The Research Of Hydrothermal Biochemistry Based On The Solid Catalyst

The problem of the origin of life, especially about when, where and how did lifearise, has been pending and attracted greater attention in recent years. For thousandsof years, human keeps on studying on the problem, but it is still very difficult toexplore the process occurred billions of years ago. However, this study is not onlymeeting people’s curiosity about the origin of life and the prehistoric environmentexploration, but also making people understand the variation of nature, find morechemical reactions from inorganic compounds to organic compounds, grasp theemergence of life and have more in-depth understanding of the mechanism of geneticvariation, metabolism. If the process of origin of life determined by human, cells,tissues and even organs could be cultivated from simple inorganic compounds. Thegoal of controlling and manufacturing of life would be realized.In the present study, the role of iron powder in reducing carbon dioxide wassummarized, and the possible morphology characteristics of the catalyst were putforward before the origin of life by studying the reaction of methane from carbondioxide under the hydrothermal conditions. The synthesis and the chiral imbalance ofamino acid under hydrothermal condition were investigated. And the stability ofdipeptide of amino acid under hydrothermal condition was discussed. The researchoffered a clue for origin of biohomochirality. Furthermore, the synthesis of bases from propanamide in hydrothermal condition was attempted.1. In the previous work, it was found that different reductions from carbondioxide happened in the presence of different size of iron catalyst. Firstly, thereducing product, phenol, from carbon dioxide with iron catalyst was analyzed andthe size of iron was between micron-sized and nano-sized. Secondly, methane wassynthesized from carbon dioxide in the presence of nanoparticles100nm in diameter.Through the analysis of the type and the kinds of products, it was found that theactivity of iron powder was affected by the particle size; furthermore, the productionand the yield of reduction from carbon dioxide were influenced by the activity of ironpowder. When the size of iron powder was larger, the activity was low, the catalyticproperty was the main property. As the size diminished, the activity heightened, thereduction property was the main property. And when the diameter went down to100nm, carbon dioxide was reduced to methane. The possible reaction mechanism wasproposed. Analysis on the dynamics and the thermodynamics of the reaction werecarried out.There were two directions of reducing carbon dioxide by controlling the size ofiron powder: one was the origin of life and another was the chemical synthesis. Thepreliminary judgment of the morphology characteristics of catalyst before origin oflife was given. These results provided important clues for further exploring the originof life.2. Propanamide and alanine acid were synthesized from propionic acid andaqueous ammonia in the presence of ferric oxide. The analysis on the dynamics andthe thermodynamics of the reaction were carried out, the max yield of alanine acidwas3.58mmol/L, and other factors which can affect the reaction were inquired. Thenthe possible mechanism was proposed, alanine acid was synthesized from aqueousammonia and propionic acid which transformed into enol form from keto form. Thechiral imbalance of alanine was analyzed, when the reaction temperature was low, theyield of L-form was more than that of D-form, the ratio was L:D=4:1. Theoreticalcalculation proved that L-form was more stable than D-form, depending on theparity-violating energy difference (PVED), but the experimental evidences were lacking. And our experiments provide clear clue for understanding the chiral breakingor monochirality of simple amino acid in possible prebiotic environment.3. The stability of D-amino acid under hydrothermal condition was discussed.D-form wasn’t as stable as L-form. Racemization of D-form occurred when thetemperature is low. As the temperature up to160°C the racemization almostcompletely took place. And dimerization of D-form was more easily occurred thanL-form. Then, the stability of four types of dipeptide of alanine acid was explored.LL-form was the most stable form, when the temperature was under100°C,racemization and hydrolyzation didn’t happen. DD-form was most astable.Racemization started at60°C, but the hydrolyzation didn’t happen as the temperaturewent up. If the enrichment of the L-form could happen through adsorption by themineral，it was possible to achieve biohomochirality at last.4. The hydrothermal reaction of propanamide which was one of the productsfrom propionic acid and ammonia was carried out. The mineral catalyzedpropanamide to react. After analyzing by GC-MS, LC-HRMS,1H-NMR,13C-NMRand IR, analogs for nucleobases were found. It meant that amide compounds maybethe precursor of the nucleobases.The problem of the origin of life is a highly interdisciplinary subject. As theorigin of life occurred in billions of years ago, many details could only be inquiry orspeculation through the experiment. Thus, no clear answer of the origin of life whichis the worldwide difficult puzzle arises till now. In the process of the research inhydrothermal biochemistry based on solid catalyst, experimental evidences whichprovide basis for exploring origin of life are accumulated.