Chemical Investigation On Hericium Caputmedusae And Other Higher Fungi

This thesis is presented in six chapters.In chapters 1-5,an overview of natural occurences of higher fungi was described,and chemical constituents of four higher fungi,including Hericium caputmedusae,Hericium erinaceus,Hericium alpestre and Ganoderma lucidum,and bioactivities of several compounds were investigated.In the last chapter,research pogress about diterpenes from higher fungi was reviewed from 2013 to 2018.52 compounds,including 31 new compounds were isolated from the aforementioned higher fungi based on normal phase column chromatography on silica gel,gel-filtration Sephadex^?LH-20,medium pressure liquid chromatography and preparative high performance liquid chromatography,while the structures of these compounds were elucidated by extensive spectroscopic methods?including NMR,MS,HR-MS,IR,UV?along with comparison of optical rotation,and NMR calculation based on quatum chemistry.The classes of these compounds involved diterpenes,sesquiterpenes,meroterpenoids,polyketides,cyclopeptides,etc.Eight cyathane diterpenes,including five novel diterpenes were isolated from the culture of Hericium erinaceus.It was reported that cyathane diterpenes isolated from Hericium erinaceus can stimulate the synthesis of NGF,inducing outgrowth in PC-12 cells.Thus these novel compounds were tested on the enhancement of NGF-induced neutrite outgrowth in PC-12 cells.However,all new diterpenes exhibited no stimulation effect on the synthesis of NGF,instead some compounds exhibited significant cytotoxicities.Hericinoids B,D and E showed potent cytotoxicity against HL-60 cell lines with IC₅₀0 values of 18.39,8.97,and 0.59?M,respectively.Hericinoids D and E showed moderate cytotoxicity against MCF-7 cell lines with IC₅₀0 values from 13.49 to 15.80?M.Hericium caputmedusae is taxonomically related to Hericium erinaceus.Twenty seven meroterpenoids including twenty two novel ones were obtained from the broth of Hericium caputmedusae.Caputmedusins A–C showed moderate inhibitory activity against?-glucosidase with IC₅₀ values of 39.2,36.2 and 40.8?M,respectively.Chemical investigation of Hericium alpetres fermented on rice led to the isolation of six compounds including three novel ones.The types of these isolates were classified as meroterpenoids,polyketides,and benzene derivatives.Eleven compounds including one previously undescribed furan derivative,ten known constituents were isolated from the culture of Ganoderma lucidum,a precious species.The known compounds involved types of sesquiterpenoids,cyclopeptides and benzene derivatives.