Menor-Salván César, Ruiz-Bermejo Dra Marta, Guzmán Marcelo I, Osuna-Esteban Susana, Veintemillas-Verdaguer Sabino
Centro de Astrobiología, Consejo Superior de Investigaciones Científicas, Instituto Nacional de Técnica Aeroespacial, Carretera Torrejón-Ajalvir, Km. 4,2, 28850 Torrejón de Ardoz, Madrid, Spain.
Chemistry. 2009;15(17):4411-8. doi: 10.1002/chem.200802656.
Herein, we report the efficient synthesis of RNA bases and functionalized s-triazines from 0.1 M urea solutions in water after subjection to freeze-thaw cycles for three weeks. The icy solution was under a reductive, methane-based atmosphere, which was subjected to spark discharges as an energy source for the first 72 h of the experiment. Analysis of the products indicates the synthesis of the s-triazines cyanuric acid, ammeline, ammelide, and melamine, the pyrimidines cytosine, uracil, and 2,4-diaminopyrimidine, and the purine adenine. An experiment performed as a control at room temperature, with the urea solution in the liquid phase and with the same atmosphere and energy source, led to the synthesis of hydantoins and insoluble tholin, but there was no evidence of the synthesis of pyrimidines or triazines. The synthesis of pyrimidines from urea is possible under a methane/nitrogen atmosphere only at low temperature, in the solid phase. The generation of both pyrimidines and triazines in comparable yields from urea, together with a possible role for triazines as alternative nucleobases, opens new perspectives on the prebiotic chemistry of informational polymers.
在此，我们报告了在将0.1 M尿素水溶液进行为期三周的冻融循环后，在以甲烷为基础的还原气氛中，通过火花放电作为能源，高效合成RNA碱基和功能化均三嗪的过程。在实验的前72小时，冰冷的溶液处于还原气氛中，以火花放电作为能源。对产物的分析表明合成了均三嗪氰尿酸、三聚氰酸一酰胺、三聚氰酸二酰胺和三聚氰胺，嘧啶胞嘧啶、尿嘧啶和2,4 -二氨基嘧啶，以及嘌呤腺嘌呤。在室温下进行的对照实验中，尿素溶液处于液相，且具有相同的气氛和能源，结果合成了乙内酰脲和不溶性的索林，但没有嘧啶或三嗪合成的证据。仅在低温下的固相甲烷/氮气氛中，由尿素合成嘧啶才是可能的。从尿素中以相当的产率同时生成嘧啶和三嗪，以及三嗪作为替代核碱基的可能作用，为信息聚合物的前生物化学开辟了新的前景。
