Lin Li-Lin, Huang Feng, Chen Si-Bao, Yang Da-Jian, Chen Shi-Lin, Yang Jun-Shan, Xiao Pei-Gen
Institute of Medicinal Plant Development, Peking Union Medical College & Chinese Academy of Medical Sciences, Beijing, PR China.
Planta Med. 2005 Apr;71(4):372-5. doi: 10.1055/s-2005-864108.
Three new xanthones, 2-hydroxy-1,6,7-trimethoxyxanthone (1), 1,4-dimethoxy-2,3-methylenedioxyxanthone (2), and 7-hydroxy-1,2-dimethoxyxanthone (3), together with five known compounds, 2,7-dihydroxy-1-methoxyxanthone (4), 1-methoxy-2,3-methylenedioxyxanthone (5), 7-hydroxy-1-methoxyxanthone (6), euxanthone (1,7-dihydroxyxanthone) (7), and gentitein (1,3,7-trihydroxyxanthone) (8), were isolated from the roots of Polygala caudata. Their structures were established on the basis of spectral evidence. In the antioxidation activity screening in vitro with luminol chemiluminescence methods, compounds 1 - 5 and 7 and 8 showed H2O2 scavenger activity, with a scavenging effect of 58.4 - 94.5% at 10 microg/mL, and 26.0 - 84.7% at 2 microg/mL. Compounds 4 and 8 also exhibited scavenging effects on the reactive oxygen free radicals produced by macrophage respiratory bursts, with a scavenging effect of 71.7% and 63.4% at 10 microg/mL, 41.2% and 47.8% at 2 microg/mL, respectively. In the vasodilatation assay, compounds 4 - 7 exhibited relaxing activity on the contractions evoked by KCl in Wistar rat thoracic aorta rings in a dose-dependent manner.
从尾叶远志的根中分离出三种新的呫吨酮，即2-羟基-1,6,7-三甲氧基呫吨酮（1）、1,4-二甲氧基-2,3-亚甲二氧基呫吨酮（2）和7-羟基-1,2-二甲氧基呫吨酮（3），以及五种已知化合物，即2,7-二羟基-1-甲氧基呫吨酮（4）、1-甲氧基-2,3-亚甲二氧基呫吨酮（5）、7-羟基-1-甲氧基呫吨酮（6）、呫吨酮（1,7-二羟基呫吨酮）（7）和三叶豆紫檀苷（1,3,7-三羟基呫吨酮）（8）。它们的结构是根据光谱证据确定的。在用鲁米诺化学发光法进行的体外抗氧化活性筛选中，化合物1 - 5以及7和8表现出清除H2O2的活性，在10微克/毫升时清除率为58.4 - 94.5%，在2微克/毫升时清除率为26.0 - 84.7%。化合物4和8对巨噬细胞呼吸爆发产生的活性氧自由基也有清除作用，在10微克/毫升时清除率分别为71.7%和63.4%，在2微克/毫升时清除率分别为41.2%和47.8%。在血管舒张试验中，化合物4 - 7对Wistar大鼠胸主动脉环中由氯化钾引起的收缩具有剂量依赖性的舒张活性。
