X comparisoii IJf all the riiig isonieric halopheriylalatiiiies inhibitors of pheriylalaiiirie aiid t. yro4tie hytiriisyl-: we revealed that optimal iiihihitioti was achieved with 3-iodopheiiylalaiiiIie. a-llethylation of the 3-halopheiiylalaniiies was fourid to eiihniice iiihibition of 1. yrosiiie hydroxylase, but have no effect, on phenylalaniiie hydroxylase. The implic. at, iotis of these findings are discussed.
