墨脱产滇藏五味子次生代谢产物及两个二萜的合成研究

	墨脱产滇藏五味子次生代谢产物及两个二萜的合成研究; Studies on the Secondary Metabolites from Schisandra neglecta Distributed in Medog County, and Synthesis of Two Diterpenoids
	王彬
导师	普诺·白玛丹增
摘要	This dissertation reports the investigation on the chemical constituents and their biological activities of Schisandra neglecta collected from Medog County, Tibet, China, as well as the research on the total synthesis of two diterpenoids, rugosiformisin A and jiadifenoic acid A. In chapter one, the secondary metabolites of S. neglecta produced in Medog featuring special habitat, were studied. As a result, 98 compounds, including 36 new ones, were isolated from the aerial parts (5 kg) of S. neglecta. The obtained compounds involved diverse structural types, including schinortriterpenoids (SNTs), lanostane and cycloartane triterpenoids, dibenzocyclooctadiene lignans, neolignans, etc. A series of new SNTs (10, 12–17, 21) were found to show moderate protective activity against corticosterone-induced nerve injury, the cell viability of PC12 cells ranged from 62.95–66.97% under the compound concentration of 20 μM. In chapter two, the total synthesis of rugosiformisin A and jiadifenoic acid A is discussed. Rugosiformisin A is a tricyclic diterpenoid cotaining a spiro [4.5] decane motif which was isolated from Isodon rugosiformis by our research group; Jiadifenoic acid A is a diterpene dimer, and one of its monomers shares the same scaffold with rugosiformisin A. For the synthesis of rugosiformisin A, starting from geraniol, the model intermediate (2.3-22) with the same scaffold as rugosiformisin A was synthesized in 11 steps with a yield of 2.5%. For the synthesis of jiadifenoic acid A, the model compound (2.5-2) of the left diterpene monomer was synthesized via Saegusa oxidation reaction with 2.3-22 as the substrate. Meanwhile, starting from geraniol, the right diterpene monomer model compound (2.5-3) was afforded in 8 steps with a yield of 8%. Thus, model compounds of the two monomers of jiadifenoic acid A were synthesized in a total of 21 steps. Considering that the spiro [4.5] decane motif is rather common in natural products and is widely applied in drug research and development, in the chapter three, the research progress on the bioactivity and synthesis of 187 natural products with spiro [4.5] decane motif are reviewed. These compounds involve sesquiterpenoids, sesquiterpene polymers, diterpenoids, triterpenoids, tetracycline antibiotics and proaporphines alkaloids. This dissertation provides material basis for us to understand the differences between the secondary metabolites of S. neglecta distributed in different habitats, as well as to further explore the medicinal value of S. neglecta. Besides, it also enriches the research content of chemical constituents of Schisandraceae species. During the synthesis of rugosiformisin A, a Lewis acid catalyzed semi-pinanol rearrangement reaction was used to achieve the one-step construction of the diterpenoid scaffold containing a spiro[4.5]decane motif from the 6/6/6 polycyclic diterpenoid scaffold. This strategy provides a new method for bioinspired synthesis of other natural products with spiro [4.5] d
	2021-05
文献类型	学位论文
条目标识符	http://ir.kib.ac.cn/handle/151853/74569
专题	昆明植物所硕博研究生毕业学位论文
推荐引用方式 GB/T 7714	王彬. 墨脱产滇藏五味子次生代谢产物及两个二萜的合成研究, Studies on the Secondary Metabolites from Schisandra neglecta Distributed in Medog County, and Synthesis of Two Diterpenoids[D],2021.

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