The Research On The Biological Activity Of Secondary Metabolites Fom Gynura Divaricata Endophytic Fungi And The Relationship Between The Growth Of Gynura Divaricata With Its Endophytic Fungi

Gynura divaricata has a great pharmacological value in reducing blood sugar, blood pressure and blood lipid. Endophytic fungi one of drug sources produce the same or similar chemical compositions with the host. Because there is no report about the research on endophytic fungi from Gynura divaricata, the research chose it as a plant material to study the biological activity of the secondary metabolites from its endophytic fungi and the relationship between Gynura divaricata growth and its endophytic fungi.39 strains of endophytic fungi were isolated from Gynura divaricata by the tissue mass separation method, and 14 strains were identified through the colony morphology observation and microscopic observation. The result shows that 5 strains are Fusarium, 1 strain is Alternaria, 1 strain is Penicillium, 1 strain is Rhizopus and 1 strain is Aspergillus, 3 strains are Cephalosporium.117 samples were extracted from 39 endophytic fungi fermentation liquor using ethyl acetate, n-butyl alcohol and methanol, and their inhibitory activities for antioxidation, antibiosis and α-glucosidase were studied.Antioxidation experiments were tested by the potassium ferricyanide reduction method, the salicylic acid method and so on. The result shows that there are 7 extracted samples’ VCEAC is over 300μg/mg. The highest data is the ethyl acetate extraction from strain R-12, and its VCEAC is 959.37μg/mg, whose EC50 is higher than vitamin C. 13 extractions DPPH clearance rates reach 80%, and all samples show low hydroxyl free radical activities.(All samples’ concentration are 0.1mg/mL)The activities of antibiosis were tested by filter-paper method. The result shows that 4 samples have inhibitory effects towards 6 kinds of indicator bacteria, 11 samples have inhibitory effects towards 5 kinds of indicator bacteria. The ethyl acetate extraction from strain L-7 has a good antibiosis to Klebsiella pneumonia, Pseudomonas aeruginosa and Streptococcus uberi. The methanol extraction from strain L-4 were has a good antibiosis to Bacillus licheniformis.(All samples’ concentration are 10mg/mL)α-Glycosidase activity was assayed by the improved PNPG method. The result shows that 78 samples have α-glucosidase inhibitions, strain R-1 and S-3 have 100% inhibition, respectively.The ethyl acetate extractions play significantly higher activities against test α-glycosidase than the extractions of n-butyl alcohol and methanol.56 samples of polysaccharide were extracted from 28 endophytic fungi to study their polysaccharide extraction qualities and anti-oxidation inhibitory activities.The result shows that strain L-14 contents the largest extracellular polysaccharides. There are only 1 extracted samples’ VCEAC is over 100μg/mg, 7 extracted samples’ DPPH clearance rates reach 80%, and 11 extracted samples’ hydroxyl free radical clearance rate reach 80%.( All samples’ concentration are 1mg/mL)28 strains of endophytic fungi isolated from Gynura divaricata, were inoculated in tissue culture container seedlings of Gynura divaricata in order to find the relationship between the growth of Gynura divaricata and its endophytic fungi. The result shows that 11 endophytic fungi can grow with plants, strain L-1 and R-6 primote plant heights and increase the number of leaves, and all endophytic fungi show some inhibition to root. There are 5 endophytic fungi strains make all plants die, they are S-4、S-6、R-3、R-11 and L-9。5 endophytic fungi strains fermentation liquor added to tissue culture flasks, in order to study its effections on the growth of plantlets. The results show that the fermentation broths have no significant effects on the plantlets’ moisture content, number of leaves, plant height growth, chlorophyll content, and aboveground proline content, but show some influence on the soluble sugar content, MDA content, proline content, SOD activity.Gynura divaricata has broad development prospects, because of its aboundent endophytic fungi and its secondary metabolites which have good inhibitory activities for anti-oxidation, antibiosis and α-glucosidase.The research also make a contribution on finding the relationship between the growth of Gynura divaricata and its endophytic fungi.