NMR studies of low-spin ferric complexes of natural porphyrin derivatives. 4. Proton relaxation characterization of the dimer structure of dicyanohemin in aqueous solution

1981 ◽  
Vol 103 (18) ◽  
pp. 5383-5388 ◽  
Author(s):  
Gerd N. La Mar ◽  
M. J. Minch ◽  
J. S. Frye
Keyword(s):  
Aqueous Solution ◽  
Proton Relaxation ◽  
Nmr Studies ◽  
Dimer Structure ◽  
Porphyrin Derivatives

DNA and RNA: NMR studies of conformations and dynamics in solution

1987 ◽  
Vol 20 (1-2) ◽  
pp. 35-112 ◽  
Author(s):  
Dinshaw J. Patel ◽  
Lawrence Shapiro ◽  
Dennis Hare
Keyword(s):  
Aqueous Solution ◽  
Data Analysis ◽  
Nucleic Acids ◽  
Nmr Studies ◽  
Magnet Design ◽  
Dna And Rna ◽  
Qualitative Nature ◽  
Abundant Supply

The early NMR research on nucleic acids was of a qualitative nature and was restricted to partial characterization of short oligonucleotides in aqueous solution. Major advances in magnet design, spectrometer electronics, pulse techniques, data analysis and computational capabilities coupled with the availability of pure and abundant supply of long oligonucleotides have extended these studies towards the determination of the 3-D structure of nucleic acids in solution.

Synthesis, Characterization, and Dynamic Behavior of Well-defined Dithiomaleimide-functionalized Maltodextrins

2020 ◽  
Vol 17 (2) ◽  
pp. 85-89
Author(s):  
Francisco J. Hidalgo ◽  
Nathan A.P. Lorentz ◽  
TinTin B. Luu ◽  
Jonathan D. Tran ◽  
Praveen D. Wickremasinghe ◽  
...  
Keyword(s):  
Physicochemical Properties ◽  
Dynamic Behavior ◽  
Industrial Applications ◽  
19F Nmr ◽  
Nmr Studies ◽  
Synthetic Pathway ◽  
End Groups ◽  
Sugar End

: Maltodextrins have an increasing number of biomedical and industrial applications due to their attractive physicochemical properties such as biodegradability and biocompatibility. Herein, we describe the development of a synthetic pathway and characterization of thiol-responsive maltodextrin conjugates with dithiomaleimide linkages. 19F NMR studies were also conducted to demonstrate the exchange dynamics of the dithiomaleimide-functionalized sugar end groups.

The interactions of gallium with various buffers and chelating agents in aqueous solution: Gallium-71 and hydrogen-1 NMR studies

1978 ◽  
Vol 8 (1) ◽  
pp. 11-19 ◽  
Author(s):  
C.H.Francis Chang ◽  
T.Phil Pitner ◽  
Robert E. Lenkinski ◽  
Jerry D. Glickson
Keyword(s):  
Aqueous Solution ◽  
Chelating Agents ◽  
Nmr Studies

Synthesis and characterization of 19F NMR chelators for measurement of cytosolic free Ca

1987 ◽  
Vol 252 (4) ◽  
pp. C441-C449 ◽  
Author(s):  
L. A. Levy ◽  
E. Murphy ◽  
R. E. London
Keyword(s):  
Chemical Shifts ◽  
Cell Types ◽  
Free Calcium ◽  
Tetraacetic Acid ◽  
Nmr Studies ◽  
Cytosolic Free Calcium ◽  
Fluorine Nmr ◽  
Dissociation Constant Kd

Fluorine 19 nuclear magnetic resonance (NMR) studies of intracellular fluorinated calcium chelators provide a useful strategy for the determination of cytosolic free calcium levels in cells and perfused organs. However, the fluorinated chelator with the highest affinity for calcium ions which has been described to date. 1,2-bis-(2-amino-5-fluorophenoxy)ethane-N,N,N',N'-tetraacetic acid (5FBAPTA), exhibits a dissociation constant (Kd) value 5- to 10-fold greater than the intracellular calcium concentration levels in most cell types, thus limiting the ability of fluorine NMR to report these concentrations reliably. We have consequently designed and synthesized several fluorinated calcium chelators with higher affinity for calcium. The best of these, 2-(2-amino-4-methyl-5-fluorophenoxy)-methyl-8 aminoquinidine-N,N,N',N'-tetraacetic acid (quinMF), has a Kd value approximately 10 times lower than that of 5FBAPTA. Several of the newly synthesized indicators have different chemical shifts for the calcium complexed and uncomplexed chelators to allow the simultaneous use of two indicators. In addition to providing information about the level of cytosolic free calcium, chelators containing a quinoline ring exhibit considerable sensitivity to magnesium levels and hence have potential application for the determination of cytosolic-magnesium concentrations. Application of these chelators is illustrated by determination of the cytosolic-free calcium level in erythrocytes. Use of quinMF, the chelator with the lowest Kd value, gives a calcium value of 25-30 nM.

Optical Absorption Spectroscopy of DNA-Wrapped HiPco Carbon Nanotubes

2019 ◽  
Vol 943 ◽  
pp. 95-99
Author(s):  
Li Jun Wang ◽  
Kazuo Umemura
Keyword(s):  
Carbon Nanotubes ◽  
Aqueous Solution ◽  
Optical Absorption ◽  
Absorption Spectroscopy ◽  
Near Infrared ◽  
Nir Spectroscopy ◽  
Optical Characterization ◽  
Optical Absorption Spectroscopy ◽  
Double Stranded Dna

Optical absorption spectroscopy provides evidence for individually dispersed carbon nanotubes. A common method to disperse SWCNTs into aqueous solution is to sonicate the mixture in the presence of a double-stranded DNA (dsDNA). In this paper, optical characterization of dsDNA-wrapped HiPco carbon nanotubes (dsDNA-SWCNT) was carried out using near infrared (NIR) spectroscopy and photoluminescence (PL) experiments. The findings suggest that SWCNT dispersion is very good in the environment of DNA existing. Additionally, its dispersion depends on dsDNA concentration.

Sign in / Sign up

Export Citation Format

Share Document