Chemical Constituents Of Three Dendrobium Plants And Their Activities

This dissertation elaborated the investigations of the chemical constituents of three Dendrobium plants (Orchidaceae), Dendrobium findlayanum Par. et Rchb. f, D. aphyllum (Roxb.) C. E. Fischer, D. crystallinum Rchb. f. All of the components were separated by column chromatography (siliga gel, sephadex LH-20, RP-18, MPLC and semipro-HPLC).111compounds, including33new ones, were isolated by a variety of chromatographic methods and their structrues were elucidated on the basis of extensive spectroscopie methods (UV, IR, MS,1D-and2D-NMR). The types of structures among the isolated compounds include sesquiterpenoids, alkaloids, stilbenes, phenanthrenes, flavonoids, phenylpropanoids, lignans and their derivatives, and so on. Through collaboration with other researchers, some of the isolated compounds were evaluated for anti-tumor activity in vitro, the effect on the activity of acetylcholine esterase (AChE), the effect on the activity of butyrylcholine esterase (BuChE), the effect on Neurite outgrowth-promoting activity of pheochromocytorna cells (PC12cells), the inhibitors of NF-κB signaling pathway, the inhibitory activities on nitric oxide production and the DPPH radical scavenging activity.The main results of this dissertation are as follows:1) Seven new novel alkaloids related to three kinds of unprecedented backbones;2) Two (propylphenyl) bibenzzyl derivatives (dendrofindlaphenol A and dendrofindlaphenol B) showed significant activity in inhibiting tumor cell (HL-60, A549, SMMC-7721, MCF-7, SW480) grouth in vitro, and dendrofindlaphenol A with IC50(μM) value2.25,5.06,4.36,4.69and5.29, cisplatin used as positive control with IC50(μM) value1.01,5.29,6.13,13.62and14.03.In addition, the progress on chemical constituents of the sesquiterpenoids and alkaloids from Dendrobium plants was reviewed.