Structure Identification, Antioxidation And Hypoglyxcemic Activities Of Anthocyanins From Purple Sweet Potato

Purple sweet potato, convolvulaceae, was a special kind of sweet potato with mauve flesh. Anthocyanins from purple sweet potato(APSP), which were nontoxic and multi-functional such as nutrition, pigmentation, health protection, had broad future of development.The molecular structures of APSP were identified. BAW was selected as the eluent of GC through TLC. After separation and purification, two anthocyanins were obtained. The experiments of PC, UV-Vis spectra and acid hydrolyzation indicated that Fra I and Fra II were peonidin-3- sophoroside-5-glucoside with different acids; the experiment of MS showed that Fra I was peonidin-3-caffeyl-eruly-sophoroside-5-glucoside, and Fra II was peonidin-3-caffeyl-p-hydroxybenzoly-sophoroside-5-glucoside.The antioxidant activities of APSP were studied: the scavenging ability on superoxide radical (O₂·^-),droxyl(·OH) and H₂O₂; the inhibition ability on oxidation of liposome in oleic acid system; the inhibition ability on spontaneous peroxidation and induced peroxidation by Fe²⁺-H₂O₂ of liposome in rat tissue homogenates in vitro. Results showed that APSP had strong capacity of scavenging O₂·^- ,OH and H₂O₂ respectively in a dose-dependent manner; APSP can stain the spontaneous oxidation of oleic acid; APSP can inhibit the generation of MDA in peroxidation of liposome obviously in a dose-dependent manner.At last, the hypoglycemic effect of APSP was investigated. Results showed that APSP had no obvious effect on blood glucose in normal rats; however APAP had remarkable (P<0.05) hypoglycemic effect on diabetic rats induced by alloxan, at a dose level of 100mg/(kg·d).