The Development of Ex vivo and In vivo Multiphase NMR Spectroscopy

Most biological and environmental samples are complex heterogenous mixtures composed of multiple phases (solids, liquids and gels). It is the interaction between these phases that give rise to environmental reactivity and biological function in intact samples. As traditional NMR has evolved as separate fields of research (either solid or solution-state NMR), often the molecular level interactions and structural changes are overlooked. This dissertation will focus on the multiphase changes in intact organisms, which requires a non-invasive approach with minimal sample preparation. Using a unique NMR technique, termed Comprehensive Multiphase (CMP) NMR spectroscopy, real-time observations of all phases in unaltered samples can be monitored. CMP-NMR combines all aspects of High Resolution – Magic Angle Spinning (HR-MAS) and solid-state NMR into a single probe. This research explores a variety of novel tools and techniques used to improve the detection of metabolites, in ex vivo and in vivo samples, using multiphase NMR. However, there are a few conditions to consider when monitoring real-time, biochemical interactions in living organisms. These include specialized hardware, spinning stress under MAS, oxygen and water requirements for organism survival, as well as limited NMR sensitivity and spectral overlap. To address these concerns, this work uses: 1) ex vivo multiphase NMR to provide complementary information to in vivo processes, 2) novel NMR hardware to improve the carbon detection of natural samples, 3) a novel NMR experiment called SimultAneous Solid and Solution spectroscopy (SASSY NMR) to monitor simultaneous, multiphase changes using standard, solid-state hardware, and 4) highly selective NMR techniques (DREAMTIME NMR) to monitor user-desired metabolic changes in complex samples under both fast and slow MAS conditions. These non-invasive techniques are highly versatile and can find widespread use across a number of research domains.

Department dc:contributor.department

Chemistry

Year dc:date.issued

2024

Author dc:creator

• Ghosh Biswas, Rajshree

Advisor dc:contributor.advisor

• Simpson, Andre J.

• Comprehensive Multiphase NMR
• Environmental Chemistry
• HR-MAS NMR
• Hyalella azteca
• Metabolomics
• Nuclear Magnetic Resonance

Handle dc:identifier.uri

http://hdl.handle.net/1807/140165

OAI identifier oai:identifier

oai:utoronto.scholaris.ca:1807/140165