Lyophilized CHOS (10mg) were dissolved in deuterium
oxide (D2O, 0.5 ml) and the pH was adjusted to 4.2 with
sodium deuteroxide (NaOD) and deuterium chloride
(DCl) prior to lyophilization. This process was repeated
once. Finally the lyophilized CHOS sample was dissolved
in D2O (700 μl) and 1H-NMR analysis was
performed on a 300 MHz Varian Gemini instrument
(Varian, USA) at 85 °C (1H-NMR spectra is shown in and acetylated (A) units respectively, D is the integral of
the signals from deacetylated units GlcN) in internal and
non-reducing end positions, and A is the integral of the
signals from acetylated units (GlcNAc) in internal and
non-reducing end positions (Sørbotten et al. 2005).
Fig. 1). The DPn was calculated with the equation (Dα+
Dβ+D+Aα+Aβ+A)/(Dα+Dβ+Aα+Aβ),where Dα,
Dβ, Aα and Aβ are the integral of the reducing end
signals of the α and β anomers of the deacetylated (D)