Water-proton relaxivities of DNA oligomers carrying TEMPO radicals

• Published in: Magnetic resonance in chemistry Vol. 46; no. 11; pp. 1055 - 1058
• Main Authors: Sato, Yuichiro, Hayashi, Hiroyuki, Okazaki, Manami, Aso, Mariko, Karasawa, Satoru, Ueki, Shoji, Suemune, Hiroshi, Koga, Noboru
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 01.11.2008; Wiley
• Subjects: Chemistry; Chemistry, Multidisciplinary; Chemistry, Physical; Cyclic N-Oxides; Electron Spin Resonance Spectroscopy - methods; EPR; MRI; NMR; nucleic acid; Oligodeoxyribonucleotides - chemistry; Physical Sciences; Protons; Rotation; Science & Technology; Spectroscopy; Spin Labels; Technology; TEMPO radical; Water - chemistry; MAGNETIC-RESONANCE RELAXATION; ELECTRON-SPIN-RESONANCE; MACROMOLECULES; MRI; CONTRAST AGENTS; EPR; TEMPO radical; DENDRIMERS; nucleic acid; H-1; MODEL-FREE APPROACH; GD-DTPA; NMR; DYNAMICS
• ISSN: 0749-1581; 1097-458X
• DOI: 10.1002/mrc.2310

5‐Uridine derivative carrying a TEMPO radical (UST) was prepared and its single strand (ssUST) and a double strand (dsUST) with its complementary strand were obtained. Similarly, single strands carrying two and five radicals (ssUST2 and ssUST5, respectively) and the corresponding double strands (dsUST2 and dsUST5) were prepared. Their electron paramagnetic resonance (EPR) spectra showed typical anisotropic broadening in the high field line. The rotational correlation times, τR, estimated by analyzing the EPR spectra are 1.1 × 10−10, 5.9 × 10−10, and 14 × 10−10 s for UST, ssUSTm, and dsUSTm, respectively. The water‐proton relaxivities, r1 and r2, at 25 MHz, 0.59 T, and 25 °C, also increased in the same order and the r1 values were 0.26, 0.41, and 0.56 mM−1 s−1 for UST, ssUSTm, and dsUSTm, respectively. The r1 values of 1.00 and 2.06 mM−1 s−1 for dsUST2 and dsUST5, respectively, were obtained. Copyright © 2008 John Wiley & Sons, Ltd.