Study On The Chemical Constituents Of Epimedium Koreanum Nakai And Epimedium Wanshanense

This doctoral dissertation deals with the study on the chemical constituents of Epimedium koreanum Nakai (Berberidaceae) recorded in the Chinese Pharmacopoeia (1990), and of E. wanshanense a newly named species of the genus.Forty four (1~44) natural products were isolated from the EtOAc extract of the aerial part of E. koreanum . On the basis of physicochemical properties and spectroscopic analyses, 2,9,10, 11,14,16,18,26,31,36 and 44 were determined to be eleven new compounds. They were named as follows: epimedokoreanone A(2); epimedokoreanin A(18),B(9),C(14) ,D(36); epimedoicarisoside A(44); caohuoside A(10), B(11), C(26), D(16) and E(31).Sixteen (45~60) known compounds were obtained from the EtOAc and n—BuOH extract of the whole plant of E. wanshanense.In the course of structural elucidation of the new compounds, techniques such as 2D NMR including 1H-1H COSY, 1H-13C COSY, 1H-1H TOCSY and 1H-13C long range COSY (HMBC) besides IR, UV, MS and 1D NMR, were extensively employed.On the basis of 2D NMR spectral analyses, the disaccharide of 27 and 38, as well as 29 (58) , 30, 32(59),33(48),34,49,50,52,53,54 was confirmed as 1→2 linkage. With this set of criteria, the literatures published 3—O—L—rhamnosyl— (1→2/1→4) —L — rhamnoside, 3—O -D—xylosyl— (1→2/1→4) -L-rhamnoside and 3-O-D — glucosyl- (1 →2/1→4) —L — rhamnoside structures of anhydroicaritin and desmethylanhydroicaritin were re-evaluated.The 13C NMR chemical shift assignments for C—5, C—7 and C—4' published in literatures for some anhydroicaritin and desmethylanhydroicaritin glycosides were re-appraised by analysing the cross—peaks in HMBC spectra of 10 and 27 and the chemical shift effects of glycosylation and methylation of phenoxyl groups and prenylation in flavonoids.Pharmacological tests revealed that hyperoside (5) possessed marked antioxidative activity. The biological activities of other isolated compounds are currently under investigation.Recent advances on the study of medicinal plants from the genus Epimedium, an outline on the research of icariin in China, and the resources and bioactivities of prenoid — substituted flavonoids were also reviewed.