Microwave Assisted Extraction Optimization And Antioxidant Activity Research Of Flavonoids From Amomum Tsao-ko

ObjectiveThe microwave-assisted extraction method was used to optimize the extraction process of flavonoids from Amomum tsao-ko,and response surface methodology was used to determin the optimum extraction process.The antioxidant activities of Amomum tsao-ko,Amomum villosum Lour,Alpinia galangal,and Elettaria cardamomum combinations were measured,to find whether there was synergistic antioxidant effect between Amomum tsao-ko and the other three.This paper studied the changes of the antioxidant activity in zingiberaceae plants during digestive process by simulating in vitro.Methods1.The microwave-assisted extraction process of Amomum tsao-ko flavonoids was researched.The factors affecting the yield of flavonoids were microwave power,ethanol concentration,liquid-solid ratio and microwave time.All these factors were studied and ethanol concentration,liquid-solid ratio,microwave time were chosen to design response surface analysis tests to optimize the extraction process in accordance with Box-Benhnken central composite experimental design principles.2.Mixing the ethanol extracts of Amomum tsao-ko,Amomum villosum Lour,Alpinia galangal,and Elettaria cardamomum in a volume ratio of 1:9,3:7,1:1,7:3,and 9:1respectively,isobolographic analysis was used to assess the antioxidant interactions of different combinations.3.The antioxidant activity of ethanol extracts in Amomum tsao-ko,Amomum villosum Lour,Alpinia galangal,and Elettaria cardamomum were studied systematically by using DPPH and ABTS assay.Samples were taken at 0.5,1.0,1.5,2.0,and 3.0 h in vitro gastric simulated digestion process,and samples were taken at 0.5,1.0,2.0,3.0,and 4.0 h in vitro intestinal simulated digestion process.Results1.Optimum the microwave-assisted extraction process parameters of flavonoids from Amomum tsao-ko were ethanol concentration 60%,liquid-solid ratio 30 mL/g,microwave time 34s.In this case,the yield of flavonoids was 1.23 mg/g.2.Most of the binary mixtures?Amomum tsao-ko-Elettaria cardamomum,Amomum tsao-ko-Amomum villosum Lour,Amomum tsao-ko-Alpinia galangal,Elettaria cardamomum-Amomum villosum Lour,Elettaria cardamomum-Alpinia galangal,and Amomum villosum Lour-Alpinia galangal combinations?showed the synergistic antioxidant effects.In DPPH assay,the greatest antioxidant activity of zingiberaceae plants combinations was 9:1 Amomum villosum Lour-Alpinia galangal(IC₅₀:0.10±0.01 mg/mL),followed by 7:3 Amomum tsao-ko-Alpinia galangal(IC₅₀:0.12±0.01mg/mL)and 9:1 Amomum tsao-ko-Elettaria cardamomum(IC₅₀:0.12±0.03 mg/mL).In ABTS assay,the greatest antioxidant activity of zingiberaceae plants combinations was 7:3 Amomum tsao-ko-Alpinia galangal(IC₅₀:0.34±0.01 mg/mL),followed by 9:1Amomum tsao-ko-Amomum villosum Lour(IC₅₀:0.34±0.02 mg/mL)and 7:3 Amomum tsao-ko-Amomum villosum Lour(IC₅₀:0.38±0.01 mg/mL).3.The results of in vitro simulated digestion showed that,the ethanol extract of Amomum tsao-ko reached the lowest DPPH IC₅₀ value?1.12±0.09 mg/mL?at 3.0 h in the in vitro gastric simulated digestion process,and reached the lowest DPPH IC₅₀ value?0.57±0.04 mg/mL?at 4.0 h in the in vitro intestinal digestion process;the ethanol extract of Amomum tsao-ko reached the lowest ABTS IC₅₀ value?1.11±0.03 mg/mL?at 3.0 h in the in vitro gastric simulated digestion process,and reached the lowest ABTS IC₅₀ value?0.80±0.00 mg/mL?at 3.0 h in the in vitro intestinal digestion process.And the antioxidant activity of ethanol extract of Amomum tsao-ko was still better than that of Amomum villosum,Alpinia galangal,and Elettaria cardamomum after the vitro simulated digestion process.Conclusions1.The advantages of microwave-assisted extraction method are short extraction time,less solvent,and simple operation.The verification results show that the optimization process of flavonoids from Amomum tsao-ko using the response surface analysis method is reasonable and feasible.2.There are certain anti-oxidation synergistic effects between Amomum tsao-ko,Amomum villosum Lour villosum,Alpinia galangal,and Elettaria cardamomum,and the scavenging activities of DPPH free radical and ABTS free radical are enhanced in these combinations.3.The optimal time for the ethanol extract of Amomum tsao-ko in vitro stomach simulated digestion and in vitro intestinal simulated digestion are 3.0 h,and the antioxidant activity of the ethanol extract of Amomum tsao-ko is stronger than the other three zingiberaceae plants during the digestion process.