Determination of Binding Constants for Inclusion Complexes of Cyclodextrins with Organic Solvents, Ethylene Glycol, and Its Related Compounds by Means of 1H NMR Spectroscopy

2012 ◽  
Vol 85 (11) ◽  
pp. 1206-1209 ◽  
Author(s):  
Keisuke Yoshikiyo ◽  
Yoshihisa Matsui ◽  
Tatsuyuki Yamamoto
Keyword(s):  
Nmr Spectroscopy ◽  
Ethylene Glycol ◽  
Organic Solvents ◽  
Inclusion Complexes ◽  
1H Nmr ◽  
1H Nmr Spectroscopy ◽  
Binding Constants ◽  
Related Compounds

scholarly journals pKa Determination of a Histidine Residue in a Short Peptide Using Raman Spectroscopy

Molecules ◽  
2019 ◽  
Vol 24 (3) ◽  
pp. 405 ◽  
Author(s):  
Brett H. Pogostin ◽  
Anders Malmendal ◽  
Casey H. Londergan ◽  
Karin S. Åkerfeldt
Keyword(s):  
Raman Spectroscopy ◽  
Nmr Spectroscopy ◽  
1H Nmr ◽  
1H Nmr Spectroscopy ◽  
Peptide Sequence ◽  
Short Peptide ◽  
Dependent Behavior ◽  
Pka Determination ◽  
Key Functional Groups

Determining the pKa of key functional groups is critical to understanding the pH-dependent behavior of biological proteins and peptide-based biomaterials. Traditionally, 1H NMR spectroscopy has been used to determine the pKa of amino acids; however, for larger molecules and aggregating systems, this method can be practically impossible. Previous studies concluded that the C-D stretches in Raman are a useful alternative for determining the pKa of histidine residues. In this study, we report on the Raman application of the C2-D probe on histidine’s imidazole side chain to determining the pKa of histidine in a short peptide sequence. The pKa of the tripeptide was found via difference Raman spectroscopy to be 6.82, and this value was independently confirmed via 1H NMR spectroscopy on the same peptide. The C2-D probe was also compared to other Raman reporters of the protonation state of histidine and was determined to be more sensitive and reliable than other protonation-dependent signals. The C2-D Raman probe expands the tool box available to chemists interested in directly interrogating the pKa’s of histidine-containing peptide and protein systems.

1H NMR Spectroscopy for Determination of the Geographical Origin of Hazelnuts

2018 ◽  
Vol 66 (44) ◽  
pp. 11873-11879 ◽  
Author(s):  
René Bachmann ◽  
Sven Klockmann ◽  
Johanna Haerdter ◽  
Markus Fischer ◽  
Thomas Hackl
Keyword(s):  
Nmr Spectroscopy ◽  
1H Nmr ◽  
1H Nmr Spectroscopy ◽  
Geographical Origin

scholarly journals Synthesis of Mono- and Dithiols of Tetraethylene Glycol and Poly(ethylene glycol)s via Enzyme Catalysis

Catalysts ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 228 ◽  
Author(s):  
Prajakatta Mulay ◽  
Gayatri Shrikhande ◽  
Judit Puskas
Keyword(s):  
Nmr Spectroscopy ◽  
Ethylene Glycol ◽  
1H Nmr ◽  
Enzyme Catalysis ◽  
1H Nmr Spectroscopy ◽  
13C Nmr Spectroscopy ◽  
Tetraethylene Glycol ◽  
Candida Antarctica Lipase ◽  
Poly Ethylene Glycol ◽  
Poly Ethylene

This paper investigates the transesterification of methyl 3-mercaptopropionate (MP-SH) with tetraethylene glycol (TEG) and poly(ethylene glycol)s (PEG)s catalyzed by Candida antarctica Lipase B (CALB) without the use of solvent (in bulk). The progress of the reactions was monitored by 1H-NMR spectroscopy. We found that the reactions proceeded in a step-wise manner, first producing monothiols. TEG-monothiol was obtained in 15 min, while conversion to dithiol took 8 h. Monothiols from PEGs with Mn = 1000 and 2050 g/mol were obtained in 8 and 16 h, respectively. MALDI-ToF mass spectrometry verified the absence of dithiols. The synthesis of dithiols required additional fresh CALB and MP-SH. The structure of the products was confirmed by 1H-NMR and 13C-NMR spectroscopy. Enzyme catalysis was found to be a powerful tool to effectively synthesize thiol-functionalized TEGs and PEGs.

scholarly journals Composition Determination of Low-Pressure Gas-Phase Mixtures by 1H NMR Spectroscopy

2019 ◽  
Vol 91 (7) ◽  
pp. 4429-4435 ◽  
Author(s):  
Christopher L. Suiter ◽  
Mark O. McLinden ◽  
Thomas J. Bruno ◽  
Jason A. Widegren
Keyword(s):  
Nmr Spectroscopy ◽  
Gas Phase ◽  
1H Nmr ◽  
1H Nmr Spectroscopy ◽  
Low Pressure ◽  
Composition Determination
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