Robust Imidazole-15N2 Synthesis for High-Resolution Low-Field (0.05 T) 15N Hyperpolarized NMR Spectroscopy | Sciact - CRIS-system of Boreskov Institute of Catalysis

Robust Imidazole-15N2 Synthesis for High-Resolution Low-Field (0.05 T) 15N Hyperpolarized NMR Spectroscopy Full article

Journal

ChemistrySelect
, E-ISSN: 2365-6549

Output data

Year: 2017, Volume: 2, Number: 16, Pages: 4478-4483 Pages count : 6 DOI: 10.1002/slct.201700718

Tags

15N NMR spectroscopy, hyperpolarization, isotopic enrichment, parahydrogen, SABRE-SHEATH

Authors

Shchepin Roman V. ^1,2,3 , Barskiy Danila A. ^1,2,3 , Coffey Aaron M. ^1,2,3 , Feldman Matthew A. ^1,2,3 , Kovtunova Larisa M. ^4,5 , Bukhtiyarov Valerii I. ^4,5 , Kovtunov Kirill V. ^4,6 , Goodson Boyd M. ^7,8 , Koptyug Igor V. ^4,6 , Chekmenev Eduard Y. ^1,2,3,9

Affiliations

1	Vanderbilt University Institute of Imaging Science (VUIIS), Department of Radiology, Nashville, Tennessee, 37232-2310 (United States)
2	Department of Biomedical Engineering, Nashville, Tennessee, 37232-2310 (United States)
3	Department of Physics and Astronomy, Nashville, Tennessee, 37232-2310 (United States)
4	Novosibirsk State University, 2 Pirogova St., Novosibirsk 630090 (Russia)
5	Boreskov Institute of Catalysis SB RAS, 5 Acad. Lavrentiev Pr., Novosibirsk 630090 (Russia)
6	Laboratory of Magnetic Resonance Microimaging International Tomography Center (ITC), SB RAS, 3 A Institutskaya St., Novosibirsk 630090 (Russia)
7	Southern Illinois University, Department of Chemistry and Biochemistry, Carbondale, IL 62901 (United States)
8	Southern Illinois University, Materials Technology Center, Carbondale, IL 62901 (United States)
9	Russian Academy of Sciences, Leninskiy Prospekt 14, 119991 Moscow (Russia)

Funding (11)

1	Federal Agency for Scientific Organizations	0303-2015-0010
2	Russian Foundation for Basic Research	16-03-00407
3	The Ministry of Education and Science of the Russian Federation	МК-4498.2016.3
4	National Institutes of Health	1R21EB018014
5	National Institutes of Health	1R21EB020323
6	National Science Foundation	CHE-1416268
7	United States Department of Defense	W81XWH-12-1-0159/BC112431
8	United States Department of Defense	W81XWH-15-1-0271
9	National Science Foundation	CHE-1416432
10	United States Department of Defense	W81XWH-15-1-0272
11	Federal Agency for Scientific Organizations	V.44.1.8. (0333-2016-0001)

NMR hyperpolarization techniques have the potential to revolutionize the field of NMR spectroscopy and molecular MRI because they can transiently enhance nuclear spin polarization by 4–8 orders of magnitude, with corresponding gains in NMR signal-to-noise ratio (SNR). The SABRE-SHEATH (Signal Amplification By Reversible Exchange in SHield Enables Alignment Transfer to Heteronuclei) technique, first demonstrated in 2015, allows for direct, efficient (>20 % nuclear spin polarization), and fast (in under one minute) hyperpolarization of 15N sites. Several classes of biologically relevant 15N hyperpolarized contrast agents have been efficiently hyperpolarized to date including pH sensors, which can be potentially useful for non-invasive pH imaging of cancer and other diseases with altered metabolism. Here, we report the optimized 15N enrichment of imidazole-15N2 – a promising in vivo pH sensor with pKa ∼ 7.0. A hyperpolarized 0.1 M aqueous solution (ϵ15N ∼ 146,000 fold, P15N ∼ 0.24 %) was used to record 15N NMR spectra at 0.05 T, demonstrating the feasibility of high-resolution (full width at half maximum ∼ 1 Hz corresponding to 5 ppm at 0.05 T) NMR spectroscopy near its pKa (7.0) at ultra-low magnetic field. Given that proton-binding events modulate the chemical shift by ∼ 30 ppm for this pH-sensing probe, our results demonstrate the feasibility of ultra-low-field pH sensing near its pKa (7.0) with SNR approaching that of high-field (9.4 T) MR.

Shchepin R.V. , Barskiy D.A. , Coffey A.M. , Feldman M.A. , Kovtunova L.M. , Bukhtiyarov V.I. , Kovtunov K.V. , Goodson B.M. , Koptyug I.V. , Chekmenev E.Y.
Robust Imidazole-15N2 Synthesis for High-Resolution Low-Field (0.05 T) 15N Hyperpolarized NMR Spectroscopy

ChemistrySelect. 2017. V.2. N16. P.4478-4483. DOI: 10.1002/slct.201700718 WOS Scopus РИНЦ AN OpenAlex

Full text from publisher

Submitted:	Apr 5, 2017
Accepted:	May 19, 2017
Published print:	May 31, 2017
Published online:	Jun 1, 2017

Web of science:	WOS:000403256200027
Scopus:	2-s2.0-85021254253
Elibrary:	35479206
Chemical Abstracts:	2017:963145
OpenAlex:	W2620576658

DB	Citing
Web of science	25
Scopus	26
Elibrary	26
OpenAlex	27