Inhibitory Effect Of Flavonoid Extracts From Safflower On Tyosinase

Safflower is traditional Chinese medicine for promoting blood circulation and it is a medicinal and edible flower.Safflower contains a variety of nutrients and biologically active substances including plenty flavonoids.It is studied that preparation conditions of flavonoids of safflower(SF)were optimized,and the inhibitory effects on the activity of tyrosinase is investigated.At the sametime,the preservation on apple slices is discussed.1 The microwave-assisted extraction technology of SF was studied.The single factor and orthogonal design methods were applied for the optimal technological conditions.The influencing factors of SF were studied: alcohol concentration,microwave time,microwave power and ratio of solid to liquid.The results showed that 10.231% extraction rate of flavonoids could be obtained with 60% alcohol,ratio of solid to liquid 1:35,microwave time for 25 min,microwave power 800 W,microwave temperature 50? and extraction of times 2.2 The characteristic of absorption an adsorption of four kinds of macroporous resins to SFE was studied.Suitable resin for purification of flavonoids was screened from four resins,and its characteristic of absorption and adsorption was investigated,through single factor experiments.The results indicated that AB-8macroporous resins had better absorption and adsorption property for purification of flavonoids from safflower.The optimum absorption conditions of macroporous resin AB-8 was as follows: resin to sample 1:10(g/mL),sample concentration3mg/mL,the value of pH4.7,the time of absorption and desorption was 6h and 4h.The optimum dynamic adsorption was obtained with the flow rate 2BV/h,sample concentration 3mg/mL,and70% alcohol as eluant for desorption with the flow rate 2 BV/h.63.31% purity can be separated from SFE(about 21.85% purity)with AB-8 resin by the following optimum dynamic adsorption and desorption conditions.3 The inhibitory mechanism of SFP on tyrosinase was studied.Inhibition kinetics was discussed with L-Tryosine substrate.The inhibitory mechanism was investigated considering the antioxidation activities and the interaction of copper ion of SFP.The results showed that SFP could inhibit the activity of tyrosinase at the range of experimental concentration and the maximum inhibition rate was 78.03% at flavonoids concentration of 3.0 mg/mL;IC50 was estimated to be 0.834 mg/mL,KI value was 0.036 mg/mL and KIS value was 0.0064 mg/mL.The maximum inhibition rate was 63.5% at flavonoids concentration of 3.0 mg/mL.SFP had good performance in scavenging DPPH·?O2-·and ·OH.At the same time,flavonoid from safflower can coordinate with metal ions such as Cu2+ and Fe2+ and UV-visible spectra changes a lot.Conclusion: SFP could inhibit the activity of tyrosinase obviously and the type of inhibition belonged to be mixed-type.And SFP can inhibit the activity of tyrsinase by scavenging free radicals and coordinating with metal ions.4 Preservation of flavonoid extracts from safflower on apple slices was studied.VC content,TSS content and browning of fresh-cut apple was discussed,with different concentration.The results showed SFE of 1mg/mL immersed 2min,VC content is 4.44,TSS content is 10.5% and VC content is 0.017mg/100 g.The experiment proved that flavonoid extracts form safflower have a role in preservting fresh fruits5After separated by sephadex LH-20,HPLC separation and UV absorption spectra analysis,Hydroxysafflower yellow A and luteolin was identified to be contained in the safflower flavonids.