LC-ESI-Mass Spectrometer for the Analysis of Highly-Modified RNA- and DNA-Derivatives

法兰克福歌德大学（Goethe University Frankfurt）自然科学的研究重点之一是对RNA的研究——从转录调控、后续加工（例如剪接）一直到翻译调控。特别令人感兴趣的是不编码蛋白质的RNA。过去15年的特点是知识大幅增加，特别是在后一个领域，冠状病毒大流行表明RNA具有巨大的治疗潜力。能够合成新的RNA衍生物是至关重要的，例如具有更高的稳定性或新的功能。这些功能可以作为智能探针来收集关于RNA的新知识，尤其是RNA功能调节的新机制。例如，开发以光作为外部触发的RNA活性调控方法是法兰克福发展的专业之一。这项研究目前由SFB 902 （rna调控的分子原理）或GRK 1986（复杂光控制）资助。所有这些项目都需要对新合成的寡核苷酸衍生物进行分析。表征的黄金标准是质谱法，这是没有其他选择的。此外，由于当前申请人的贡献，现在可以引入一系列新的修饰，新的化学酶，固相支持的合成策略使合成比以往更长，更高修饰的衍生物成为可能。他们的分析非常复杂，只为此需要一台质谱仪。在过去，在同一设备上分析其他物质类别也伴随着严重的问题。当前可用的设备正在接近其最大寿命。新设备的检测限需要降低，分辨率需要提高。特别还要求新设备现在也能够执行碎片和片段分析，从而可以提供序列分析。前者很重要，因为到目前为止，由于更长更复杂的探针，很大一部分库存被用于表征。后者将允许更好地分析衍生物，特别是在合成后需要优化反应的寡核苷酸进一步衍生的情况下。

One of the research focusses of the natural sciences at Goethe University Frankfurt is the investigation of RNA - ranging from the regulation of transcription, its subsequent processing (for example splicing) all the way to the regulation of translation. Of particular interest is RNA that does not code for proteins. The past 15 years are characterized by an enormous increase of knowledge especially in the latter field and the corona pandemic has shown that RNA has a large therapeutic potential. It is essential to be able to synthesize new RNA derivatives for example with increased stability or new functionalities. Such functionalities can be intelligent probes to gather new knowledge about RNA or especially also new mechanisms for the regulation of the RNA's function. For example, the development of methods for the regulation of RNA activity with light as external trigger is one of the specialities developed in Frankfurt. This research is currently funded for example by SFB 902 (Molecular Principles of RNA-Based Regulation) or GRK 1986 (Complex Light Control).For all of these projects the newly synthesized oligonucleotide derivatives need to be analyzed. The gold standard for the characterization is mass spectrometry - and this is without alternative. Also by contributions of the present applicants, an array of new modifications can now be introduced and new chemoenzymatic, solid-phase supported synthesis strategies enable the synthesis of longer and higher modified derivatives than ever before. Their analysis is very complicated and requires a mass spectrometer only for this purpose. Also analyzing other substance classes on the same device was accompanied with severe problems in the past. The currently available device is approaching its maximal life time. With a new device the detection limit needs to be lowered and the resolution needs to be enhanced. It is especially also required that the new device is now also able to perform fragmentation and fragment analysis and can hence provide sequence analysis. The former is important since with longer and more complex probes a significant part of the stock was used up for the characterization up to now. The latter will allow better analysis of the derivatives, especially in cases where the oligonucleotide is further derivatized after synthesis with reactions that need to be optimized.