Fmoc-D-Agb(Boc)2-OH is an Fmoc-protected, D-configured amino acid derivative featuring a guanidino-bearing side chain (Agb) that is further protected as two tert-butoxycarbonyl (Boc) groups, along with a free carboxylic acid for coupling chemistry. The molecule contains an N-terminal 9H-fluoren-9-ylmethoxycarbonyl (Fmoc) carbamate that masks the amino functionality, while the side-chain guanidinium is converted into Boc-protected carbamates to reduce undesired side reactions and modulate basicity during peptide assembly. In peptide chemistry, this protected amino acid is employed as a building block for stepwise solid-phase or solution-phase synthesis where orthogonal protection and controlled chemoselectivity support incorporation of the protected guanidino residue into peptide or peptidomimetic structures.
CAT No: CP25272
CAS No:1263047-29-5
Synonyms/Alias:N-2-Fmoc-D-N-4-(bis-Boc-amidino)-2,4-diaminobutyric acid;2-(Fmoc-amino)-4-(bis-Boc-guanidino)-D-butyric acid;Fmoc-D-Norarginine(Boc)2-OH;Fmoc-D-Nar(Boc)2;Fmoc-D-norArg(Boc)2;Fmoc-D-Agb(Boc)2
Chemical Name:Fmoc-D-Norarginine(Boc)2-OH, (R)-N-alpha-(9-Fluorenylmethyloxycarbonyl)-N,N-bis-t-butyloxycarbonyl-2-amino-4-guanidino-butyric acid
Fmoc-D-Agb(Boc)2-OH is a chiral, N-Fmoc protected amino acid derivative bearing a D-stereocenter and an Agb side-chain substituted with two Boc-protecting groups, expressed as Fmoc-D-Agb(Boc)2-OH. The structure combines an aromatic fluorenylmethoxycarbonyl (Fmoc) group for orthogonal base-labile N-protection with two acid-labile tert-butoxycarbonyl (Boc) groups that mask side-chain functionalities and modulate nucleophilicity. The free carboxylic acid enables standard peptide coupling chemistry, while the protected side-chain architecture is designed to tolerate peptide assembly conditions and to enable later side-chain deprotection. The presence of multiple protecting groups and a defined stereochemical configuration makes the compound a controlled chiral intermediate for amino acid derivatization and peptide building block preparation.
1. Peptide Synthesis
Fmoc-D-Agb(Boc)2-OH is applied in solid-phase and solution-phase peptide synthesis workflows where orthogonal protecting-group strategies are required for stepwise construction. The Fmoc carbamate on the amino terminus supports base-mediated deprotection to expose a reactive amine for peptide coupling, while the carboxylic acid participates as the activated coupling partner under amide-forming conditions. The two Boc groups on the Agb side chain can remain stable during typical peptide assembly steps and can be removed selectively later to reveal side-chain functionality for downstream modifications. Peptide building block preparation using this chiral derivative can support the construction of stereochemically defined peptide analogs and protected intermediates for library synthesis.
2. Side-Chain Functionalization
Fmoc-D-Agb(Boc)2-OH is suitable for side-chain functionalization strategies in synthetic organic chemistry and peptide analog development where controlled unveiling of functional groups is necessary. The Agb side chain is masked by dual Boc groups, enabling protection of nucleophilic sites during coupling and purification while preserving a defined stereochemical framework at the D-center. Side-chain deprotection can generate reactive amine or related protected functionalities (depending on the Agb substitution pattern) that can then be converted into conjugation handles, post-assembly derivatization sites, or further protected intermediates. The resulting functionalized amino acid derivative can feed into secondary synthesis steps such as cyclization precursor preparation, linker installation, or generation of chemically diverse peptide variants for structure-focused studies.
3. Chemical Biology Labeling
Fmoc-D-Agb(Boc)2-OH supports chemical biology and biomolecule modification programs that require orthogonally protected, stereodefined amino acid incorporation into peptides or peptide-like probes. The free carboxylic acid and Fmoc-protected amine enable incorporation into peptide scaffolds that can later be processed to expose reactive side-chain functionality for conjugation chemistry. The dual Boc protection pattern can be leveraged to tune the timing of deprotection so that labeling reagents encounter the intended functional group without interfering with other protected regions. Peptide-based molecular probes prepared from this chiral building block can be used as intermediates for generating labeled constructs, affinity probes, or chemically tractable biomolecule conjugates.
4. Peptidomimetics And SAR
Fmoc-D-Agb(Boc)2-OH is used in peptidomimetic construction and structure-activity relationship studies where stereochemistry and side-chain chemistry must be controlled across analog series. The D-configuration and protected side-chain groups allow systematic variation of exposed functionality after assembly, enabling consistent comparison of analogs differing in side-chain reactivity or linkage chemistry. The Fmoc group facilitates reliable incorporation into peptide backbones, while the Boc groups provide a means to delay side-chain unveiling until after scaffold assembly and purification. Downstream deprotection and derivatization of the Agb side chain can generate a set of chemically defined analogs suitable for SAR-oriented medicinal chemistry workflows and fragment-based scaffold elaboration.
5. Pharmaceutical Intermediate Preparation
Fmoc-D-Agb(Boc)2-OH is relevant to pharmaceutical intermediate preparation and specialty chemical production where protected amino acid derivatives serve as controlled inputs for manufacturing-grade peptide intermediates. The combination of base-labile Fmoc and acid-labile Boc groups supports manufacturing-compatible protection/deprotection sequences that can be aligned with process controls for minimizing side reactions during peptide assembly. The carboxylic acid functionality enables conversion into activated coupling forms and incorporation into larger protected peptide fragments, while the stereochemical D-center helps maintain stereochemical integrity through synthetic steps. The compound can therefore function as a chiral, multi-protected amino acid building block for producing defined peptide intermediates and downstream functionalized derivatives used in applied chemical manufacturing routes.
If you have any peptide synthesis requirement in mind, please do not hesitate to contact us at . We will endeavor to provide highly satisfying products and services.
Creative Peptides is a trusted CDMO partner specializing in high-quality peptide synthesis, conjugation, and manufacturing under strict cGMP compliance. With advanced technology platforms and a team of experienced scientists, we deliver tailored peptide solutions to support drug discovery, clinical development, and cosmetic innovation worldwide.
From custom peptide synthesis to complex peptide-drug conjugates, we provide flexible, end-to-end services designed to accelerate timelines and ensure regulatory excellence. Our commitment to quality, reliability, and innovation has made us a preferred partner across the pharmaceutical, biotechnology, and personal care industries.
Read More