Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

Chemistry

Portland State University

Series

2011

Lanthanide shift reagents

Articles 1 - 3 of 3

Full-Text Articles in Physical Sciences and Mathematics

Towards The Rational Design Of Mri Contrast Agents: Δ-Substitution Of Lanthanide(Iii) Nb-Dota-Tetraamide Chelates Influences But Does Not Control Coordination Geometry, Christiane E. Carney, Anh D. Tran, Jing Wang, Matthias C. Schabel, A. Dean Sherry, Mark Woods Sep 2011

Towards The Rational Design Of Mri Contrast Agents: Δ-Substitution Of Lanthanide(Iii) Nb-Dota-Tetraamide Chelates Influences But Does Not Control Coordination Geometry, Christiane E. Carney, Anh D. Tran, Jing Wang, Matthias C. Schabel, A. Dean Sherry, Mark Woods

Chemistry Faculty Publications and Presentations

LnDOTA-tetraamide chelates (DOTA=1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid) have received considerable recent attention as a result of their potential to act as PARACEST contrast agents for magnetic resonance imaging (MRI). Although PARACEST agents afford several advantages over conventional contrast agents they suffer from substantially higher detection limits; thus, improving the effectiveness of LnDOTA-tetraamide chelates is an important goal. In this study we investigate the potential to extend conformational control of LnDOTA-type ligands to those applicable to PARACEST. Furthermore, the question of whether δ- rather than α-substitution of the pendant arms could be used to control the chelate coordination geometry is addressed. Although δ-substitution does …


Analysis Of The Conformational Behavior And Stability Of The Sap And Tsap Isomers Of Lanthanide(Iii) Nb-Dota-Type Chelates, Gyula Tircso, Benjamin Charles Webber, Benjamin E. Kucera, Victor G. Young, Mark Woods Aug 2011

Analysis Of The Conformational Behavior And Stability Of The Sap And Tsap Isomers Of Lanthanide(Iii) Nb-Dota-Type Chelates, Gyula Tircso, Benjamin Charles Webber, Benjamin E. Kucera, Victor G. Young, Mark Woods

Chemistry Faculty Publications and Presentations

Controlling the water exchange kinetics of macrocyclic Gd(3+) chelates, a key parameter in the design of improved magnetic resonance imaging (MRI) contrast media, may be facilitated by selecting the coordination geometry of the chelate. The water exchange kinetics of the mono- capped twisted square antiprism (TSAP) being much closer to optimal than those of the mono capped square antiprism (SAP) render the TSAP isomer more desirable for high relaxivity applications. Two systems have been developed that allow for selection of the TSAP coordination geometry in 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA)-type Gd(3+) chelates, both based upon the macrocycle nitrobenzyl cyclen. In this paper …


Investigations Into Whole Water, Prototropic And Amide Proton Exchange In Lanthanide(Iii) Dota-Tetraamide Chelates, Mark Woods, Azhar Pasha, Piyu Zhao, Gyula Tircso, Somdatta Chowdhury, Garry Kiefer, Donald E. Woessner, A. Dean Sherry Jul 2011

Investigations Into Whole Water, Prototropic And Amide Proton Exchange In Lanthanide(Iii) Dota-Tetraamide Chelates, Mark Woods, Azhar Pasha, Piyu Zhao, Gyula Tircso, Somdatta Chowdhury, Garry Kiefer, Donald E. Woessner, A. Dean Sherry

Chemistry Faculty Publications and Presentations

Lanthanide(III) chelates of DOTA-tetraamide ligands have been an area of particular interest since the discovery that water exchange kinetics are dramatically affected by the switch from acetate to amide side-chain donors. More recently these chelates have attracted interest as potential PARACEST agents for use in MRI. In this paper we report the results of studies using chemical exchange saturation transfer (CEST) and some more recently reported chelates to re-examine the exchange processes in this class of chelate. We find that the conclusions of Parker and Aime are, for the most part, solid; water exchange is slow and a substantial amount …