Synthesis of tritium labeled isotopomers of L ‐tyrosine

The synthesis of four selectively labeled isotopomers of L ‐tyrosine, ( L ‐Tyr), using chemical and enzymatic methods is reported. Four tritium labeled isotopomers of L ‐phenylalanine ( L ‐Phe) – [2‐ 3 H]‐, [2′,6′‐ 3 H 2 ]‐, [3R‐ 3 H]‐ and [3S‐ 3 H]‐ have been synthesized using a combination of chemical and enzymatic methods. The labeled isotopomers of L ‐Phe have been converted into [2 ‐ 3 H]‐, [2′,6′‐ 3 H 2 ]‐, [3R‐ 3 H]‐, and [3S‐ 3 H]‐ L ‐Tyr by using the enzyme L ‐phenyl‐alanine 4′‐monooxygenase. Copyright © 2002 John Wiley & Sons, Ltd.