title: A functional model of extradiol-cleaving catechol dioxygenases: mimicking the 2-his-1-carboxylate facial triad.
abstract: The synthesis and characterization of an iron-catecholate model complex of a tridentate 2-N-1-carboxylate ligand derived from L-proline are reported. The X-ray crystal structure of the complex [(L)(3)Fe(3)(DBC)(3)] (1) (where L is 1-(2-pyridylmethyl)pyrrolidine-2-carboxylate and DBC is the dianion of 3,5-di-tert-butyl catechol) reveals that the tridentate ligand binds to the iron center in a facial manner and mimics the 2-his-1-carboxylate facial triad motif observed in extradiol-cleaving catechol dioxygenases. The iron(III)-catecholate complex (1) reacts with dioxygen in acetonitrile in ambient conditions to cleave the C-C bond of catecholate. In the reaction, an equal amount of extra- and intradiol cleavage products are formed without any auto-oxidation product. The iron-catecholate complex is a potential functional model of extradiol-cleaving catechol dioxygenases.
authors.affiliation: Department of Inorganic Chemistry, Indian Association for the Cultivation of Science (IACS), 2A and 2B Raja S. C. Mullick Road, Jadavpur, Kolkata 700032, India.
authors.forename: Sayantan
authors.initials: S
authors.lastname: Paria
authors.forename: Partha
authors.initials: P
authors.lastname: Halder
authors.forename: Tapan Kanti
authors.initials: TK
authors.lastname: Paine
mesh_terms: D032701:Biomimetics; D002264:Carboxylic Acids / Q000737:chemistry* / Q000378:metabolism*; D050548:Catechol 1,2-Dioxygenase / Q000378:metabolism*; D002396:Catechols / Q000737:chemistry* / Q000378:metabolism*; D018360:Crystallography, X-Ray; D007501:Iron / Q000737:chemistry; D008024:Ligands; D008958:Models, Molecular; D008968:Molecular Conformation; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D010100:Oxygen / Q000737:chemistry; D013056:Spectrophotometry, Ultraviolet
chemical_list: D002264:Carboxylic Acids; D002396:Catechols; D008024:Ligands; D009942:Organometallic Compounds; D007501:Iron; D050548:Catechol 1,2-Dioxygenase; D010100:Oxygen