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

ABSTRACT

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 80.12.3, 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.