TY - JOUR
T1 - Effects of Substituents on the Properties of Metal-Free MRI Contrast Agents
AU - Shiraishi, Ryoma
AU - Kaneko, Tomoyo
AU - Usui, Kazuteru
AU - Naganuma, Tatsuya
AU - Iizuka, Naoko
AU - Morishita, Kosuke
AU - Kobayashi, Shigeki
AU - Fuchi, Yasufumi
AU - Matsuoka, Yuta
AU - Hirai, Go
AU - Yamada, Ken Ichi
AU - Karasawa, Satoru
N1 - Funding Information:
This work was partially supported by the JST PRESTO (grant numbers JPMJPR1337 for K.-i.Y. and JPMJPR14K4 for S.K.) and a Grant-in-Aid for Scientific Research (C) (19K07016 for S.K.).
Publisher Copyright:
© 2019 American Chemical Society.
PY - 2019/12/10
Y1 - 2019/12/10
N2 - Materials possessing electron spin can shorten the T1 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, which provided a basis for the rational design of practical metal-free contrast agents.
AB - Materials possessing electron spin can shorten the T1 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, which provided a basis for the rational design of practical metal-free contrast agents.
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U2 - 10.1021/acsomega.9b03003
DO - 10.1021/acsomega.9b03003
M3 - Article
AN - SCOPUS:85075694559
SN - 2470-1343
VL - 4
SP - 20715
EP - 20723
JO - ACS Omega
JF - ACS Omega
IS - 24
ER -