Boc-Phe-Gly-OH is a preassembled, N-terminally Boc-protected L-phenylalanine-glycine (Phe-Gly) dipeptide with a free C-terminal carboxylic acid. It is designed for peptide fragment coupling, solution-phase synthesis and step-economical incorporation of the Phe-Gly motif when a Boc-compatible protection strategy is preferred.

Using a defined dipeptide fragment can remove one amino-acid coupling and one intermediate deprotection from a multistep route. This can be useful when the Phe-Gly junction is already fixed in the target sequence or when fragment-based assembly provides a cleaner route than rebuilding the motif residue by residue.

Product Information

Why Use a Preassembled Phe-Gly Dipeptide?

Phe and Gly represent chemically different sequence environments: phenylalanine contributes a bulky aromatic side chain, while glycine has no side-chain carbon and provides high local conformational freedom. A preassembled Phe-Gly fragment fixes both sequence orientation and stereochemical identity before the fragment is introduced into a larger target.

This is especially relevant for procurement because Phe-Gly is not interchangeable with Gly-Phe. The residue composition may look similar in a simple search, but the sequence order changes the molecular structure, downstream peptide sequence and biological interpretation of the final product.

Boc Protection and Synthetic Strategy

The Boc group protects the N-terminal amino function during downstream carboxyl activation and fragment coupling. Boc is acid-labile, so its removal should be planned together with other acid-sensitive protecting groups in the synthesis route.

Boc-Phe-Gly-OH is therefore particularly useful in solution-phase and fragment-based workflows that deliberately use Boc chemistry. For an Fmoc-compatible version of the same L-Phe-Gly sequence, compare Fmoc-Phe-Gly-OH.

Application Scope

Typical applications include protected peptide-fragment synthesis, peptidomimetic SAR, assembly of Phe-Gly-containing sequences, solution-phase amide formation and preparation of intermediates for cyclic or modified peptides.

The building block itself is a synthetic intermediate rather than a direct assay reagent. After assembly, global deprotection, purification and analytical confirmation, the final peptide may be used in biochemical, binding, cellular or in vivo studies according to the target sequence and research design.

Purchasing and QC Considerations

For a protected dipeptide, procurement should verify more than nominal mass. Important checks include exact L-Phe-Gly sequence orientation, CAS identity, protecting-group identity, chemical purity and stereochemical control at phenylalanine. Lot-specific COA data should be used for acceptance and synthesis planning.

Product Documents

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

MSDS_Boc-Phe-Gly-OH_AS4049

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 Boc-Phe-Gly-OH used for?

It is used as a protected L-Phe-Gly dipeptide fragment in peptide synthesis, fragment coupling and peptidomimetic chemistry.

Is Boc-Phe-Gly-OH the same as Boc-Gly-Phe-OH?

No. Phe-Gly and Gly-Phe are sequence isomers with different residue order and are not interchangeable in a defined peptide sequence.

Why use a dipeptide instead of coupling Phe and Gly separately?

A preassembled fragment can reduce the number of synthetic operations and provides a defined sequence junction before incorporation into a larger peptide.

Is Boc-Phe-Gly-OH directly used in biological assays?

Normally no. It is an upstream synthetic intermediate; the final purified peptide is the material evaluated in biological assays.

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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