Enzymatic synthesis of tritium — labelled prostaglandin D 2 and its conversion to other prostaglandins

The one‐stage enzymatic synthesis of tritium‐labelled prostaglandin D 2 from labelled arachidonic acid was performed by using the enzyme system PGH‐synthetase/PGH‐PGD‐isomerase. By enzymatic and chemical transformation of [ 3 H]PGD 2 the following compounds were obtained: 15‐keto‐13,14‐dihydro‐[ 3 PGD 2 , 9α,11β‐[ 3 H]PGD 2 , 9‐deoxy‐Δ 9 ‐[ 3 H]‐PGD 2 ([ 3 H]PGJ 2 ) and Δ 12 ‐13,14‐dihydro‐[ 3 H]PGJ 2 . It was found that L‐selectride is a more effective reducing agent than sodium borohydride in the synthesis of 9 α,11β‐[ 3 H]PGF 2 .