aspartimide formation during peptide synthesis one of the major obstacles that impedes the solid phase synthesis - Aspartimide formationmechanism peptide Mastering Aspartimide Formation During Peptide Synthesis: Strategies for Purity and Yield

Aspartimidestructure Aspartimide formation is a significant challenge that continues to complicate the peptide synthesis, particularly within the realm of Fmoc solid phase peptide synthesis (SPPS)The use of the aspartic acid derivatives according to the present invention leads to the minimization of base catalyzedaspartimide formation during peptide.... This undesirable side reaction arises from the cyclization of the aspartic acid residue, specifically when the alpha-carboxyl amide bond undergoes ring-closure with the beta-carboxyl side chain. This process often occurs during peptide elongation and deprotection steps, leading to a decrease in overall yield and requiring extensive purification efforts, sometimes even rendering target peptides inaccessible. Understanding the mechanisms and implementing effective prevention strategies are crucial for successful peptide production.The use of the aspartic acid derivatives according to the present invention leads to the minimization of base catalyzedaspartimide formation during peptide...

The root cause of aspartimide formation is frequently attributed to the repeated exposure of aspartic acid-containing sequences to basic conditions.2025年8月26日—Aspartimide formationremains a persistent challenge in Fmoc solid phasepeptide synthesis. This review surveys strategies to prevent ... Common reagents used in Fmoc SPPS, such as piperidine, are notorious for promoting this cyclization. This is particularly evident in sequences containing Asp-Gly or Asp-Xaa motifs, where the proximity and nature of the adjacent amino acid residues can exacerbate the issue. For instance, research by Nicol et al作者：JL Lauer·1995·被引用次数：158—We have examined the sequence dependence ofaspartimide formationduring Fmoc-based solid-phase synthesis of the peptide Val-Lys-Asp-X-Tyr-Ile.. in 1989 highlighted the marked tendency of piperidine to induce aspartimide formation during Fmoc deprotection in Asp-Gly sequences. Similarly, Lauer et al作者：J Bouchenna·2020·被引用次数：5—Aspartimide formation often complicates the solid phase synthesis of peptides. Much less discussed is the potential occurrence of this .... in 1995 examined the sequence dependence of this phenomenon in Fmoc-based SPPS, further underscoring the critical role of sequence context.

The consequence of aspartimide formation is multifacetedPreventing aspartimide formation during peptide synthesis. The cyclic imide intermediate (also referred to as aspartimide) itself can be a contaminant, but it also readily undergoes hydrolysis. This hydrolysis can lead to the formation of two epimers: the desired alpha-peptide bond and the undesired beta-peptide bond (beta-isoaspartyl peptides). This epimerization, often occurring during synthesis, compromises the structural integrity and biological activity of the final peptide product. The formation of these byproducts not only lowers the yield of the target peptide but also significantly increases the complexity and cost of purification.How to prevent aspartimide formation during Microwave- ...

Fortunately, considerable effort has been dedicated to developing methods to mitigate and prevent aspartimide formation. Several approaches have emerged, focusing on modifying reaction conditions, employing specific protecting groups, and utilizing different coupling reagents.

One primary strategy involves careful selection of protecting groups for the aspartic acid side chain. While standard protecting groups can be susceptible to cleavage under basic conditions that facilitate aspartimide formation, alternative strategies aim to prevent thisThe CSY-protecting group in the microwave-assisted .... For example, the use of (R)-Aspartimide derivatives, or more broadly, specific aspartic acid derivatives, has been explored to minimize base-catalyzed aspartimide formation during peptide synthesis. Patents like EP2886531A1 and the associated patent 2886531 describe the utility of such derivatives in reducing this problematic reaction. Furthermore, research has investigated novel protecting groups, such as cyanosulfurylides, for carboxylic acids, demonstrating their efficacy in preventing aspartimide formation during peptide synthesis. Another promising avenue, explored by Sato et al. in 2024, involves utilizing hydrazide as a carboxylic-acid-protecting group to effectively reduce the formation of aspartimides.

Modifying the deprotection strategy is also critical.Aspartimide formation in peptide chemistry While piperidine is commonly used for Fmoc removal, its basicity can be problematic. Exploring milder deprotection conditions or alternative reagents can help. Additionally, the rate of peptide synthesis can play a role. As noted by Flora et al. in 2005, aspartimide formation is more likely to occur during rapid peptide synthesis. Therefore, employing slower-acting coupling reagents or optimizing reaction times can contribute to suppression.作者：V Aucagne·2025·被引用次数：1—We show that theformationofaspartimideand derived byproducts can be limited by adopting “good NCL practices”, which involve restricting the ligation ...

The role of reaction parameters such as temperature, acidity, and basicity has been extensively studied. Tam et al. in 1988 investigated these factors using a model tetrapeptide, providing valuable insights into optimizing reaction conditions to minimize aspartimide formationPreventing aspartimide rearrangements during fmoc-based ....

Some approaches focus on blocking the cyclization pathway directly. One such method, described in the literature, involves incorporating a blocking group on the alpha-nitrogen of the amino acid preceding aspartic acid in the peptide sequence作者：D Samson·2019·被引用次数：32—Abstract. Aspartimide (Asi) formation isa notorious side reaction in peptide synthesisthat is well characterized and described in literature.. This steric hindrance can effectively prevent or significantly reduce the likelihood of cyclization.

For complex peptide structures, such as cyclic peptides, aspartimide formation during the synthesis of cyclic peptides on solid phase requires specific attention.2021年5月26日—I'm studying solid-phasepeptide synthesis(SPPS) at the moment, and a common problem is theformationof aspartimides, which disrupt the synthetic process. Methods developed by Flora et al. (2005) offer diagnostic and control strategies tailored for these intricate molecules.作者：J Bouchenna·2020·被引用次数：5—Aspartimide formation often complicates the solid phase synthesis of peptides. Much less discussed is the potential occurrence of this ...

The ultimate goal in peptide synthesis is to achieve high purity and yield, and overcoming the challenge of aspartimide formation is paramountIn solid-phase peptide synthesis, why are the formation of .... While aspartimide formation remains a persistent challenge in Fmoc solid phase peptide synthesis, the continuous development of innovative strategies—from advanced protecting group chemistry to refined reaction protocols—offers promising solutionsNovabiochem® Innovations 1 .16. By understanding the intricacies of the aspartimide formation mechanism, its structure, and the factors that drive its occurrence, researchers can better implement these preventative measures, leading to more efficient and successful peptide production. The ability to prevent aspartimide formation during peptide synthesis is a testament to the ongoing advancements in peptide chemistry, ensuring the reliable generation of peptides for research and therapeutic applications作者：K Neumann·2020·被引用次数：80—Aspartimide formationleads to low yieldsin addition to costly purification or even inaccessible peptide sequences..