2-Amino-3-(5-phenylfuran-2-yl)propionic Acids and 5-Phenylfuran-2-ylacrylic Acids are Novel Substrates of Phenylalanine Ammonia-Lyase

Both racemic 2-amino-3-(5-phenylfuran-2-yl)propionic acids and 5-phenylfuran-2-ylacrylic acids were synthesized and spectroscopically characterized (UV, EI-MS, 1 H-NMR and 13 C-NMR).The phenyl group of the 5-phenylfuranyl residue carried no (rac-1a) para-Br (rac-1b) or Cl para or ortho (rac-1c, d) substituents.The novel furanylalanines were used as substrates of recombinant phenylalanine ammonia-lyase (PAL).When 50% of the racemic 5-phenylfuranylalanines were converted into the corresponding acrylates, the D-enantiomers of the substrates could be isolated.The L-enantiomers could be prepared from the substituted acrylates when the PAL reaction was reversed in the presence of 6 M ammonia at pH 10.