Natural Product Research Center, KIST Gangneung Inst., Daejeon-dong, Gangneung, Gangwon, Republic of Korea.
J Food Sci. 2010 Aug 1;75(6):C530-5. doi: 10.1111/j.1750-3841.2010.01714.x.
The plant Ligularia fischeri var. spiciformis Nakai, a well-known edible medicinal herb in Korea, has been used to treat maladies such as jaundice, scarlet fever, rheumatoid arthritis, and hepatic function failure. In this research, 4 major antioxidant compounds were detected from this plant's leaves using an on-line high-performance liquid chromatography (HPLC)-ABTS screening system, which can determine the antioxidant activity based on a decrease in absorbance at 734 nm after postcolumn reaction of HPLC-separated antioxidants with the 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radicals (ABTS(*)). In order to isolate these active compounds, a preparative HPLC was applied and their chemical structures were identified as 5-O-caffeoylquinic acid (5-CQA), 3,4-di-O-caffeoylquinic acid (3,4-DCQA), 3,5-di-O-caffeoylquinic acid (3,5-DCQA), and 4,5-di-O-caffeoylquinic acid (4,5-DCQA) by ESI/MS(n) and (1)H NMR. These 4 isomers comprised over 10% of the dried leaves, with 3,5-DCQA being the most abundant compound. The radical scavenging activity of each isomer was also evaluated simultaneously through the on-line HPLC-ABTS method, which showed 94% antioxidant activity of the ethanol extract derived from caffeoylquinic acids. Among these isomers, 3,4-DCQA contained the most strong antioxidant activity while 3,5-DCQA accounted for the highest radical scavenging capacity due to having the highest content.
韩国一种广为人知的药食两用植物——山梗菜 Ligularia fischeri var. spiciformis Nakai，具有治疗黄疸、猩红热、类风湿性关节炎和肝功能衰竭等疾病的功效。本研究采用在线高效液相色谱（HPLC）-ABTS 筛选系统从该植物的叶子中检测到 4 种主要抗氧化化合物，该系统可以根据 HPLC 分离的抗氧化剂与 2,2'-联氮双（3-乙基苯并噻唑啉-6-磺酸）自由基（ABTS(*)) 柱后反应后吸光度在 734nm 处的降低来确定抗氧化活性。为了分离这些活性化合物，应用制备型 HPLC，并通过 ESI/MS(n) 和 (1)H NMR 将它们的化学结构鉴定为 5-O-咖啡酰奎宁酸（5-CQA）、3,4-二-O-咖啡酰奎宁酸（3,4-DCQA）、3,5-二-O-咖啡酰奎宁酸（3,5-DCQA）和 4,5-二-O-咖啡酰奎宁酸（4,5-DCQA）。这 4 种异构体占干叶的 10%以上，其中 3,5-DCQA 含量最丰富。通过在线 HPLC-ABTS 方法同时评估了每种异构体的自由基清除活性，结果表明，来自咖啡酰奎宁酸的乙醇提取物具有 94%的抗氧化活性。在这些异构体中，3,4-DCQA 具有最强的抗氧化活性，而 3,5-DCQA 由于含量最高，具有最高的自由基清除能力。
