[Callus cultivation and determination of flavonoids from Tetrastigma hemsleyanum].

OBJECTIVE: The feasibility of producting flavonoids from callus of Tetrastigma hemsleyanum was investigated through callus induction, proliferation, differentiation and determination of flavonoids. METHODS: The leaves of sterile plantlet, leaves and stems of wild plants were used as explants to induce calluses; The root tuber, the leaves and calluses were selected for the determination of flavonoids. With ethanol as the solvent, the total flavonoids were extracted by ultrasonic and determined by spectrophotometry at 500 nm after stained with NaNO2-Al(NO3) 3. RESULTS: The optimum medium where the calluses were induced was 2/3MS +2.0 mg/L 6-BA +2.0 mg/L NAA; MS +2.0 mg/L 6-BA +2.0 mg/L NAA was the optimum for callus proliferation; for callus root differentiation, the optimum medium was 1/2MS +1.0 mg/L 6-BA +1.0 mg/L NAA. The content of total flavonoids was 31.121 mg/g in root tuber, 12.830 mg/g in leaves while it was up to 18.088 mg/g in calluses. CONCLUSION: The calluses had a high level of total flavonoids, it could produce flavonoids through the calluses induced by Tetrastigma hemsleyanum in a large scale. In that case, the pressing requirement in medical market will be solved.

[Morphological identification of 20 medicinal species in Hypericum].

OBJECTIVE: To provide anatomical evidences for the morphological and histological identification of 20 medicinal species in Hypericum. METHOD: Morphological and anatomical study on the organs of 20 medicinal species in Hypericum using tissue clearing, paraffin sectioning and thin sectioning. RESULT: According to their anatomical characteristics, the secretory structures can be divided into nodules, secretory cavities (canals) and tiny secretory tubes of 20 medicinal species in Hypericum. Hypericin was produced and stored in the nodules, while the volatile oil was produced and stored in the secretory cavities (canals) and tiny secretory tubes. The types differed markedly from each other in location, diameter and distributional density of leaf, and the anatomical structures differed from each other of stem, calyx, petal, anther and fruit among the 20 species in Hypericum. CONCLUSION: The secretory structures may be as anatomical evidences for the morphological and histological identification of 20 medicinal species in Hypericum.

[The development of secondary cells in the callus of Hypericum perforatum L. and hypericins accumulation].

Hypericum perforatum L. is a kind of traditional herbal medicine that has been used as an anti-depression medicine in Europe for centuries. One of its biological active compound, hypericins, is stored in the special secondary structure,black nodules,which located in the stems, leaves and flowers. Most researches focus on the development of the black nodules in vivo and how to culture the plant to produce more hypericins. We studied the process of de-differentiation from explants to callus and the pathway of hypericins biosynthesis in callus and cells of H. perforatum L. which reflected the relationship between the cell development and secondary metabolites accumulation. The morphogenesis of cells development and hypericins accumulation were studied by electron microscopy and histological technologies. Hypericins began to accumulate in a bunch of secondary cells located on the surface of the callus in late development period. Hypericins initially produced in the cytoplasm and were transported into the vacuole and then accumulated. E.R. took apart in the process of hypericins production. Theses results supplied the gap of hypericins production and accumulation in vitro and gave some useful information regarding mass-production hypericins by tissue and cell culture technology.