Figure 4. 1H NMR data (400 MHz, 298 K) of glucosamine hydrochloride in D O: a) 1H NMR spectrum with anomeric distribution at equilibrium; 2 b) mutarotation mechanism of glucosamine; c) anomeric region of the 1H NMR spectra recorded at different elapsed times; and d) relative amount of each anomer as a function of time.