A new theoretical model for the origin of amino acid homochirality

Abstract

Amino acid homochirality, as a unique behavior of life, could have originated synchronously with the genetic code. In this paper, phosphoryl amino-acid-5'-nucleosides with P-N bond are postulated to be a chiral origin model in prebiotic molecular evolution. The enthalpy change in the intramolecular interaction between the nucleotide base and the amino-acid side-chain determines the stability of the particular complex, resulting in a preferred conformation associated with the chirality of amino acids. Based on the theoretical model, our experiments and calculations show that the chiral selection of the earliest amino acids for L-enantiomers seems to be a strict stereochemical/physicochemical determinism. As other amino acids developed biosynthetically from the earliest amino acids, we infer that the chirality of the later amino acids was inherited from the precursor amino acids. This idea probably goes far back in history, but it is hoped that it will be a guide for further experiments in this area.

Hydrothermal decomposition of potassium feldspar under alkaline conditions

“…Recently, important developments on K-rich feldspar as an alternative potash have been reported in a broad spectrum of geographical contexts and soils. 1,2 Many authors [3][4][5][6][7][8][9][10][11][12][13][14][15][16] have conducted signicant research on extracting K from K-rich feldspar by the hydrothermal reaction of K-feldspar and lime (CaO) in order to look for an alternative of K salts for agriculture. Some researchers [5][6][7][9][10][11][12] investigated the hydrothermal reaction mechanism of K-feldspar and lime and calculated their thermodynamics and kinetics.…”

Combined Hydrotreating and Fluid Catalytic Cracking Processing for the Conversion of Inferior Coker Gas Oil: Effect on Nitrogen Compounds and Condensed Aromatics

“…This observation can be explained by the mechanism of condensed aromatic hydrogenation, HDN, and hydrodesulfurization (HDS). According to the condensed aromatic hydrogenation mechanism, the equilibrium constant of the first ring hydrogenation saturation is the highest, followed by the second ring hydrogenation, all the way until the highest ring hydrogenation. − Additionally, the hydrogenation activity of single aromatics is much lower than that of condensed aromatics. − Accordingly, the condensed aromatic hydrogenation products should include many 1-ring aromatics. Following the HDN mechanism, the five-membered ring nitrogen compound of the indole hydrogenation path is different from other nitrogen compounds.…”

“…Furthermore, the products of condensed aromatic hydrogenation were mainly cycloalkylbenzenes. The C–C bond between a cycloalkane ring and an aromatic ring is easily cracked to produce lighter oil. , Contrary to these reaction routes, unhydrotreated condensed aromatics in the ICGO feedstock was dominated by hydrogen transfer and condensation reactions under FCC conditions, which, in turn, led to more coke formation. , …”

Prebiotic chemistry: a review of nucleoside phosphorylation and polymerization

“…More discoveries and advancements will be achieved in the future as the chemistry of phosphorylation and polymerization of nucleosides under prebiotic conditions—a hot spot for research on the subject of life origins—is explored. Because organisms show chiral preferences for L-amino acids and D-nucleosides, it's possible that chirality had a role in biological evolution [130,131]. We believe that considering chirality will lead to a breakthrough in this field of study.…”