Studies On Flavonoid Constituents And Bioactivities Of Bidens Cernua L.

Bidens ceruna L., a herb of Compositae family, is widely distributed in many regions of China. It has been used as a folk medicine to treat neoplasms, diarrhea, traumas, sore throat and inflammations. According to the literature, it contains tannins, ascorbic acid(Vitamin C), carotene, flavonoid and essential oil. The flavonoids (butin - 7 - O -β- D - glucopyranoside, isookanin - 7 - O -β- D - glucopyranoside, quercitrin, sulfurein, maritimein), sesquiterpene phenol and cerbiden have been obtained from Bidens ceruna L. in previous studies. And sesquiterpene phenol and cerbiden have been shown to have antimicrobial, antibacterial and antifungal activity.In order to further study on the chemical constituents and bioactivities of Bidens ceruna L., the extraction, separation and determination of Bidens ceruna L. from Huinan country of Jilin Province were preformed. Flavone monomers were tested for their DPPH radical scavenging activity and inhibition activity of oxidative erythrocyte hemolysis induced by AAPH. Furthermore, the bioactivities of total flavonoids on experimental cerebral ischemia were studied also.From the EtOAc extract of Bidens ceruna L, 14 compounds were separated and identified by 1H NMR, 13C NMR, 1H-1H COSY, HMQC, HMBC, MS and IR as Quercitrin (compound 1), Butein - 4 - methoxyl - 4' - O - (6" - O - acetyl) -β- D - glucopyranoside (compound 2), Luteolin - 7 - O -β- D - glucopyranoside (compound 3) , Butein - 4' - O -β- D - glucopyranoside (compound 4), Butein - 4 - methoxyl - 4' - O -β- D - glucopyranoside (compound 5), Butin - 7 - O -β- D - glucopyranoside (compound 6), Isoquercitrin (compound 7), Sulfurein (compound 8), Daucosterol (compound 9), 3'– hydroxyl - 4'– methoxyl– 7– O–β– D– glucopyranosyl– flavonone (compound 10), 3'– methoxyl - 4', 5 - dihydroxyl - 7 - O -β- D– glucopyranosyl– flavone (compound 11), 3'– methoxyl - 4', 5– dihydroxyl– 7– O–β– D– glucopyranosyl– flavonone (compound 12), 4'– methoxyl - 3', 5– dihydroxyl– 7 - O–β– D– glucopyranosyl– flavonone (compound 13), Eriodictyol -7 - O -β- D - glucopyranoside (compound 14). Among these 14 compounds, compound 2 is new compound. All other compounds are obtained from Bidens ceruna L for the first time except for compound 1, 6 and 8.To determine the contents of three flavonoids, luteolin - 7 - O -β- D -glucopyranoside, quercitrin, butein - 4 - methoxyl - 4' - O -β- D - glucopyranoside in aerial parts of Bidens ceruna L., the separation was carried out on ZORBAX SB-C18 column (250 mm×4.6 mm,5μm), using CH3CN-H2O(0.1%HAc) (0-30 min, 16:84; 31-46 min, 24:76) as mobile phase with the rate of 1.0 mL?min-1 at 25℃,and the wavelength for measurement was set at 350 nm. The results showed that the linearity was in the range of 0.01-5.0μg for compoundsⅠ～Ⅲ, and the correlation coefficients were more than 0.9992 (n=8). The RSD of precision, stability and reprodurity for compoundsⅠ～Ⅲwere all less than 2.0%. The average recoveries (n=6) for compoundⅠ～Ⅲwere 102.8%(RSD =1.57%), 100.1%(RSD =1.29%) and 100.4%(RSD=2.07%), respectively. This method is accurate, reliable and sensitive for determination of three flavonoids in Bidens ceruna L.. The contents of compoundⅠ～Ⅲin Bidens ceruna L with different batches were determined by the above method, the results showed that their contents were less variety in diffrernt batches.In this paper, Flavone monomer were tested for their DPPH radical scavenging activity and inhibition activity for oxidative hemolysis of red blood cell induced by AAPH radical. The results showed that compound 1, 3, 4, 6, 7 and 8 exhibited a radical scavenging activity against DPPH radical with IC50 0.26, 0.21, 0.20, 0.33, 0.18, 0.35 mg·mL-1 respectively,but compound 2 and 5 have no obvious scavenging activity against DPPH radical, which have something to do with the structures of flavonoids. And compound 1, 3, 5, 6 showed varying degrees of inhibition for oxidative erythrocyte hemolysis induced by AAPH radical, and with the increase of drug concentration, the stronger the inhibition.The bioactivities of the total flavonoids extracted from the aerial parts of Bidens ceruna L. has studied in this thesis, the results showed that it has a protective effect on experimental cerebral ischemia.Compared with model group, the monitoring team(100 mg·kg -1 and 30 mg·kg -1) of the total flavonoids can enhance hyperoxide mutase SOD activities in the blood serum and the brain organization, obviously (P<0.01, P<0.05); the monitoring team (100 mg·kg -1, 30 mg·kg -1 and 10 mg·kg -1) can decrease the content of MDA in the blood serum and the brain organization, obviously (P<0.01, P<0.05, P<0.05); the monitoring team(100 mg·kg -1 and 30 mg·kg -1) can reduce the content of NO and LDH in the blood serum, obviously (P<0.01, P<0.05); various monitoring teams(100 mg·kg -1, 30 mg·kg -1 and 10 mg·kg -1) of the total flavonoids can remarkably improve nerve function damage symptom of the brain ischemia of big mouse (P<0.01, P<0.01, P<0.05); and the monitoring team(100 mg·kg -1 and 30 mg·kg -1) can reduce areas of brain stem dead and the water content of the big mouse, obviously (P<0.01, P<0.05).