Using enantioselective indicator displacement assays to determine the enantiomeric excess of alpha-amino acids.
Enantioselective indicator displacement assays (eIDAs) were used for the determination of enantiomeric excess (ee) of alpha-amino acids as an alternative to the labor-intensive technique of chromatography. In this study, eIDAs were implemented by the use of two chiral receptors [(Cu(II)(1)](2+), [Cu(II)(2)](2+)) in conjunction with the indicator chrome azurol S. The two receptors were able to enantioselectively discriminate 13 of the 17 analyzed alpha-amino acids. Enantiomeric excess calibration curves were made using both receptors and then used to analyze true test samples to check the system's ability to determine ee accurately. The proposed method uses a conventional UV-vis spectrophotometer to monitor the colorimetric signal, which allows for a potential high-throughput screening (HTS) method for determining ee. The techniques created consistently produced results accurate enough for rapid preliminary determination of ee.
Leung
Diana
D
Department of Chemistry and Biochemistry, The University of Texas at Austin, 1 University Station A5300, Austin, Texas 78712, USA.
Folmer-Andersen
J Frantz
JF
Lynch
Vincent M
VM
Anslyn
Eric V
EV
D000596:Amino Acids / Q000032:analysis* / Q000737:chemistry; D001557:Benzenesulfonates / Q000737:chemistry; D001667:Binding, Competitive; D020650:Combinatorial Chemistry Techniques / Q000379:methods*; D003300:Copper / Q000737:chemistry*; D018360:Crystallography, X-Ray; D062385:Hydroxybenzoates / Q000737:chemistry; D007202:Indicators and Reagents / Q000737:chemistry; D008024:Ligands; D008698:Mesylates / Q000737:chemistry; D009942:Organometallic Compounds / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D013237:Stereoisomerism
D000596:Amino Acids; D001557:Benzenesulfonates; D062385:Hydroxybenzoates; D007202:Indicators and Reagents; D008024:Ligands; D008698:Mesylates; D009942:Organometallic Compounds; C009134:pyrocatechol violet; C015076:chrome azurol S; D003300:Copper; C012077:trifluoromethanesulfonic acid