Sun Bohang, Morikawa Toshio, Matsuda Hisashi, Tewtrakul Supinya, Wu Li Jun, Harima Shoichi, Yoshikawa Masayuki
Kyoto Pharmaceutical University, Misasagi, Yamashina-ku, Kyoto 607-8412, Japan.
J Nat Prod. 2004 Sep;67(9):1464-9. doi: 10.1021/np040080a.
The aqueous ethanolic extract from the roots of Stellaria dichotoma showed an antiallergic effect on ear passive cutaneous anaphylaxis (PCA) reaction in mice (in vivo) and inhibitory activity on the release of beta-hexosaminidase in RBL-2H3 cells (in vitro). From the aqueous ethanolic extract, new beta-carboline-type alkaloids, dichotomines A (1), B (2), C (3), and D (4) and dichotomides I (5) and II (6), were isolated. The structures of the new constituents (1-6) were determined on the basis of chemical and physicochemical evidence, including the application of the modified Mosher's method. The effects of the isolated constituents on the release of beta-hexosaminidase in RBL-2H3 cells were examined, and 3 was found to show inhibitory activity (IC(50) = 62 microM). Moreover, 3 also inhibited the releases of antigen-IgE-mediated TNF-alpha and IL-4 (19 and 15 microM, respectively) in RBL-2H3 cells, both of which participate in the late phase of type I allergic reactions.
银柴胡根的乙醇水提取物对小鼠耳部被动皮肤过敏反应（PCA）（体内）显示出抗过敏作用，并对RBL-2H3细胞（体外）中β-己糖胺酶的释放具有抑制活性。从乙醇水提取物中分离出新型β-咔啉类生物碱，即银柴胡碱A（1）、B（2）、C（3）和D（4）以及银柴胡酰胺I（5）和II（6）。基于化学和物理化学证据，包括改良的莫舍尔方法的应用，确定了新成分（1-6）的结构。研究了分离出的成分对RBL-2H3细胞中β-己糖胺酶释放的影响，发现化合物3具有抑制活性（IC50 = 62 μM）。此外，化合物3还抑制RBL-2H3细胞中抗原-IgE介导的TNF-α和IL-4的释放（分别为19和15 μM），这两种物质均参与I型过敏反应的晚期阶段。
