The Temporal And Spatial Distribution Of Contents Of Flavonoids In Ginkgo Biloba L.

Ginkgo biloba L. a dioecious, precious relict plant which contains rich flavonoids, terpene lactone and polyprenols with important biological activities producing from secondary metabolites, originated from China, has been known as "living fossil " with important value of research and utilization. The content of flavonoid compounds is an important quality indicator for national standard of " Grades of seed stone quality for ginkgo" and seed stone, extraction of Ginkgo biloba EGb productions in the international market. With the standardized implementation use of nuclears and leaves of ginkgo and the rapid development of the ginkgo production industry, the need for varieties structure of nuclear and leaf with high content of flavonoids is urgent to promote the upgrading of Ginkgo industry and sustinable development. In this study, A total of 15 male and 15 female plants with the same cultivation and management are 13 years old from Yangzhou University ginkgo germplasm, where the female plants for the main cultivars are Buddha finger, horse bell and round stone types. In 2013-2014. the tested plants were randomly taken 100 pieces of leaves from April to October, but the nuclear plants were randomly taken 50 seeds from July to October. Rutin, quercetin, kaempferol and isorhamnetin were extracted from leaves, seeds, exotesta by applying response surface method and then were determined by HPLC, solid-liquid ratio, solvent concentration, extraction time, extraction temperature and other major role that influencing flavonoids content factors were optimized to response surface method, At the same time measured seed size, weight, water content, soluble sugar, starch, protein and fat content were measured. The main results were as followings:1. The regression equation of the yield of rutin (Y) according to the solid liquid ration (A), the concentration of ethanlol (B), extraction time (C), extraction temperature (D) is Y=+0.94-0.041 A+0.055B-9.773*10-3C+0.018D-8.959*10-3 AB-0.090AC+0.038AD-0.060BC-0.1 4B D-0.075CD-0.066 A2-0.079B2-0.11C2-0.30D2(R2=0.9286), existing interaction between the main factors. The optimization system that maximize the extraction of rutin were 1:17.11 (A), 71.92%(B),38.93min(C),70.24℃(D), in this condition, the maximize extraction of rutin was 0.940767mg/g.2. The optimization extraction system to extract quercetin, kaempferol, isorhamnetin from ginkgo leaves was liquid ratio of 1:15,70% ethanol-25% hydrochloric acid 4:1, extraction temperature 80℃, extraction time 40min, ultrasonic extraction time 2. They were determinated by RP-HPLC,and then calculated as quercetin glycosides, kaempferol glycosides, isorhamnetin glycosides by Hasler three-factor method that coefficients were 2.51,2.64,2.39, in this way, total flavonoids of leaves were measured.3. Seasonal changes of rutin of male and female plants leaves showed the different trend, decreased by April of 1.749mg/g and 1.699mg/g to August of 0.772mg/g and September of 0.762mg/g, after the emergence of up to October’s 1.111mg/g and 0.968mg/g. The content of rutin of female plant leaf was higher than male plants in June and July, but the difference was not significant, so male plant with high content of flavonoids as quality resources had more productive and theoretical significance.4. Seasonal variation of the content of quercetin, kaempferol, isorhamnetin was basically same with flavonoids. The content of Male’s and female’s flavonoid in April were 4.347mg/g and 3.458mg/g as the highest value. after a declining trend, The contents of female plants were peaked in June and September, but male plants only peaked in September. Between male and female plants the content of flavonoids, quercetin,and Isorhamnetin were not significantly different, kaempferol were significant.5. The seasonal content of flavonoids from kernels changed same with exotesta which had significant correlation (r=0.970**). Their content of flavonoids in July were 0.1070mg/g and 0.0989 mg/g, after declining to a trough in September, which then began to rise, until October their contents were 0.0049mg/g and 0.0048mg/g.6. JSYX-2, JSYX-4, JSYX-11, JSYX-12, JSYX-13, which the content of flavonoids of leaves, exotesta, seeds, reached a significant level, JSYX-11 was the highest in leaves, JSYX-12 are the highest in kernels and exotesta. Between strains of kernels of soluble sugar, starch, protein, fat content difference reached a significant level, its highest respectively JSYX-12, JSYX-4, JSYX-13, JSYX-13, the contents respectively were 3.689%,68.849%, 4.354%,5.500%.7. By cluster analysis, the tested male plants can be divided into four categories. Class IV included 3-9,3-10,9-12,3-1,7-9 with high content of flavonoids, rutin, quercetin, kaempferol, and isorhamnetin, these compounds contents averages were 1.0056mg/g,0.3468mg/g, 0.4916mg/g,0.2554mg/g and 2.2814mg/g in September, can be recommended as selected plant for leaf-purpose.8. Female plants were divided into two categories by cluster analysis, the category I had higher content of flavonoids, which includes 6-5,9-15,10-1,2-15,4-9, Where the average weight of single was 2.236g, average length of kernel was 2.454cm, average width of kernel was 1.643cm, average thickness of kernel was 1.0407cm, average of rate of nucleation was 28.376%, average of rate of kernel was 88.018%, total flavonoids the average content was 0.000862%.