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Simultaneous Determination of Concentration and Enantiomeric Composition of Amino Acids in Aqueous Solution by Using a Tetrabromobinaphthyl Dialdehyde Probe
Author(s) -
Iqbal Shahzad,
Yu Shanshan,
Jiang Le,
Wang Xinjing,
Chen Yu,
Wang Yalin,
Yu Xiaoqi,
Pu Lin
Publication year - 2019
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201901374
Subject(s) - chemistry , aqueous solution , enantioselective synthesis , fluorescence , enantiomer , amino acid , substrate (aquarium) , tryptophan , enantiomeric excess , composition (language) , derivative (finance) , medicinal chemistry , organic chemistry , stereochemistry , catalysis , biochemistry , physics , oceanography , quantum mechanics , financial economics , economics , geology , linguistics , philosophy
3,3′‐Diformyl‐1,1′‐bi‐2‐naphthol or its methoxymethyl‐protected derivative is found to undergo a highly selective reaction with excess bromine in CH 2 Cl 2 at reflux to give the novel 5,5′,6,6′‐tetrabrominated product ( S )‐ or ( R )‐ 2 . The observed electrophilic substitution at the 5,5′‐positons of an optically active binaphthyl compound is unprecedented. Unlike unbrominated 3,3′‐diformyl‐1,1′‐bi‐2‐naphthol, which is not suitable for fluorescent recognition in water, compound ( S )‐ 2 , in combination with Zn 2+ , exhibits a highly enantioselective fluorescent response toward amino acids in aqueous solution (HEPES buffer, pH 7.4). It is further found that the condensation product of ( R )‐ 2 with tryptophan, ( R )‐ 3 , shows dual‐responsive emissions toward amino acids; the short wavelength ( λ 1 =350 nm) emission is sensitive to the concentration of the substrate regardless of the chiral configuration and the long wavelength ( λ 2 >500 nm) emission is highly enantioselective. Thus, the use of ( R )‐ 3 allows the simultaneous determination of the concentration and enantiomeric composition of an amino acid sample from one fluorescence measurement.