Bioassay-guided fractionation of the leaves of Eugenia rigida yielded three stilbenes, (Z)-3,4,3′,5′-tetramethoxystilbene (1), (E)-3,4,3′,5′-tetramethoxystilbene (2), and (E)-3,5,4′-trimethoxystilbene (3). Their structures were determined using 1D- and 2D-NMR spectroscopy and HRESIMS. The sterically hindered Z-stereoisomer 1, a new natural product, was prepared by time-dependent photoisomerization
的叶子的
生物测定引导的分级分离尤
金尼亚杜松产生了三种
芪,(Ž)-3,4,3',5'- tetramethoxystilbene(1),(ê)-3,4,3',5'- tetramethoxystilbene(2)和(E)-3,5,4'-
三甲氧基methoxy(3)。使用1D和2D-NMR光谱和HRESIMS确定了它们的结构。所述空间位阻Ž -立体异构体1,新的
天然产物,是由随时间的光异构化反应制备ë -异构体(2)紫外光照射下,在λ 254纳米,而2,3,5,7-tetramethoxyphenanthrene(5通过UHPLC / APCI-MS和NMR光谱在365 nm处鉴定)。化合物1 - 3针对
萤光素酶报道
基因测定该评估许多癌症相关的
信号转导途径的活性的面板进行了测试,并且ž -异构体(1)被发现是比更有效ë -异构体(2抑制) Stat3,Smad3 / 4,myc,Ets,Notch和Wnt信号的激活,IC