Studies On Chemical Constituents And Bioactivities Of Inula Racemosa And Amoora Tsangii

This dissertation covers the phytochemical studies of two medicinal plants(Inula racemosa Hook.f. and Amoora tsangii (Merr.) X. M. Chen). A total of54compounds including10new ones were isolated through various separation techniques and structurally identified on the basis of diverse spectroscopic methods, single crystal X-ray diffraction analysis, and CD spectroscopic methods.A total of42compounds (Ir1-Ir42) including30sesquiterpenoids were isolated from the root of Inula racemosa, seven of which were new compounds. Compounds Ir1-Ir4were four new eudesmane-type sesquiterpene lactones. Compound Ir5was a new eremophilane-type sesquiterpene lactone. Compounds Ir6and Ir8were two new trinorsesquiterpenes. Furthermore, the structure of compound Ir7was revised from (4aR,5S,8aR)-4a,5,6,7,8,8a-hexahydro-4a-hydroxy-5,8a-dimethylnaphthalen-2(1H)-one to racemosalactone G with X-ray analysis. The absolute configuration of compounds Ir2and Ir6-Ir8were determined by X-ray diffraction analysis and CD spectra.Furthermore, a method for the rapid and straightforward preparative-scale isolation of compound Ir9from alantolides is described.Compounds Ir1-Ir28were screened for their cytotoxic activities against human non-small lung cancer A549, hepatocellular carcinoma HepG2, and human fibrosarcoma HT1080cell lines. Compounds Ir1,7,9,11,13,17, and20exhibited cytotoxic activities with1C5O values ranging from0.38to5.94μg/mL against three human cancer cell lines, and their structure-activity realationships were also discussed.Compounds Ir9and Ir11exhibited cytotoxic activities against HUVEC with IC50values of2.4and2.5μg/mL, respectively. Furthermore, compounds Ir9and Ir11both inhibited endothelial cell tube formation at1.0μg/mL.The antibacterial activities of some sesquiterpenoids were studied. Compound Ir9displaying moderate antibacterial activities against Bacillus cereus (L), Bacillus subtilis (K), and Escherichia coli with MIC values of62.5μg/mL. Compound Ir11also displaying moderate antibacterial activities against Bacillus cereus (L), Bacillus subtilis (K), and Eschrichia coli with MIC values of62.5,31.25and62.5μg/mL, respectivly.The antifungal activities of compounds Ir9and Ir11were also studied. Compounds Ir9and Ir11exhibited moderate inhibitory activities against five plant pathogenic fungi:Botrytis cineren, Fusarium oxysporum f. sp. Niveum, Sclerotinia sclerotiorum, Helminthosporium sativum, and Penicillium digitatum with EC50values ranging from23.56to92.31μg/mL.A total of12triterpenoids (At1—At12) including two lupine alkyl-type, two nor-dammarane-type, and seven cycloartan-type triterpenoids were isolated from stems of Amoora tsangii, three of which were new compounds. Compounds At1, At2, At3, and At10were rare29-nor-cycloartan-type triterpenoids, compound At12was rare28,29-dinor-cycloartan-type triterpenoids,and compounds At8and At9were two trinor-dammarane-type triterpenoids.Finally, the chemical constituents and their bioactivities of the species of genus Dysoxylum reported from1976were reviewed. This review demonstrated that the genus of Dysoxylum is a rich source of bioactive natural products with chemical diversity.