ISSN:
1573-3904
Keywords:
TBTU cyclization
;
Linear aspartimidyl peptide
;
Palladium cleavage
;
Peptide chemical grafting
;
Orthogonality
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Summary This paper discusses the application of a method developed for cyclic peptide synthesis using allyl-based sidechain-protecting groups to obtain a so-called tailed cyclic peptide, a cyclic peptide bearing a side-chain anchoring tail. The method used for the synthesis of cyclo[-d-Val-Arg-Gly-Asp-Asp(-εAhx-Cys-NH2)-]incorporates the α-allyl-protected aspartic acid Fmoc-l-Asp-OAl. A major side reaction, resulting in aspartimide formation, was observed when Fmoc-l-Asp-OAl was incorporated into the sequence at the N-terminus of 6-aminohexanoic acid (εAhx). This side reaction leads to an aspartimidyl linear peptide with the same molecular weight as the expected cyclized peptide. Additionally, the undesired peptide contains a free amino terminus, which was responsible for further side reactions during the subsequent steps of the synthesis, mainly tetramethylguanidinium formation (M+98) in TBTU-induced cyclization, and acetylation (M+42).
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00126738
Permalink