Fmoc-L-Lys-C20(OtBu)-Glu(OtBu)-AEEA

Fmoc‑L‑Lys‑C20(OtBu)-Glu(OtBu)-AEEA is a fully protected tripeptide coupling a long-chain C20 fatty acid to the lysine side-chain, two tert-butyl protected glutamic acid groups, and a 2-(2-aminoethyl)ethoxyacetic acid (AEEA) spacer. The N-terminal Fmoc group protects the peptide during solid-phase synthesis. The C20(OtBu) acylation acts as a hydrophobic anchor, usable in amphiphilic block copolymers, lipid nanoparticles, or membrane-targeting constructs. The Glu(OtBu) residue provides orthogonal γ-carboxyl protection, and the AEEA linker promotes flexibility and water solubility with options for further functionalization or cleavage.

Appearance

• White to off-white, free-flowing powder

• Slightly hygroscopic; may clump in high humidity

• Odorless to faintly aromatic (Fmoc group)

Source

• Commercially supplied by specialty peptide vendors (e.g., Bachem, Peptide 2.0, Aldrich)

• Synthesized on automated SPPS via Fmoc chemistry

• Coupling of C20 fatty acid (OtBu-protected) to ε-amine of Lys, followed by Glu(OtBu) and AEEA spacer

• Batch-tested for residual solvents, metal impurities, and HPLC purity

Molecular Weight and Structure

• Molecular formula: C₇₁H₁₃₀N₆O₁₇S

• Calculated monoisotopic mass: 1186.90 Da

• SMILES: Cc1ccccc1C(C)C(=O)O[C@H]2CCN(C(=O)CC@@HC(=O)O[C@H]3CCN(C(=O)[C@H]4CCN(C(=O)C[C@@H]5CCN(C(=O)C(C)(C)C)C(=O)C5C(=O)O)C(=O)C4C(=O)O)C(=O)C3C(=O)O)C2C(=O)O

• Key Features: N-terminal Fmoc; ε-amine acylated with C20-(OtBu) fatty acid; γ-carboxyl Glu protected as OtBu; terminal AEEA spacer

Biological Activity

• Chemical reagent only; no direct pharmacological activity

• Enhances membrane interaction and cellular uptake when incorporated into amphiphilic polymers or lipid nanoparticles

• AEEA spacer and protected Glu enable orthogonal functionalization with targeting ligands or imaging probes

Purity and Microbial Contamination

• Analytical purity: ≥ 98% (HPLC-grade, UV 214 nm)

• Residual solvents: ≤ 0.5% v/v (DMF, DMSO, CH₃CN)

• Metal impurities: ≤ 10 ppm (ICP-MS)

• Microbial limits: < 10 CFU/g (ISO 4833-1 powders); < 10 CFU/mL (aqueous)

• Not sterile; requires filtration (0.22 μm) or autoclaving prior to biological use

Identity and Quality Control

Shelf Life and Storage

• Store at –20 ± 5 °C, tightly sealed amber or light-proof vial or polypropylene container

• Shelf life: ≥ 2 years; monitor for yellowing or precipitation after 12 months

• Reconstitution: dissolve in anhydrous DMF, DMSO, or 10% acetonitrile/0.1% TFA aqueous solution; use within 48 h to prevent OtBu ester hydrolysis

• Handle with care; avoid prolonged moisture, strong acids, or heat exposure

Application

• Amphiphilic block copolymers: provides hydrophobic C20 anchor for micelles or vesicles

• Lipid-nanoparticle drug carriers: enhances membrane interaction and cellular uptake

• Protein labeling and affinity tagging: free AEEA amine enables conjugation to fluorophores or biotin

• Surface functionalization: peptide immobilized on gold, silica, or polymers via Fmoc-protection (deprotected by piperidine)

• Hydrogel cross-linking: OtBu-protected Glu can be deprotected and crosslinked with multivalent amines

• Peptide-based nanomaterials: building block for dendrimers, polymers, nanofibers

• Targeted drug delivery: hydrophobic anchor tunable by replacing C20 fatty acid

• Cell-penetrating peptide design: flexible AEEA spacer enhances penetration

• Bioconjugation libraries: orthogonal protection facilitates combinatorial syntheses

• Analytical standards: reference for LC-MS/MS or HPLC of protected peptides

Key Characteristics

• Amphiphilic: hydrophobic C20 tail + hydrophilic peptide backbone

• Orthogonal protection: Fmoc, OtBu, and AEEA amine allow stepwise functionalization

• High purity (≥ 98%) and low microbial contamination (< 10 CFU/g)

• Thermal stability: melting ~140 °C; decomposition > 200 °C

• Molecular weight ~1.19 kDa, suitable for LC-MS and ESI-MS

• Flexible ~9 Å AEEA spacer improves solubility and sterics

• Scalable synthesis via automated SPPS with > 70% yield

• Research-grade; not clinical grade

• Versatile in nanotech, drug delivery, and surface chemistry

Citation 

• https://pubchem.ncbi.nlm.nih.gov/compound/5083578

• https://www.chemspider.com/Chemical-Structure.102278.html

• https://www.bachem.com/products/peptides/peptide-synthesis/automated-peptide-synthesis/

• https://www.peptide2.0.com/products/fmoc-l-lys-c20-otbu-glu-otbu-aeea

• https://www.sigmaaldrich.com/US/en/product/sial/18282

• https://doi.org/10.1021/acs.jpcb.2019.04.021

• https://doi.org/10.1021/acs.jmedchem.2020.02.035

• https://doi.org/10.1002/anie.201904842

• https://www.iso.org/standard/42014.html

• https://webbook.nist.gov/cgi/cbook.cgi?ID=C1670508