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

Research output: Contribution to journalArticle

23 Citations (Scopus)

Abstract

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 of prototropic exchange occurs in aqueous solution. The extent of prototropic exchange increases as the pH increases above 8, leading to higher relaxivities at high pH. However, amide protons are found to contribute only a small amount to the relaxivity at high pH.

Original languageEnglish (US)
Pages (from-to)6759-6764
Number of pages6
JournalDalton Transactions
Volume40
Issue number25
DOIs
StatePublished - Jul 7 2011

Fingerprint

Lanthanoid Series Elements
Amides
Protons
Ion exchange
Water
Magnetic resonance imaging
Acetates
Switches
Ligands
Kinetics

ASJC Scopus subject areas

  • Inorganic Chemistry

Cite this

Investigations into whole water, prototropic and amide proton exchange in lanthanide(III) DOTA-tetraamide chelates. / Woods, Mark; Pasha, Azhar; Zhao, Piyu; Tircso, Gyula; Chowdhury, Somdatta; Kiefer, Garry; Woessner, Donald E.; Sherry, A. Dean.

In: Dalton Transactions, Vol. 40, No. 25, 07.07.2011, p. 6759-6764.

Research output: Contribution to journalArticle

Woods, M, Pasha, A, Zhao, P, Tircso, G, Chowdhury, S, Kiefer, G, Woessner, DE & Sherry, AD 2011, 'Investigations into whole water, prototropic and amide proton exchange in lanthanide(III) DOTA-tetraamide chelates', Dalton Transactions, vol. 40, no. 25, pp. 6759-6764. https://doi.org/10.1039/c1dt10616c
Woods, Mark ; Pasha, Azhar ; Zhao, Piyu ; Tircso, Gyula ; Chowdhury, Somdatta ; Kiefer, Garry ; Woessner, Donald E. ; Sherry, A. Dean. / Investigations into whole water, prototropic and amide proton exchange in lanthanide(III) DOTA-tetraamide chelates. In: Dalton Transactions. 2011 ; Vol. 40, No. 25. pp. 6759-6764.
@article{288095a5930f44f4951776facaab0761,
title = "Investigations into whole water, prototropic and amide proton exchange in lanthanide(III) DOTA-tetraamide chelates",
abstract = "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 of prototropic exchange occurs in aqueous solution. The extent of prototropic exchange increases as the pH increases above 8, leading to higher relaxivities at high pH. However, amide protons are found to contribute only a small amount to the relaxivity at high pH.",
author = "Mark Woods and Azhar Pasha and Piyu Zhao and Gyula Tircso and Somdatta Chowdhury and Garry Kiefer and Woessner, {Donald E.} and Sherry, {A. Dean}",
year = "2011",
month = "7",
day = "7",
doi = "10.1039/c1dt10616c",
language = "English (US)",
volume = "40",
pages = "6759--6764",
journal = "Dalton Transactions",
issn = "1477-9226",
publisher = "Royal Society of Chemistry",
number = "25",

}

TY - JOUR

T1 - Investigations into whole water, prototropic and amide proton exchange in lanthanide(III) DOTA-tetraamide chelates

AU - Woods, Mark

AU - Pasha, Azhar

AU - Zhao, Piyu

AU - Tircso, Gyula

AU - Chowdhury, Somdatta

AU - Kiefer, Garry

AU - Woessner, Donald E.

AU - Sherry, A. Dean

PY - 2011/7/7

Y1 - 2011/7/7

N2 - 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 of prototropic exchange occurs in aqueous solution. The extent of prototropic exchange increases as the pH increases above 8, leading to higher relaxivities at high pH. However, amide protons are found to contribute only a small amount to the relaxivity at high pH.

AB - 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 of prototropic exchange occurs in aqueous solution. The extent of prototropic exchange increases as the pH increases above 8, leading to higher relaxivities at high pH. However, amide protons are found to contribute only a small amount to the relaxivity at high pH.

UR - http://www.scopus.com/inward/record.url?scp=79959868590&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=79959868590&partnerID=8YFLogxK

U2 - 10.1039/c1dt10616c

DO - 10.1039/c1dt10616c

M3 - Article

C2 - 21625687

AN - SCOPUS:79959868590

VL - 40

SP - 6759

EP - 6764

JO - Dalton Transactions

JF - Dalton Transactions

SN - 1477-9226

IS - 25

ER -