不同臺灣產山藥黏質多醣抗氧化能力的研究
Antioxidant activities of mucilages from different
Taiwanese yam cultivars
林時宜
Lin SY;Liu HY;Lu YL;Hou WC
摘要
由臺灣產台農一號山藥、台農二號山藥與名間長紅山藥塊莖抽取其粗黏質多醣與經部分純化後之 黏質多醣進行抗氧化活性分析比較。利用分光光度計方法分析 DPPH 自由基，氫氧自由基與超 氧自由基之清除實驗；也利用電子自旋共振儀分析氫氧自由基之清除實驗。以 50%清除濃度(IC50) 顯示，台農一號山藥、台農二號山藥與名間長紅山藥多醣在清除 DPPH 自由基而言，純化前後 分別為 0.329、0.279；0.547、0.653 和 0.847、0.631mg/ml。在清除氫氧自由基而言，純化前後分 別為 0.668、1.146；l.461、1.096 和 0.946、1.554mg/ml。在清除超氧自由基而言，純化前後分別 為 0.802、0.368；0.681、0.258 和 0.086、0.148mg/ml。利用電子自旋共振儀分析氫氧自由基清除 實驗，純化之台農一號山藥、台農二號山藥與名間長紅山藥多醣之 50%清除濃度為 0.083、0.47、 0.004mg/ml。以上結果顯示栽培種之間與純化前後之多醣有不同抗氧化活性。Abstract
The antioxident effects of crude mucilages (CM) and partially purified mucilages (PPM) from three different Taiwanese yam cultivars-including Dioscorea alata L. cv. Tainong 1 (Th1), Dioscorea alata L. cv. Tainong 2 (TN2), and D. alata L. var. purpurea (Roxb.) Ming-Jen (MJ)-were evaluated, including
1,1-diphenyl-2-picrylhy-drazyl (DPPH) radical, hydroxyl radical, and superoxide radical scavenging activities Electron spin resonance (ESR) spectrometry was used to measure hydroxyl radical scavenging activities. The IC50 stands for the
concentration required for 50% scavenging activity. The IC50 of CM and PPM against DPPH radical was 0.329, 0.279; 0.547, 0.653; and 0.847, 0.631 mg/ml, respectively, for TN1, TN2 and MJ. The IC50 of CM and PPM against hydroxyl radical by spectrophotometry was 0.668, 1.146; 1.461, 1.096; and 0.946, 1.554 mg/ml, respectively, for TN1, 1N2 and MJ. The IC50 of CM and PPM against superoxide radical was 0.802, 0.368; 0.681, 0.258; and 0.086, 0.148 mg/ml, respectively, for TN1, TN2 and MJ. Using ESR to detect hydroxyl radicals, the IC50 of PPM against hydroxyl radical was 0.083, 0.47, and 0.004 mg/ml, respectively, for TN1, TN2 and MJ. The results demonstrated that different cultivars of yams exhibited different antioxidant ability, and the purification process was able to partially increase the antioxidant activity of the mucilage polysaccharide. Taken together, these results
suggest that mucilage polysaccharides of the yam tuber might play an important role on antiradicals and antioxidants.
