Radical scavenging activity and cytotoxicity of active quinic acid derivatives from Scorzonera divaricata roots

Five new quinic acid derivatives and two known 3-O-feruloylquinic acids were isolated from the roots of Scorzonera divaricata Turcz. The new compounds were elucidated as (-)-1,4-di-O-feruloyl-3-O-dihydrocaffeoylquinic acid, (-)-1-O-feruloyl-4-O-dihydrocaffeoylquinic acid, (-)-3,5-di-O-feruloylquinic acid, (-)-1-O-feruloyl-3-O-dihydro-caffeoylquinic acid, and(-)-1-O-feruloyl-5-O-dihydrocaffeoylquinic acid based on extensive spectroscopic studies, including one- and two-dimensional NMR, HRESIMS, UV, and IR results. Five compounds were assessed for antioxidant activity by ABTS and DPPH radical-scavenging assays and for their cytotoxicity against HL-60 and Hep-G2 cell lines by the MTT assay. Three quinic acid derivatives exhibited strong antioxidant activity, with IC50 values of 3.95, 5.87, and 7.45 mu g/mL against ABTS(center dot+) and 11.7, 13.6, and 50.1 mu g/mL against DPPH center dot. (-)-1,4-Di-O-feruloyl-3-O-dihydrocaffeoylquinic acid also exhibited moderate activity against Hep-G2 cell lines with an IC50 value of 14.6 mu g/mL. (C) 2012 Elsevier Ltd. All rights reserved.

从叉枝鸦葱（Scorzonera divaricata Turcz.）的根中分离出五种新的奎尼酸衍生物和两种已知的3 - O -阿魏酰奎尼酸。通过广泛的光谱研究，包括一维和二维核磁共振、高分辨率电喷雾质谱、紫外和红外光谱结果，新化合物被鉴定为（ - ） - 1,4 - 二 - O -阿魏酰 - 3 - O -二氢咖啡酰奎尼酸、（ - ） - 1 - O -阿魏酰 - 4 - O -二氢咖啡酰奎尼酸、（ - ） - 3,5 - 二 - O -阿魏酰奎尼酸、（ - ） - 1 - O -阿魏酰 - 3 - O -二氢咖啡酰奎尼酸和（ - ） - 1 - O -阿魏酰 - 5 - O -二氢咖啡酰奎尼酸。通过ABTS和DPPH自由基清除试验评估了五种化合物的抗氧化活性，并通过MTT法评估了它们对HL - 60和Hep - G2细胞系的细胞毒性。三种奎尼酸衍生物表现出较强的抗氧化活性，对ABTS（·+）的IC50值分别为3.95、5.87和7.45μg/mL，对DPPH·的IC50值分别为11.7、13.6和50.1μg/mL。（ - ） - 1,4 - 二 - O -阿魏酰 - 3 - O -二氢咖啡酰奎尼酸对Hep - G2细胞系也表现出中等活性，IC50值为14.6μg/mL。（C）2012爱思唯尔有限公司。保留所有权利。