Studies On The Micromorphological Characters Of Leaf Epidermis Of Lespedeza Michx And The Flavonoids From L. Dunnii

The Lespedeza Michx of Fabaceae are all perennial deciduous shrubs and distribute all over the world. The foregoing studies about this genus were focused on its functions as pasture, landscape plants, environmental remediation and so on, but as for the studies about systematics, especiacially about the micromorphological features of leaves, the public report hadn't been seen yet. Most Lesepezas were Chinese traditional medicine, while the medicine elements of only a few species were separated and identified. Using light microscope and SEM scanning viewing , the researching of leaf micromorphological features of 32 species and 3 variations were studied. As comparison, Campylotropis macrocarpa(Bge.) Rehd was studied, as well. Whereafter, using L.dunnii as representation, the flavonoids, one of the main officinal ingredients of Lespedezas, were studied primarily. The results were as follows:1.The micromorphological characters of the leaf epidermis of the Lespedezas distributing in China and some species in Korea, Japan and North America were reported detailedly. The results showed: Some features of the leaf epidermis such as shape of surface cells or pattern of anticlinal, inner margin of outer stomatal rim size, cuticular membrance, the cell wall etc, all showed more or less differences among the species. Those features provided some usful experimental evidences for the pharacognostical identification, division of species and systematic evolution relationships of Lespedeza.2.The leaf powder of L.dunnii.being dried under 103℃was extracted by using 70% ethanol as extracting reagent, and the flavonoids were testified to exsist in L.dunnii. by the characteristic coloration reactions of the flavaonoids and the comparison of UV and Visible spectrum between the extracted substance and rutin. The technological conditions were approached by single factor and orthogonal experiments for the extraction of the flavonoids from L.dunnii. The results showed the best technological conditions were: temperature at 75℃, the extraction reagent of 75% ethanol, material to extraction reagent 1:30, the extraction time for 3.5 hours.The flavonoids ratio yield of extraction reached 89.46% . 3. AB-8 macroporous resin could be used to purify the crude flavonoid powder extracted from the leaves of L. dunnii. The refined flavonoid powder in which the pure flavonoids reached 78.15% could be obtained after being purified by AB-8 macroporous resin. AB-8 macroporous resin had an excellent purification effect to crude flavonoid powder of L.dunnii.4. The antioxidant experiments indicated that L.dunnii flavonoids had some functions to clear free radical and superoxide anion, and the effect of clearance became more obvious with the contents of flavonoids inceased. The clearing ability of refined flavonoid powder was stronger than that of crude flavonoid powder. The POV of lard was decreased remarkably after some L.dunnii flavonoids were put into, but the degree of decreased POV was less than that of PG. The synergistic experiment showed that L.dunnii flavonoids couldn't strengthen the antioxidant ability of PG. L.dunnii flavonoids are worth exploring as a natural antioxidant material.5. The crude flavonoid powder in which the content of flavonoid was different could be gained from the leaves of L.dunnii by using methanol,elthanol and water as extracting reagent.The refined flavonoid powder in which the content of pure flavonoid reached 74.8% was obtained after being purified by AB-8 macroporous resin. All of the four kinds of flavonoid powders had some inhibition function against the yeast, fusarium graminearum, colletotrichum gloeosporioides, staphyloccus aureus, Escherichia colibacillus, bacillus subtilis but great differences were existed as the concentration of flavonoid powder and the category of bacteria changed. The abilities of L.dunnii flavonoid inhibiting Yeast, Fusarium graminearum and Colletotrichum gloeosporioides were much greater than those of Staphyloccus aureus,Escherichia colibacillus and Bacillus subtilis.The pH value had great effect , the inhibition activity of L. dunnii flavonoid against bacteria declined sharply when the pH was above or under the optimistic pH range.