Hou Wen-Rui, Su Zhi-Qiang, Pi Hui-Fang, Yao Guang-Min, Zhang Peng, Luo Xiang, Xie Sheng-Nan, Xiang Ming
Department of Pharmacology, School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
J Asian Nat Prod Res. 2010 Aug;12(8):707-13. doi: 10.1080/10286020.2010.490779.
A novel biscoumarin, 6,6',7,7'-tetramethoxyl-8,8'-biscoumarin (1), was isolated from the ethyl acetate extract of Urtica dentata Hand, together with five known compounds named as 7,7'-dihydroxy-6,6'-dimethoxy-8,8'-biscoumarin (2), 7,7'-dimethoxy-6,6'-biscoumarin (3), scoparone (4), vanillic acid (5), and daucosterol (6). Structures of the isolated compounds were elucidated on the basis of spectroscopic analysis including 2D NMR experiments. Compounds 1 and 2 were confirmed to be a rare carbon-carbon linked symmetrical biscoumarin. Compounds 1-4, especially 1 (IC(50) = 8.18 x 10(- 5) mol/l), showed potent immunosuppressive activities as determined by the Cell Counting Kit-8 assay for lymphocyte proliferation. Also, in the FACS analysis, 1 (IC(50) = 5.19 x 10(- 4) mol/l) promoted the differentiation of CD4(+)CD25(+)Foxp3(+) T regulatory cells distinctly compared to the normal control. Thus, 1 possessed specific immunosuppressive property by eliciting T regulatory cells, which may provide a potential treatment strategy for autoimmune diseases.
从荨麻的乙酸乙酯提取物中分离出一种新型双香豆素，即6,6',7,7'-四甲氧基-8,8'-双香豆素（1），同时还分离出五种已知化合物，分别为7,7'-二羟基-6,6'-二甲氧基-8,8'-双香豆素（2）、7,7'-二甲氧基-6,6'-双香豆素（3）、滨蒿内酯（4）、香草酸（5）和胡萝卜苷（6）。通过包括二维核磁共振实验在内的光谱分析确定了分离出的化合物的结构。化合物1和2被确认为一种罕见的碳-碳连接对称双香豆素。通过细胞计数试剂盒-8法检测淋巴细胞增殖，发现化合物1-4，尤其是1（IC50 = 8.18×10-5 mol/l）具有较强的免疫抑制活性。此外，在流式细胞术分析中，与正常对照相比，1（IC50 = 5.19×10-4 mol/l）能明显促进CD4(+)CD25(+)Foxp3(+)调节性T细胞的分化。因此，1通过诱导调节性T细胞具有特异性免疫抑制特性，这可能为自身免疫性疾病提供一种潜在的治疗策略。
