Iron Catalysis for In Situ Regeneration of Oxidized Cofactors by Activation and Reduction of Molecular Oxygen: A Synthetic Metalloporphyrin as a Biomimetic NAD(P)H Oxidase

Abstract

An enzyme substitute: A synthetic FeIII porphyrin was used as a catalyst for the activation and reduction of O2 into H2O with the cofactor NAD(P)H in aqueous solution. The catalyst is compatible with different preparative enzymatic oxidation reactions. Thus, a new method is provided for the in situ regeneration of the oxidized cofactor NAD(P)+ with help from a non‐enzymatic, synthetic catalyst (see scheme).

New artificial fluoro-cofactor of hydride transfer with novel fluorescence assay for redox biocatalysis

“…Although there are several methods for in situ regeneration of NAD(P), including enzymatic, 1 chemical, 2 and electrochemical 3 regeneration, the high cost and low-stability of NAD(P) urge people to find out artificial cofactors which can replace and even surpass NAD(P). 4 NAD(P) contain two parts, the nicotinamide moiety acting as a hydride donor or acceptor and the adenine dinucleotide moiety playing an important role in separating between the anabolic and catabolic pathways.…”

Biomimetic Conversion of Glucose to Organic Acid Facilitated by Metalloporphyrin under Mild Conditions

“…-5 mmol (based on moles of metal atom), 0.05 M NaOH = 5 mL, P(O2) = 2.0 MPa, T= 433 K, and t= 2 h; b in 0.5 M H3PO4 aqueous solution; c in 0.5 M NaOH aqueous solution; d P(O2) = 0.6 MPa; e P(O2) = 1.0 MPa; f P(air) = 2 MPa Product analysis revealed that gluconic acid was the major oxidative product in the absence of a catalyst and that selectivity was up to 56%, as seen in Table 1, entry 1. Instead of gluconolactone, a primary product of TSPPFeCl-catalyzed oxidation of a glucose C-H bond with an in situ reduced coenzyme (Maid et al 2011), LWM acids were the main products in the present catalytic approach without a reductant. Furthermore, the product selectivity also depends noticeably on the temperature, O2 pressure, and the pH value of the reaction solution (Tables S1, S2, and S3 in the Appendix).…”

Iron(III)‐porphyrin Complex FeTSPP: A Versatile Water‐soluble Catalyst for Oxidations in Organic Syntheses, Biorenewables Degradation and Environmental Applications

“…[18] In addition, very recently even the use of molecular oxygen as the oxidation agent of choice in combination with 1 as a catalyst was reported (see also next chapter about synthetic applications). [19][20][21] Although the mechanism and role of 1 in these specific applications has not been clarified in detail yet, for one of these applications it was postulated that a hydroperoxo species (with a comparable structure as 1 f shown in Scheme 6) is formed in situ. [20] Applications of FeTSPP (1) …”

“…[19][20][21] Although the mechanism and role of 1 in these specific applications has not been clarified in detail yet, for one of these applications it was postulated that a hydroperoxo species (with a comparable structure as 1 f shown in Scheme 6) is formed in situ. [20] Applications of FeTSPP (1) …”