In view of the increasing interest in peptides in various market sectors, a stronger emphasis on topics related to their production has been seen. Fmoc-based solid phase peptide synthesis, although being fast and efficient, provides final products with significant amounts of trifluoroacetate ions in the form of either a counter-ion or an unbound impurity. Because of the proven toxicity towards cells and peptide activity inhibition, ion exchange to more biocompatible one is purposeful. Additionally, as most of the currently used counter-ion exchange techniques are time-consuming and burdened by peptide yield reduction risk, development of a new approach is still a sensible solution. In this study, we examined the potential of peptide counter-ion exchange using non-aqueous organic solvents saturated with HCl. Counter-ion exchange of a model peptide, citropin 1.1 (GLFDVIKKVASVIGGL-NH₂), for each solvent was conducted through incubation with subsequent evaporation under reduced pressure, dissolution in water and lyophilization. Each exchange was performed four times and compared to a reference method—lyophilization of the peptide from an 0.1 M HCl solution. The results showed superior counter-ion exchange efficiency for most of the organic solutions in relation to the reference method. Moreover, HCl-saturated acetonitrile and tert-butanol provided a satisfying exchange level after just one repetition. Thus, those two organic solvents can be potentially introduced into routine peptide counter-ion exchange.

中文翻译：

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在盐酸饱和的有机溶液中，Citropin 1.1三氟乙酸盐与氯离子的离子交换作用：另一种方法。

鉴于在各个市场领域对肽的兴趣日益增加，已经看到对与肽生产有关的主题的更加重视。基于Fmoc的固相肽合成虽然快速高效，但却为终产物提供了以抗衡离子或未结合杂质形式存在的大量三氟乙酸根离子。由于已证明对细胞具有毒性并抑制了肽的活性，因此将离子交换为更具生物相容性的物质是有目的的。另外，由于大多数当前使用的抗衡离子交换技术既耗时又受肽产量降低风险的困扰，因此开发新方法仍然是明智的选择。在这项研究中，我们检查了使用饱和HCl的非水有机溶剂进行肽抗衡离子交换的潜力。模型肽的抗衡离子交换，₂），对于每种溶剂，通过温育进行，随后减压蒸发，溶于水并冻干。每次交换进行四次，并与参考方法进行比较-从0.1 M HCl溶液中冻干肽。结果表明，与参考方法相比，大多数有机溶液的抗衡离子交换效率更高。而且，HCl饱和的乙腈和叔丁醇仅重复一遍即可提供令人满意的交换水平。因此，这两种有机溶剂可以潜在地引入常规肽抗衡离子交换中。