3.7. 1H NMR

Seven mg each of acetylated samples (Ac-AE, Ac-HAE-1, Ac-HAE-2, Ac-HAE-3, Ac-HAE-4, Ac-HAE-5, Ac-HAE-10) and 0.35 mL of CD₃OD were put in a 10 mL conical beaker. The beaker was sonicated for about 1–2 min for complete dissolution and/or dispersion of the sample. Then, the filtrate, obtained by passing the sample through a filter made by packing fine glass fibers inside the Pasteur pipette, was received directly into the NMR tube. Approximately 0.4 mL of fresh CD₃OD was poured into a conical beaker for rinsing and then transferred to the tapered Pasteur pipette for filtration to dissolve the portion remaining on the filter. The rinsed solution was transferred to the NMR tube. ¹H NMR analysis was performed using an NMR spectrometer (600 MHz, JNM-ECA600, JEOL Ltd., Tokyo, Japan) at CURF, JBNU.