Fast parallel enantiomeric analysis of unmodified amino acids by sensing with fluorescent β-cyclodextrins

Abstract

Modified cyclodextrins bearing a metal binding site and a dansyl fluorophore 6-deoxy-6-N-(N a -[(5-dimethylamino-1-naphthalenesulfonyl)aminoethyl]-aminocylamino-b-cyclodextrin, containing L-Phe (S-1), L-PhGly (S-2) or L-Pro (S-3) moieties, were used as enantioselective fluorescence sensors for the discrimination of enantiomers of the amino acids valine and proline, according to a ligand exchange mechanism. The best conditions to perform enantiomeric analyses were studied and a fast protocol using fluorescence quenching by the copper(II)/amino acid complexes in a fluorescence microplate reader was developed, allowing the detection of samples with high enantiomeric excess. Calibration of the fluorescence response as a function of enantiomeric composition was obtained using the Stern-Volmer model; the calibration curves showed good linearity, allowing fast evaluation of enantiomeric excess within 6% error. Two calibration curves and triplicate analyses of six valine samples were performed in two minutes.

Synthesis and Enantiomeric Recognition Studies of Optically Active Pyridino‐Crown Ethers Containing an Anthracene Fluorophore Unit

“…D), the Stern–Volmer equation can be used in the following form (Eq. ) where [NapEt] is the sum of concentrations of ( R )‐ and ( S )‐NapEt, x ( S ) is the molar fraction of ( S )‐NapEt, K SV , ( R ) and K SV , ( S ) are the Stern–Volmer constants for the quenching processes with ( R )‐ and ( S )‐NapEt, respectively.…”

“…during the experiment, I 0 /I varied linearly with x (S) giving a calibration curve ( Fig. 4), which can provide an opportunity [45][46][47][48][49] for the determination of the enantiomeric composition of NapEt.…”

Fluorescent glycoconjugates and their applications

“…Sensing of amino acids was reported for the discrimination of enantiomers of valine and proline, based on a ligand exchange mechanism. 232 A fluorescence-quenching method mediated by Cu 2+ /amino acid complexes was designed for the detection of samples with high enantiomeric excess. The CD-based detecting probe was bearing a three-point metal binding site in the linker arm between the CD and a dansyl fluorophore ( Figure 86).…”

Solid‐phase extraction with metal–organic frameworks for the analysis of chiral compounds

“…Dragna et al have used self‐assembled octahedral Fe(II)‐imine complexes to determine the ee of α‐chiral primary amines using circular dichroism spectroscopy with an error of 5% . Roberto et al developed a model of fluorescent sensors based on modified β‐cyclodextrins containing a binding site for copper(II) and a dansyl fluorophore, the evaluations of the ee of valine and proline have a 6% error . Hyun et al developed the ee determination of host–guest systems to measure the ee with a 7% error .…”

“…41 Roberto et al developed a model of fluorescent sensors based on modified β-cyclodextrins containing a binding site for copper(II) and a dansyl fluorophore, the evaluations of the ee of valine and proline have a 6% error. 42 Hyun et al developed the ee determination of host-guest systems to measure the ee with a 7% error. 43 When compared to the previously reported methods, our method is very simple, easy to prepare, and displays a low standard error and good linearity.…”