Alpha-glucosidase Inhibitory Assay Guided Isolation And Idenytification Of Bioactive Constituents From Inonotus Obliquus

Inonotus obliquus is a wood-rotting fungus that has been folkly used for the treatment of cancer,heart diseases,leukemia,and diabetes in east Europe and Russia.In the first chapter of this thesis,the chemical constituents and the related biological activities of Inonotus obliquus was reviewed.In the second chaper,as guided by the in vitro ?-glucosidase inhibitory assay,twenty-nine compounds were isolated and identified from the isopropanol extract of Inonotus obliquus.Compounds 1-2 possessed an unprecedented novel skeleton,as established by spectroscopic methods(NMR,MS,and X-ray diffraction crystallography).The biosynthetic pathway of the novel skeleton was also proposed.In addition,compounds 3-12 were new lanostane-type triterpenoids.In the third chapter,24 compounds(1,3-4,7-18,20-25,27-29)of the isolates were evaluated for their in-vitro ?-glucosidase inhibitory activities.As a result,twenty-one triterpenoids of them exihibited satisfactory activities.In the subsequent study,seven compounds(1,11,12,13,14,25,and 27)that showed potent activities in the assay were investigated for their inhibition modes against ?-glucosidase.The result indicated that compounds(1,11,12,13,14,25,and 27)were potent,reverse,and competitive inhibitors of ?-glucosidase.The study revealed the antihypoglycemic effect of Inonotus obliquus from the ?-glucosidase inhibition perspective.The result of this study may lay the groundwork for the exploiment and quality control of Inonotus obliquus,and offered lead structures for the development of ?-glucosidase inhibitors.