Fmoc-Phe-Gly-OH is an Fmoc-protected L-phenylalanine-glycine (Phe-Gly, FG) dipeptide with a free C-terminal carboxylic acid. It combines an aromatic L-Phe residue with flexible glycine in a preassembled fragment that can be incorporated directly into longer peptides using Fmoc-compatible chemistry.

This format is particularly useful when the Phe-Gly junction is fixed in the target sequence or when a chemist wants to reduce the number of individual coupling/deprotection cycles needed to construct a longer peptide.

Product Information

Why Use a Preassembled Fmoc-Phe-Gly Fragment?

A preformed dipeptide fixes the L-Phe stereocenter and FG sequence orientation before incorporation into a larger molecule. This can be useful for fragment-based synthesis, peptidomimetic routes and sequences where an aromatic-to-glycine junction is already defined.

Compared with separate Fmoc-Phe and Gly couplings, the dipeptide reduces one peptide-bond-forming operation in the downstream route.

Fmoc-Phe-Gly-OH vs Boc-Phe-Gly-OH

The peptide sequence is the same, but the N-terminal protecting group is different. Boc-Phe-Gly-OH is acid-labile at the N-terminus, whereas Fmoc-Phe-Gly-OH uses the base-labile Fmoc strategy that is standard in modern Fmoc-SPPS.

The appropriate product therefore depends on the overall protecting-group scheme rather than on sequence alone.

Phe-Gly vs Gly-Phe

Fmoc-Phe-Gly-OH should not be confused with Fmoc-Gly-Phe-OH. Reversing the sequence changes which residue occupies each peptide position and can alter secondary structure, protease recognition and biological activity of the final peptide.

Application Scope

Applications include Fmoc-SPPS, protected-fragment coupling, peptide library construction, peptidomimetic synthesis, cyclic-peptide precursors and SAR studies involving an FG sequence motif.

The protected dipeptide is an upstream synthesis intermediate. Final products may be used in biochemical, cellular or in vivo research after deprotection, purification and identity confirmation.

Purchasing and QC Considerations

Confirm exact sequence order, L-Phe stereochemistry, Fmoc protection, CAS number and lot-specific purity. Because chemical purity and enantiomeric purity measure different attributes, stereochemical documentation can be important for sensitive research.

Product Documents

A Material Safety Data Sheet (MSDS) is available for this product to support laboratory handling, storage and safety assessment.

MSDS_Fmoc-Phe-Gly-OH_AS4068

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

Is Fmoc-Phe-Gly-OH suitable for Fmoc-SPPS?

Yes. Its N-terminal Fmoc protection is designed for Fmoc-compatible peptide synthesis.

What is the difference between Fmoc-Phe-Gly-OH and Boc-Phe-Gly-OH?

They contain the same Phe-Gly sequence but use different N-terminal protection strategies: Fmoc is base-labile, while Boc is acid-labile.

Is Phe-Gly the same as Gly-Phe?

No. The residue order is reversed and the compounds are structurally distinct.

Related Technical Resources

Explore additional Specialty Peptide Building Blocks for protected fragments, linker motifs and peptide-synthesis intermediates.

For sequence-specific synthesis, protected-fragment assembly and modified peptide projects, see our Chemical Peptide Synthesis service.

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