Document Type
Poster
Publication Date
Spring 2024
Abstract
Amino acids combine to form proteins in living organisms; most are chiral. On Earth amino acids appear only in the L- form, which is likely due to the amplification of enantiomeric excess (ee). However, a small ee for the L-form of amino acids has been observed in meteorites that have fallen on Earth. One possibility for this ee is the effect of antisymmetric components of the magnetic shielding tensor for 14N nuclei in amino acids, which in NMR manifests as the antisymmetric chemical shift (ACS). This can result in preferential destruction of their D-form through interactions with polarized leptons (e.g., neutrinos) in high-field extraterrestrial environments, such as star formation or supernovae. This study outlines the plan to measure the shielding tensor components of 14N in single crystals of N-Acetyl Cysteine (NAC) and N-Acetyl Valine (NAV) amino acids. The ACS components will be measured using a custom, goniometer-based, single-crystal Nuclear Magnetic Resonance (NMR) probe to be deployed in a 600 MHz (14.1 T) magnet at the National High Magnetic Field Laboratory (NMHFL). The measurement will be done using the method described in Wi. et al. [1] — monitoring the chemical shifts of the two 14N (I=1) resonances as a single crystal of the sample is rotated about the three principal laboratory-frame axes (x, y, z). This experiment will help verify the effect of ACS components in preferential destruction of D-form of amino acids in an extraterrestrial environment. Also, NMR is blind to chirality and this experiment should provide a new strategy to study chirality of molecules using NMR without the use of chiral auxiliaries.
Department
Physics
Medium
research poster
WMU ScholarWorks Citation
Agarwal, Shiva, "Probing Shielding Tensor Components of Amino Acids Using Nuclear Magnetic Resonance" (2024). Waldo Library Student Exhibits. 3.
https://scholarworks.wmich.edu/student_exhibits/3