$3692.00 - $9231.00
Fmoc-Orn(ivDde)-OH is Nalpha-Fmoc-Ndelta-ivDde-L-ornithine, an orthogonally protected diamino acid for Fmoc solid-phase peptide synthesis. Fmoc controls the alpha amino group while ivDde protects the ornithine side-chain delta amine.
Selective removal of ivDde can expose the side-chain amine while the peptide remains resin-bound, creating a controlled site for acylation, labeling, lipidation, branching or cyclization. This is one of the most practical reasons to choose an orthogonally protected noncanonical/basic residue instead of adding a modification after global cleavage.
Product Information
| Product Name | Fmoc-Orn(ivDde)-OH |
| Catalog No. | AS2115 |
| CAS No. | 1198321-33-3 |
| Molecular Formula | C33H40N2O6 |
| Molecular Weight | 560.68 g/mol |
| Chemical Identity | Nalpha-Fmoc-Ndelta-ivDde-L-ornithine |
| Building Block Type | Orthogonally protected ornithine building block |
| Primary Applications | Selective on-resin side-chain deprotection, labeling, lipidation, branching and cyclization |
Why ivDde Is Used Instead of a Standard Acid-Labile Side-Chain Group
ivDde is designed for selective hydrazine-mediated removal and is more resistant to repeated piperidine exposure than Dde. That makes it useful in longer Fmoc-SPPS sequences where the side-chain amine must remain protected through many deprotection cycles. We consider protecting-group stability during the entire synthesis more important than the convenience of any single deprotection step.
Ornithine Places the Modification Closer to the Backbone
Ornithine has one fewer methylene than lysine. A fluorophore, lipid, linker or lactam attached to Orn therefore occupies a different spatial position relative to the peptide backbone. The change can affect cyclization geometry and biological recognition, so Orn is not simply a cheaper or shorter Lys equivalent.
Compare with Fmoc-Dab(Dde)-OH
Fmoc-Dab(Dde)-OH places its side-chain amine even closer to the backbone and uses Dde rather than ivDde. Comparing the two helps separate side-chain-length effects from protecting-group stability. For complex modification sequences, the SPPS workflow guide provides the broader resin/deprotection context.
Procurement and QC Considerations
Confirm CAS 1198321-33-3, formula C33H40N2O6, MW 560.68 g/mol, L-ornithine stereochemistry and the Fmoc/ivDde protection map. Lot-specific HPLC/MS should be reviewed for partially deprotected or protection-migrated species. Storage conditions vary among suppliers, so the Alan Scientific lot label/COA should control final handling.
Product Documents
A Safety Data Sheet (SDS / MSDS) is available for this product to support laboratory handling, storage and safety assessment.
Certificates of Analysis (COAs) are batch-specific. Please contact us to request the COA for your product, and we will provide it by email.
Frequently Asked Questions
What is Fmoc-Orn(ivDde)-OH used for?
It introduces an ornithine residue whose side-chain amine can later be selectively exposed for labeling, lipidation, branching, acylation or cyclization.
Why choose ivDde?
ivDde provides hydrazine-sensitive orthogonality and improved stability toward repeated piperidine/Fmoc deprotection compared with Dde in many workflows.
How is ornithine different from lysine for side-chain modification?
Ornithine has one fewer methylene in its side chain, so the modification sits closer to the peptide backbone and can produce different geometry or biological effects.
Related Technical Resources
Compare the shorter Fmoc-Dab(Dde)-OH side-chain handle.
Discuss a labeled, lipidated, branched or cyclic custom peptide.