title: Mimicking the Aromatic-Ring-Cleavage Activity of Gentisate-1,2-Dioxygenase by a Nonheme Iron Complex.
abstract: Gentisate-1,2-dioxygenase (GDO), a nonheme iron enzyme in the cupin superfamily, catalyzes the cleavage of the aromatic-ring of 2,5-dihydroxybenzoic acid (gentisic acid) to form maleylpyruvic acid in the microbial aerobic degradation of aromatic compounds. To develop a functional model of GDO, we have isolated a nonheme iron(II) complex, [(TpPh2)FeII(DHN-H)] (TpPh2=hydrotris(3,5-diphenylpyrazole-1-yl)borate, DHN-H=1,4-dihydroxy-2-naphthoate). In the reaction with O2, the biomimetic complex oxidatively cleaves the aromatic ring of the coordinated substrate with the incorporation of both the oxygen atoms from molecular oxygen into the cleavage product. The presence of para-hydroxy group on the substrate plays a crucial role in directing the aromatic-ring cleaving reaction.
authors.affiliation: Department of Inorganic Chemistry, Indian Association for the Cultivation of Science, 2A & 2B Raja S. C. Mullick Road, Jadavpur, Kolkata-, 700032, India.
authors.forename: Rubina
authors.initials: R
authors.lastname: Rahaman
authors.affiliation: Department of Inorganic Chemistry, Indian Association for the Cultivation of Science, 2A & 2B Raja S. C. Mullick Road, Jadavpur, Kolkata-, 700032, India.
authors.forename: Biswarup
authors.initials: B
authors.lastname: Chakraborty
authors.affiliation: Department of Inorganic Chemistry, Indian Association for the Cultivation of Science, 2A & 2B Raja S. C. Mullick Road, Jadavpur, Kolkata-, 700032, India. ictkp@iacs.res.in.
authors.forename: Tapan Kanti
authors.initials: TK
authors.lastname: Paine
keywords: C−C bond cleavage; biomimetic models; dioxygen; gentisate; iron complexes