Ring Structure and Aromatic Substituent Effects on the pKa of the Benzoxaborole Pharmacophore
journal contributionposted on 12.01.2012, 00:00 by John W. Tomsho, Arnab Pal, Dennis G. Hall, Stephen J. Benkovic
In this work, we present an investigation into the physical properties of a unique class of aromatic boronic acids, the benzoxaboroles. Using spectrophotometric methods, the ionization constants of a family of substituted benzoxaboroles are determined. Heterocyclic ring modifications are examined to determine their effects on the ionization of the boronic acid moiety. It is also shown that the substituent effects about the aromatic ring follow a Hammett relationship with the compounds' measured pKa values. Finally, these substituent effects are also shown to extend to the sugar binding properties of these compounds under physiologically relevant conditions. Combined, these data will inform medicinal chemists wishing to tailor the ionization and/or ability of this class of compound to bind diol-containing biomolecules.