A neodymium-(S)-PDTA (PDTA = N,N,N',N'-tetrakis[(hydroxycarbonyl)methyl]-1,2-diaminopropane) complex was found exceptionally useful in the quantitative determination of enantiomer ratios of water-soluble natural amino acids by (13)C-NMR. The method is demonstrated on mixtures of l- and d-enantiomers of various amino acids. The interactions of the chiral shift reagent with the amino acid molecules were rationalized by molecular orbital calculations.
Aqueous-phase quantitative NMR determination of amino acid enantiomer ratio by (13)C-NMR using chiral neodymium shift reagent / FLORINI, Nicola; FAGLIONI, Francesco; ZUCCHI, Claudia; L., Caglioti; PALYI, Gyula. - In: AMINO ACIDS. - ISSN 1438-2199. - STAMPA. - 38:5(2010), pp. 1343-1350. [10.1007/s00726-009-0341-9]