Rare Sugars and Antioxidants in Itea virginica, Itea oblonga Hand.-Mazz., and Itea yunnanensis Franch Leaves

摘要

Except Itea virginica, Itea ilicifilia, and Itea yunnanensis Franch, there had been few reports of other itea plants related to rare sugars. Likewise, little had been known about the antioxidants in itea plants. In this study, the rare sugars, phenolic profiles, as well as their antioxidant activities in the itea leaves, which were from Itea virginica, Itea oblonga Hand.-Mazz., and Itea yunnanensis Franch, were determined and compared. The first discovery of D-psicose and allitol in Itea oblonga Hand.-Mazz. further demonstrated the great potential application of itea plants in the production of rare sugars. Moreover, the leaves of Itea virginica and Itea oblonga Hand.-Mazz. showed good antioxidant activities in the assays of free radical scavenging activities and reducing power. The high performance liquid chromatography-tandem mass spectrometry experiment revealed the presence of several flavonoid glycosides as major antioxidant components in these leaves. These results indicated that the itea plants, especially Itea virginica, could be used for potential antioxidants in addition to functional sweeteners.