Preparation And Bioactivity Evaluation Of Flavonoids From Sophora Flavescens

This thesis consists of three parts.The first part reviews the research progress of the chemical constituents and biological activities of flavonoids from S.flavescens.The second part discusses the phytochemistical and bioactive studies on S.flavescens.The third part summarizes the work in this paper.S.flavescens is a kind of Sophora plants,and it is one of the common Chinese medicines.It is cold-natured and bitter in taste.It has the effectiveness of clearing heat,drying and dampness,killing insects and diuresis.Flavonoids are one of the main active components in S.flavescens.Recent studies have shown that the flavonoids in this genus are mostly substituted by isopentenyl,and have many potential medicinal values.Therefore,the study on the isopentenyl flavonoid and its biological activities of S.flavescens is beneficial to the further development and utilization of the medicinal plant resources.A total of 55 compounds were isolated and identified,including 18 dihydroflavonoids（1-18）,7 flavonols（19-25）,4 dihydroflavonols（26-29）,3 isoflavones（30-32）,4 chalcones（33-36）,8 pterocarpane derivatives（37-44）,4 phloroglucinols（45-48）,3 stilbenes（49-51）,2phenylpropanoids（53 and 54）and one carbohydrate（55）.The structures of the compounds were identified by 1D,2D-NMR and MS techniques.Among them,there are six new compounds,namely sophoraflavanol A（17）,sophoraflavanol B（18）,3-hydroxy-5α-methoxydicarpin（39）,flavescensin A（44）,flavescenol A（45）,and flavescenol B（46）.All the monomers were screened for H1N1,anti-inflammatory and anti-tumor activities in vitro.The results showed that flavonoids 10,15,19 and 25 had moderate anti influenza activity with EC₅₀ of 43.9,38.1,23.8 and 32.0μM,respectively.Compounds 1,2,3,4,11,12,13,15,16,19,21,22,29,33,34,36,41 and 45 significantly inhibited no induced by LPS,with IC₅₀ of38.31,8.39,38.24,33.60,43.62,11.25,14.43,9.30,16.24,12.40,12.22,5.73,23.76,4.62,39.03,6.77,41.88 and 32.29μM,respectively.Compounds 5,16,19,21,22,35,36 and 45 showed obvious inhibitory effects on the growth of tumor sensitive strains,with IC₅₀ of 37.62,30.76,41.40,26.39,0.46,48.63,46.24 and 34.90μM,respectively.Compounds 3 and 15 inhibited the growth of drug-resistant tumor cells,and the IC₅₀ were 22.77 and 33.20μM,respectively.