AUTHOR=An Feiyu , Ren Guangyu , Wu Junrui , Cao Kaixin , Li Mo , Liu Yumeng , Liu Yanfeng , Hu Xinyu , Song Meijun , Wu Rina 

TITLE=Extraction, purification, structural characterization, and antioxidant activity of a novel polysaccharide from Lonicera japonica Thunb.

JOURNAL=Frontiers in Nutrition

VOLUME=9

YEAR=2022

URL=https://www.frontiersin.org/journals/nutrition/articles/10.3389/fnut.2022.1035760

DOI=10.3389/fnut.2022.1035760

ISSN=2296-861X

ABSTRACT=<p>A novel water-soluble polysaccharide (HEP-4) with a molecular weight of 1.98 × 10<sup>5</sup>Da was extracted from honeysuckle. Structural characterization was performed using high-performance liquid chromatography (HPLC), gas chromatography, Fourier transform-infrared (FT-IR) spectrum, nucleus magnetic resonance (NMR) spectra, and scanning electron microscopy. The results showed that HEP-4 is primarily composed of mannose, rhamnose, galacturonic acid, glucose, galactose, and arabinose with a mole ratio of 6.74:1.56:1.04:14.21:4.31:5.4, and the major types of the glycosidic bond types of HEP-4 were 1-α-D-Glc<italic>p</italic>, 1,4-β-D-Glc<italic>p</italic>, 1-β-D-Ara<italic>p</italic>, 1,3,4-β-D-Ara<italic>p</italic>, and 1,3,6-β-D-Man<italic>p</italic>. The results of bioactivity experiments revealed that HEP-4 had antioxidant <italic>in vitro</italic>. In addition, HEP-4 inhibited H<sub>2</sub>O<sub>2</sub>-induced oxidative damage and increased the activity of HepG2 cells by reducing MDA levels and inhibiting ROS production. Meanwhile, HEP-4 significantly enhanced the activities of GSH-Px and CAT, indicating that HEP-4 exerts a protective effect on H<sub>2</sub>O<sub>2</sub>-induced oxidative stress. These results indicate that HEP-4 could be a potential natural antioxidant.</p>