ORCID Profile
0000-0002-2792-9595
Current Organisations
Ludwig-Maximilians-Universitat Munchen
,
Tohoku University
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Publisher: American Association for the Advancement of Science (AAAS)
Date: 04-10-2019
Abstract: In the absence of biological catalysts and metabolism, can atmospheric and geochemical processes provide the substrates and conditions required for production of biological molecules? Becker et al. devised an abiotic synthetic scheme that allows for accumulation of both purine and pyrimidine nucleoside mono- and diphosphates (see the Perspective by Hud and Fialho). A key starting material for this chemistry, hydroxylamine and/or hydroxylamine disulfonate, can form under plausible early atmospheric conditions. Cycles between wet and dry conditions provide the environments necessary to complete formation of purine and pyrimidine bases essentially in one pot. Science , this issue p. 76 see also p. 32
Publisher: Wiley
Date: 30-10-2019
Publisher: Springer Science and Business Media LLC
Date: 11-01-2018
DOI: 10.1038/S41467-017-02639-1
Abstract: The molecules of life were created by a continuous physicochemical process on an early Earth. In this hadean environment, chemical transformations were driven by fluctuations of the naturally given physical parameters established for ex le by wet–dry cycles. These conditions might have allowed for the formation of (self)-replicating RNA as the fundamental biopolymer during chemical evolution. The question of how a complex multistep chemical synthesis of RNA building blocks was possible in such an environment remains unanswered. Here we report that geothermal fields could provide the right setup for establishing wet–dry cycles that allow for the synthesis of RNA nucleosides by continuous synthesis. Our model provides both the canonical and many ubiquitous non-canonical purine nucleosides in parallel by simple changes of physical parameters such as temperature, pH and concentration. The data show that modified nucleosides were potentially formed as competitor molecules. They could in this sense be considered as molecular fossils.
Publisher: Wiley
Date: 17-04-2018
Abstract: The RNA-world hypothesis assumes that life on Earth started with small RNA molecules that catalyzed their own formation. Vital to this hypothesis is the need for prebiotic routes towards RNA. Contemporary RNA, however, is not only constructed from the four canonical nucleobases (A, C, G, and U), it also contains many chemically modified (noncanonical) bases. A still open question is whether these noncanonical bases were formed in parallel to the canonical bases (chemical origin) or later, when life demanded higher functional ersity (biological origin). Here we show that isocyanates in combination with sodium nitrite establish methylating and carbamoylating reactivity compatible with early Earth conditions. These reactions lead to the formation of methylated and amino acid modified nucleosides that are still extant. Our data provide a plausible scenario for the chemical origin of certain noncanonical bases, which suggests that they are fossils of an early Earth.
Publisher: Wiley
Date: 30-10-2019
Publisher: Wiley
Date: 17-04-2018
No related grants have been discovered for Hidenori Okamura.