umu.sePublications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
1H NMRD profiles and ESR lineshapes of Gd(III) complexes: a comparison between the generalized SBM and the stochastic Liouville approach
Umeå University, Faculty of Science and Technology, Department of Chemistry.
Umeå University, Faculty of Science and Technology, Department of Chemistry.
2005 (English)In: Journal of magnetic resonance, ISSN 1090-7807, E-ISSN 1096-0856, Vol. 173, no 1, 75-83 p.Article in journal (Refereed) Published
Abstract [en]

A complete description of the T1-NMRD profiles and the ESR lineshape of Gd(III) complexes (S = 7/2) was presented using second-order perturbation theory (GSBM) by Zhou et al. [J. Magn. Reson. 167 (2004) 147]. This report compares the GSBM with the stochastic Liouville approach (SLA) to determine the validity of the closed analytical expressions of NMRD and the ESR lineshape functions. Both approaches give the same results at high fields while a very small divergence is observed for X- and W-band ESR lineshapes when the magnitude of the perturbation term times the correlation time approaches the limit of the perturbation regime, ΔZFSτf ≈ 0.1. There was a clear discrepancy between the theoretical GSBM X-band spectrum and the recorded ESR spectrum of the Gd(III) MS-325 + HSA complex. This is probably due to a slow-motion effect caused by a slow modulation of the ZFS interaction. The characteristic correlation time of this slow modulation is in the range of 150 ps, which therefore cannot be due to the reorientational motion of the whole MS-325 + HSA complex.

Place, publisher, year, edition, pages
San Diego: Academic Press, 2005. Vol. 173, no 1, 75-83 p.
Keyword [en]
GSBM, SLA, NMRD, ESR, MS-325
National Category
Biochemistry and Molecular Biology
Identifiers
URN: urn:nbn:se:umu:diva-14677DOI: 10.1016/j.jmr.2004.10.014ISI: 000227103500010OAI: oai:DiVA.org:umu-14677DiVA: diva2:154349
Available from: 2008-03-31 Created: 2008-03-31 Last updated: 2017-05-04Bibliographically approved
In thesis
1. An Analysis of NMRD profiles and ESR lineshapes of MRI Contrast Agents
Open this publication in new window or tab >>An Analysis of NMRD profiles and ESR lineshapes of MRI Contrast Agents
2004 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

To optimize contrast agent in MRI scan region, e.g. to enhance paramagnetic relaxation in the MRI scan fields(0.1T-3T), one possible way is to slow down the tumbling of the paramagnetic complex. The effect of slowing down the reorientational motion of the complex to increase relaxivity is obvious and this strategy has already been employed in producing MRI contrast agent that can bind to specific proteins. An example is MS-325 binds to human serum albumin(HSA). The slow down effects on the ligands around paramagnetic ion, and on the zero field splitting(ZFS) interaction are under studies and the physics behind is still not clear. In this thesis, a generalized Solomon-Bloembergen-Morgan(GSBM) theory together with stochastic Liouville approach(SLA), is applied to investigate the mechanism behind the slow down effects. Two gadolinium complexes, MS-325+HSA and Gd(H2O)83++glycerol are studied by means of NMRD and ESR experiments.

GSBM is a second order perturbation theory with closed analytical form. The computation based on this theory is fast, but it has its limitation and in the case of Gd(S=7/2) the ZFS strength times its correlation time(Δt.τƒ) should be less than 0.1. In comparison, the SLA is an "exact" theory that can evaluate the validity of GSBM calculation. However, the calculation in SLA is time consuming due to the large matrix it constructed. The major model used in GSBM is a two dynamic model, characterized by transient ZFS Δt and static ZFS Δs and their corresponding correlation time τƒ and τR, while in SLA the model is only described by Δt and τƒ. A combined NMRD and ESR analysis is used to understand the details of ZFS interaction. Both models can reproduce experimental NMRD profiles and model parameters are similar; for ESR linewidths the model parameters are quite different. The fitting results indicate the NMRD profiles are less sensitive to the detail expression of ZFS correlation function. In order to interpret both NMRD and ESR experiments with identical parameters, a more complex ZFS interaction model should be developed.

Place, publisher, year, edition, pages
Umeå: Kemi, 2004. 40 p.
Keyword
Physical chemistry, MRI contrast agent, MS-325, Spin relaxation, NMRD, ESR, Fysikalisk kemi
National Category
Physical Chemistry
Research subject
Physical Chemistry
Identifiers
urn:nbn:se:umu:diva-361 (URN)91-7305-777-0 (ISBN)
Public defence
2004-12-09, KB3A9, KBC, Umeå University, Umeå, 10:00
Opponent
Supervisors
Available from: 2004-11-12 Created: 2004-11-12 Last updated: 2017-05-04Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Zhou, XiangzhiWestlund, Per-Olof
By organisation
Department of Chemistry
In the same journal
Journal of magnetic resonance
Biochemistry and Molecular Biology

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 70 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf