Studies On The Secretory Structures And Their Relation To The Content Of Hypericin In Hypericum L.

Hyericum L. is about 400 species all over the world, belongs to Clusiaceae. 55 species and 8 subspecies in 8 sections were reported in China, and the concentration region is located in southwest China. Many of them can be used as medicinal plants or ornamental plants. As for medicine, its main composition is hypericin and its derivatives which be used for antidepressant, depressing the central nervous system, and has immunotropic activity and marked anti-DNA virus and anti-RNA virus, therefore, it used as to cure AIDS in last decade. It is reported that the hypericin and its derivatives in Hypericum are accumulated in a secretory structure. Some contributions have reported about the secretory structures in Hypericum which mainly on their generation, development and histochemistry. So far, systematically reports about the comparative anatomy, histochemistry and phytochemistry, the accumulation of the secretory products and the change of ultrastructure in the cause of development of the secretory structures haven' t been seen in the genus.In the first part of the dissertation is a summary of advances in the studies of systematic and resources, morphological anatomy, chemical composition, pharmacology and clinical medicine in Hypericum. The structure, type and distribution of secretory structures of different organs in Hypericum were systematically studied using morphological anatomy (tissue clearing, paraffin sectioning and thin sectioning), phytochemistry (TLC and HPLC) and histochemistry combines with fluorescent technique, so as to determine the chemical properties of secretory products in different secretory structures and to analyze the relationship between density of nodules and hypericin content, to study the change of micro-structure and ultra-structure during the accumulation of hypericin. Then, the change of the structures, the epidermal micro-morphology and infrared spectrum of leaves in Hypericum were comparatively studied. Finally, we discussed the systematic of the genus. All results can be summarizedas follows:(1) The secretory structures exist in all organs in Hypericum according to the anatomical studies on roots, stems, and leaves, flowers and fruits. According to their anatomical characters, the secretory structures can be divided into three types: nodules (or tubular nodules), secretory cavities (or tubular cavities) and tiny secretory tubes. On the transparent leaves and perianthium, the nodules (or tubular nodules) appeared as black spots or black lines, and the secretory cavities appeared as lighter spots, lighter lines or irregular transparent spots. The nodule, which distributed in leaf, calyx, petal, connective and young stem, is composed of 1-3 layers of sheath cell which is flat in tangential direction and a cluster of secretory cells which were wrapped by the sheath cells. Secretory cavity, which distributed in leaf, calyx, petal and parenchyma of carp, is composed of one layer of sheath cells that is flat in tangential direction, and one layer of epithelial cells and a secretory cavity. Tiny secretory tube, which distributed in the phloem of root, stem, leaf, calyx, petal and carp, is composed of 4-6 epithelial cells and a secretory duct with no sheath cells around it. The types, distribution and density of secretory structures are different among different organs and plants of this genus. The results above-mentioned have provided some new basis for the classification in the genus.(2) We have carried out histochemistry location and fluorescent observation on the secretory substances in different secretory structures of Hypericum according to some specific properties of hypericin, such as its color is changed when meet with alkaline solution and Mg(CHsCOOH)2 methanol solution, deposit is created when meet with metal ion (Pb++) and it can emit red fluorescence; as well as the color of oil substances is changed when meet with Sudan black or Sudan IV. The results showed that the color of the nodules in cryosections of fresh materials and in semi-sections treated with 5% N...