Extraction And Isolation Of Chemical Composition From Viola Tianshanica Maxim And Their Antioxidantive Activities

Viola tianshanica Maxim had a long history of drug use in the southern region of Xinjiang, which had the ability of clear away heat and toxic materials. Experimental results showed that Viola tianshanica Maxim contain flavonoids, volatile oil, alkaloids and amino acid etc.Because flavonoids and tannins contain phenoic hydroxyl group, and they have the effect of scavenging radical. Under normal circumstances, the free radicals in our body are always in homeostasis which have important biological functions. However, if free radical's production and removal are out of balance, it will lead to excessive accumulation in our body, which is easy to cause aging and various diseases.Many experimental studies have shown that taking antioxidant or free radical scavenger reasonably, can control these diseases, play a preventive role. So seeking a series of effective, nontoxic and economic natural antioxidants from natural plants is of great significance.Polysaccharides, flavonoids and tannins in Viola tianshanica Maxim were extracted by ultrasonic technique, determined by colorimetry.Tannins were determined by complexometric titration and phospham olybdium tungstic acid-casein method. The antioxidant activity in vitro of flavonoids and tannins from Viola tianshanica Maxim, and compaired with Tea polyphenols and VC.The results were as follows:1. We used ultrasonic technique extracte the polysaccharides, flavonoids and tannins in Viola tianshanica Maxim,the polysaccharides in Viola tianshanica Maxim was 1.911%,the flavonoids in Viola tianshanica Maxim was 1.662%. Tannins in Viola tianshanica Maxim were 0.973% and 1.363% when we used Complexometric titration and phosphomolybdium tungstic acid-casein method.2. The orthogonal experimental design showed:The optimum technologies of polysaccharides were:water as extracting solvent, extracting time was 50 mins, the ratio of material over solvent was 1:50, and the temperature was 60℃, extracting three times. The best condition for total flavonoids were:50% alcohol as extracting solvent,the temperature was 60℃extracting time was 30mins, extracting three times.The best condition for tanins were:40% acetone as extracting solvent extracting time was 30mins,the ratio of material over solvent was 1:30, extracting three times.3. The antioxidantive activity experiments of total flavonoids and tannins from Viola tianshanica Maxim showed that at certain concentrate,when the total flavonoids and tannins'concentrate were 0.14mg/mL,the scavenging rate to hydroxyl radical (·OH) were up to 63.2% and 77.3%; when the total flavonoids and tannins'concentrate were 0.10mg/mL,the scavenging rate to hydroxyl radical (·OH) were up to 82.6% and 83.1%.The total flavonoids and tannins of Viola tianshanica Maxim have scavenging efficiency to 1, 1-diphenyl-2-picryl-hydrazyl radical (DPPH-) and hydroxyl radical (·OH). In a certain scope, the effect grew stronger as mass concentration increased. When total flavonoids and tannins were used with Tea polyphenols and VC, they had a better antioxidantive activity effect.