Isolation And Identification Of Flavonoids And Saponins From Old Leaves Of Toona Sinensis And Their Antioxidant Activies

Toona sinensis as a kind of perennial and woody plant belongs to the family of Meliaceae.The buds have unique flavor and rich nutrition which is China's specialty vegetables which has been distributed for over two thousand years.It is widely planted in south China and other regions and welcomed by the majority of people.According to a large number of studies,the extracts of Toona sinensis leaves have anti-oxidation,hypoglycemic,anti-tumor and other biological activity,but the type and chemical structure of flavonoids and saponins has not fully clear.In this paper,using the conventional method to separate and purificate flavonoids monomer and high purity of saponins,and the preliminary study in vitro antioxidant activity,get the following conclusion to study the antioxidant activity in vitro.Experimental results are as follows.According to the macroporous resin adsorption and desorption properties of flavonoids and saponins,compared with different types of resin such as D101,AB-8,Sp700,LX-20,D3520,S-8 and screened out suitable macroporous resin for the old leaves of total flavonoids and saponins were AB-8 and D.101.The results showed that stepcompounds were identified by column chromatography and high performance liquid chromatography(HPLC),Getting six monomer flavonoids by NMR and IR spectroscopic analysis:(?)rutin(?)epicatechin(?)quercetin(?)isoquercetin(?)Sammangaoside A(?)Guavain.The preliminary qualitative identification of toon saponins by color reaction included steroidal saponins and triterpenoid saponins.In vitro antioxidant activity of extracts of total flavonoids and total saponins before and after purification showed that the anti-oxidant effect increased by increasing of extract concentration.By comparing the antioxidative effect of each monomer compounds shows that rutin>isoquercetin>guavain>quercitrin>Sammangaoside A>epicatechin.Purified crude extract,the antioxidant effect was significantly enhanced.The results showed that the extraction rate of(DPPH·)of the extract from Toona sinensis flavonoids mixture was higher,reaching 90.35%,slightly lower ability to scavenge(O2-),and the clearance rate was 80.93%.The saponin extract(DPPH·)scavenging rate reached 68.18%,the crude extract was 30.15%.Saponin crude extract on the ability to clear(O2-)to reach 60.64%,the crude extract was 36.80%,the data shows that flavonoids and saponins purified antioxidant capacity has improved significantly.