RNA生成に向けた初期海洋での糖の生成

抄録

Ribose is the sole sugar component of RNA, which is regarded as the biopolymer that supported both replication and metabolism of the first life based on the RNA world hypothesis. Thus, ribose has been regarded as a particularly important sugar in the origin of life. Ribose could be formed on prebiotic Earth from aldehydes by formose reaction. In previous studies, its formation has been limited under alkaline conditions, where product ribose is quickly consumed in the subsequent reactions. Thus, Hadean environments where ribose was available remain unclear. We evaluated different chemical conditions on the formation of ribose. Among the conditions, high pH, high glycolaldehyde concentrations, and high Ca abundance substantially increased the ribose yields. Even in a neutral solution, the formation of ribose was confirmed due to the sensitive analysis of this experiment. The quantitative effects of the chemical conditions shown in this study suggest that ribose continuously formed in a near-neutral Hadean open ocean. Although its yield was low, reactions in the vast amount of oceanic water might have served a substantial amount of ribose on prebiotic Earth.