Extraordinary Accumulations of Antioxidants in Ammopiptanthus mongolicus (Leguminosae) and Tetraena mongolica (Zygophyllaceae) Distributed in Extremely Stressful Environments

沙冬青和四合木分佈於我國西北和蒙古的沙漠和戈壁地區，是耐極度乾旱、極端溫度、貧瘠和鹽鹼的孑遺植物。沙冬青在夏季攝氏四十度高溫和冬季零下攝氏三十度低溫的沙漠上能維持常綠不落葉，被當地居民製成傳統藥物治療呼吸道疾病、凍瘡、類風濕和止痛。本研究的主要目的是分析極端逆境下植物體內抗氧化劑的積累，並據此推測沙冬青用於多種傳統疾病治療的可能機理。利用化學分離的手段，借助於電子順磁共振波譜法、DPPH染色法和脂質過氧化的方法，通過對各組份浸膏抗氧化活性的分析測定，進而對主要抗氧化成分進行追蹤分離。利用不同有機溶劑及其不同配比組合分離獲得的浸膏與對照相比都顯示出了較高的清除自由基活性，其中以1份石油醚與1份乙酸乙酯的配比從沙冬青中提取出的浸膏清除自由基活性最高。從高活性組份中繼續分離獲得了大量的白藜蘆醇（占總幹重植株的0.05%）以及兩種異黃酮。這一結果表明，極端惡劣的生態環境有利於植物中強抗氧化劑的累積；同時也表明沙冬青對多種傳統疾病的治療功效可能與其強抗氧化作用有關。

關鍵字

活性氧；沙冬青；四合木；白藜蘆醇；超氧陰離子； DPPH自由基；脂質過氧化；電子順磁共振波譜法

並列摘要

Ammopiptanthus mongolicus (Leguminosae) and Tetraena mongolica (Zygophyllaceae) are distinctively distributed in the northwestern Gobi and desert areas of China. Their environments involve seasonally extreme drought and temperatures, extraordinarily high UV radiation and poor soil qualities with high salinity. Ammopiptanthus mongolicus remains evergreen for all four seasons and has been traditionally used as anti-inflammatory, anti-infectious and pain-killing medicines. All the extracts prepared from the two species exhibited significantly higher scavenging activities against the •O2(superscript -) than a control. Five selected extracts also showed wider spectra of antioxidative capacities. An activity-guided fractionation led to identification of four major compounds. Resveratrol, a super strong antioxidant, accounted for as high as 0.05% of the dried weight of A. mongolicus. Two isoflavones isolated are also reported to be antioxidative and antiinflammatory. Our results imply that plant species living in the extremely stressful environments may become an abundant natural resource of strong antioxidants. Considering the fact that oxidation is involved in the processes of infections, inflammation and other disorders, these results collectively suggest that efficacies of A. mongolicus in treating infections, inflammatory disorders and in killing pains may be attributed, at least partly, to its significantly larger non-enzymatic antioxidative capacities.

並列關鍵字

1,1-diphenyl-2-picrylhydrazyl DPPH radical ； Active-oxygen scavenging activity ； Ammopiptanthus mongolicus ； Electron paramagnetic resonance EPR ； Lipid peroxidation ； Resveratrol ； Superoxide anion radical•O2(su

國際替代計量

Extraordinary Accumulations of Antioxidants in Ammopiptanthus mongolicus (Leguminosae) and Tetraena mongolica (Zygophyllaceae) Distributed in Extremely Stressful Environments

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