Instituto de Química e Biotecnologia, Universidade Federal de Alagoas, Maceió-AL, Brazil.
Pharm Biol. 2010 Jan;48(1):63-9. doi: 10.3109/13880200903046146.
In this work, the total phenolic content and antioxidant activity of extracts and four flavonoids isolated from leaves of two Boraginaceae species (Cordia multispicata Cham. and Tournefortia bicolor Sw.) were evaluated using Folin-Ciocalteu reagent, DPPH free radical scavenging and inhibition of peroxidation of linoleic acid by FTC method. For comparison, ascorbic acid, alpha-tocopherol and BHT were used. In general, extracts from T. bicolor (68.8 +/- 0.001 to > 1000 mg/g) showed higher phenolic content than C. multispicata (66.1 +/- 0.009 to 231 +/- 0.07 mg/g), and also scavenged radicals (IC(50) 12.8 +/- 2.5 to 437 +/- 3.5 mg/L) and inhibited lipid peroxide formation (IC(50) 51.2 +/- 2.29 to 89 +/- 0.59 mg/L). For these extracts a good correlation between the phenolic content and antioxidant activity was observed, suggesting that T. bicolor is richer in phenolic compounds and that it could serve as a new source of natural antioxidants or nutraceuticals with potential applications. Chromatographic procedures monitored by antioxidant assays afforded seven compounds, which were identified by spectral analyses (IR, MS and 1D and 2D NMR) and comparison with reported data as being trans-phytol (1), taraxerol (2), 3,7,4'-trimethoxyflavone (3), 5,3'-dihydroxy-3,7,4'-trimethoxyflavone (4), quercetin (5), tiliroside (6), and rutin (7). Compounds (4-7) were also evaluated and were effective as DPPH quenching (IC(50) 7.7 +/- 3.6 to 79.3 +/- 3.4 mg/L) and as inhibition of lipid peroxidation (IC(50) 80.1 +/- 0.98 to 88.7 +/- 3.62 mg/L). This is the first report on the total phenolic content, radical-scavenging and antioxidant activities of these species.
在这项工作中，使用 Folin-Ciocalteu 试剂、DPPH 自由基清除和 FTC 法抑制亚油酸过氧化评估了两种紫草科植物（ Cordia multispicata Cham. 和 Tournefortia bicolor Sw.）叶提取物和四种分离得到的类黄酮的总酚含量和抗氧化活性。为了进行比较，还使用了抗坏血酸、α-生育酚和 BHT。总的来说，T. bicolor（68.8 +/- 0.001 至 > 1000 mg/g）的提取物比 C. multispicata（66.1 +/- 0.009 至 231 +/- 0.07 mg/g）具有更高的酚含量，并且还能清除自由基（IC（50）12.8 +/- 2.5 至 437 +/- 3.5 mg/L）和抑制脂质过氧化形成（IC（50）51.2 +/- 2.29 至 89 +/- 0.59 mg/L）。对于这些提取物，观察到酚含量和抗氧化活性之间存在良好的相关性，表明 T. bicolor 富含酚类化合物，可作为天然抗氧化剂或具有潜在应用的营养保健品的新来源。通过抗氧化测定监测的色谱程序提供了七种化合物，通过光谱分析（IR、MS 和 1D 和 2D NMR）以及与文献数据的比较鉴定为反式植醇（1）、角鲨烯（2）、3,7,4'-三甲氧基黄酮（3）、5,3'-二羟基-3,7,4'-三甲氧基黄酮（4）、槲皮素（5）、水飞蓟素（6）和芦丁（7）。还对化合物（4-7）进行了评价，它们作为 DPPH 淬灭剂（IC（50）7.7 +/- 3.6 至 79.3 +/- 3.4 mg/L）和抑制脂质过氧化（IC（50）80.1 +/- 0.98 至 88.7 +/- 3.62 mg/L）有效。这是首次报道这些物种的总酚含量、自由基清除和抗氧化活性。
