Takahashi Hironobu, Kosaka Masamiti, Watanabe Yasutoshi, Nakade Kousuke, Fukuyama Yoshiyasu
Institute of Pharmacognosy, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan.
Bioorg Med Chem. 2003 Apr 17;11(8):1781-8. doi: 10.1016/s0968-0896(02)00666-1.
Norbergenin, which is the O-demethyl derivative of bergenin, the main component of Mallotus japonicus, has been found to show moderate antioxidant activity (IC(50) 13 microM in DPPH radical scavenging; 32 microM in superoxide anion scavenging). Modification of sugar part on norbergenin by coupling with a variety of fatty acids was employed for increasing its antioxidant activity. Selective esterification of hydroxyl groups on the sugar part enhanced greatly antioxidant activity. The most potent one is norbergenin 11-caproate, which not only exhibits stronger antioxidant activity than that of catechin but also prevents neuronal death at 10 microM on the primary culture of rat cortical neurons in DMEM supplemented with N2.
去甲岩白菜素是日本常山主要成分岩白菜素的O-去甲基衍生物，已发现其具有中等抗氧化活性（在DPPH自由基清除实验中IC(50)为13微摩尔；在超氧阴离子清除实验中为32微摩尔）。通过与多种脂肪酸偶联对去甲岩白菜素的糖部分进行修饰，以提高其抗氧化活性。糖部分羟基的选择性酯化极大地增强了抗氧化活性。最有效的是去甲岩白菜素11-己酸酯，它不仅表现出比儿茶素更强的抗氧化活性，而且在添加N2的DMEM中对大鼠皮质神经元原代培养物在10微摩尔浓度时可防止神经元死亡。
