Purification Identification And Application Research On Flavonoids And Saponins From Old Leaves Of Toona Sinensis

Toona sinensis as a kind of perennial and woody plant belongs to the family of Meliaceae, the Genus of Toona. It is widely distributed in China and has long histoiyof cultivation. Its development prospect is very broad and valuable because of its nutritive value and health function. This thesis was focused on the purification identification and application of flavonoids and saponins from the old leaves of Toona sinensis which were picked on October.The total flavonoids and saponins content of 60% ethanol (in water, V/V) heating extracts from Toona sinensis old leaves were determined by spectrophotometric method. The results showed that the quality of total flavonoids and saponins was 6.615 g±0.021g, 3.917 g+0.050 g, respectively.The absorption and desorption properties of five kinds of macroporous resin (D-101, D-312, S-8, AB-8, X-5) were screened to choose the best resin of flavonoids and saponins purification. The screening results showed that AB-8 n D-101 were suitable respectively.Thin-layer chromatography and HPLC were developed for simultaneously determining four kinds of major flavonoids compounds in the purified extract. The results showed that the percentage contents of rutin, gallic acid, quercetin and kaempferol were 1.55%,0.87%,2.27% and 1.31% from purified extract, respectively. The results of chemistry color response showed that the constituents of the saponin were steroid saponin and triterpenoid saponins.Free radical scavenging ability of total flavonoids and saponins which were disposed before and after purified investigated through antioxidant tests in vitro. The research revealed that antioxidation activity of Toona sinensis extracts increased with the augment of their concentration. The results indicated that the flavonoids in Toona sinensis leaves that of purified had a significant capacity for scavenging DPPH free radical and superoxide anion radical but less effective on scavenging hydroxyl radical. The scavenging rate was 81.32%, 74.67%, and 30.85%, respectively. The flavonoids existed in Toona sinensis leaves showed obvious antioxidant effect on soybean oil. The antioxidation activity of saponins in Toona sinensis extracts was determined under the same conditions. The capacity for scavenging DPPH free radical, superoxide anion radical, and hydroxyl radical were 71.86%,1.98%, and 38.60%, respectively. The saponins also displayed strong antioxidation activity on soybean oil obviously.