Characterization of selenium-containing polysaccharides isolated from selenium-enriched tea and its bioactivities

• Published in: Food chemistry 2020-06, Vol.316, p.126371-126371, Article 126371
• Main Authors: Gu, Yangeng, Qiu, Yue, Wei, Xin, Li, Zhao, Hu, Zhongqiu, Gu, Yuanyuan, Zhao, Yuzhu, Wang, Yidi, Yue, Tianli, Yuan, Yahong
• Format: Article
• Language: English
• Subjects: Antioxidant; Antioxidants - pharmacology; DNA damage; Molecular Weight; Polysaccharides; Polysaccharides - chemistry; Polysaccharides - isolation & purification; Selenium; Selenium - analysis; Tea - chemistry
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2020.126371

•Two novel Se-polysaccharides, SeTPS-1 and SeTPS-2, were purified from natural Se-enriched tea.•SeTPS-1 and SeTPS-2 were characterized by FT-IR, GC, NMR, AFM, HPGPC and SEM.•SeTPS-1 and SeTPS-2 exhibited superior antioxidant effects and prevented DNA damage in vitro. Two novel selenium polysaccharide fractions (SeTPS-1 and SeTPS-2) were isolated purified, characterized from Se-enriched tea. The results showed that the molecular weights and Se content of SeTPS-1 and SeTPS-2 were 1.7 × 104 Da, 1.3 × 104 Da, and 23.50 μg/g and 13.47 μg/g, respectively. SeTPS-1 and SeTPS-2 had absorption spectra typical of selenium esters. SeTPS-1 was composed of glucose and galactose at a molar ratio of 80.1:2.3, respectively, while SeTPS-2 was composed of arabinose, glucose, galactose and galacturonic acid with a molar ratio of 2.04: 48.83: 3.21: 1.30, respectively. Both SeTPS-1 and SeTPS-2 adopted a random coil conformation. Importantly, in vitro assessment of the antioxidant capacity revealed that SeTPS-1 is a more potent antioxidant compared to SeTPS-2. Both compounds were effective at reducing DNA damage induced by H2O2. The promising data suggesting that these compounds confer natural protection against DNA-damaging agents, thereby contributing to the functional food qualities of tea.