Investigation of the discrimination ability and molecular dynamic properties of a chiral micelle aganist amino acids by NMR

This study involves investigation of binding and dynamic properties of complexes of chiral micelle R-dodecly(1-hydroxymethyl-propyl)dimethylammonium bromine with phenyl alanine enantiomers using 1H NMR chemical shifts, 2D NOESY, T1 spin-lattice relaxation time, T2 spin-spin relaxation time.Dissociation constants of the micelle for R or S enantiomer were calculated from non-linear curve fitting obtained from varying concentrations of each enantiomer against 1H NMR chemical shifts in the presence of a constant micelle concentration. They were found as 8.23x10-3 M and 4.86x10-3 M respectively. The results indicate that the micelle bindings better to S- enantiomer compared to R- enantiomer. 2D NOESY demonstrated that Hc, Hf and Hh groups of micelle interact with Gha2 and Gha parts of phenyl alanine respectively. Temperature dependent measurements of T1 and T2, although they were not significantly different to discriminate between two enantiomers, may indicate the existence of a dipolar interaction mechanism for the complex of both enantiomers with the micelleIn conclusion data illustrate that a combination of NMR techniques could be successfully employed in understanding of interaction of micelles possessing macroscopic properties with small organic molecules.