| The dissertation described the studies on the chemical constituents of Uncaria scandens.Uncaria scandens is a kind of Uncaria plant in Rubiaceae,which is a common plant medicine of Tibetan,Dai and Jinuo nationality.However,the reports of pharmacodynamic bases on Uncaria scandens was inadequate.By the means of chromatography and spectroscopic evidences,38 compounds were isolated and identified from this plant,including 10 news(scandines A-J).The classifications of compounds mainly contain alkaloids,triterpenoids,phenylpropanoids,flavonoids and organic acids,etc.In addition,we studied a lot of activities about new compounds,including tumor cytotoxicity,inhibition of NO production and relaxation of vascular smooth muscle.The first chapter introduced the chemical constituents on Uncaria scandens.Thirty-eight compounds were isolated and identified from the 95%ethanol extract of this plant,including 10 new compounds(scandines A-J).Scandines A-D(2-5)were a series of new monoterpenoid indole alkaloids,and derived from the oxidation or epoxidation of the C18-C19 terminal double bond of the common corynanthe indole alkaloids.Scandine E(14),a new monoterpenoid indole-pyridine alkaloid,was not reported in precedent studies.Scandines F-G(19-20)were two new monoterpenoid oxyindole alkaloids.Scandine H(22)was a new indolicidine alkaloid.Scandine Ⅰ(29)was a new ursane triterpenoid.Scandine J(33)was a new dibenzyl compound.In addition,20 known compounds(6-13,15-18,23,31-32,and 34-38)were isolated from the plant for the first time.The results of this experiment further enriched the research content of chemical composition of this plant.The second chapter described the study of bioactivity of the new compounds isolated from Uncaria scandens.All the new compounds were screened for cytotoxic activity.And it found that scandine J(33)significantly inhibited the proliferation of HL-60,A-549,SMMC-7721,MCF-7 and SW480,with IC50 values of 15.72,17.40,17.45,15.58 and 12.87 μM,respectively.The results of NO generation inhibitory activity screening showed that all the new compounds did not have obvious activities,but scandine J showed obvious toxicity to RAW264.7 cells at 50μM concentration.Compounds 2,3 and 29 were evaluated for the diastolic activities of rat thoracic aortic smooth muscle in vitro.The results showed that scandine A(2)had a certain diastolic activity on noradrenaline induced contraction of rat thoracic aortic smooth muscle(IC50=15.27 μM).The third chapter introduced the progresses of chemical constituents and pharmacological activities of monoterpenoid indole alkaloids from 2010 to 2019.Since 2010,139 monoterpenoid indole alkaloids have been isolated from various plants.The pharmacological activities of these monoterpenoid indole alkaloids are mainly related to antihypertensive,anti-tumor,anti-bacterial,anti-inflammatory and antiviral effects. |
