On the reactivity of bromoperoxidase I (Ascophyllum nodosum) in buffered organic media: formation of carbon bromine bonds.

Peroxidase (PO) activity of vanadate(V)-dependent bromoperoxidase (BPO) I (Ascophyllum nodosum) (V Br PO(AnI)) was retained with a half-life time of ~60 days, if stored in H 2 O 2 -incubated, morpholin-4-ethane sulfonic acid (MES)-buffered aqueous alco- holic solutions. These conditions were applied for converting bromide and, e.g., methyl pyr- role-2-carboxylate into bromopyrroles with an almost quantitative peroxide yield. δ,e-unsat- urated alcohols furnished β-bromohydrins and products of bromocyclization, i.e., tetrahydrofurans and tetrahydropyrans (70-84 % mass balance), if treated with H 2 O 2 , KBr, and V Br PO(AnI) in phosphate-buffered, CH 3 CN-diluted media.