The backbone nitrogen after an aspartic acid can attack its side chain, closing a five-membered succinimide ring and losing water (−18.011 Da). In Fmoc synthesis the repeated base steps promote it, especially in Asp-Gly, Asp-Asn and Asp-Ser sequences.
The ring re-opens to the original α-aspartyl peptide, to a β-aspartyl (isoaspartyl) peptide, or to their D-forms, all with the intended mass, so they are found by chromatography rather than mass spectrometry.
See also
Cite this page
Text
Cosmic Peptides. (2026, October 25). Aspartimide: glossary entry. Cosmic Peptides Research Library. Retrieved October 26, 2026, from https://cosmicpeptides.com/research/glossary/aspartimide
BibTeX
@misc{cosmicpeptides_research_glossary_aspartimide,
author = {{Cosmic Peptides}},
title = {Aspartimide: glossary entry},
howpublished = {Cosmic Peptides Research Library},
year = {2026},
month = oct,
url = {https://cosmicpeptides.com/research/glossary/aspartimide},
urldate = {2026-10-26},
note = {Last reviewed 2026-10-25}
} RIS
TY - ELEC AU - Cosmic Peptides TI - Aspartimide: glossary entry T2 - Cosmic Peptides Research Library PB - Cosmic Peptides PY - 2026 DA - 2026/10/25 UR - https://cosmicpeptides.com/research/glossary/aspartimide Y2 - 2026/10/26 LA - en ER -
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