On ancient Earth, environmental conditions favored prebiotic chemical reactions. In the Archean, some molecules with conjugated rings might have been synthesized, displaying structural stability in the Archean in the presence of ionizing radiation and hydration-dehydration events. Additionally, it is suggested that on ancient Earth, calcite was a common mineral promoting organic compound synthesis. In the present work a study of the interaction of amino acid mixtures with the (104) surface of calcite is presented. Our preliminary results show the abiotic synthesis of alloxazine (a flavin with relevant photochemical properties). Computer simulations were performed in HyperChem 8.0.1. by means of MM+ molecular mechanics and PM3 semi-empirical methods, in 27 possible amino acid trimers of alanine, glycine and lysine. Alloxazine formation is possible by the gamma irradiation of amino acids. The computer simulations show that trimers GGG and GGA promote the further transformation from diketopiperazines (DKP's) and KGK to alloxazine. The computer simulations with free radicals are not stable when alloxazine is interacting with the calcite surface. Experiments in anoxygenic environments with hydration-dehydration events in gamma irradiated samples allow the abiotic formation of flavins, DKP's and a heterocycle compound with possible relevance in prebiotic chemistry.

中文翻译：

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冰岛石晶上γ射线辐照氨基酸合成别恶嗪的计算机和实验模拟：益生元化学视角。

在古代地球上，环境条件有利于益生元化学反应。在太古代中，可能已经合成了一些带有共轭环的分子，在存在电离辐射和水合脱水事件的情况下，太古代中显示出结构稳定性。另外，建议在古代地球上，方解石是促进有机化合物合成的常见矿物。在本工作中，提出了氨基酸混合物与方解石（104）表面相互作用的研究。我们的初步结果显示了Alloxazine（一种具有相关光化学特性的黄素）的非生物合成。在HyperChem 8.0.1中执行了计算机模拟。通过MM +分子力学和PM3半经验方法，在27种可能的氨基酸三聚体中分别存在丙氨酸，甘氨酸和赖氨酸。通过氨基酸的γ射线辐照可以形成别恶嗪。计算机模拟表明，三聚体GGG和GGA促进了从二酮哌嗪（DKP's）和KGK到四恶嗪的进一步转化。当四氧嘧啶与方解石表面相互作用时，具有自由基的计算机模拟不稳定。在有氧环境中进行的伽马射线辐照样品中发生水合-脱水事件的实验，使得黄素，DKP和杂环化合物的非生物形成可能与益生元化学有关。当四氧嘧啶与方解石表面相互作用时，具有自由基的计算机模拟不稳定。在有氧环境中进行的伽马射线辐照样品中发生水合-脱水事件的实验，使得黄素，DKP和杂环化合物的非生物形成可能与益生元化学有关。当四氧嘧啶与方解石表面相互作用时，具有自由基的计算机模拟不稳定。在有氧环境中进行的伽马射线辐照样品中发生水合-脱水事件的实验，使得黄素，DKP和杂环化合物的非生物形成可能与益生元化学有关。