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Updated: May 23, 2026

Synthesis and Structure Determination of µ-Conotoxin PIIIA Isomers with Different Disulfide Connectivities
Published on: October 2, 2018
4-Methoxybenzyloxymethyl group, a racemization-resistant protecting group for cysteine in Fmoc solid phase peptide
Hajime Hibino1, Yuji Nishiuchi
1SAITO Research Center, Peptide Institute, Inc., Ibaraki, Osaka 567-0085, Japan.
Abstract:
The 4-methoxybenzyloxymethyl (MBom) group was introduced for sulfhydryl protection of Cys in combination with Fmoc chemistry. The MBom group proved to substantially suppress racemization of Cys during its incorporation mediated by phosphonium or uronium reagents. Furthermore, this group was found to significantly reduce racemization of the C-terminal Cys linked to a hydroxyl resin during repetitive base treatment, in comparison with the usually used trityl (Trt) and acetamidomethyl (Acm) groups.
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