Fmoc-D-Tyr(Et)-OH

Fmoc-D-Tyr(Et)-OH is an innovative building block in peptide chemistry, incorporating both N‑α‑Fmoc protection and side‑chain O‑ethyl protection on the D‑tyrosine scaffold. The Fmoc group on Fmoc-D-Tyr(Et)-OH enables direct use in standard Fmoc/tBu solid‑phase peptide synthesis (SPPS) workflows without the need for additional side‑chain protection or post‑synthetic modification. The O‑ethyl ether of Fmoc-D-Tyr(Et)-OH enhances hydrophobic character and alters the electronic properties of the aromatic ring compared to the native tyrosine phenol, providing distinct advantages in the development of stabilized peptides for biotechnological and pharmaceutical applications. Fmoc-D-Tyr(Et)-OH is a key building block in solid‑phase peptide synthesis, allowing researchers to create complex peptides with high purity and yield, particularly in applications where enhanced steric properties and unique hydrophobicity are desired. The D‑amino acid configuration of Fmoc-D-Tyr(Et)-OH imparts resistance to proteolytic degradation, making it especially valuable for the development of stabilized peptide therapeutics and research tools with extended in vivo half‑lives. As an N‑Fmoc protected, O‑alkylated tyrosine derivative, Fmoc-D-Tyr(Et)-OH expands the chemical diversity accessible in synthetic peptide libraries beyond the standard 20 proteinogenic amino acids.

Product Parameters

Why Cosperpharm?

When your research or manufacturing requires non‑natural, D‑amino acid building blocks with advanced protection strategies—and the analytical confidence that comes with comprehensive quality documentation—Cosperpharm delivers Fmoc-D-Tyr(Et)-OH with the purity, consistency, and technical support that advanced peptide chemistry demands.

Proteolytic stability depends on correct stereochemistry. The D‑configuration of Fmoc-D-Tyr(Et)-OH is what confers resistance to proteases—but only if the building block is enantiomerically pure. Any contamination with the L‑enantiomer in your starting material will compromise the proteolytic stability of your final peptide. Cosperpharm’s analytical release protocol for Fmoc-D-Tyr(Et)-OH includes HPLC purity verification (≥98%), identity confirmation, and we can provide chiral purity data upon request to ensure the D‑configuration of your building block is maintained.

Documentation that supports your research and regulatory goals. Whether you are preparing a manuscript for peer review, filing an IND for a stabilized peptide therapeutic, or validating a quality control method, the quality of your documentation matters. Every shipment of Fmoc-D-Tyr(Et)-OH includes a Certificate of Analysis (COA) with batch‑specific purity and characterization data. Stability summaries, NMR spectra, and custom quality agreements are available upon request.

Flexible supply for all development stages. Cosperpharm supplies Fmoc-D-Tyr(Et)-OH across the full range of advanced peptide synthesis applications—from 1g–5g vials for exploratory research and structure‑activity relationship studies, to 10g–50g batches for lead optimization and preclinical development, to larger quantities for process development and manufacturing. R&D samples ship within 5–7 business days; bulk orders ship within 2–3 weeks.

Technical support for non‑natural amino acid integration. Our process chemistry team has extensive experience with the synthesis and SPPS integration of non‑natural and D‑amino acid building blocks. Whether you need advice on coupling conditions for Fmoc-D-Tyr(Et)-OH (the O‑ethyl side chain can influence solubility and coupling kinetics), troubleshooting incorporation into challenging sequences, or developing purification strategies for D‑peptide containing sequences, Cosperpharm‘s technical specialists are available to assist.

Global reach with transparent communication. Cosperpharm ships to peptide research laboratories, pharmaceutical manufacturers, and CROs worldwide, with full customs documentation included. We communicate lead times and shipping options upfront—no hidden fees, no unexpected delays.

Product Advantages

D‑enantiomer configuration — built‑in proteolytic stability

Fmoc-D-Tyr(Et)-OH incorporates the D‑enantiomer of tyrosine (rather than the natural L‑tyrosine). Peptides containing D‑amino acids are resistant to degradation by proteases that recognize L‑α‑amino acid sequences, extending serum half‑life and improving in vivo stability. This feature makes Fmoc-D-Tyr(Et)-OH invaluable for developing stabilized peptide therapeutics, D‑peptide antagonists, and retro‑inverso peptide mimetics.

O‑ethyl side chain — enhanced hydrophobicity and distinct electronic properties

The phenolic –OH of native tyrosine is alkylated to the ethyl ether (–OEt) in Fmoc-D-Tyr(Et)-OH, introducing additional hydrophobic character and altering the electronic properties of the aromatic ring compared to the natural tyrosine phenol. This modification expands the chemical diversity accessible in synthetic peptides and can improve membrane permeability and modulate target binding affinity. The side chain is fully protected during SPPS, eliminating the need for the tBu protection and deprotection steps required for natural tyrosine.

Dual protection — ready for direct SPPS incorporation

Fmoc-D-Tyr(Et)-OH is supplied with both the N‑α‑amino group protected as the Fmoc carbamate and the side chain protected as the ethyl ether. This dual protection strategy means the building block is ready for direct incorporation into standard Fmoc/tBu SPPS workflows without any additional protection or deprotection steps for the side chain. The O‑ethyl ether is stable under standard Fmoc removal conditions (20% piperidine in DMF) and remains intact through the entire synthesis.

Fully compatible with automated SPPS

Fmoc-D-Tyr(Et)-OH is fully compatible with all major commercial automated peptide synthesizers and standard Fmoc/tBu coupling protocols. The compound can be activated with standard coupling reagents including HBTU, HATU, PyBOP, and DIC, and can be incorporated using both conventional and microwave‑assisted SPPS cycles.

Extended utility in pharmaceutical peptide research

Fmoc-D-Tyr(Et)-OH is an excellent building block for the preparation of D‑phosphotyrosine‑containing peptides by Fmoc SPPS using standard activation methods such as PyBOP® and TBTU. D‑tyrosine derivatives are also of interest in the development of opioid peptides, neuropeptide analogs, and other bioactive peptides where resistance to enzymatic degradation is critical.

Well‑defined physicochemical properties

Fmoc-D-Tyr(Et)-OH has been characterized with established density (1.3±0.1 g/cm³), boiling point (654.3±55.0 °C), flash point (349.5±31.5 °C), and LogP (5.85), providing reliable reference data for quality control and formulation development.

Excellent stability under recommended storage

When stored as a powder at –20 °C under inert atmosphere, Fmoc-D-Tyr(Et)-OH maintains ≥98% purity for up to 3 years. The compound is stable at ambient temperature for several days during ordinary shipping, eliminating the need for dry‑ice shipping in most cases.

Quality Assurance at Cosperpharm

Each batch undergoes:

lGas chromatography (GC) – purity ≥97.0%

 Non‑aqueous titration – purity ≥97.0%

 Refractive index – confirmatory analysis

 ¹H NMR – structural verification

 Appearance – colorless to light yellow to light orange clear liquid

A comprehensive COA, MSDS (with full GHS information), and certificate of origin accompany every shipment.

Contact Us

Whether you are exploring Fmoc-D-Tyr(Et)-OH for stabilized peptide therapeutic development, routine D‑peptide synthesis, or quality control method validation—or if you have a custom requirement for other D‑amino acid building blocks—reach out to the Cosperpharm team today. We will respond with product specifications, pricing, and shipping timelines tailored to your project needs.