Silicate-, Magnesium Ion-, and Urea-Induced Prebiotic Phosphorylation of Uridine via Pyrophosphate; Revisiting the Hot Drying Water Pool Scenario

Abstract

The availability of nucleotides on the early Earth is of great significance for the origin of a self-replicating system capable of undergoing evolution. We hereby report the successful phosphorylation reactions of the nucleoside uridine under heating in the “drying pool” prebiotic model at temperatures ranging from 60–75 °C, and by using pyrophosphate as a phosphorylation agent. Uridine monophosphates (UMP) such as uridine-5′-monophosphate (5′-UMP), 2′-UMP, and 3′-UMP, as well as cyclic 2′-3′-UMP, were identified by 31P-NMR. In addition to the above-mentioned products, a dimer of uridine-phosphate-uridine (U-P-U) was also observed. The reactions were promoted by white quartz sand, Mg2+, and by using urea as a condensation agent. The reactions also proceeded without this mixture; however, the yields increased remarkably with the presence of the above-mentioned materials. The results suggest that a hot/evaporating-drying pool of water containing organics, salts, and reactive phosphorus could be sufficient to form significant phosphate esters.

Urea-Assisted Synthesis and Characterization of Saponite with Different Octahedral (Mg, Zn, Ni, Co) and Tetrahedral Metals (Al, Ga, B), a Review

“…Research studies making use of the thermal decomposition of urea as a means to control the pH during the synthesis of saponites include those of Besselink et al [40], Prihod'ko et al [47], Sychev and Prihod'ko [37], Xue and Pinnavaia [38], and Yu et al [48]. Given that urea has more potential than just controlling the pH in clay mineral synthesis as it is a potential precursor of nucleobases and related molecules and a promoter of phosphorylation [25,26,49], the urea-assisted synthesis of saponites might be useful as starting point in extending research into urea assisting the synthesis of clay minerals while at the same time providing a source of precursors for nucleobases formation.…”

The Role of Glycerol and Its Derivatives in the Biochemistry of Living Organisms, and Their Prebiotic Origin and Significance in the Evolution of Life

“…In experiments with both deep eutectic solvents employed for prebiotic synthesis of glycerol phosphates [113,114] and the semi-aqueous eutectic solvents [115], the yields of the glycerol phosphates were higher when formamide was used as a solvent along with silicates as catalysts [113]. The DESs are more stable to water as C-N bond hydrolysis is minimal, but it may be harder to justify pools arising of these two components [125,[133][134][135][136].…”

“…Glycerol diphosphate was also seen as a minor product (Figure 10). An important note is that the 31 P-NMR yields of the organophosphates and the inorganic phosphate were calculated on the basis of the total phosphorus dissolved and by the peak integration method, along with semiquantitative concentration estimation by using signal to noise ratios [135][136][137].…”

The Grayness of the Origin of Life

“…Furthermore, even though the rich chemistry produced from HCN and other molecules potentially present on the early Earth is referred to as a solution to the prebiotic origin of RNA in a chemical system, it also poses the obvious problem of the need for selection among the complex mixture. Prebiotic RNA synthesis is actively being researched, and some potential solutions have been found, such as phosphorylation of uridine monophosphates under hot evaporating pool conditions [40]. However, as RNA building blocks require several specific steps in their formation, they are often seen as too complex to form the basis of a first informational polymer.…”