A Shared Prebiotic Formation of Neopterins and Guanine Nucleosides from Pyrimidine Bases

Abstract

The prebiotic origins of biopolymers and metabolic co-factors are key questions in Origins of Life studies. In a simple warm-little-pond model, using a drying phase to produce a urea-enriched solution, we present a prebiotic synthetic path for the simultaneous formation of neopterins and tetrahydroneopterins, along with purine nucleosides. We show that, in the presence of ribose and in a formylating environment consisting of urea, ammonium formate, and water (UAFW), the formation of neopterins from pyrimidine precursors is robust, while the simultaneous formation of guanosine requires a significantly higher ribose concentration. Furthermore, these reactions provide a tetrahydropterin-pterin redox pair. This model suggests a prebiotic link in the origin of purine nucleosides and pterin cofactors that provides a possible deep prebiotic temporal connection for the emergence of nucleic acids and metabolic cofactors.

Potential Prebiotic Pathways in Extraterrestrial Atmosphere: A Computational Exploration of HCN and NH3 Reactions

“…Then, we found P22 as another important precursor as it can lead to tetraminopyrimidine 68 upon reaction with HCN trimer, aminomalononitrile. Subsequently, tetraminopyrimidine reacts with formamide for the formation of guanine.…”

Coenzyme-Protein Interactions since Early Life

“…“Ancient” coenzymes comprise those that could be prebiotically synthesized, according to available studies (Miller and Schlesinger, 1993; Keefe et al, 1995; Holliday et al, 2007; Kirschning, 2021; Menor-Salván et al, 2022; Pinna et al, 2022); while the subcategory “Nucleotide derived” includes cofactors chemically derived from nucleotides (White, 1975; (White, 1975; Monteverde et al, 2017). “LUCA” coenzymes were presumably present in the last universal common ancestor (LUCA) and exhibit a universal distribution among Bacteria, Archaea, and Eukarya, although their prebiotically feasible synthesis was not established.…”

“…Those are found at the very heart of cellular metabolism and some of them quite possibly branch deep to life’s early start (White, 1976). The core chemistries of the most abundant and ancient coenzymes have been repeatedly detected in material and experiments mimicking prebiotic environments (Miller and Schlesinger, 1993; Keefe et al, 1995; Holliday et al, 2007; Kirschning, 2021; Menor-Salván et al, 2022; Pinna et al, 2022). Along with metal ions and minerals, some of the extant coenzymes could probably catalyze metabolic reactions in the absence of enzymes, before their emergence (Muchowska et al 2020; Henriques Pereira et al 2022; Cvjetan et al, 2023; Dherbassy et al 2023).…”

Autocatalytic Selection as a Driver for the Origin of Life

“…Secondly, for similar reasons, the class of "nucleic acid bases" should be expanded to include chemicals with similar composition, structure, function and biosynthesis to the canonical adenine, guanine, thymine, cytosine and uracil. Therefore, we should also include, for example, nicotinamide and pterins [80]. We note that this class, therefore, includes the majority of the enzyme cofactors, further strengthening the case that the reason for their existence was catalysis.…”