Abstract:In order to explore the activities changed in acetylated modification of Dendrobium huoshanense polysaccharides(DHP), the study used acetic anhydride method obtained Acetylated Dendrobium huoshanense polysaccharides(A-DHP) and optimized its preparation process. Used substitution degree as indicator, the synthesis conditions of A-DHP were optimized by single-factor experiments and response surface methodology. The structure of A-DHP were characterized by Fourier Transform Infrared Spectrometer (FTIR) and Scanning Electron Microscopy (SEM). The activity changes of polysaccharides modification were detected by vitro antioxidant and antitumor experiments. The results showed that the optimal preparation conditions of A-DHP were: reaction time of 3.8 h, acetic anhydride to polysaccharides ratio of 14:1 (mL:g), and reaction temperature of 36 ℃. Under this condition, the substitution degree of A-DHP was 0.226. FTIR and SEM results confirmed that acetyl groups were successfully combined with DHP. The results of vitro antioxidant and vitro cytotoxicity experiments showed that after acetylated modification, the clearance rate of ABTS and DPPH free were increased by 14.91% and 7.76%, while the inhibitory effect on HepG2 and C918 cell were increased by 15.90% and 16.24%. In summary the antioxidant and antitumor activities of DHP can improved by acetylated modification, this study provide base theories for further investigate of acetylated polysaccharides.
