Studies On Chemical Constituents Of Rhododendron Concinnum And On Volatile Constituents Of Rhododendronpurdomii And Rhododendron Concinnum

More than eight hundred rhododendron plants, most of which are evergreen frutices or arbores, are widely distributed in the frigid zone and temperate zone of the Northern Hemisphere, South Asia, Malaya and the Oceanian alp zone. A variety of rhododendron plants (more than seven hundred) are widespread in China, mostly in Southeast China.The rhododendron plants are now used as effective medicines for chronic tracheitis and have effects of making bloods active, balancing menstrual flows, getting rid of rheumatisms, relieving a cough, driving away sputums, relieving an asthma, and so on. In addition, it was reported that some rhododendron plants have the effects of lowering blood pressure. Researchers have investigated chemical components and pharmacology of several rhododendron plants. The main active components from the rhododendron plants are flavones, volatile alkenes and diterpenes. However, no studies on chemical components of Rhododendron concinnum have been reported. In this dissertation, we have investigated the components of Rhododendron concinnum, and hope to provide the theoretical basis for its pharmacology activity studies.This dissertation includes studies regarding the chemical constituents of alcoholic extraction of Rhododendron concinnum. Twenty compounds have been isolated and purified by crystallization, re-crystallization, polyamide and silica gel column chromatography;eighteen of them have been identified on basis of modern spectral techniques such as EI-MS, FAB-MS, ESI(NI)-MS, NMR, CD. Compounds that have been identified from Rhododendron concinnum are as follows: (S)-4',5,7-trihydroxy-flavanone(1), (2R,3R)-(+)-texifolin(2), aricularin(3),quercetin-3-O-β-D-rhamnoside(4), hyperoside(5), quercetin(6), 19-kaurene acid(7), isoscopoletin(8), ledol(9), stigmast-4-en-6p-ol-3-one(10), β-amyrin(11), a-amyrin(12), Lupeol(13), 28-OH-β- amyrin(14), uvaol(15), oleanolic acid(16), p-sitosterol(17), P-daucosterol(18). All of them are isolated from Rhododendron concinnum for the first time, in which (1), (7), (8), (9) and (10) are isolated for the first time fromrhododendron plants.This dissertation also includes analyses of volatile oils from Rhododendron concinnum and Rhododendron purdomii, which were obtained by means of SPE-CO2 and SD extraction, and the chemical constituents of extractions have been identified by GC-MS. Forty one and eighty three compounds have been identified respectively from Rhododendron purdomii Rehd.et Wils.volatile oil, mainly including a-caryophyllene, caryophyllene, trans-nerolidol and cadina-l(10),4-diene. Twenty and twenty nine compounds have been identified respectively from Rhododendron concinnum, mainly including dehydroxy-isocalamendiol,germacra-3,7(ll),9-trien-6-one, lup-20(29)-en-3p-ol acetate and lupeol. We have investigated pharmacological activity of volatile oil from Rhododendron purdomii. The result shows the volatile oil inhibits MDA formation induced by Fe2+-Vit C in liver and kidney slurry of mice, which will provide gist for developing and utilizing Rhododendron purdomii.