厚朴多糖提取工艺及其体外抗氧化活性

Extraction and Antioxidant Activities of Polysaccharides from Magnolia officinalis Rehd. et Wils. Barks

通过Box-Behnken试验优化提取厚朴多糖的工艺;以超氧阴离子自由基、1,1-二苯基-二苦基肼(1,1-diphenyl-2-picrylhydrazyl,DPPH)自由基和2,2’-连氮基-双-(3-乙基苯并噻唑-6-磺酸)(ABTS+·)清除能力,Fe2+螯合力、铁离子还原抗氧化力(ferric reducing antioxidant power,FRAP)为指标,探究厚朴多糖的体外抗氧化活性。结果表明,提取厚朴多糖的最佳工艺条件为p H 7.3、液固比32∶1(m L/g)、提取温度78℃、提取时间139 min,此条件下多糖提取率达3.35%~3.52%。体外抗氧化活性结果表明,厚朴多糖超氧阴离子自由基清除力为(18.72±2.12)μmol·VC/mg,DPPH自由基清除能力达(0.59±0.05)μmol Trolox/mg,ABTS+·清除能力为(0.57±0.04)μmol Trolox/mg,Fe2+螯合力为(0.38±0.02)μmol·EDTA/mg,FRAP值为(2.19±0.31)μmol Trolox/mg。

In this study, we investigated the optimization of polysaccharides extraction from the dried barks of Magnolia officinalis Rehd. et Wils. by response surface methodology(RSM) based on Box-Behnken design and measured the antioxidant activities of the extracted polysaccharides by superoxide anion radical scavenging, 1,1-diphenyl-2-picrylhydrazyl(DPPH·) scavenging, 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid(ABTS+·) radical scavenging, Fe2+ chelating activity, as well as Ferric reducing antioxidant power(FRAP) assays. The results indicated that the optimal extraction conditions for polysaccharides from Magnolia officinalis Rehd. et Wils. were obtained as follows: p H, 7.3; liquid-to-solid ratio, 32:1(m L/g); temperature, 78 ℃; and extraction time, 139 min. Under these conditions, the yield of polysaccharides was 3.35%-3.52%. The extracted polysaccharides exhibited powerful antioxidant activities. The radical scavenging activities against superoxide anion, DPPH and ABTS+· radicals, Fe2+ chelating activity and FRAP value were(18.72 ± 2.12) μmolascorbic acid equivalent(AAE)/mg,(0.59 ± 0.05) μmol Trolox equivalent(TE)/mg,(0.57 ± 0.04) μmol TE/mg,(0.38 ± 0.02) μmol EDTA-2Na equivalent(EE)/mg, and(2.19 ± 0.31) μmol TE/mg, respectively.