College of Pharmacy, Chungnam National University, Daejeon 305-764, Korea.
Phytother Res. 2010 Jan;24(1):101-6. doi: 10.1002/ptr.2890.
The aim of this work was to study the structure-activity relationships of the antioxidant activity of natural coumarins isolated from four Korean medicinal plants (1-17) and four purchased coumarins (18-21). The free radical scavenging and lipid peroxidation assays revealed that five phenolic coumarins, scopoletin (1), aesculetin (2), fraxetin (3), umbelliferone (18) and daphnetin (19), possessed considerable antioxidant activities. The coumarins having a catechol group, 2, 3 and 19, showed significant free radical scavenging activity and inhibitory effects on lipid peroxidation, indicating that the catechol group significantly contributed to the antioxidant activities of coumarins. In contrast, the sugar moiety markedly reduced the activities of coumarin glycosides. The results also demonstrate that the alpha-pyrone ring of coumarins significantly enhanced the capacity of inhibiting oxidative reactions of coumarins.
本工作旨在研究从四种韩国药用植物(1-17)和四种购买的香豆素(18-21)中分离出的天然香豆素的结构-活性关系。自由基清除和脂质过氧化测定表明,五种酚类香豆素,东莨菪内酯(1)、花椒毒素(2)、秦皮素(3)、伞形酮(18)和瑞香素(19)具有相当强的抗氧化活性。具有邻苯二酚基团的香豆素,如 2、3 和 19,具有显著的自由基清除活性和抑制脂质过氧化作用,表明邻苯二酚基团对香豆素的抗氧化活性有显著贡献。相比之下,糖基部分明显降低了香豆素苷的活性。结果还表明,香豆素的α-吡喃酮环显著增强了抑制香豆素氧化反应的能力。