| China is bestowed with a bountiful resource of Caragana Fabr. However, the exploitation and research of the species in the genus had been focused on their applications in ecological forestation and livestock forage due to the restriction of traditional concept and geographical distribution of the plants. As the result, chemical constituents and the related applications of only a few species in Caragana Fabr had been studied and there is a wide margin of researching in this area. Some researchers have presently paid great attention to C. microphylla as a plant resource of natural products. It will be of great contribution and implementation to the change of the agriculture and forestry products structure of the distributed area of the species, the west development strategy and the construction of ecological environment if the regenerative parts of C. microphylla such as stem, leaf and flower can be used efficiently and sufficiently without doing harm to the plant resource and the ecological environment. According to the deficiency of the references, flavonoid compounds in C. microphylla were studied comprehensively and systematically in this dissertation, and total flavonoids (TF) content in different organs of several species in Caragana Fabr. was also determined. Firstly, total flavonoids contents of samples from different organs of C. microphylla Lam, C. zahlbruckneri C.K. Schneid, C. arborescens(Amm) Lam, C. chinghaiensis Liou, C. boisi Schneid, C. jubata (Pall) Pior were determined with the method of spectrophotometry to learn about the general distribution of flavonoid compounds in these plants and provide theoretical basis for the comprehensive exploitation of the plants. Secondly, The seasonal changes of total flavonoid content in leaf, stem, cortex and xylem of C. microphylla in different growth periods were studied with the method of spectrophotometry. The result showed that total flavonoids content in leaf, stem, cortex and xylem of C. microphylla in different growth periods reaches two peaks in a year, with the higher one falls in September. The result will offer theoretical basis for useful parts and best exploitation time of the plant. In addition, the physiological reasons of the seasonal changes of total flavonoids content in the plant were discussed. Thirdly, different extraction methods of total flavonoids in flower, cortex and leaf of C. microphylla using ethanol, hot water and alkaline and acid were studied. It was found that the yield of flavonoids and the total flavonoids content in crude extract are both highest when ethanol was used to extract. Thus the most suitable extraction method of total flavonods in C. microphylla was chosen. Fourthly, the optimum extraction technologies of total flavonoids with ethanol in the leaf and flower of C. microphylla were determined using the factorial and orthogonal design. The optimum extraction technology in leaf is as following: ethanol concentration 60%, extracting duration 3 hours, solution/solid ratio 40:1 and extracting temperature 70℃. The optimum extraction technology in flower is as following: ethanol concentration 60%, extracting duration 7 hours, solution/solid ratio 30:1 and extracting temperature 60℃. Lastly, the content of rutin, morin and quercetin in flower, cortex and leaf of C. microphylla was determined with high performance liquid chromography (HPLC). It was found that flower, cortex and leaf of C. microphylla all contain the above-mentioned flavonoids, while the proportion of them in different organs varies. Among the three organs, flower contains the highest content of rutin that reaches 0.6448mg/g and the lowest content of quercetin that is only 0.0629 mg/g. The content of morin in cortex is the highest and reaches 0.3076mg/g and leaf contain more quercetin than other organs with a content of 0.4675 mg/g. It can be found from the result that there should be many other flavonoid compounds or other flavonoids of high content in C. microphylla.
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