共价硒化修饰对马齿苋多糖水吸附作用及抗氧化活性的影响OA

Purslane(Portulaca oleracea L.)is a plant with both medicinal and edible properties,while soluble purslane polysaccharides(POP)have multiple biological activities.However,it is still unknown whether covalent selenylation of POP could impact the water adsorption and antioxidant activity.In this study,POP was extracted from wild Portulaca oleracea and selenylated by the HNO3-Na2SeO3 reaction system.Two prepared POP products namely POPSe-I and POPSe-II had Se contents of 0.75 mg/g and 1.33 mg/g(dry weight),respectively,while POP only had Se content of 0.08 mg/g(dry weight).The results showed that the water adsorption capacity of POPSe-I and POPSe-II was lower than that of POP,and Se content showed insignificant impact on this capacity(P>0.05).The assaying results for antioxidant activity revealed that POP at 0.5-2 mg/mL caused respective 6.8%-15.7%and 36.4%-62.9%scavenging ratios for both hydroxyl and ABTS radicals and led to absorbance values of 2.079-2.183 in the Fe3+-reducing power assay.Meanwhile,POPSe-I and POPSe-II caused higher scavenging ratios for both hydroxyl(10.2%-19.9%)and ABTS radicals(40.7%-72.1%)and brought about increased absorbance values(2.102-2.243)in the Fe3+-reducing power assay.Interestingly,POPSe-II with higher Se content showed greater antioxidant activity than POPSe-I with lower Se content.It is thus concluded that this covalent selenylation reduced water adsorption of POP slightly but promoted antioxidant activity efficiently,offering new scientific basis for the application of POP in the food,pharmaceutical,and other fields.