Kamiya Kohei, Tanaka Yohei, Endang Hanani, Umar Mansur, Satake Toshiko
Faculty of Pharmaceutical Sciences and High Technology Research Center, Kobe Gakuin University, Nishi-ku, Kobe 651-2180, Japan.
J Agric Food Chem. 2004 Sep 22;52(19):5843-8. doi: 10.1021/jf040114k.
The oxidative modification of low-density lipoprotein (LDL) plays an important role in the genesis of arteriosclerosis. The present study focused on the effects of the fruits of Morinda citrifolia on preventing arteriosclerosis. The MeOH extract and CHCl(3)-, EtOAc-, n-BuOH-, and H(2)O-soluble phases derived from the fruits of M. citrifolia were evaluated for their inhibitory activity on copper-induced LDL oxidation by the thiobarbituric acid-reactive substances (TBARS) method. The MeOH extract and EtOAc-soluble phase showed 88 and 96% inhibition, respectively. Six lignans were isolated by repeated column chromatography from the EtOAc-soluble phase. These compounds were determined by spectroscopic analysis to be 3,3'-bisdemethylpinoresinol (1), americanol A (2), americanin A (3), americanoic acid A (4), morindolin (5), and isoprincepin (6), of which 4 and 5 are novel compounds. These compounds inhibited copper-induced LDL oxidation in a dose-dependent manner. 1, 2, 5, and 6 exhibited remarkably strong activities, which were the same or better than that of the known antioxidant 2,6-di-tert-butyl-p-cresol. The IC(50) values for 1, 2, 5, and 6 were 1.057, 2.447, 2.020, and 1.362 microM, respectively. The activity of these compounds is mainly due to their number of phenolic hydroxyl groups.
低密度脂蛋白（LDL）的氧化修饰在动脉粥样硬化的发生过程中起重要作用。本研究聚焦于巴戟天果实对预防动脉粥样硬化的作用。采用硫代巴比妥酸反应物质（TBARS）法，对巴戟天果实的甲醇提取物以及氯仿、乙酸乙酯、正丁醇和水可溶相抑制铜诱导的LDL氧化的活性进行了评估。甲醇提取物和乙酸乙酯可溶相的抑制率分别为88%和96%。通过反复柱色谱从乙酸乙酯可溶相中分离出6种木脂素。经光谱分析确定这些化合物为3,3'-双去甲基松脂醇（1）、美登醇A（2）、美登素A（3）、美登酸A（4）、巴戟天苷（5）和异虎刺素（6），其中4和5为新化合物。这些化合物以剂量依赖方式抑制铜诱导的LDL氧化。1、2、5和6表现出非常强的活性，与已知抗氧化剂2,6-二叔丁基对甲酚的活性相同或更好。1、2、5和6的IC50值分别为1.057、2.447、2.020和1.362 microM。这些化合物的活性主要归因于其酚羟基的数量。
