Fmoc-Phe(4-tBu)-OH

Fmoc-Phe(4-tBu)-OH serves as a valuable building block in Fmoc/t-Bu solid-phase peptide synthesis, enabling the incorporation of 4-tert-butyl-L-phenylalanine residues into peptide sequences. The bulky 4-tert-butyl substituent of Fmoc-Phe(4-tBu)-OH introduces significant steric bulk and hydrophobicity, which can modulate peptide conformation, enhance membrane permeability, and influence receptor binding interactions. Fmoc-Phe(4-tBu)-OH has been used in the synthesis of rOicPaPhe(p-Me)-NH₂, a peptide with platelet aggregation activation inhibitory activity. The Fmoc protecting group of Fmoc-Phe(4-tBu)-OH is removed under standard piperidine treatment during SPPS, enabling efficient peptide chain elongation. As a commercially available reagent, Fmoc-Phe(4-tBu)-OH is offered with purity ≥98% and is widely used in peptide drug discovery and development.

 Product Parameters

Why Cosperpharm?

When your peptide drug discovery program requires hydrophobic aromatic amino acid building blocks with verified purity and documented batch-to-batch consistency, Cosperpharm delivers Fmoc-Phe(4-tBu)-OH with the analytical rigor that pharmaceutical researchers demand.

Hydrophobic building block integrity begins with verified quality. The bulky 4-tert-butyl substituent in Fmoc-Phe(4-tBu)-OH must remain intact through multiple synthesis cycles. Any impurity or degradation in this building block will compromise your peptide’s hydrophobicity and biological activity. Our analytical release protocol includes HPLC purity verification (≥98%), appearance verification, and identity confirmation.

Documentation that supports regulatory submission. Every shipment includes a Certificate of Analysis (COA) with batch-specific purity and characterization data. Custom quality agreements and comprehensive documentation packages are available upon request.

Flexible supply across all development stages. Cosperpharm supplies Fmoc-Phe(4-tBu)-OH from research-grade quantities for exploratory peptide synthesis, to bulk quantities for commercial peptide manufacturing. R&D samples ship within 5–7 business days; bulk orders ship within 2–3 weeks.

Technical support for the full synthetic cascade. Our process chemistry team can advise on coupling condition optimization, deprotection strategies, and analytical methods for detecting process-related impurities — because we have worked extensively with hydrophobic Fmoc-protected amino acids across multiple peptide manufacturing campaigns.

Global reach with transparent pricing. Cosperpharm ships to pharmaceutical manufacturers, CROs, and research institutions worldwide, with full customs documentation included. Volume discounts apply at larger scales.

Product Advantages

1. Bulky Hydrophobic Aromatic Building Block

Fmoc-Phe(4-tBu)-OH incorporates a 4-tert-butyl substituent on the phenyl ring, introducing significant steric bulk and hydrophobicity (computed LogP of 7.09). This represents a substantial increase in hydrophobicity compared to unsubstituted Fmoc-Phe-OH (LogP approximately 3.5–4.0).

2. Conformation-Modulating Properties

The bulky 4-tert-butyl group can modulate peptide conformation, enhance membrane permeability, and influence receptor binding interactions. This makes Fmoc-Phe(4-tBu)-OH valuable for structure-activity relationship studies and peptide drug optimization.

3. Validated for Bioactive Peptide Synthesis

Fmoc-Phe(4-tBu)-OH has been used in the synthesis of rOicPaPhe(p-Me)-NH₂, a peptide with platelet aggregation activation inhibitory activity. This demonstrates its utility in the development of bioactive peptides and therapeutic candidates.

4. High Purity for Reproducible Synthesis

Cosperpharm supplies Fmoc-Phe(4-tBu)-OH with HPLC purity ≥98%. Each batch is accompanied by a comprehensive COA documenting purity and identity — ensuring reproducibility across peptide synthesis campaigns.

5. Stable Under Recommended Storage

Fmoc-Phe(4-tBu)-OH is stable when stored at 0–8 °C, with powder stability of 3 years at –20 °C and 2 years at 4 °C.

FAQ

Q1: What is the difference between Fmoc-Phe(4-tBu)-OH and Fmoc-Phe-OH?

A: Fmoc-Phe(4-tBu)-OH has a bulky 4-tert-butyl substituent on the phenyl ring, whereas Fmoc-Phe-OH is the unsubstituted phenylalanine derivative. The 4-tert-butyl group introduces significant hydrophobicity (LogP 7.09 vs. 3.5–4.0) and steric bulk, which can modulate peptide conformation, membrane permeability, and receptor binding.

Q2: How should this compound be stored?

A: Store Fmoc-Phe(4-tBu)-OH at 0–8 °C. For long-term storage (>12 months), store at –20 °C in a tightly sealed, dry container. Protect from moisture and light.

Contact Us

Looking for Fmoc-Phe(4-tBu)-OH for your peptide drug discovery or development project? Reach out to Cosperpharm — we‘re ready to supply the quality building blocks you need.