Abstract: | By comparison of pKa values derived from 15N and 13C nuclear magnetic resonance (NMR) spectroscopies, the assignment of the 15N resonances of apramycin is completed. 13C NMR spectra appear to provide accurate pKa determinations with this aminoglycoside. Hydroxylation adjacent to one of the basic nitrogens of apramycin appears to change the pKa values of all five amines of the molecule. |