A Universal Geochemical Scenario for Formamide Condensation and Prebiotic Chemistry

Abstract

The condensation of formamide has been shown to be a robust chemical pathway affording molecules necessary for the origin of life. It has been experimentally demonstrated that condensation reactions of formamide are catalyzed by a number of minerals, including silicates, phosphates, sulfides, zirconia and borates, and by cosmic dusts and meteorites. However, a critical discussion of the catalytic power of the tested minerals, and the geochemical conditions under which the condensation would occur, is still missing. We show here that mineral self-assembled structures forming under alkaline silica-rich solutions are excellent catalysts for the condensation of formamide as compared to other minerals. We also propose that these structures were likely forming as early as 4.4 billion years ago when the whole Earth surface was a reactor, a global scale factory, releasing large amounts of organic compounds. Our experimental results suggest that the conditions required for the synthesis of the molecular bricks from which life self-assembles, rather than being local and bizarre, appears to be universal and geologically rather conventional.

Coenzymes and Their Role in the Evolution of Life

“…[86] Figure 6. Coenzymes ATP (62), lipoic acid (63), biotin (64), PQQ (65), and urogen III (66), with the last being a precursor for key iron and cobalt-dependent cofactors. carbohydrate building blocks with HCN oligomers) and Carell (imine formation instead of N-glycosidation).…”

Taming the Combinatorial Explosion of the Formose Reaction via Recursion within Mineral Environments

“…In particular, the presence of mineral surfaces is known to sometimes truncate the combinatorial explosions generated by one‐pot reaction of simple compounds. Two relevant examples are the preferential formation of ribose when borate minerals are added to the formose reaction, a system known for the incredible complexity of its product distribution, and the clear selectivity towards the production of certain nucleobases when formamide condensation is carried out on different mineral surfaces . Notably, these previous results were obtained in batch reactions, leaving the possibility that this effect could be amplified if the reaction mixture was cycled over a given environment.…”

Self‐catalytic mechanism of prebiotic reactions: From formamide to purine bases

“…[ 6 ] Since the first synthesis of adenine, reported by Oro and Kimball [ 7 ] in 1961, by hydrogen cyanide polymerization, and the formation of guanine in a comparable chemical system, [ 8 ] three routes for prebiotic synthesis of nucleobases have been outlined [ 5,6 ] : (a) formation of purines by hydrogen cyanide oligomerization, [ 9 ] (b) formation of pyrimidines from cyanoacetylene or cyanoacetaldehyde and urea or guanidine, [ 9 ] and (c) formation of both purines and pyrimidines from formamide in the presence of mineral catalysts or meteorites. [ 10–12 ]…”

“…Formamide has been proposed as an excellent starting molecule in prebiotic chemistry. [ 10 ] It is the simplest amide containing the four most important elements: carbon, hydrogen, oxygen, and nitrogen, which are needed for the synthesis of nucleobases. However, there are four simpler compounds, in singlet ground electronic state, containing only one atom of these elements in the molecule itself: isocyanic acid (HNCO), cyanic acid (HOCN), fulminic acid (HCNO), and isofulminic acid (HONC).…”

“…In papers that focused on the chemistry of formamide, Saladino, Di Mauro et al [ 10–12 ] reported experimental evidence that formamide may have been the starting molecule in primitive Earth for the synthesis of nucleobases, sugars, amino acids, carboxylic acids, acyclonucleosides, and nucleosides in the presence of naturally‐occurring minerals or meteorites as catalysts. Various substances have been used to catalyze these reactions: calcium carbonate, alumina, silica and zeolite (Y type), [ 22 ] titanium dioxide, [ 23 ] montmorillonites, [ 24 ] cosmic dust analogues, [ 25 ] mineral phosphates, [ 26 ] iron‐sulfur minerals, [ 27 ] zirconium minerals, [ 28 ] borate minerals, [ 29 ] iron oxide and iron oxide hydroxides, [ 30 ] metal octacyanomolybdates [ 31 ] and meteorites.…”