Study On Chemical Constituents And Their Bioactivities Of Harrisonia Perforata (Blanco) Merr.

Harrisonia perforata（Bl.）Merr.,a shrub plant of genus Harrisonia perforata（family Simaroubaceae）.Its roots,stems,and leaves have been used as famous folk medicines for the treatment of malaria,skin ulcers,fever,cough,and sore throat.Previous studies of the fruit,branches,and stems of Harrisonia perforata have revealed that the Harrisonia perforata was a profound source of highly rearranged,complex ring system with the quassinoids and limonoids,including a C-25 quassinoid compound shows excellent insecticidal activity.In order to further enrich the diversity of the chemical constituents of the Harrisonia perforata and explore its biological activity,this thesis studied the chemical composition and biological activity of the Harrisonia perforata twigs collected from Hainan.The thesis consists of two chapters.The first chapter detailed the chemical constituents of the Harrisonia perforata twigs.At first,the LC/MS guided analysis method was established for the target C-25 quassinoid with excellent activity.As a result,the compound has been collected and guide for the subsequent separation of chemical components.Secondly,a total of 50compounds,including 14 quassinoids（2-15）,12 limonoids（1,16-26）,4 sesquiterpenoids（27-30）and 20 phenolic compounds（31-50）were obtained through various methods like MCI gel,silica gel,Sephadex LH-20,Styrogel,reverse phase C-18（RP-18）silica gel and high performance liquid chromatography（HPLC）.Their structure and relative configuration were determined by spectroscopic analysis,physicochemical characteristics,and X-ray diffraction analysis.Among them,10 new compounds were identified,including compound 1,possesses an A,B,D-seco limonoid skeleton with a highly rearranged ring B incorporating unusually exocyclic C-30.The second chapter detailed the bioactivities of the compounds of Harrisonia perforata twigs.In order to find the active chemical constituents in the Harrisonia perforata,this study carried out biological activity studies on the antioxidant activity,cotton bollworm insecticidal activity and Aβactivity.DPPH radical scavenging method was used to evaluate antioxidant activity,compound 48,49 showed strong DPPH free radical scavenging capacity with EC₅₀values of 53.88±5.34μM and 32.67±3.96μM.And then,focus on compound 1,we discussed its potential activity to anti-Aβrelated to Alzheimer’s disease.As a result,it was found that it could reduce the expression ofβ-amyloid Aβ42 and Aβ40,and showed certain activity in preventing and treating Alzheimer’s disease.The third chapter reviews the genus of Harrisonia including the main chemical constituents and bioactivities,then looking forward to the study of the genus.