Enzymatic synthesis of C-11 formaldehyde: concise communication.

We present an enzymatic synthesis of C-11 formaldehyde from C-11 methanol, with immobilized alcohol oxidase and catalase: a rapid, simple procedure, with a high and reproducible yield. Carbon-11 methanol is oxidized to C-11 formaldehyde by passage over a column on which the enzymes alcohol oxidase and catalase are immobilized. The catalase increases reaction velocity by recycling the oxygen, and prevents destruction of the alcohol oxidase by eliminating the excess of hydrogen peroxide. The yield of the enzyme-catalyzed oxidation was 80-95%. A specific activity of 400-450 mCi/mumole was obtained at EOB + 20 min. Various immobilization techniques and the optimal reaction conditions of the immobilized enzymes are investigated.