INTRODUCTION Cysteine is a versatile amino acid for selective chemical modification of proteins with both chemical and biological innovations, which plays a key role in different organic reactions. MATERIALS AND METHODS Chemical modification of proteins is a rapidly expanding area in chemical biology. Selective installation of biochemical probes has led to a better understanding of natural protein modification and macromolecular function. In other cases, such as chemical alterations, the protein function has entirely changed.This review paper considers the organic reaction of cysteine, concerning reactivity of this α-amino acid containing sulfur and several methodologies are also discussed. Herein, we focused on the reaction of cysteine and its application in organic synthesis, which includes addition, condensation, substitution, condensation, oxidation and ring-opening reactions. RESULTS AND DISCUSSION Hence monitoring of cysteine is pivotal through the preparation of some fluorescent probe which can detect cysteine in high sensitivity. Also, a bibliometric analysis was carried out using Web of Science and Scopus databases that demonstrated significant contributions being observed in organic synthesis. Analysis of keywords revealed that research hotspots were cysteine, sensor, unclassified drug and amino acid. The topographical distribution maps showed the pattern of collaboration with the strongest links which have long work together along with high coverage of active researchers. CONCLUSION Therefore, it seems that future research focuses on using cysteine amino acid in various fields as natural products and organic reactions. This focus Review highlights the enduring utility of cysteine in protein modification and sensor preparation with a special focus on recent innovations in chemistry and biology associated with such modifications.

中文翻译：

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半胱氨酸在有机合成中的化学行为。

简介半胱氨酸是一种多功能氨基酸，可通过化学和生物学创新对蛋白质进行选择性化学修饰，在不同的有机反应中发挥关键作用。材料与方法蛋白质的化学修饰是化学生物学中一个迅速扩展的领域。选择性安装生化探针已使人们对天然蛋白质修饰和大分子功能有了更好的了解。在其他情况下，例如化学变化，蛋白质功能也已完全改变。这篇综述文章考虑了半胱氨酸的有机反应，涉及这种含硫的α-氨基酸的反应性，并讨论了几种方法。在此，我们主要研究半胱氨酸的反应及其在有机合成中的应用，包括加成，缩合，取代，缩合，氧化和开环反应。结果与讨论因此，通过制备一些可以高灵敏度检测半胱氨酸的荧光探针，对半胱氨酸的监测至关重要。此外，使用Web of Science和Scopus数据库进行了文献计量分析，结果表明在有机合成中已观察到重大贡献。对关键词的分析显示，研究热点是半胱氨酸，传感器，未分类的药物和氨基酸。地形分布图显示了具有最强联系的协作模式，这些联系长期合作，活跃研究人员的覆盖率很高。结论因此，似乎未来的研究集中于在各个领域中使用半胱氨酸氨基酸作为天然产物和有机反应。