Isolation and antioxidant activities of plumbagin from Plumbago zeylanica_ | 白花丹素的提取及其抗氧化活性研究_

صينى. ［目的］从白花丹中提取活性成分白花丹素，研究抗氧化活性并探讨作用机理。［方法］利用柱层析法从白花丹的乙醇提取液中分离得到其活性成分白花丹素，通过核磁共振、红外光谱，质谱等谱学方法鉴定化合物结构；运用磷钼酸盐法测定不同浓度白花丹素的总抗氧化能力；运用碘量法测定不同浓度白花丹素抑制花生油脂过氧化的能力。［结果］白花丹素表现出较强的总抗氧化能力，能明显抑制油脂过氧化，且呈正相的剂量效应和时间效应，各处理浓度的抗氧化能力也基本表现出优于BHT（1.0 mg/ml）的抗氧化能力。 ［结论］白花丹素萘醌环的酚羟基是抗氧化作用的主要活性基团，白花丹素的抗氧化能力是抗肿瘤作用的重要机制之一。

إنجليزي. ［Objective］ Plumbagin, the active ingredient, was isolated from _Plumbago zeylanica, and its antioxidant activities and mechanism were studied and evaluated. ［Method］ Plumbagin was isolated through the methods of column chromatography from ethanol extract of Plumbago zeylanica. The structure was identified by using IR, 1H-NMR, 13C-NMR, IR and Ms. The total antioxidant capacity of different concentrations of plumbagin was evaluated by the method for the determination of phosphorus molybdate, and the antioxidant activities in inhibition of lipid peroxidation was tested by lodometric method. ［Result］ Plumbagin showed stronger total antioxidant abilities than that of BHT (1.0 mg/ml) in almost different concentrations of plumbagin towards the inhibition in lipid peroxidation of peanut oil, and exhibited the “dose-dependent” and “time-dependent” effects. ［Conclusion］ The phenolic hydroxyl in plumbagin naphthoquinone ring was the main active radical to have antioxidant capacity, and the antioxidant ability of plumbagin was an important mechanism for anti-cancer activities. _