Phenomena, including gelation and fluorescence, are used as easily detected sensors of chiral recognition. Qin et al. have developed a new type of isomerized diphenylalanine-based supramolecular gel (LFDF), which showed the visible enantiomeric discrimination of phenylalaninol enantiomers via fluorescence and gelation measurements. The addition of L- or D-phenylalaninol to the peptide gel led to complete collapse within one minute after adding the L-form, which was not observed in D-phenylalaninol. Meanwhile, by doping with the fluorescent dye thioflavin T (ThT), the prepared ThT-LFDF gel system can sensitively detect the L/D-phenylalanine enantiomer through fluorescence quenching, which has the advantages of visualization, easy manipulation, and high detection sensitivity.
D-phenylalanine is the D-enantiomer of phenylalanine. It is a conjugate base of a D-phenylalaninium and an enantiomer of a L-phenylalanine. D-Phenylalanine is a metabolite found in or produced by Escherichia coli (strain K12, MG1655). It may be light-sensitive. This compound reacts with strong oxidizing agents, acids and bases. It acts as a weak acid in solution.
white to light yellow crystal powde
D-Phenylalaninol is used as a chiral auxiliary for asymmetric Michael reactions. It is an enantiomer of L-Phenylalaninol, an inhibitor of intestinal Phenylalanine absorption. It acts as an inhibiting agent to the enzymes which are responsible for the breakdown of endorphins.
It can be recrystallised from Et2O, *C6H6/pet ether (b 40-60o) or toluene and distilled in a vacuum. It has been purified by dissolving in Et2O, drying over K2CO3, filtering, evaporating to a small volume, cooling in ice and collecting the plates. Store them in the presence of KOH (i.e. CO2—free atm). [Karrer & Ehrhardt Helv Chim Acta 34 3203 1951, Oeda Bull Chem Soc Jpn 13 465 1938.] The picrate has m 141-141.5o (from EtOH/pet ether). The hydrogen oxalate has m 177o, 161-162o [Hunt & McHale J Chem Soc 2073 1957]. The racemate has m 87-88o from *C6H6/pet ether (75-77o from Et2O), and the hydrochloride has m 139-141o [Fodor et al. J Chem Soc 1858 1951]. [Beilstein 13 IV 1920.]
