Study On Flavonoids Antioxidant Of Rhododendron Dauricum L

Rhododendron dauricum L. which is also called Manshanhong or Dazixiang is the rhododendron genus plant. It is also an extensive use of plant. It has ornamental and medicinal value. It has the function of relieving a cough, eliminating phlegm and reducing asthma which is used to cure asthma and the acute and chronic bronchitis in the clinical practice. It has high curative effect, little side effect and the resource of it is very rich. It mainly distributes in the northeast areas.This article was to use the vacuum distillation to separate and extract the volatile composition of stems of Rhododendron dauricum L. and to use GC-MS to test and analysis the chemical composition of it. It was known that the key chemical volatile compositions of the stems of Rhododendron dauricum L. were trimethyl silyl methanol,4-hexene-l-alcohol, eduesmol, germacrone and terpilenol. Compared with the leaves of it, we had got the result that mostly volatile compositions of stems and leaves from Rhododendron dauricum L. were the same, but the content and some part of compositions species of them were different. The chemical compositions of different parts of the same plant was different..In addition, the content and application of total flavonoids from the leaves and stems of Rhododendron dauricum L. were explored preliminarily. Total flavonoids from leaves and stems of Rhododendron dauricum L. were obtained by ultrasonic extraction process and95%ethanol was the solvent which was used to extract flavonoids. The total flavonoids of leaves and stems from Rhododendron dauricum L. had the scavenging effects to·OH,O2-and NaNO2and the blocking effect for the synthesis of nitrosamines. The scavenging and blocking effects were increased with the concentration of total flavonoids added and the dose-effect relationship existed between them. Rhododendron dauricum L. is a kind of natural antioxidants which had scavenging effects to multiple radicals.The antibacterial effect of total flavonoids of Rhododendron dauricum L. leaves was explored in this article. The antibacterial functions of Staphylococcus aureus and Escherichia coli of extractions which obtained from petroleum ether, chloroform, ethyl acetate and aqueous phase were explored. The antibacterial effects of ethyl acetate phase and the aqueous phase were the most obvious and the petroleum ether phase was the weakest. The minimum antibacterial concentration of Staphylococcus aureus was explored and calculated. The result showed that the minimum antibacterial concentration of each phases of Staphylococcus aureus were:petroleum ether phase35mg/L, chloroform phase179mg/L, ethyl acetate278mg/L and the water phase197mg/L. The minimum antibacterial concentration of each phases of Escherichia coli were petroleum ether phase35mg/L, chloroform phase179mg/L, ethyl acetate556mg/L and the water phase394mg/LFinally, the allelopathic effects of different concentrations of flavonoid extractions which were extracted from Rhododendron dauricum L. leaves with chloroform, ethyl acetate and95%ethanol as solvents to mung bean and large leaf radish seeds. The results showed that chloroform phase extraction had functions which could promote the mung bean and large leaf radish seeds sprout. The optimal concentration of mung bean and larger leaf radishi seeds were1.86g/L and0.23g/L. Ethyl acetate phase has the functions which could inhibit the mung bean and the large leaf radish seeds germinate. The best promoting concentrations for them were0.35g/L. Ethanol phase could inhibit mung bean germinate. To make full use of the resources of Rhododendron dauricum L. in northeast Forest and provide the certain basis in the fields of agricultural production, the optimal total flavonoids concentration was explored deeply to different seeds.