Extraction, Purification, Component Analysis And Antioxidant Activities Of Flavonids From Curcuma Phaeocaulis Leaves

Curcuma phaeocaulis Valeton,a perennial herbaceous plant of the family Zingiberaceae,has the effect of destroying blood and eliminating pain.In this paper,the total flavonoids of C.phaeocaulis leaves were extracted by ethanol extraction method,and purified by macroporous resins.In order to study its biological activity ingredient,the preliminary analysis and its antioxidant activity were evaluated.Since C.phaeocaulis rhizomes as medicinal parts,the results of study can promote the full development and effective utilization of Curcuma resources,and provide the theoretical basis for the development and industrial production of flavonoids.The main results are as follows:1.The extraction process of flavonoids from C.phaeocaulis leaves was carried out by ethanol extraction method.The yield of flavonoids was 1.024%by response surface analysis,while C.phaeocaulis rhizomes were extracted with the same method.The yield of flavonoids only was 0.561%,it indicated that the flavonoid yield of leaves was about 1.8 times that of rhizomes.Therefore,C.phaeocaulis leaves were more valuable for flavonoids.As the results showed,the best extracting parameters of total flavonoids from C.phaeocaulis leaves were ethanol concentration 70%,ratio of liquid to solid 25 mL/g,extraction time 100 min,extracting temperature 80 ℃.2.The flavonids of C.phaeocaulis leaves extracted was purified by macroporous resins.AB-8 was selected from 8 kinds of macroporous resins to isolate and purify the flavonoids.The optimum conditions of purification of total flavonoids from C.phaeocaulis leaves were determined by static,dynamic adsorption and desorption experiments of macroporous resin,and the optimum conditions were sample pH value 5.34,concentration 0.3601 mg/mL,eluent concentration 80%ethanol,eluent pH value 8.12,eluent rate 2.0 mL/min and the volume of eluent 100 mL.Under this condition,the content of total flavonoids in C.phaeocaulis leaves was 36.65%,and the content of flavonoids before purification was 20.73%,differing 13.9%,the yield was 61.4%,Compared with the total amount of flavonoids before purification was significantly improved,the enrichment effect is good.3.The reducing power and scavenging ability of DPPH,hydroxyl radical and superoxide anion of purified and unprified flavonoids of C.phaeocaulis leaves were determined. The result shows that purified flavonoids was higher than that of unpurified.The IC50 values of scavenging ability of DPPH,hydroxyl radical and superoxide anion of purified flavonoids were 0.382 mg/mL,0.276 mg/mL and 0.119 mg/mL.In the anti-oxidation test of lard,the higher concentration of flavonoids of C.phaeocaulis leaves,the higher anti-oxidation effect,but the purified flavonoids still contained other impurities,which may also affect the antioxidant effect.In the minimum inhibitory concentration determination,it indicated that the flavonoids have a certain inhibitory effect.4.After the flavonoids were purified,the components were preliminarily analyzed.The flavonoids contain specific functional groups that react with different compounds that differ in oxidation or reducing ability,which caused color changes.According to the color changes,it could be speculated there were flavonoids and flavonols.The purified flavonids were isolated into four components by silica gel column.Through the characteristic UV spectrum of flavonoids and the displacement change of the UV spectrum adding shift agents,the positions of flavonids substituent were speculated that flavonols of the third component was determined and 7-OH,4’-OH around had ophenolic hydroxyl.The results of thin layer chromatography and high performance liquid chromatography show that purified flavonoids may contain rutin and quercetin.So the leaves of Rhizoma Curcumae flavonoids have a certain development and utilization value.