We present a set of novel low-molecular-mass (LMM) compounds possessing ampholytic properties. The compounds were designed to perform as markers of isoelectric point (pI) in different isoelectric focusing (IEF) formats and feature direct detectability in UV and visible wavelength regions. Capillary isoelectric focusing (cIEF) was used to determine the purity of the focusing species and the compounds’ pI values. Nitrophenol-based pI markers (NPIMs) published previously were used as standards for the pI value calibration. The presented compounds focused very well, but small portion of them contained focusing impurities, thus, we recommend them for use in other IEF formats like gel IEF and preparative IEF. Moreover, multi-wavelength detection enabled determination of individual markers based on their specific spectral profiles and different absorption at selected detection wavelengths in the electropherogram. The presented compounds compose a group of chemicals featuring excellent shelf stability and isoelectric focusing properties, inexpensive synthesis, universal/multimode detectability, and good solubility at pI. The presented results provide a solid ground for their use as reference standards in various isoelectric focusing methods.

我们提出了一组具有两性特性的新型低分子量 (LMM) 化合物。这些化合物被设计用作不同等电聚焦 (IEF) 格式的等电点 (p I ) 标记，并在紫外和可见波长区域具有直接检测能力。毛细管等电聚焦 (cIEF) 用于确定聚焦物质的纯度和化合物的 p I值。以前发表的基于硝基苯酚的 p I标记 (NPIM) 被用作 p I的标准品值校准。所介绍的化合物聚焦非常好，但其中一小部分含有聚焦杂质，因此，我们建议将它们用于其他 IEF 形式，如凝胶 IEF 和制备 IEF。此外，多波长检测能够根据其特定的光谱分布和电泳图中选定检测波长处的不同吸收来确定单个标记。所提出的化合物由一组化学物质组成，具有优异的货架稳定性和等电聚焦特性、廉价的合成、通用/多模式可检测性以及在 p I下的良好溶解性。所呈现的结果为它们在各种等电聚焦方法中用作参考标准提供了坚实的基础。