Dalton Transactions p. 3399 - 3406 (2006)
Update date:2022-08-05
Topics:
Lebdukova, Petra
Sour, Angelique
Helm, Lothar
Toth, Eva
Kotek, Jan
Luke, Ivan
Merbach, Andre E.
A DTPA-based chelate containing one phosphinate group was conjugated to a generation 5 polyamidoamine (PAMAM) dendrimer via a benzylthiourea linkage. The Gd(iii) complex of this novel conjugate has potential as a contrast agent for magnetic resonance imaging (MRI). The chelates bind Gd3+ via three nitrogen atoms, four carboxylates and one phosphinate oxygen, and one water molecule completes the inner coordination sphere. The monomer Gd(iii) chelates bearing nitrobenzyl and aminobenzyl groups ([Gd(DTTAP-bz-NO2)(H 2O)]2- and [Gd(DTTAP-bz-NH2)(H 2O)]2-) as well as the dendrimeric Gd(iii) complex G5-(Gd(DTTAP))63) were studied by multiple-field, variable temperature 17O and 1H NMR. The rate of water exchange is faster than that of [Gd(DTPA)(H2O)]2- and very similar on the two monomeric complexes (8.9 and 8.3 × 106 s-1 for [Gd(DTTAP-bz-NO2)(H2O)]2- and [Gd(DTTAP-bz-NH2)(H2O)]2-, respectively), while it is decreased on the dendrimeric conjugate (5.0 × 106 s -1). The Gd(iii) complex of the dendrimer conjugate has a relaxivity of 26.8 mM-1 s-1 at 37 °C and 0.47 T (corresponding to 1H Larmor frequency of 20 MHz). Given the contribution of the second sphere water molecules to the overall relaxivity, this value is slightly higher than those reported for similar size dendrimers. The experimental 17O and 1H NMR data were fitted to the Solomon-Bloembergen-Morgan equations extended with a contribution from second coordination sphere water molecules. The rotational dynamics of the dendrimeric conjugate was described in terms of global and local motions with the Lipari-Szabo approach. The Royal Society of Chemistry 2006.
View MoreShandong Xingshun New Material Co., Ltd.
website:http://www.sd-xingshun.com
Contact:+86-519-86461196/+86-519-86464994
Address:Middle of Luhua East Road, Dingtao District
HENAN NEW BLUE CHEMICAL CO.,LTD
website:http://www.newbluechem.com
Contact:86-371-55170693/55170694
Address:Zhengzhou International Trade New Territory,Jinshui District,Zhengzhou ,China
Jiangxi Hito Chemical Co., Ltd.
Contact:+86-792-3170318
Address:No. 6, Tianhong Ave., Xinghuo Industry Park, Yongxiu, Jiujiang, Jiangxi, China
AstaTech ( Chengdu) BioPharmaceutical Corp.
website:http://www.astabiochem.cn/
Contact:+86-15198215156-15198215156
Address:SICHUAN CHENGDU
Taizhou YOJOY Chemical Co., Ltd.
Contact:13857143241
Address:Yangfu Industrial Park, Xianju, Zhejiang, P. R. China
Doi:10.1021/ja00181a035
(1990)Doi:10.1021/jo061535z
(2006)Doi:10.1021/ic061014u
(2006)Doi:10.1021/jo971738a
(1998)Doi:10.1002/aoc.3192
(2014)Doi:10.1016/j.tetasy.2006.10.030
(2006)