Circular fluorescence detected

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

Fang JM, Selvi S, Liao JH et al (2004) Fluorescent and circular dichroic detection of monosaccharides by molecular sensors bis[(pyrrolyl)ethynyl]naphthyridine and bis [(indoili)ethynyl]naphthyridine. J Am Chem Soc 126 3559-3566... 

Maupin, C. L. Riehl, J. P. Circularly polarized luminescence and fluorescence detected circular dichroism. In Encyclopedia of Spectroscopy and Spectrometry, Lindon, J. C. Trantner, G. E. Holmes, J. L., Eds. Academic Press, 2000 pp 319-326. 

Analogous g-values may be defined for the degree of circular polarization in emission [or circularly polarized photoluminescence (CPPL)] and circularly polarized electroluminescence (CPEL), eg. gCppL = 2(JL - 1R)/(1L + 1r), where IL and IR denote the intensity of left- and right-handed circularly polarized emission, respectively. CPPL should not be confused with fluorescence-detected CD. 

Chiral isocyanides such as 198 have also been used for the synthesis of chiral 4,5-disubstituted oxazoles such as 199, which are potentially useful in fluorescence-detected circular dichroism for on-column capillary electrophoresis (Equation 12) <1996JOC8750>. 

Synovec, R.E. Yeung, E.S. Fluorescence detected circular dichroism as a detection principle in high-performance liquid chromatography. J. Chromatogr. 1986, 368, 85-93. 

Thomas, M.P. Patonay, G. Warner, I.M. Fluorescence-detected circular dichroism studies of serum albumins. Anal. Biochem. 1987,164, 466-473. 

Among the various methods useful for monitoring two-photon absorption by solutes, fluorescence detection has proved most popular that is, excitation spectra (cf. Section 5.3) are measured. When both photons are taken from a single beam and linearly as well as circularly polarized light is used, two independent measurements are possible and provide the absorption cross sections and oo respectively. The quantity... 

Fluorescence-detected circular dichroism (FDCD) is a chiroptical technique in which the spectrum is obtained by measuring the difference in total luminescence obtained after the sample is excited by left- and right-circularly polarized light. For the FDCD spectrum of a given molecular species to match its CD spectrum, the luminescence excitation spectrum must be identical to the absorption spectrum. 

More esoteric experimental procedures which can be applied to complex molecules include, for example, picosecond time-resolved circular dichroism. A spectrometer for this purpose has been described and used to observe carbon monoxide elimination from excited carbon raonoxymyoglobulin.Fluorescence detected CD has also been used to observe riboflavin in capillary electrophoresis. 

The large environmental dependence of the ll-(3-hexyl-l-indolyl)undecyltri-methylammonium bromide fluorescence lifetime and fluorescence spectrum has led to its continued use as a fluorescence probe for micellar systems.76 Fluorescence-detected circular dichroism, a technique which appears to have considerable potential, has been applied to the determination of the c.d. spectra of L-tryptophan and L-cystine and two macromolecular systems.78... 

Since polypeptides are chiral polymers, the chromophore arrangement shows some chirality. Therefore, additional information on the chromophore arrangement in the ground state, as well as in the excited state, may be obtained from chiroptical spectroscopy, such as circular dichroism (CD), circularly polarized fluorescence (CPF) [43], and fluorescence-detected circular dichroism (FDCD) [44). 

Applications in Biotechnology. Biopharmaceutical products must be well characterized by means of analytical techniques. RP-HPLC with UV detection is suitable for the content assay and impurity profiling because of its high resolution. However, the bioactivity of protein-based pharmaceuticals not only relies on the primary structure but also on the higher order structure, i.e., the molecular confirmation, which is not revealed by UV absorbance. Circular dichroism and intrinsic fluorescence detection have been combined with UV detection in RP-HPLC to monitor the conformational properties of active compounds and impurities in biopharmaceutical products [57]. 

Use of polarized light to excite fluorescence, and measurement of the state of polarization of the emitted light introduce another set of measurable parameters that can characterize structures and dynamics of molecules. The anisotropy of the polarization of fluoresence after excitation by linearly polarized light provides the rotational diffusion coefficient, or rotational correlation time, of the fluorophore. When there is fluorescence energy transfer, analysis of the anisotropy of both donor and acceptor can reveal the relative orientation, and the relative motion. Measurement of fluorescence after excitation by circularly polarized light provides the fluorescence-detected circular dichroism. This measurement characterizes the chiral environment of the ground state of the fluorophore. If the circular polarization of the fluorescence is measured, the circularly polarized luminescence is obtained. This measurement characterizes the chirality of the excited state. 

Application of fluorescence-detected circular dichroism (FDCD) to the determination of the major pterin (L-monapterin) from Escherichia coli has been published <01H(54)283>. Identification of (6/ )-5,6,7,8-tetrahydro-D-monapterin as the native pleridine in Tetrahymena pyriformis has been reported <01HCA918>. A novel modified pterin has been isolated from... 

Nehira T, Parish CA, Jockusch S, et al. (1999) Fluorescence-detected exciton-coupled circular dichroism scope and limitation in structural studies of organic molecules. Journal of the American Chemical Society 121 8681-8691. 

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