Characteristic Chemical Constituents And Biological Activity Evaluation Of Two Sophora Medicinal Plants

This thesis consists of four chapters.Chapter 1 summarizes the research progress of quinolizidine alkaloids and biological activities in Sophora L.In chapter 2,the preparation and biological activity evaluation of alkaloids in Sophora moorcroftiana seeds were discussed in detail.In chapter 3,the preparation and biological activity evaluation of flavonoids from the branches and leaves of Sophora tonkinensis were discussed in detail.Chapter 4 summarizes and prospects the work done in this paper.Sophora mainly contain alkaloids and flavonoids,which are also the main active components of Sophora plants.Sophora moorcroftiana is a plant of Sophora Linn.The quinolizidine alkaloids contained in its seeds have significant anti-inflammatory and antiviral activities.Therefore,in this paper,the alkaloids in its seeds were systematically isolated and purified by various chromatographic methods,and the isolated structures were identified by 1D-,2D-NMR and HR-ESI-MS.Results A total of 24 alkaloids were isolated and identified,including 18 matrine type（1-18）,3cinchona alkaloid type（19-21）,1 aloperine type（22）and 2 cytisine type（23-24）alkaloids.Compounds 8,13,14,15,16 and 17 are new compounds,and compounds13,14 and 15 are new skeleton compounds derived from matrine.The isolated compounds were evaluated for LPS-induced NO production inhibition activity and hepatitis B surface antigen activity.The results of biological activity showed that compounds 3,19 and 24 had certain inhibitory activity on NO production,and their IC₅₀ values were 39.86±0.65,34.56±0.45 and 25.86±0.58μM,respectively.Unfortunately,these compounds did not significantly inhibit HBV activity.Sophora tonkinensis is also a plant of Sophora.The previous study of the research group found that its non-medicinal parts are rich in isopentenyl flavonoids.A total of 22 flavonoids were isolated and identified by various chromatographic and spectral methods,including 1 chalcone（25）,7 isoflavones（26-32）,3 flavonoids（33-35）,7 flavonols（36-42）,1 dihydroflavonol（43）and 3 dihydroflavones（44-46）.Among them,there are four new flavonols named 6-（2-hydroxy-3-methylbut-3-enyl）-8-prenylkaempferol（37）,6,8-di（2-hydroxy-3-methylbut-3-enyl）-kaempferol（39）,8-（2-hydroxy-3-methylbut-3-enyl）-kaempferol（40）,4,6,6′-trihydroxy-8-（2-hydroxy-3-methylbut-3-en1yl）-3′″,3″′-dimethylpyrano[2,3-g]-fl avone（42）.The anti-inflammatory activity of these compounds was screened.It was found that compounds 30,31,39 and 42 had obvious inhibitory activity against LPS-induced NO,and their IC₅₀ values were 19.91±1.08,35.72±2.92,33.72±2.15and 22.76±4.19μM,respectively.In this paper,some novel compounds were obtained by systematically studying the characteristic components of two Sophora medicinal plants,which enriched the types of quinolizidine alkaloids and isopentenyl flavonoids in Sophora plants.The alkaloids in the seeds of S.moorcroftiana were systematically studied for the first time,and their biological activities were evaluated.To a certain extent,the active alkaloids of S.moorcroftiana seeds were elucidated.The systematic study of the anti-inflammatory active representative component isopentenylflavones in the branches and leaves of S.tonkinensis（non-medicinal parts）provides a theoretical basis for the utilization and development of non-medicinal parts of the plant.