Study On Extraction And Antioxidant Properties Of Flavonoids From Ablemoschus Manihot

Ablemoschus manihot were widely distributed in mostly region of China,whose flavonoids have several effects.In this paper,the extraction conditions of flavonoids from Ablemoschus manihot flower powder were studied.Then,the flavonoids crude extraction were separated and purified,and the structure of flavonoids were analyzed.The protection of flavonoids on DNA oxidative damage induced by ·OH and H₂O₂ and hair damage and the inhibition effects on XO were further investigated.The main content was as follows:?1?The basic composition of Ablemoschus manihot flower was studied.There were 4.17% of water,7.82% of ash,2.19% of fat,15.56% of polysaccharides and 12.13% protein.Ultrasonic-assisted ethanol extraction was selected to extract flavonoids from Ablemoschus manihot flower.The extraction conditions of flavonoids crude extraction from Ablemoschus manihot flower?AFC?were optimized through mono-factor experiment and orthogonal test.The highest flavonoids yield of 5.14% was achieved under the optimal conditions: ethanol concentration 60%,solid-to-liquid ratio?W/V?1:20 g/mL,ultrasonic temperature 50 ? and ultrasonic time 30 min.?2?The flavonoids crude extraction of Ablemoschus manihot flower were separated and purified by solvent extraction method and polyamide column chromatography with flavonoids content and antioxidant activities of DPPH·,·OH and H₂O₂ as indexes.AFB-2 was obtained by polyamide column chromatography from the n-butyl alcohol phase.The flavonoids content of AFB-2 was 802.61 mg/g,increased by 47.96%,the IC50 value of DPPH·,·OH and H₂O₂ experiment were 0.031 mg/m L?0.098 mg/m L?0.305 mg/mL,which indicated the antioxidant activities of DPPH·,·OH and H₂O₂ scavenging also improved.AFB-2 was further separated by Sephadex LH-20 column chromatography,and two components AFB-2a and AFB-2b were obtained.The two components were analyzed by HPLC-MS,6 flavonoids were speculated,i.e.,myricetin-3-O-glucoside,quercetin-3-O-glucoside,quercetin-7-O-glucoside,myricetin-7-O-glucoside,cottonseed-3'-O-glucoside and quercetin-3'-O-glucoside.?3?Protection of AFC,AFB,AFB-2 on DNA oxidative damage induced by ·OH and H₂O₂ were investigated by fluorescence method.In the experiment of DNA oxidative damage induced by ·OH,the intensity of AFC,AFB,AFB-2 were increased and then decreased with the increased of concentration.When the concentration of AFB-2 was 0.12 mg/mL,the intensity reached the maximum of 249.83 a.u.,which had the best protection on DNA oxidative damage induced by ·OH.And in the experiment of DNA oxidative damage induced by H₂O₂,the intensity of AFC and AFB were increased and then decreased with the increase of concentration,however,the intensity of AFB-2 increased with increasing concentrations,the intensity reached about 264.55 a.u.at the concentration of 0.6 mg/mL,which had the best protection on DNA oxidative damage induced by H₂O₂.?4?The inhibition of Ablemoschus manihot flower flavonoids on xanthine oxidase was investigated.The results showed that AFC,AFB,AFB-2 all had inhibition effects on XO at the concentration from 0.02 to 0.12 mg/mL,and AFB-2 had the best inhibition on XO.The further research showed that the inhibition of AFB-2 on XO was reversible inhibition,the dynamic characteristic was the type of competitive inhibition and inhibition constant was 0.032 mg/mL.?5?The protection of AFB-2 on hair damaged by ultraviolet and H₂O₂ were studied by protein loss and SEM method.The results showed that AFB-2 had protection on hair damaged by ultraviolet and H₂O₂.