Several methods were used to extract the flavonoids from the leaves of Sargentodoxa cuneata while concentration of flavonoids in the extraction was determined by different methods. The suitable quantitative methods used in the ecological analysis of flavonids was that using ultraviolet and 70% ethanol was the best reagent for extraction. Heating was not necessary for extraction. The content of flavonoids from different organs was leafblade, annual twig, leafstalk and perennial stem in turn.
The contents of flavonoid in the leaf and stem of Sargentodoxa cuneata (Oliv.) Rehd. et Wils. were determined. In a whole growth season, the dynamic chang of flavonoid in the leafblade of S. cuneata showed the two-peak pattern. The first peak appeared at June and the second at September. The seasonal dynamic change of flavonoids in leafstalk, annual twig and perennial stem were different and inconspicuous. The flavonoid cumulated maximally in the leafblade and the followed was seccessively annual twig, leafstalk, and perennial stem. The flavonoid content in leafblade was 31.79 mg/g(DW), while that in annual twig, leafstalk and perennial stem was 5.41 mg/g(DW), 5.30 mg/g(DW) and 3.95 mg/g(DW) respectively. There was markedly higher flavonoid content in leafblade. It is considered that the leaf of Sargentodoxa cuneata is significant in further exploitation.
