Biocatalytic carboxylation of phenol derivatives: kinetics and thermodynamics of the biological Kolbe–Schmitt synthesis. (23rd February 2015)

• Record Type: Journal Article
• Authors: Pesci, Lorenzo; Glueck, Silvia M.; Gurikov, Pavel; Smirnova, Irina; Faber, Kurt; Liese, Andreas
• Is Part Of: FEBS journal. Volume 282:Number 7(2015)
• Page Start: 1334
• Page End: 1345
• Publication Date: 2015-02-23
• Subjects: Biochemistry -- Periodicals; Molecular biology -- Periodicals; Pathology, Molecular -- Periodicals; 572
• DOI: 10.1111/febs.13225
• Languages: English
• ISSNs: 1742-464X

Abstract

<abstract abstract-type="main" id="febs13225-abs-0001"> <title> <x xml:space="preserve">Abstract</x> </title> <p>Microbial decarboxylases, which catalyse the reversible regioselective <italic>ortho</italic>‐carboxylation of phenolic derivatives in anaerobic detoxification pathways, have been studied for their reverse carboxylation activities on electron‐rich aromatic substrates. <italic>Ortho</italic>‐hydroxybenzoic acids are important building blocks in the chemical and pharmaceutical industries and are currently produced via the Kolbe–Schmitt process, which requires elevated pressures and temperatures (≥ 5 bar, ≥ 100 °C) and often shows incomplete regioselectivities. In order to resolve bottlenecks in view of preparative‐scale applications, we studied the kinetic parameters for 2, 6‐dihydroxybenzoic acid decarboxylase from <italic>Rhizobium </italic>sp. in the carboxylation‐ and decarboxylation‐direction using 1, 2‐dihydroxybenzene (catechol) as starting material. The catalytic properties (<italic>K</italic><sub>m</sub>, <italic>V</italic><sub>max</sub>) are correlated with the overall thermodynamic equilibrium via the Haldane equation, according to a reversible random bi–uni mechanism. The model was subsequently verified by comparing experimental results with simulations. This study provides insights into the catalytic behaviour of a nonoxidative aromatic decarboxylase and reveals key limitations (e.g. substrate oxidation, CO<sub>2</sub> pressure, enzyme deactivation, low turnover frequency) in view of the employment of this system as a 'green' alternative to the Kolbe–Schmitt processes.</p> </abstract>