Tautomerism, protonation, and ionization of formycin in aqueous solution by the ph dependence of 13c chemical shifts and 13c-1h coupling constants

Document Type

Article

Date of Original Version

3-1-1994

Abstract

Analyses of the pH dependence of 13C chemical shifts and 13C-1H coupling constants of formycin in aqueous solution revealed two pKa’s, at 4.4 and 9.7, corresponding to a protonation at N4 and an ionization at N1. The N4-protonation results in the transfer of a pyrazolo ring hydrogen from N1 to N2. At physiological pH, formycin was found to exist as a mixture of N1H and N2H tautomers, with the former being predominant (>94%). © 1994, Taylor & Francis Group, LLC. All rights reserved.

Publication Title, e.g., Journal

Nucleosides and Nucleotides

Volume

13

Issue

1-3

Share

COinS