Fmoc-Gln(Trt)-Ser-OH is a preassembled Fmoc-protected dipeptide fragment corresponding to Fmoc-L-Gln(Trt)-L-Ser-OH. The glutamine side-chain amide is protected with Trt, while the serine side-chain hydroxyl is unprotected in the product name and formula.

This distinction matters because Fmoc-Gln(Trt)-Ser-OH is not the same material as Ser(tBu)-protected or pseudoproline Gln-Ser derivatives. Those alternatives have different molecular formulas, molecular weights and synthetic behavior.

Product Information

Why Use a Preassembled Gln-Ser Fragment?

A preassembled dipeptide can reduce the number of individual coupling/deprotection cycles required to introduce a Gln-Ser motif. This can be useful in convergent synthesis, peptide library construction, route development or sequences where a validated dipeptide fragment provides better process control than assembling the two residues independently.

Free Serine Hydroxyl: What to Consider

The serine side-chain hydroxyl remains free. Depending on the downstream chemistry, this can be advantageous when the hydroxyl is needed for selective modification, but it can also require attention to activation conditions, acylation selectivity and other side reactions. Researchers who require protected serine should not assume this material is equivalent to Fmoc-Gln(Trt)-Ser(tBu)-OH.

Fragment Coupling and Stereochemical Control

The C-terminal serine carboxyl group is used for further coupling. Fragment coupling conditions should be optimized to maintain stereochemical integrity and complete conversion. Lot-specific analytical data are especially useful for preassembled fragments because both sequence identity and stereochemical purity affect downstream peptide quality.

Application Scope

Applications include Fmoc-SPPS, solution-phase fragment coupling, Gln-Ser motif installation, modified peptide synthesis and peptide library workflows. Downstream biochemical or cellular testing applies to the final peptide rather than to the protected dipeptide building block.

Product Documents

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

MSDS_Fmoc-Gln-Trt--Ser-OH_AS4060

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 the serine side chain protected?

No. The product identity is Ser-OH, and the listed formula is consistent with an unprotected serine hydroxyl.

Is this the same as a Gln-Ser pseudoproline dipeptide?

No. Pseudoproline derivatives have a different cyclic protection architecture and different formula/molecular weight.

Why use a preassembled dipeptide?

It can reduce synthetic steps and provide a defined Gln-Ser fragment for SPPS or solution-phase coupling.

Related Technical Resources

Browse Specialty Peptide Building Blocks and Custom Peptide Synthesis.

Research Use Only.