Antioxidant Activity,Structure-activity Relationship,and Action Mechanism Of Flavonoids From Guangxi Jasminum Samba Leaves

Objective: This experiment by guangxi jasmine leaf as the research object,some of flavonoids in the extraction and separation,clear guangxi jasmine antioxidant activity of flavonoids in the leaves,clarify the jasmine leaf flavonoids antioxidant activity and structure-activity relationship and mechanism.Methods: Guangxi jasmine leaf extract with 95% ethanol impregnation method,and reduced pressure concentration ethanol extract of M1 points two parts: the part in turn by petroleum ether,chloroform,ethyl acetate extraction and stress concentration to the petroleum ether extract M2 ethyl acetate extract,chloroform extract M3,M4.Another part after soxhlet extracted by the reduced pressure concentration extract M5,respectively by AB-8 and H103 enrichment of two kinds of macroporous adsorption resin separation respectively to richment enrichment of M6 and M7.Each part was determined by ultraviolet light component flavonoids content,by HPLC separation conditions were determined,choose AB-8 macroporous adsorption resin in combination with the preparation of liquid chromatography separation and purification technology of flavonoids monomer,through modern spectrum and spectrum technology structure identification of the flavonoids monomer.Removal of monomer flavonoid compounds DPPH,O2-· and ·OH radicals,reducing Fe3 + and Fe2 + chelating and study the protective effect of indirect damage to DNA,and explore the antioxidant activity of structure-activityrelationship and mechanism.Results: Using spectrophotometry,rutin as the standard,drawing standard curve,the regression equation : y=10.633x-0.0008,R2=0.9995.To extract the M1,M2,M3,M4 flavonoids content,the result is: M1(0.0743g/g),M2(0.0993 g/g),M3(0.2306 g/g)?M4(0.2149 g/g)?M6(0.2943 g/g)?M7(0.2495 g/g).Got five compounds: compounds 1 Alcesefoliside;compounds 2 Mauritianin;compounds 3 Kaempferol3-O-?-L-rhamnopyranosyl-(1?6)-?-D-galactopyranoside;compounds 4Quercetin 3-?-robinobioside;compounds 5 Kaempferol 3-?-rutinoside.Experiments in antioxidant activity,five kinds of monomer flavonoid compounds to remove DPPH,O2-· and ·OH radicals,reduction of Fe3 + and Fe2 + chelating and indirect DNA damage protection showed good antioxidant activity,and antioxidant capacity and its dosage was positively related to relationship.Five kinds of monomer flavonoid compounds antioxidant activity structure-activity relationship mainly contain the following: instead of the number and location of phenolic hydroxyl group;C-2,3 a double bond;The hydroxyl glycosidation;The space structure,etc.Mechanism: is the activity of scavenging free radicals by inhibiting and to avoid oxidation damage.Conclusion: This topic from guangxi jasmine leaves five kinds of flavonoid compounds were isolated from monomer,five kinds of monomer flavonoid compounds are good antioxidant activity,and discusses its mechanism,structure-activity relationship and for further study of structure modification and synthesis of flavonoids,finding lead compounds,and pharmacological activities of jasmine flower leaves with in-depth development lay the foundation.