Synthesis of N‐[N‐L‐γ‐glutamyl‐L‐cysteinyl‐(carbonyl‐¹⁴C)]‐glycine (glutathione‐¹⁴C) and of [Cys‐¹⁴CO]‐(5S,6R)‐LTC₄

[Cys‐¹⁴CO]‐glutathione or N‐[N‐L‐γ‐glutamyl‐L‐cysteinyl‐¹⁴CO] glycine was prepared by chemical synthesis, with the L,L‐natural configuration and a radiochemical yield of 1% based on sodium [¹⁴C] cyanide. This labelled compound was used to obtain [Cys‐¹⁴CO] with a yield of 15%. [Cys‐¹⁴CO]‐glutathione and [Cys‐¹⁴CO]LTC₄ had a specific activity of 50 mCi/mmol (1.85 GBq/mmol).