Ligands of retinoid X receptors (RXRs) are effective against various diseases, so there is a need for efficient screening methods to discover new ligands. Existing screening methods are complex and time-consuming, and a simple fluorescence assay would be highly desirable. Here, we focused on NEt-SB (4), which has a stilbene structure, as a candidate for this purpose, and examined its fluorescence properties in detail. The fluorescence intensity of 4 was remarkably increased in highly viscous solvents and upon binding to hRXRα-LBD, due to suppression of free rotation of the stilbene moiety. Although the relatively low fluorescence intensity and the short fluorescence wavelength of 4 make this compound itself unsuitable for use in RXR binding assay, our findings provide a basis for further structural evolution, which may lead to a derivative that would be suitable for fluorescence assay of RXR binders.

类视黄醇X受体（RXR）的配体可有效抵抗多种疾病，因此需要一种有效的筛选方法来发现新的配体。现有的筛选方法是复杂且费时的，并且非常需要简单的荧光测定法。在这里，我们将注意力集中在具有二苯乙烯结构的NEt-SB（4）上，并详细研究了其荧光性质。在高粘度溶剂中和与hRXRα-LBD结合后，由于抑制了二苯乙烯部分的自由旋转，荧光强度4显着增加。尽管荧光强度相对较低且荧光波长短于4 使得该化合物本身不适合用于RXR结合测定，我们的发现为进一步的结构进化提供了基础，这可能会导致衍生出一种适合于RXR结合物荧光测定的衍生物。