On a hypothetical generational relationship between HCN and constituents of the reductive citric acid cycle.
Encouraged by observations made on the course of reactions the HCN-tetramer can undergo with acetaldehyde, I delineate a constitutional and potentially generational relationship between HCN and those constituents of the reductive citric acid cycle that are direct precursors of amino acids in contemporary metabolism. In this context, the robustness postulate of classical prebiotic chemistry is questioned, and, by an analysis of the (hypothetical) reaction-tree of a stepwise hydrolysis of the HCN-tetramer, it is shown how such a non-robust chemical reaction platform could harbor the potential for the emergence of autocatalytic cycles. It is concluded that the chemistry of HCN should be revisited by focussing on its non-robust parts in order to demonstrate its full potential as one of the possible roots of prebiotic self-organizing chemical processes.
Eschenmoser
Albert
A
Laboratory of Organic Chemistry, Swiss Federal Institute of Technology, Hönggerberg HCI H309, Wolfgang-Pauli-Strasse 10, CH-8093 Zürich. eschenmoser@org.chem.ethz.ch
D002384:Catalysis; D019343:Citric Acid / Q000737:chemistry / Q000378:metabolism; D002952:Citric Acid Cycle / Q000187:drug effects / Q000235:genetics; D006856:Hydrogen Cyanide / Q000494:pharmacology; D008958:Models, Molecular; D008968:Molecular Conformation; D010084:Oxidation-Reduction
D019343:Citric Acid; D006856:Hydrogen Cyanide