Studies On Chemical Constituents Of Hypericum Hookerianum And Tetradium Trichotomum

Natural products is a very important resource for drug discovery.The chemical constituents of two medicinal plants Hypericum hookerianum and Tetradium trichotomum were studied in this thesis.A total of 54 compounds,including 14 new compounds,were isolated by mean of column chromatographys of macroporous resin,MCI,silica gel,ODS,cation exchange resin and preparative HPLC,and identified through comprehensive analyses of NMR,MS,IR,UV,CD,ORD and other spectroscopic techniques.In chapter 1,polycyclic polyprenylated acylphloroglucinols(PPAPs),the characteristic metabolites of Hypericum genus,were summarized according to their structures from the view of biosynthetic pathway,and some of their biological activities were reviewed.In chapter 2,a study on chemical components of H.hookerianum is described.Thirty-four compounds,including 7 new ones(1-7),were separated from the aerial part of H.hookerianum.The isolated compounds included 14 monocyclic PPAPs,10 bicyclic PPAPs,2 simple acylphloroglucinols,5 terpenoids,2 steroids and one xanthone.Among the compounds,1-4 were monocyclic PPAPs with a menthane-type monoterpene,which have a keto-enol tautomerism caused byβ,β’-triketone moiety.Compounds 5,6,8 and 9 were monocyclic PPAPs with an osmane-type monoterpene.Compounds 7 and 10 - 14 were spirocyclic PPAPs with a octahydrospiro-[cyclohexan-1,5′-indene] core.The 1D NMR rules of some PPAPs were summarized at the same time.This study enriches the types of PPAPs and provides material basis for the study on medicinal effects of this genus.In chapter 3,the origins,representative compounds and bioactivities of different types of alkaloids in Tetradium plants such as indole,quinolones and quinolines were outlined.In chapter 4,the chemical compositions of the stems of T.trichotomum were studied.Twenty compounds comprising of 18 alkaloids with the structure-types of rutaecarpine,phenethylamide,quinolone were isolated.Among which,7 alkaloids(35-39,40 a and 40b)were identified to be new compounds.Phenethylamides 35-39 were analysed to be racemes by the chiral HPLC.Compounds 40 a and 40 b were a pair of enantiomeric rutaecarpines.This study improves the understanding of phytochemistry of T.trichotomum,enriches the small molecule library of alkaloids,and also provides a material basis for the further study on their bioactivities.