Probing Shielding Tensor Components of Amino Acids Using Nuclear Magnetic Resonance

Date of Award

6-2025

Degree Name

Doctor of Philosophy

Department

Physics

First Advisor

Zbigniew Chajecki, Ph.D.

Second Advisor

Michael A Famiano, Ph.D.

Third Advisor

John B Miller, Ph.D.

Fourth Advisor

David Huffman, Ph.D.

Keywords

Amino Acids, Chirality, DFT, homochirality, nuclear magnetic resonance, single crystal

Abstract

Chirality is fundamental to terrestrial life. While most amino acids exist as nonsuperimposable mirror images, amino acids in terrestrial life are homochiral, with the L-enantiomer being ubiquitous. The detection of an excess of L-amino acids in carbonaceous meteorites suggests that extraterrestrial processes may have contributed to this enantiomeric excess (ee). One proposed mechanism, the magnetochiral model, provides a potential explanation for this phenomenon in stellar environments characterized by strong magnetic and electric fields and the presence of relativistic leptons. According to this model, subtle differences in the electronic environments of chiral amino acids under such conditions can lead to chirality dependent nuclear interaction rates for 14N nuclei of opposite handedness, ultimately resulting in the preferential destruction of D-amino acids.

Since experimental verification of the magnetochiral model is lacking, we present the first effort to test the model predictions using single-crystal Nuclear Magnetic Resonance (NMR) spectroscopy. These experiments employed a custom-built single-crystal NMR probe developed at the National High Magnetic Field Laboratory (NHMFL) and operated in a 14.1 T NMR magnet. We report NMR parameters for quadrupolar nuclei in enantiomers of alanine and other chiral systems, offering insights into their electronic environments. Our results demonstrate the potential of single-crystal NMR spectroscopy as a sensitive chirality probe. This study establishes an experimental foundation for further testing of the magnetochiral model and contributes to a deeper understanding of chirality, essential for advancing our understanding of life’s origins.

Access Setting

Dissertation-Abstract Only

Restricted to Campus until

6-1-2026

This document is currently not available here.

Share

COinS