Enzymatic synthesis of isotopomers of tyramine labeled with deuterium and tritium

The combined chemical and enzymatic methods of synthesis of five isotopomers of L ‐tyrosine, L ‐Tyr, and their derivatives, i.e. corresponding isotopomers of tyramine (TA), labeled with deuterium and tritium have been reported. Two‐step synthesis consists with introduction of deuterium or tritium label into intermediate L ‐Tyr using isotope exchange followed by enzymatic decarboxylation using enzyme tyrosine decarboxylase (EC 4.1.1.25). This way five isotopomers of L ‐tyrosine, i.e. [2‐ 2 H]‐L‐, [2‐ 3 H]‐L‐,[2‐ 2 H/ 3 H]‐L‐, [3′,5′‐ 2 H 2 ]‐L‐,[3′,5′‐ 3 H 2 ]‐ L ‐Tyr, and six isotopomers of tyramine i.e. [1S‐ 2 H]‐, [1S‐ 3 H]‐, [1S‐ 2 H/ 3 H]‐, [3′,5′‐ 2 H 2 ]‐, [3′,5′‐ 2 H 2 ]‐, [2′,6′‐ 2 H 2 ]‐TA were obtained.