Exploring Geometrical, Electronic and Spectroscopic Properties of 2-Nitroimidazole-Based Radiopharmaceuticals via...

Area of Science:

• Radiochemistry
• Computational Chemistry
• Molecular Imaging

Background:

• Tumor hypoxia is critical in cancer management and treatment planning.
• 2-nitroimidazole-based radiopharmaceuticals are key for noninvasive positron emission tomography (PET) and single photon emission computed tomography (SPECT) imaging of tumor hypoxia.

Purpose of the Study:

• To perform detailed computational investigations of five widely used 2-nitroimidazole-derived PET imaging agents.
• To correlate computational findings with experimental data and deepen the understanding of their electronic structures.

Main Methods:

• Density functional theory (DFT) calculations were employed for conformational analysis, structural parameters, vibrational IR and Raman properties, and NMR shielding tensors.
• Time-dependent DFT computations were used to investigate excited states.

Main Results:

• A significant change in conformational landscape was predicted when transitioning from gas phase to aqueous solution for most compounds.
• The 2-nitroimidazole moiety was identified as the primary determinant of the spectroscopic properties of its derivatives.
• Computational data were correlated with available experimental findings.

Conclusions:

• The study provides valuable insights into the electronic structures of five important radiopharmaceuticals.
• Findings deepen the understanding of these agents, aiding in the development and application of hypoxia imaging.