Marchington, Rebecca Emily;
(2020)
Studies of prebiotic physical models towards understanding the emergence of biological homochirality.
Doctoral thesis (Ph.D), UCL (University College London).
Preview |
Text
Rebecca Marchington Thesis Corrections.pdf - Accepted Version Download (31MB) | Preview |
Abstract
The homochirality of biological molecules is critical to the structure of biological polymers which form the structures in living organisms that allow them to exist. It is central to the fundamental mechanisms of life such as molecular recognition and the helical structure of DNA; and what is most profound is the universality of it – everywhere we look in nature, amino acids exist in the L-enantiomer and carbohydrates exist as the D-enantiomer, and that homochirality is carried forward throughout the construction of living things on the macro level. The origin of this homochirality has perplexed generations of scientists since it was first discovered by Pasteur in the 19th century and is a fundamental problem within the study of the Origin of Life. In recent years, prebiotic synthesis has leaped forward, identifying a number of not only plausible, but likely routes to the precursors of RNA, thought by some to be the first biological polymer on Earth and the root of simple living organisms. However, it has been demonstrated that for chiral RNA to polymerise, its constituent building blocks (nucleotides) must be enatio- pure, otherwise oligomerisation is inhibited. As yet, chemistry has lacked a robust explanation for how such homochirality would have arisen under prebiotic conditions when all thermodynamic rules should form both enantiomers in equal amounts. Here, we report prebiotically-plausible enantio-enrichment of nucleotide precursor molecules (aminooxazolines, oxazolidinone thiones and oxazolidinones) and related compounds, from near-racemic conditions using crystallographic approaches and applying them to new substrates. This work views the homochirality problem from a new angle and in so doing expands the crystallographic landscape of pre-biotic chemistry, opening the door to crystal engineering in Origin of Life studies.
| Type: | Thesis (Doctoral) |
|---|---|
| Qualification: | Ph.D |
| Title: | Studies of prebiotic physical models towards understanding the emergence of biological homochirality |
| Event: | UCL (University College London) |
| Open access status: | An open access version is available from UCL Discovery |
| Language: | English |
| Additional information: | Copyright © The Author 2020. Original content in this thesis is licensed under the terms of the Creative Commons Attribution 4.0 International (CC BY 4.0) Licence (https://creativecommons.org/licenses/by/4.0/). Any third-party copyright material present remains the property of its respective owner(s) and is licensed under its existing terms. Access may initially be restricted at the author’s request. |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Chemistry |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10109005 |
Archive Staff Only
 |
View Item |
