Structural characterization and antioxidant activity of pectic polysaccharides from Veronica peregrina L

Su Yan; Xianbin Liu; Yuwen Wang; Xiaomin Yang; Lu Bai; Lin Sun; Yifa Zhou; Sisi Cui

doi:10.3389/fnut.2023.1217862

Structural characterization and antioxidant activity of pectic polysaccharides from Veronica peregrina L

Front Nutr. 2023 Jun 29:10:1217862. doi: 10.3389/fnut.2023.1217862. eCollection 2023.

Authors

Su Yan¹, Xianbin Liu¹, Yuwen Wang¹, Xiaomin Yang¹, Lu Bai¹, Lin Sun¹, Yifa Zhou¹, Sisi Cui¹

Affiliation

¹ Engineering Research Center of Glycoconjugates of Ministry of Education, Jilin Provincial Key Laboratory On Chemistry and Biology of Changbai Mountain Natural Drugs, School of Life Sciences, Northeast Normal University, Changchun, China.

Abstract

Background: Pectins are a class of acidic polysaccharides with complex structures. Different pectin molecules are composed of different domains, which have an important impact on their biological activity.

Objective: This study aimed to determine the structural features and the antioxidant activities of the pectic polysaccharides isolated from Veronica peregrina L.

Methods: The polysaccharide was isolated from Veronica peregrina L by water extraction and fractionated by ion exchange chromatography and gel permeation chromatography. The structure features of the pectic polysaccharides were determined by Fourier transforminfrared spectroscopy (FT-IR) and Nuclear magnetic resonance (NMR). The antioxidant activities was evaluated by the DPPH, OH and ABTS radical scavenging ability.

Results: WVPP-A2b and WVPP-A3b, with molecular weights of 48.7 × 10⁴ and 77.6 × 10⁴ kDa, respectively, contained homogalacturonan (HG), rhamnogalacturonan I (RG-I), and rhamnogalacturonan II (RG-II) domains with a mass ratio of 2.08:2.64:1.00 and 3.87:4.65:1:00, respectively. The RG-I domain contained an arabinogalactan II backbone and arabinans consisting of t-Araf, (1→5)-α-Araf, and (1→3,5)-α-Araf. WVPP-A3b also contained short chains consisting of the [t-Araf-(1→5)-α-Araf-(1→] structural unit. WVPP-A3b showed stronger ability to scavenge DPPH, hydroxyl, and ABTS radicals, which was potentially associated with its high content of galacturonic acid and presence of the HG domain.

Conclusion: The results provide information for enhancing knowledge of the structureactivity relationship of pectic polysaccharides from V. peregrina and their potential application in the healthcare food field.

Keywords: Veronica peregrina; antioxidant Veronica peregrina; antioxidant activity; domain; pectin; structural analysis.