Fmoc-L-Agp(Boc)2-OH is a protected amino acid derivative featuring an Fmoc-protected α-amino group and a carboxylic acid in the free acid form, based on the L-configuration indicated in the name. The side chain incorporates two Boc (tert-butoxycarbonyl) protecting groups, yielding a polyprotected agmatine-type structure with masked basic functionalities while retaining the α-amino and carboxyl functional groups as protected and deprotected, respectively. In peptide chemistry, this compound is used as a stepwise building block for incorporating the protected side-chain motif into peptide chains via solid-phase or solution-phase strategies, where the Fmoc and Boc groups help control chemoselectivity during sequential coupling and deprotection steps.
CAT No: CP25742
CAS No:313232-63-2
Synonyms/Alias:313232-63-2;AmbotzFAA1772;Fmoc-Agp(Boc)2-OH;Fmoc-L-Agp(Boc)2-OH;C29H36N4O8;6914AH;ZINC100230493;A-7725
Chemical Name:(S)-N-alpha-(9-Fluorenylmethyloxycarbonyl)-N,N’-bis-t-butyloxycarbonyl-2-amino-3-guanidino-propionic acid
Fmoc-L-Agp(Boc)2-OH is an Fmoc-protected L-amino acid derivative bearing a side-chain acylguanidine motif (Agp) that is doubly protected as two Boc carbamates, along with a free carboxylic acid for controlled peptide coupling. The molecule retains a defined stereocenter at the L-configuration, while the Fmoc group enables orthogonal N-protection compatible with standard solid-phase peptide synthesis. The Boc-protected guanidine functionality modulates basicity and nucleophilicity during assembly, reducing undesired side reactions while preserving the ability to regenerate the cationic guanidine after deprotection. The combination of an aromatic fluorenylmethoxycarbonyl group, acid functionality, and protected side-chain carbamates makes the compound a chiral, protected amino acid intermediate suited to downstream derivatization and peptide scaffold construction.
1. Peptide Synthesis
Fmoc-L-Agp(Boc)2-OH serves as a protected peptide building block for stepwise assembly of peptide sequences that require a guanidine-containing residue with controlled chemoselectivity. The Fmoc-protected α-amine supports iterative peptide coupling and base-mediated Fmoc removal, while the free carboxylic acid participates in amide bond formation using standard peptide coupling chemistries. The two Boc groups on the side-chain guanidine suppress premature nucleophilic capture and minimize crosslinking or aggregation during chain growth, improving compatibility with peptide synthesis workflows. Deprotection of Boc groups can be applied after assembly to restore the guanidinium functionality for salt-bridge formation and electrostatic recognition in peptide products. This structure-function alignment makes the compound suitable for constructing guanidine-rich peptides and peptidomimetic segments used in biochemical research.
2. Side-Chain Functionalization
Fmoc-L-Agp(Boc)2-OH enables side-chain functionalization strategies targeting guanidine chemistry in amino acid derivatization and molecular modification. The doubly Boc-protected guanidine side chain provides a protected, masked cationic handle that can be selectively unveiled after peptide assembly or intermediate synthesis, allowing controlled introduction of positively charged motifs. The orthogonal protection pattern (Fmoc on the α-amine and Boc on the side-chain) supports sequential deprotection logic, which can be leveraged to generate guanidinium-bearing derivatives without disturbing the peptide backbone. The resulting deprotected guanidine can then be used for further transformations such as salt formation, conjugation-linker design, or incorporation into molecular recognition elements. This makes the compound relevant to amino acid chemistry workflows that require stereodefined, protected guanidine intermediates for downstream functional molecule generation.
3. Chemical Biology Probes
Fmoc-L-Agp(Boc)2-OH is applicable to chemical biology research requiring guanidine-containing peptide probes and molecular recognition reagents. The protected guanidine side chain can be incorporated into peptides that mimic arginine-like electrostatics, while the L-stereochemistry supports stereochemically consistent binding-site geometry in peptide-based probes. Fmoc compatibility supports rapid generation of peptide libraries or analog series by varying neighboring residues, enabling structure-activity relationship studies focused on charge distribution and side-chain accessibility. After assembly, Boc deprotection can restore the guanidinium group to support interactions such as hydrogen bonding and ionic pairing with nucleic acids, proteins, or receptor pockets. This positions the compound as a practical chiral intermediate for producing guanidine-functional peptide constructs used in biochemical investigation and molecular probe development.
4. Peptidomimetics And SAR Studies
Fmoc-L-Agp(Boc)2-OH supports peptidomimetic construction and SAR-oriented analog generation where a guanidine-bearing residue is used to tune binding properties. The side-chain acylguanidine protected as Boc carbamates provides a stable handle during synthesis of constrained or modified scaffolds, while the Fmoc group enables controlled N-terminal handling and orthogonal deprotection. The free carboxylic acid and protected amine arrangement facilitate incorporation into peptide analogs that can later undergo backbone or side-chain modifications while maintaining the guanidine motif. Restored guanidinium functionality can be used to modulate physicochemical properties such as charge density and solubility of analogs, supporting systematic SAR comparisons across a series of related structures. This makes the compound suitable for medicinal chemistry-adjacent research workflows that rely on protected amino acid intermediates for reproducible peptidomimetic assembly.
5. Pharmaceutical Manufacturing Intermediates
Fmoc-L-Agp(Boc)2-OH can be used in pharmaceutical manufacturing contexts as a protected amino acid intermediate for producing guanidine-containing peptide intermediates used in process development and scale-up planning. The orthogonal protection scheme, with Fmoc on the α-amine and Boc on the side-chain guanidine, supports predictable deprotection sequencing that aligns with manufacturing-grade peptide assembly strategies. The presence of a free carboxylic acid supports incorporation into peptide fragments through controlled coupling steps, while the protected side chain reduces reactivity during upstream handling and intermediate isolation. Boc-protected guanidine residues can be unveiled under conditions compatible with peptide processing, enabling generation of cationic peptide intermediates for further downstream transformations or formulation-oriented studies. This structural design makes the compound relevant to fine chemical synthesis and industrial peptide production workflows that require chiral, protected building blocks with controlled functional group behavior.
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