Studies On Dynamics Of Polyphenols Content In Several Plant Materials In Northern Arid Region

In this study, the definition, plant polyphenols (vegetable tannin) properties and the trends of development of ecology defense and the application studies of polyphenols were reviewed. Betula platyphyll, Populus euphratica,Tamarix ramosissima,Phragmites australis,Caragana were chosen as materials in the experiment, this materials from consociation in Ej ina, Wuhai, Zhenglan Banner, Hexigten Qi of Inner Mongolia region and Chengde of Hebei in April and July.The concentrations of these phenolics from different plant and parts, different provenances and growth seasons were compared and analysed. The objective of this paper was to provide scientific methods and theories for their ecologic defensive mechanism.The powered samples were extracted with 50%aqueous acetone, and Petroleum ether as extraction solvent was added into the filtrate for removing off pigments and fat.Phenoloc hydroxyl was tested through color development reaction and the content of total polyphenols and flavanoids were determined by Folin-Denis and Al(NO3)3-NaNO2-NaOH. The following results have been obtained in this research:(1) The phenol hydroxyl existed in all experimented materials.(2) There were statistically significant differences in the concentrations of these phenolics in different part of both Populus euphratica and Tamarix ramosissima. In barks, those compounds of Populus euphratica were found at much hither levels than in leaves and branches, while, the phenolic yields of Tamarix ramosissima in leaf samples was higher than in branch sample, indicating that a larger part of the phenolic pool was incorporated into leaf surfaces cell in the barks and leaves and not into lignified cell walls in the branches.(3) Pholyphenols concentrations in plant vary in response to changes in environment conditions. We found that total polyphenols and flavanoidas concentrations of both Tamarix ramosissimaand Phragmites australi increase in responsed to stress environment except for Caragana.(4) Pholyphenols concentrations of five materials except for Caragana were higher in April than in July, indicating that phenolic concentrations in plant vary in response to changes in seasons.