Avii 500 mhz

UV spectra of CICP (2 mg/mL) in the range of 200–800 nm were recorded on a UV spectrophotometer (UV-1800, Shimadzu, Kyoto, Japan). Thermo-Scientific Nicolet (5700IR) was used to take IR spectrum. A 600 MHz spectrometer (Bruker AVII 500 MHz) was used to record nuclear magnetic resonance (NMR) spectroscopy in D₂O.

⁵¹V nuclear magnetic resonance spectroscopy measurements of aqueous solutions (with 10% of D₂O used for locking, at 20 °C) were taken on a Bruker AV II+ 500 MHz instrument operating at 131.60 MHz for the ⁵¹V nucleus (2000 scans, accumulation time 0.05 s, relaxation delay 0.01 s). Chemical shift values are given with reference to VOCl₃ (0 ppm) as the standard.

The crude extract of polysaccharide ESM-C sample (15 mg) and the purifier fraction ESM-C-A sample (5 mg) were each dissolved in 400 μL deuterium oxide (99.9 atom% D, Sigma-Aldrich, Inc.) for data collection. The ¹H chemical shift spectrum was referred to D₂O at δ_H 4.49 ppm (313 K) as an internal standard. For structural elucidation of ESM-C-A, ¹H and ¹³C spectra were recorded on Bruker AVII-500 MHz and Bruker AVIII-800 instruments, respectively. In the ¹³C NMR spectra measurement, a relaxation delay and acquisition time of 3.5 and 1.3 s, respectively. And 13312 scans per spectrum were accumulated. A standard spectrum of HA at 300 MHz ¹H-NMR was used as reported^{29 (link)}.