Studies On The Chemical Constituents And Biological Activities Of The Underground Parts Of Three Plants

This thesis consisted of four chapters and the work during the master's study is summarized.Chapter one elaborated the chemical constituents from underground parts and biological activities of Astragalus acaulis.The studies of the chemical constituents and biological activities of the underground parts of Euphorbia jolkinii were described in the chapter two.Chapter three elaborated the chemical constituents from underground parts and biological activities of Isodon flavida,while the research progress of natural antimalarial drugs was summarized in the last part.Objective: To study the chemical constituents and biological activities of the underground parts of the three plants.Methods: The compounds were isolated with normal and reverse phase silica gel column chromatography,sephadex LH-20 column chromatography,and HPLC methods.Their structures were elucidated by physicochemical properties and spectroscopic data.In addition,biological activities of the extracts and some compounds from the three plants were studied in vitro.Results: 1: Twenty-one compounds were obtained from ether acetate and butyl-alcohol fractions derivated from the methanol extract of the underground parts of A.acaulis,and identified as liquiritigenin(1),isoliquiritigenin(2),isomucronulatol(3),syringaresinol-4-O-?-D-glucopyranoside(4),lariciresinol(5),lariciresinol-4'-O-?-D-glucopyrano-side(6),5'-methoxy lariciresinol-4'-O-?-D-glucopyranoside(7),isolariciresinol(8),p-hydroxy benzaldehyde(9),allitol(10),pentatriacontane(11),2?,3?-dihydroxyloleanolic acid(12),?-sitosterol(13),7-oxositosterol(14),7?-hydroxylsitosterol(15),daucosterol(16),?-sitosteryl-D-glucoside-6?palmitate(17),5?,8?-epidioxy-ergosta-6,22E-trien-3?-ol(18),methyl stearate(19),oleic acid(20),and methyl elaidate(21).All compounds were firstly obtained from A.acaulis.Biological activity test results showed that compounds 6-8 had good antioxidant activity while 7 and 8possessed significant peripheral analgesic effects as well.2: Fifteen compounds were obtained from ether acetate fractions derivated from the ethanol extract of the undergroundparts of E.jolkinii,and identified as 12-deoxyphorbol-17-hydroxy-13-acetate(1),3,12-deoxyphorbol-17-hydroxy-13-acetate(2),bryrospermol(3),24-methylenecycloartanol(4),nepehinol(5),24-methyltirucalla-5,24(24)-dine-3?-ol(6),?-sitosterol(7),gallic acid(8),methyl-gallate(9),dodecane(10),3?,25-dihy-droxy-tirucalla-7,23-diene(11),ent-1?,3?,16?,17-tetrahydroxyatisane(12),trilignocerin(13),ent-16?,17-dihydroxy-3-one-atisane(14),and 24-acetyl-nepehinol(15).Compounds 1 and 2are new compounds.Biological activity test results revealed that compounds 3 and 4 showed significant inhibitory effect of ?-hematin formation with IC50 value of 442.2 ± 13.44 ?g·m L-1.Compounds 5 and 6 also showed certain antimalarial activity with IC50 value of 1135.6 ±0.66 ?g·mL-1.3: Nine compounds were obtained from butyl alcohol fractions derivated from the 70% acetone extract of the underground parts of I.flavida,and identified as2,6-dimethoxybenzoquinone(1),methyl rosmarinate(2),2?-hydroxyoleanolic acid(3),1-methoxy-?-D-glucose(4),1-methoxy-?-D-glucose(5),sucrose(6),adenanthoside C(7),5?,6?-dihydroxydaucosterol(8),and glycerol digalactoside(9).All compounds were firstly obtained from I.flavida.Biological activity test results showed that compound 2 had both antioxidant activity and ?-hematin formation inhibitory effect with IC50 values 124.2 ± 2.7?g·mL-1and 163.9 ± 7.5 ?g·mL-1,respectively.Conclusion: A.acaulis is rich in flavonoids,lignans,and steroids,and part of the lignans had strong antioxidant and peripheral analgesic effects.Terpenoids are the major constituents of E.jolkinii and the two compounds separated from this plant,bryrospermol(3)and 24-methylenecycloartanol(4),may be the active monomers for the antimalarial activity of the plant.The constituents obtained from I.flavida were complicated including phenolic components,carbohydrates,and terpenoids.Bioactive study showed that I.flavida had some potential in anti-oxidation and antimalarial activity.This study provides a scientific basis for the deeper study and application of these three plants in the future.