Modeling of biliverdin reduction process: regio-specificity and H-bonding

OEBV was synthesized and purified from octa ethyl porphyrin iron (III) chloride, and was reduced to OEBR by sodium borohydride (NaBH4). Chemical reduction of OEBV with NaBH4 was followed in CDCl3 and CD3OD solutions and the product was characterized by 1H NMR and UV-Vis spectroscopy. The results show that γ2-isomer as the major product, forms along with γ1 via an equilibrium tautomerization reaction.