Investigations On Chemical Constituents And Bioactivities Of The Basidiomycete Boreostereum Vibrans And Ophiorrhiza Japonica

This dissertation is composed of two chapters.In chapter 1,the chemical constituents and possible biosynthetic pathway of some compounds of Boreostereum vibrans have been investigated.In the second chapter,chemical constituents and biological activities of some compounds of medical plant-Ophiorrhiza japonica has been studied.48 compounds,including 17 new ones,were isolated from the above mentioned species by varied chromatographic methods,and their structures were established on the basis of extensive spectroscopic analysis（including 1D and 2D NMR,MS,UV,IR,and single crystal X-ray diffraction analyses）.The compounds isolated are in indole alkaloids,cyclic dipeptides,vibralactone derivatives,benzene ring derivatives,etc.28 compouds,including 11 new compounds were isolated and identified from the fermentation（50L）of Boreostereum vibrans.Their relative configurations were deterimined by ROESY.The fungus of Stereum is mainly distributed in tropical or subtropical regions and contained many secondary metabolites with some highly active products,such as the vibralactone with good lipase inhibitory activity(IC₅₀=0.4μg/mL)which is composed of a four-memberedβ-lactone ring and five-membered ring together to form the basic ring system,isopentenyl substituted on carbon.Owing to the novel structure of its metabolites and the prospect of potential drug development,our research group has been devoted to the study of secondary metabolites of Boreostereum vibrans,exploring trace amounts of interesting natural products by expanding or changing the fermentation conditions.The plants of the genus Ophiorrhiza are herbs which commonly used in tuberculosis hemoptysis,bronchitis,irregular menstruation;topical contusion.It is meaningful and significant to study the above plants,because there are about 200species of the Ophiorrhiza plants in the world and there are more than 70 species known in China,but most of them were not studied much.We focused on separation of the alkaline part of the Ophiorrhiza japonica,19 indole alkaloids were isolated,including two pairs of new skeletons,6 new compounds.The absolute configuration of compound with new skeleton was determined by X-ray diffraction analyses.Some of the isolated compounds were screened for immunological activity.One compound showed significant selective inhibitory activity on B cell proliferation response.The SI（selective index SI=CC50/IC50）is 200.The result indicated that the compound might interfere with the activation of B cell signaling pathway.