Study On The Extraction And Bioactivity Of Malus Asiatica Nakai Polyphenols

This paper took air-dried Malus Asiatica Nakai leaves as experimental material, responsesurface methodology (RSM) was employed to optimize the extraction process of Malus AsiaticaNakai Polyphenols; Evaluated it‘s scavenging free radicals and antioxidant properties;Investigated the effect of Malus Asiatica Nakai Polyphenols on the microorganisms and cancercells in vitro experiments, Discussed the potential of Malus Asiatica Nakai Polyphenols asoil antioxidant; Established analysis and compound purification methods by HPLC. It providestechnical supports for exploitation and process of Malus Asiatica Nakai Polyphenols in the future.The main results are as following:On the basis of single factor experiments, response surface methodology (RSM)experimental design was employed to establish the mathematical models of Malus AsiaticaNakai Polyphenols extraction. The optimum conditions were as follows: ethanol volume ratio:60%, extraction time:60min; liquid/material ratio:13:1. Under this condition, extraction rate ofpolyphenol from Malus asiatica Nakai leaves was (4.61±0.035)%(N=3). It was closed to themodel predicted value4.74%. The RSD between them was0.03%, which revealed the validity ofthe model.Malus Asiatica Nakai Polyphenols exhibited a high scavenging activity against DPPHradicals, superoxide anions radicals and hydroxyl radicals, and the IC50of Malus Asiatica NakaiPolyphenols equivalent to32.2%gallic acid was17.2μg/mL,203.25μg/mL,82.88μg/mLrespectively. The total antioxidant capacity was68.98±3.41U/mg, which imply that it have avery powerful antioxidant capacity. The antibacterial test showed that the Malus Asiatica NakaiPolyphenols can inhibit the growth of Bacillus subtilis and E. coli, however, have no significanteffect on Staphylococcus aureus; Malus Asiatica Nakai Polyphenols with a concentration of1mg/mL promoted the growth of BGC-823and HeLa cells by MTT assay. The increase rate was45.5%and49.61%respectively; The edible oils which added sufficient Malus Asiatica NakaiPolyphenols show non different with iodine value and acid value compared to the blank one inthe simulation of the oxidation test, which indicated that the Malus Asiatica Nakai Polyphenolsmay not suitable as antioxidants additive for edible oil directly. Preparative high performance liquid chromatography condition: Column: Boston GreenODS-5μm-4.6mm ID×250mm. Conditions:280nm.1mL/min. A=0.2%formic acid (v/v) inwater, B=Methanol. Gradients(min/B):-46/100，-31/100，-30/5，0/5，15/30，40/40，60/50，65/55，90/100； Sample: saturated100μL Malus Asiatica Nakai Polyphenols in5%methanol aqueous (v/v) solution. Fraction collection setting: collect by peak; Detection channel:280nm; Delay volume:221μl; Peak start threshold:10.00mAU; Peak start slope:0.500mAU/s;Peak start true Time:1.00s; Peak end threshold:5.00mAU; Peak end slope:-1.000mAU/s;Peak end true time:1.00s; Deriv step:1.00s; Threshold no peak end:2000.00mAU; Under thiscondition, it had collected6fractions of the Malus Asiatica Nakai Polyphenols.