neither a threefold increase in the phenylalanine intake by mice nor the administration of three analogues of phenylalanine ( 4-fluoro-dl-phenylalanine , 4-chloro-dl-phenylalanine and beta- ( 2-thienyl ) -dl-alanine ) to sheep altered the composition of hair or wool .
C0031453
phenylalanine
C0030137
4-fluoro