Affiliation:
1. Laboratoire de Réactivité de Surface (LRS UMR 7197 CNRS) Sorbonne Université CNRS Case courrier 178 Sorbonne Université 4, Place Jussieu 75005 Paris France
2. Institut de Systématique Évolution Biodiversité (ISYEB UMR 7205 CNRS) Muséum national d'Histoire naturelle Sorbonne Université École Pratique des Hautes Études Université des Antilles, CNRS CP 50 57 Rue Cuvier 75005 Paris France
Abstract
AbstractRing‐closure is a key step in current pyrimidine anabolism and one may wonder whether cyclisation reactions could be promoted in the geochemical context at the origins of life, i. e. with the help of minerals. Various prebiotic minerals were tested in this work, including silica, carbonates, microporous minerals. In particular, the role of zinc ions supported on minerals was investigated in view of its presence in the catalytic site of cyclic amidohydrolase enzymes. Based on in situ (TGA: ThermoGravimetric Analysis, ATR‐IR: Attenuated Total Reflectance‐InfraRed) and ex situ (1H NMR‐ Nuclear Magnetic Resonance) characterisations, we identified the products of thermal activation of NCA (N‐carbamoyl‐aspartic acid) in wetting‐and‐drying scenarios on the surface of minerals. NCA can cyclize extensively only on some surfaces, with the predominant product being 5‐carboxymethylhydantoin (Hy) rather than dihydroorotate (DHO), while there is a competition with hydrolysis on others. Replacing the enzymes with heterogeneous catalysts also works with other reactions catalysed by enzymes of the cyclic amidohydrolases family. The role of the hydrophilicity/hydrophobicity of minerals as well as the regioselectivity of the cyclisation (5‐carboxymethylhydantoin versus dihydroorotate) are examined.
Subject
Organic Chemistry,Molecular Biology,Molecular Medicine,Biochemistry
Cited by
1 articles.
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