Medicinal Plants Daisy-like Senecio Chemical Composition

With the increasing of new diseases and drug-resistance of human body, the demand of human beings for new drugs is pressing. Searching for leading compounds is the base of drug research and development, therefore the source of leading compounds is a key to new drug discovery. Nature products are proved to be one of the most valuable source of new drugs. For instance,25%to50%of currently marketed drugs are developed from natural products. As a result, the natural products route to drug discovery based on plants continues to be a proven route to the development of clinical drugs.Senecio laetus Edgew. is from the genus of Senecio, Compositae family. The plant material used in this study is collected in Guizhou province, which is traditionally used by the locals as medicine having effects on clearing fever and detoxifcation and relieving cough activities.By using silica gel column chromatography (Silica gel CC), Sephadex LH-20column chromatography (Sephadex LH-20CC), and preparing thin-layer chromatography(PTLC),20compounds were purified from Senecio laetus Edgew. Strucutures of16compounds were elucidated by UV, IR, EI-MS,'H-NMR,13C-NMR spectral techniques and X-ray diffraction experiments, including seven jacaranone derivatives: jacaranone (1), jacaranone ethyl ester(2), jacaranone methyl ester(3), 2-jacaranone acyl-α-D-glucopyranose ester(4),2-jacaranone acyl-β-D-glucopyranose ester(5),1-jacaranone ethyl ester-β-D-glucopyranoside(6),3-hydroxy-2,3-dihydrojacaranone methy ester (7); and two sesquiterpene lactones:6β-hydroxy-8/β-methoxy-eremophil-7(11)-en-12,8a-oxide (9)6β-hydroxy-eremophil-7(11)-en-12,8/β-olide(10); and four sterols: ergosta-5a,8α-epidioxy-6,22-dien-3β-ol(12), ergosta-6,9(11),22-trine-5a,8a-epidioxy-3β-ol(13), stigmasterol(15), β-sitosterol(16); and three other types of compounds: p-hydroxybenzoic acid(8), coniferyl aldehyde(11), daucosterol(14). Furthermore, compound1-7and9-13were isolated from Senecio laetus Edgew. for the first time, and the crystal data of compound10was reported for the first time.Results of this thesis provide scientific data to the conservation and sustainable use on plant resources in ethnic rural areas in China.