Study on the extraction and antioxidant activity of total phenolic compounds from the seedpod of Nelumbo Nucifera Gaertn

The extraction technology of total phenolic compounds from the seedpod of Nelumbo nucifera Gaertn(TPNU) was studied by single-factor experiments and orthogonal test design. Furthermore,the antioxidant activities of TPNU were evaluated,using various antioxidant assays included the scavenging on DPPH,ABTS+,OH free radicals,reducing power determination,ferrous ion-chelating capacity and influence on lipid peroxidation in rats. The results showed that the optimum extraction conditions were determined by orthogonal experiment as follows:ethanol concentration 50%,solid-liquid ratio 1 ∶25,extraction temperature 80℃ and extraction time2 h,and the extraction yield was 5.23% in these conditions. TPNU had strong scavenging activity on DPPH,ABTS+and OH free radicals,also had strong reducing power and ferrous ion-chelating capacity. In addition,TPNU could significantly inhibit the brain lipid peroxidation in rats. These findings showed that TPNU had strong antioxidant activity under the optimal extraction technology.