The Role of Aqueous Aerosols in the “Glyoxylate Scenario”: An Experimental Approach

Abstract

The origin of life is one of the fundamental questions in science. Eschenmoser proposed the "glyoxylate scenario", in which plausible abiotic synthesis pathways were suggested to be compatible with the constraints of prebiotic chemistry. In this proposal, the stem compound is HCN. In this work, we explore the "glyoxylate scenario" through several syntheses of HCN polymers, paying particular attention to the role of the aqueous aerosols, together with statistical methods, as a step to elucidate the synthetic problem of the origin of life. The soluble and insoluble HCN polymers synthetized were analyzed by GC-MS. We identified, for the first time, glyoxylic acid in these polymers, together with some constituents of the reductive tricarboxylic acid cycle, amino acids and several N-heterocycles. The findings presented herein, as the first global approach to the "glyoxylate scenario", give full effect to this hypothesis and prove that aqueous aerosols could play an important role in this plausible scene of the origin of life.

Formation of Glyoxylic Acid in Interstellar Ices: A Key Entry Point for Prebiotic Chemistry

“…[14] Recently, 1 was identified in the polymerization of hydrogen cyanide in aqueous solution as proposed by Eschenmoser. [15] Mohammed et al demonstrated the synthesis of glyoxylate in non-enzymatic transamination reactions of 3 and 7 under prebiotic liquid conditions, [16] but these transformations bear only little relevance to reactions in the interstellar medium, where liquid water is unlikely to exist.…”

A Comparative Study on HCN Polymers Synthesized by Polymerization of NH4CN or Diaminomaleonitrile in Aqueous Media: New Perspectives for Prebiotic Chemistry and Materials Science

“…HCN polymers are mainly known in the fields of prebiotic chemistry, in studies on the origins of life and in astrobiology, because they are considered to play key roles in the formation of the first and primeval protometabolic and informational systems and most stable organics in space . Indeed, HCN polymers may be among the organic macromolecules that are most readily formed in the solar system .…”

“…This makes all characterization methods and separation techniques that require solubility impossible, and the water-soluble intermediates of polymerization show ab road distribution of molecular weights and highly charged structures. [4][5][6] HCN polymers are mainly known in the fields of prebiotic chemistry,i ns tudies on the origins of life and in astrobiology, because they are considered to play key roles in the formation of the first and primeval protometabolic and informational systems [7][8][9][10] and most stable organics in space. [11] Indeed,H CN polymers may be among the organic macromolecules that are most readily formed in the solar system.…”

Formation of Glyoxylic Acid in Interstellar Ices: A Key Entry Point for Prebiotic Chemistry

“…[13] Both rotamers can be photochemically interconverted with the (E,E)c onformer being enriched through H-tunneling rotamerization. [15] Mohammed et al demonstrated the synthesis of glyoxylate in non-enzymatic transamination reactions of 3 and 7 under prebiotic liquid conditions, [16] but these transformations bear only little relevance to reactions in the interstellar medium, where liquid water is unlikely to exist. Glyoxylic acid has been suggested to form via ultraviolet (UV) exposure of water and acetylene solutions.…”