Chinese Journal of Magnetic Resonance >
Positions of Protonation in Cytidine Hydrochloride Revealed by NMR Spectroscopy
Received date: 2015-06-01
Revised date: 2016-04-12
Online published: 2016-06-05
Compared to their parent forms of bases or acids, drugs in the form of salts have improved solubility, chemical stability, and capability for recrystallization. For the drug cytidine hydrochloride, whether the protonation position is at N-3 or NH2 remains unclear, and X-ray crystallography cannot provide this information. In this study, 1H and 13C NMR spectroscopy was used to study the exact protonation position in cytidine hydrochloride. It was shown clearly by chemical shift changes that the protonation position is at N-3 rather than NH2. It was further confirmed that the chemical bond between C-4 and NH2 in cytidine salts has double bond-like properties.
Key words： 1H NMR; 13C NMR; cytidine hydrochloride; protonation position
WANG Qiang , LI Yu-jiang , TAO Le , GUO Xiao-he , DONG Li-hong , SONG Chuan-jun , CHANG Jun-biao . Positions of Protonation in Cytidine Hydrochloride Revealed by NMR Spectroscopy[J]. Chinese Journal of Magnetic Resonance, 2016 , 33(2) : 281 -287 . DOI: 10.11938/cjmr20160210
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