AUTHOR=Wang Li , Mao Yi-gui , Zeng Xiang , Liu Na , Niu Chao-fei , Li Xin-xin , Ma Bing-ji , Guo Lan-ping , Yang Xiao-long 

TITLE=Structure and Bioactivities of a Novel Polysaccharide Extracted From Dendrobium huoshanense by Subcritical Water

JOURNAL=Frontiers in Nutrition

VOLUME=9

YEAR=2022

URL=https://www.frontiersin.org/journals/nutrition/articles/10.3389/fnut.2022.877871

DOI=10.3389/fnut.2022.877871

ISSN=2296-861X

ABSTRACT=<p>In this study, the polysaccharide was extracted by subcritical water from <italic>Dendrobium huoshanense</italic>. A novel polysaccharide (DHPs-1) was obtained through several purification steps and its structure and bioactivity were investigated. Structural analysis indicated that the weight-average molecular weight of DHPs-1 was 5.0 × 10<sup>4</sup> Da and it was mainly composed of glucose (65.04%), mannose (14.23%), galactose (8.17%), galacturonic acid (6.41%), rhamnose (2.34%), and xylose (1.25%). 1,4-Glc<italic>p</italic>, and 1,4,6-Gal<italic>p</italic> were existed in the backbone of DHPs-1. The residues of 1,3,4-Gal<italic>p</italic>, 1,4-Man<italic>p</italic>, 1,4-Gal<italic>p</italic>, and 1,3,4,6-Gal<italic>p</italic> could be in the backbone or the side chains with the non-reducing terminal of α-Man<italic>p</italic>. Bioactivity tests indicated that DHPs-1 had immunomodulatory activity in that it significantly enhanced transcript levels of cytokines [Tumor necrosis factor-α (TNF-α), Interleukin-6 (IL-6), Interleukin-1β (IL-1β), and Interleukin-10 (IL-10)]. DPPH and hydroxyl radical scavenging tests showed that it had good antioxidant activity. These results reveal that DHPs-1 could be developed as a safe immunomodulatory agent and antioxidant for pharmacological or functional food applications.</p>