Ex Vivo Analysis of Tryptophan Metabolism Using ¹⁹F NMR

Abstract

Tryptophan, an essential amino acid, is metabolized into a variety of small molecules capable of impacting human physiology, and aberrant tryptophan metabolism has been linked to a number of diseases. There are three principal routes by which tryptophan is degraded, and thus methods for measuring metabolic flux through these pathways can be used to understand the factors that perturb tryptophan metabolism and potentially to measure disease biomarkers. Here, we describe a method utilizing 6fluorotryptophan as a probe for detecting tryptophan metabolites in ex vivo tissue samples via 19 F nuclear magnetic resonance. As a proof of concept, we demonstrate that 6-fluorotryptophan can be used to measure changes in tryptophan metabolism resulting from antibiotic-induced changes in gut microbiota composition. Taken together, we describe a general strategy for monitoring amino acid metabolism using 19 F nuclear magnetic resonance that is operationally simple and does not require chromatographic separation of metabolites.

Identification of Psychoplastogenic N,N-Dimethylaminoisotryptamine (isoDMT) Analogues through Structure–Activity Relationship Studies

“…Ketamine was purchased from Fagron. DMT ( 1 ) and 6-F-DMT ( 29 ) were synthesized using previously published methods [purity >99% as determined by ultra-high-performance liquid chromatography (UHPLC)]. , For cellular plasticity assays (i.e., dendritogenesis), all compounds were dissolved in DMSO and stored as 10 mM stock solutions in the dark at −20 °C.…”

Psychedelic-inspired drug discovery using an engineered biosensor

“…All amphetamine and methylenedioxyamphetamine derivatives were prepared as the 1:1 fumarate salts with the exception of R-and S-MDMA, which were prepared as the 2:1 fumarate salts (i.e., hemifumarates). Lastly, N-Me-5-HT, N-Me-5-MeO-tryptamine hemifumarate, 6-fluorodiethyltryptamine (6-F-DET hemifumarate), 5-bromo-DMT hemifumarate, 5-chloro-DMT hemifumarate, 5-fluoro-DMT hemifumarate, and AAZ-A-137 hemifumarate were prepared using previously reported methods (Blair et al, 2000;Marzaro et al, 2009;Somei et al, 2001;Tombari et al, 2019). Synthetic procedures and characterization data for AAZ-A-154 and LED-C-233 are reported below.…”

Tryptophan Metabolism via Kynurenine Pathway: Role in Solid Organ Transplantation

“…However, due to the necessity of costly equipment, expensive isotope-labeled internal standards and precise sample preparation process, its utility in daily clinical practice is limited as well [ 11 , 146 , 147 , 149 , 152 , 158 ]. Nuclear magnetic resonance (NMR) is another promising technique that allows not only the rapid and precise quantification of various biochemical analytes in biological fluids or tissues but, also, the noninvasive in vivo analysis of metabolism in spectroscopic images and have also been successfully used to determine the levels of tryptophan-kynurenine pathway compounds [ 11 , 160 ]. Nevertheless, this method also requires sophisticated equipment, which currently limits its use mainly to the scientific setting.…”