L-4-Pyridylalanine , with CAS number is 37535-49-2, can be called (2R)-2-Amino-3-(4-pyridinyl)propanoic acid ; 3-(4-Pyridinyl)-D-alanine ; 3-Pyridin-4-yl-D-alanin ; 4-pyridinepropanoic acid, alpha-amino-, (alphaR)- .