Study On The Antioxidant Ability Of Malus Crabapple

As common ornamental plant, crabapples who belong to Malus genus (Rosaceae), areplanted widely in China，which have great variety and beautiful flowers. Traditional ChineseMedicine considers that crabapples fruits have the function of thirst-quenching, strengthensthe stomach and promotes digestion.We selected common crabapples in different growthstage as the experimental material, to determine the contents of total phenolics and flavonoidsand the antioxidant properties of the extracts were tested by DPPH and ABTSradical-scavenging activity, the inhibition effect on hydroxyl radical and superoxide radical,ferric reducing/antioxidant power (FRAP) assay. In addition, the compositions of activefractions were determined by HPLC-DPPH and HPLC-DAD-MS/MS methods, and proposeto provide theoretical basis for the utilization of crabapples.Phenolics and flavonoids contents, DPPH radical scavenging ability of Royalty, Hall,Radiant, Strawberry parifit, Snowdrift, Pink spires, Flame were determined. The resultsshowed that, Royalty, Hall, Radiant, Strawberry parifit had high contents of phenolics andflavonoids, and showed relatively strong antioxidant activity. So we selected Royalty, Hall,Radiant, Strawberry parifit for the future study.As phenolics and flavonoids compounds are excellent antioxidant in plants, phenolicsand flavonoids contents of screening samples in different growth stage were investigated. Theresult indicated that through the same period, Royalty had the highest contents.and theRoyalty of60DAFB had the highest contents.In our study, the vitro antioxidant assay (DPPH and ABTS radical scavenging assay,hydroxyl radical and superoxide radical inhibiting assay, FRAP assay) was applied toevaluate the antioxidant capacity of crabapples. It was found that the antioxidant activity ofdifferent extractions have large differences. The Royalty was stronger than others during thesame period, while the extracts of60DAFB exhibited strongest antioxidation in the samespecies.We take Royalty for example, to study the relationship between the contents of phenolicsand flavonoids and the antioxidant ability. It was found that flavonoids and phenolics showed high correlation with the antioxidant capacity. Correlation coefficients were: PC(Phenolic-DPPH)=-0.829*, PC (Flavoniod-DPPH)=-0.829*, PC (Phenolic-ABTS)=-0.886*,PC (Flavoniod-ABTS)=-0.886*, PC (Phenolic-Hydroxyl radical)=0.657, PC (Flavoniod-Hydroxyl radical)=0.657, PC (Phenolic-Superoxide radical)=0.771, PC (Flavoniod-Superoxide radical)=0.771, PC (Phenolic-FRAP)=0.943**, PC (Flavoniod-FRAP)=0.943**.Itmay be the main contributor to the antioxidant activity exhibited by the plants.The chemical components of Royalty were detected using the HPLC. It was found thatthere was13compounds in the ethanol extract of Royalty. Furthermore,8constituents wereidentified by HPLC-DAD-MS/MS technique: caffeic acid, eriodictyol rhamnoside, phloretinhexoside I, coumaroyl guinic acid, quercetin hexoside, phloretin hexoside II, quercetinpentoside, quercetin rhamnoside. All of these components had antioxidant activity.