Effects of Substituents on the Properties of Metal-Free MRI Contrast Agents.

ABSTRACT: Materials possessing electron spin can shorten the T ₁ relaxation times in magnetic resonance imaging (MRI). For example, gadolinium (Gd) complexes with seven f-orbital electrons are widely used as contrast agents in clinical applications. However, Gd has severe potential side effects, and thus metal-free alternatives are needed. Toward this end, we synthesized seven NO radicals consisting of a dioxa-azaspiro[4.5]decane framework having various substituents, DAD-X (X = methyl, ethyl, n-propyl, c-propyl, vinyl, phenyl, and 2-pyridyl), that functioned as metal-free MRI contrast agents. The relationship between (i) water-proton relaxivity and log P and (ii) reactivity for ascorbic acid and the spin density of the NO oxygen atom were established, w

SUBMITTER: Shiraishi R 

PROVIDER: S-EPMC6906943 | biostudies-literature | 2019 Dec

REPOSITORIES: biostudies-literature