title: NMR spectroscopic detection of chirality and enantiopurity in referenced systems without formation of diastereomers.
abstract: Enantiomeric excess of chiral compounds is a key parameter that determines their activity or therapeutic action. The current paradigm for rapid measurement of enantiomeric excess using NMR is based on the formation of diastereomeric complexes between the chiral analyte and a chiral resolving agent, leading to (at least) two species with no symmetry relationship. Here we report an effective method of enantiomeric excess determination using a symmetrical achiral molecule as the resolving agent, which is based on the complexation with analyte (in the fast exchange regime) without the formation of diastereomers. The use of N,N'-disubstituted oxoporphyrinogen as the resolving agent makes this novel method extremely versatile, and appropriate for various chiral analytes including carboxylic acids, esters, alcohols and protected amino acids using the same achiral molecule. The model of sensing mechanism exhibits a fundamental linear response between enantiomeric excess and the observed magnitude of induced chemical shift non-equivalence in the (1)H NMR spectra.
authors.affiliation: International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan.
authors.forename: Jan
authors.initials: J
authors.lastname: Labuta
authors.forename: Shinsuke
authors.initials: S
authors.lastname: Ishihara
authors.forename: Tomáš
authors.initials: T
authors.lastname: Šikorský
authors.forename: Zdeněk
authors.initials: Z
authors.lastname: Futera
authors.forename: Atsuomi
authors.initials: A
authors.lastname: Shundo
authors.forename: Lenka
authors.initials: L
authors.lastname: Hanyková
authors.forename: Jaroslav V
authors.initials: JV
authors.lastname: Burda
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Ariga
authors.forename: Jonathan P
authors.initials: JP
authors.lastname: Hill
mesh_terms: D000438:Alcohols / Q000032:analysis* / Q000737:chemistry; D000596:Amino Acids / Q000032:analysis* / Q000737:chemistry; D002264:Carboxylic Acids / Q000032:analysis* / Q000737:chemistry; D002942:Circular Dichroism; D004952:Esters; D009682:Magnetic Resonance Spectroscopy; D056004:Molecular Dynamics Simulation; D015394:Molecular Structure; D011165:Porphyrinogens / Q000737:chemistry; D011789:Quantum Theory; D013237:Stereoisomerism
chemical_list: D000438:Alcohols; D000596:Amino Acids; D002264:Carboxylic Acids; D004952:Esters; D011165:Porphyrinogens