. 2021 Jan 20;6(4):2824–2835. doi: 10.1021/acsomega.0c05138

Table 3. pK_a Values of Individual Nitrogen Atoms of Neomycin Determined Using ¹H, ¹³C, and ¹H−¹⁵N HMBC NMR Spectroscopies in this Work (n = 2) and Compared with the Published Data, as Indicated^a^,^b^,^c^,^d^,^e^,^f.

pK_a values of individual nitrogen atoms of neomycin determined using ¹⁵N NMR spectroscopy in H₂O/D₂O (90:10 v/v) relative to ¹⁵NH₄Cl at 25 °C.²³

pK_a values of individual nitrogen atoms of neomycin determined using ¹⁵N NMR spectroscopy in H₂O/D₂O (85:15 v/v) relative to ¹⁵NH₄NO₃ at 25 °C.¹⁸

pK_a values of individual nitrogen atoms of neomycin determined using ¹⁵N NMR spectroscopy in H₂O/D₂O (90:10 v/v) relative to NH₃ by using 1.0 M ¹⁵N urea in DMSO at 25 °C.²⁹

pK_a values of individual nitrogen atoms of neomycin determined using ¹H and ¹³C HSQC NMR spectroscopies in D₂O at 25 °C.³⁰

This work (n = 2).

The pK_a value of N-6′ of neomycin determined using ¹H NMR spectroscopy (in this work) is the average pK_a of the values of N-6′ obtained using ¹H NMR spectroscopic data for 6′a (8.65) and 6′b (8.70), and the pK_a value of N-6‴ of neomycin determined using ¹H NMR spectroscopy (in this work) is the average pK_a of the values of N-6‴ obtained using ¹H NMR spectroscopic data for 6‴a (8.72) and 6‴b (8.75).

Table 3. pKa Values of Individual Nitrogen Atoms of Neomycin Determined Using 1H, 13C, and 1H−15N HMBC NMR Spectroscopies in this Work (n = 2) and Compared with the Published Data, as Indicateda,b,c,d,e,f.

Table 3. pK_a Values of Individual Nitrogen Atoms of Neomycin Determined Using ¹H, ¹³C, and ¹H−¹⁵N HMBC NMR Spectroscopies in this Work (n = 2) and Compared with the Published Data, as Indicated^a^,^b^,^c^,^d^,^e^,^f.