TRYPTOPHAN 2,3-DIOXYGENASE MODEL RING-OPENING DIOXYGENOLYSIS OF 3-METHYLINDOLE CATALYZED BY M^{I OR II} (M = Cu, Mn, Fe, OR Co) WITH MONODENTATE LIGAND OR BIDENTATE LIGAND SYSTEMS

Abstract

The dioxygenolysis of tryptophan analogues by M^{I or II} (M = Cu, Mn, Fe, or Co) with monodentate ligand or bidentate ligand (monodentate ligands = pyridine (py) derivatives and bidentate ligands = 2,2′-bipyridine (bpy) derivatives) was studied as a model of tryptophan 2,3-dioxygenase (TDO). The high yields (44–54%) of the oxygenative pyrrole ring cleavage product, o-formaminoacetophenone (o-FAAP), in the dioxygenolysis of 3-methylindole at 25°C under atmospheric O₂ were obtained in tetrahydrofuran (THF). Among the monodentate ligand tested, electron donating ligands such as py and α-picoline accelerated the reaction high yields of o-FAAP. Bidentate ligands such as 2,9-dimethyl-1, 10-phenanthroline (dmphen) with the relatively weak ligation ability also promoted the present dioxygenolysis.

Key Words:

• dioxygenolysis
• tryptophon
• Cu
• Mn
• Fe
• CO