Triazoles as T₂ -Exchange Magnetic Resonance Imaging Contrast Agents for the Detection of Nitrilase Activity.

ABSTRACT: We characterized the T₂ -exchange (T_2ex ) magnetic resonance imaging (MRI) contrast of azole protons that have large chemical shifts from the water proton resonance as a function of pH, temperature, and chemical modification. Our results showed that 1,2,4-triazoles could be tuned into excellent diamagnetic T_2ex contrast agents, with an optimal exchange-based relaxivity r_2ex of 0.10 s^-1  mm^-1 at physiological pH and B₀ =9.4 T. A fit of r_2ex data to the Swift-Connick equation indicated that imino proton exchange of triazoles is dominated by a base-catalyzed process at higher pH values and an acid-catalyzed process at lower pH. The magnitude of r_2ex was also found to be heavily dependent on chem

SUBMITTER: Zhang J 

PROVIDER: S-EPMC9181901 | biostudies-literature | 2018 Oct

REPOSITORIES: biostudies-literature