signal proportional to the absorption difference between left- and right-polari2ed light, AA is recorded as a function of wavenumber. Relative differential absorptions... 

The availability of the purified transporter in large quantity has enabled investigation of its secondary structure by biophysical techniques. Comparison of the circular dichroism (CD) spectrum of the transporter in lipid vesicles with the CD spectra of water-soluble proteins of known structure indicated the presence of approximately 82% a-helix, 10% ) -turns and 8% other random coil structure [97]. No / -sheet structure was detected either in this study or in a study of the protein by the same group using polarized Fourier transform infrared (FTIR) spectroscopy [98]. In our laboratory FTIR spectroscopy of the transporter has similarly revealed that... 

Because process mixtures are complex, specialized detectors may substitute for separation efficiency. One specialized detector is the array amperometric detector, which allows selective detection of electrochemically active compounds.23 Electrochemical array detectors are discussed in greater detail in Chapter 5. Many pharmaceutical compounds are chiral, so a detector capable of determining optical purity would be extremely useful in monitoring synthetic reactions. A double-beam circular dichroism detector using a laser as the source was used for the selective detection of chiral cobalt compounds.24 The double-beam, single-source construction reduces the limitations of flicker noise. Chemiluminescence of an ozonized mixture was used as the principle for a sulfur-selective detector used to analyze pesticides, proteins, and blood thiols from rat plasma.25 Chemiluminescence using bis (2,4, 6-trichlorophenyl) oxalate was used for the selective detection of catalytically reduced nitrated polycyclic aromatic hydrocarbons from diesel exhaust.26... 

Natural circular dichroism (optical activity). Although circular dichroism spectra are most difficult to interpret in terms of electronic structure and stereochemistry, they are so very sensitive to perturbations from the environment that they have provided useful ways of detecting changes in biopolymers and in complexes particularly those remote from the first co-ordination sphere of metal complexes, that are not readily apparent in the absorption spectrum (22). It is useful to distinguish between two origins of the rotational strength of absorption bands. 

Meadows F, Narayanan N, Patonay G (2000) Determination of protein-dye association by near infrared fluorescence-detected circular dichroism. Talanta 50 1149-1155... 

Secondary structural predictions about NPAs, and direct biophysical measurements, have demonstrated that the NPAs are rich in a-helix, with no p-structure either predicted from secondary structure prediction algorithms, or detected by circular dichroism (Kennedy et al, 1995b). In this they are the antithesis of the similarly sized cLBPs and lipocalins. The predictions are that each individual NPA unit protein will fold into four main regions of helix, and it has been speculated that the tertiary structure is as a four-bundle helix protein, similar to other invertebrate carrier proteins (Sheriff et al., 1987). 

Another intermediate in the radiolysis of iron carbonyls is probably Fe(C0)4, a species which has been detected by infra-red spectroscopy (55) and by magnetic circular dichroism (56). Observation by the latter technique implies a triplet electronic ground-state for the radical, yet it has eluded detection by EPR in spite of careful searches from 0 to 25 kG at X-band (32). 

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