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Application of High-spin Species Designed by the Studies on Molecule-based on Magnet to MRI ImagingAgents

基于磁分子的研究设计的高自旋物种在MRI成像剂中的应用

基本信息

批准号：
15087205
负责人：
KOGA Noboru
金额：
$ 24.58万
依托单位：
Kyushu University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research on Priority Areas
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2006
项目状态：
已结题

项目摘要

The molecule for MRI imaging agent requires the high solubility in water and the high relaxivities, r_1 and r_2, of the water proton. One of the factors affecting to the relaxation time of the water proton is the rotational correlation time (τ_R) of the molecule for MRI imaging agent and the relaxivities increase with increasing the τR value. Because the τ_R value is affected by the size of the molecule; τR is proportional to r^3, where r is a radius of the molecule spherical in shape, the molecule with large molecular weight is expected to give high relaxivities. Based on this idea, we performed two approaches, DNA and dendrimer systems. In DNA system, the DNA monomer carrying a stable radical, its oligomer (15mer), and its duplex with a complimentary DNA oligomer were prepared and their relaxivities were investigated by a pulse NMR spectrometry. Obtained values of r_1 and r_2 increased with increasing the molecular weight, as expected. The values of r_1 for a monomer, an oligomer, and a duplex derivatives are 0.25, 0.44, and 0.57 sec^<-1>mM^<-1>, respectively. In water-soluble dendrimer system, sixteen stable radical units could be introduced to the third generation in the amine dendrimer carrying the carboxylic acid moieties by an ion exchange reaction. The value of r_1= 2.28 sec^<-1>mM^<-1> per molecule was obtained. This system is improved by using a hyper-branched polymer (HBP) and the value higher than the one for the Magnevist which is a gadolinium complex and is used in clinical field, is obtained at present stage.

作为核磁共振显像剂的分子要求在水中的高溶解度和水质子的高弛豫率r_1和r_2。影响水质子弛豫时间的因素之一是核磁共振显像剂分子的旋转相关时间τ_R，弛豫时间随τR值的增大而增大。因为τ_R值受分子大小的影响；τR与r^3成正比，其中r是球形分子的半径，较大分子量的分子预期具有较高的弛豫度。基于这个想法，我们采用了两种方法，DNA和树突分子系统。在DNA体系中，制备了携带稳定自由基的DNA单体、其低聚物（15mer）及其与互补DNA低聚物的双聚体，并用脉冲核磁共振光谱法研究了它们的弛豫度。得到的r_1和r_2值与预期的一样，随着分子量的增加而增加。单体、低聚物和双相衍生物的r_1值分别为0.25、0.44和0.57 sec^<-1>mM^<-1>。在水溶性树状大分子体系中，通过离子交换反应，可以将16个稳定的自由基单元引入到第三代胺类树状大分子中。得到r_1= 2.28 sec^<-1>mM^<-1> /分子。采用超支化聚合物（HBP）对该体系进行了改进，获得了比目前临床应用的钆配合物Magnevist更高的值。

项目成果

期刊论文数量（26）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Magnetic Property of 1 : 2 Mixture of Co(p-tolsal)_2; p-tolsal = N-p-tolylsalicylideniminato, and Cyclic Pentacarbene-pyridine with S = 10/2 in Dilute Frozen Solution

Co(p-tolsal)_2 1 : 2混合物的磁性；

DOI：
发表时间：
2007
期刊：
Polyhedron In Press
影响因子：
0
作者：
Hiroyuki Tobinaga;Madoka Suehiro;Tetsuji Ito;Guangyuan Zhou;Satoru Karasawa;Noboru Koga
通讯作者：
Noboru Koga

Synthesis and EPR studies of 2-N-tert-butylaminoxylpurin derivatives

2-N-叔丁基氨基氧基嘌呤衍生物的合成及EPR研究

DOI：
发表时间：
2005
期刊：
Org. Lett. 7
影响因子：
0
作者：
Toshiyuki Kaneko;Mariko Aso;Noboru Koga;Hiroshi Suemune
通讯作者：
Hiroshi Suemune

Molecule-Based Magnets in Heterospin Systems

DOI：
10.1246/bcsj.78.1384
发表时间：
2005-08
期刊：
Bulletin of the Chemical Society of Japan
影响因子：
4
作者：
N. Koga;S. Karasawa
通讯作者：
N. Koga;S. Karasawa

Magnetic Property of 1 : 2 Mixture of Co(p-tolsal)2; p-tolsal = N-p-tolylsalicylideniminato, and Cyclic Pentacarbene-pyridine with S= 10/2 in Dilute Frozen Solution

Co(p-tolsal)2 1 : 2 混合物的磁性；

DOI：
发表时间：
2007
期刊：
Polyhedron
影响因子：
2.6
作者：
Hiroyuki Tobinaga;Madoka Suehiro;Tetsuji Ito;Guangyuan Zhou;Satoru Karasawa;Noboru Koga
通讯作者：
Noboru Koga

Magnetic Property of 1 : 2 Mixture of Co(p-tolsal)_2; p-tolsal = N-p-tolyisalicylideniminato, and Cyclic Pentacarbene-pyridine with S = 10/2 in Dilute Frozen Solution

Co(p-tolsal)_2 1 : 2混合物的磁性；

DOI：
发表时间：
2007
期刊：
Polyhedron (In press)
影响因子：
0
作者：
Hiroyuki Tobinaga;Madoka Suehiro;Tetsuji Ito;Guangyuan Zhou;Satoru Karasawa;Noboru Koga
通讯作者：
Noboru Koga