Fmoc-L-Pen(Acm)-OH

Fmoc-L-Pen(Acm)-OH is a specialized protected amino acid building block for the introduction of L-penicillamine residues into peptides via Fmoc solid-phase peptide synthesis. The penicillamine moiety of Fmoc-L-Pen(Acm)-OH features two methyl groups at the β-carbon, creating significant steric hindrance that constrains the peptide backbone conformation and can enhance peptide stability. The Acm-protected thiol of Fmoc-L-Pen(Acm)-OH remains stable throughout SPPS assembly and cleavage, allowing the free thiol to be revealed selectively after peptide synthesis for disulfide bond formation. This makes Fmoc-L-Pen(Acm)-OH particularly valuable for the synthesis of cyclic peptides and peptide therapeutics where disulfide bridges are critical for biological activity. For researchers working with penicillamine-containing peptides—including analogs of the drug penicillamine used in Wilson's disease and cystinuria—Fmoc-L-Pen(Acm)-OH provides the definitive protected building block.

Product Parameters

Why Cosperpharm?

When your peptide therapeutic program requires the steric constraint and stability of penicillamine residues, Cosperpharm delivers Fmoc-L-Pen(Acm)-OH with the purity, documentation, and supply reliability that pharmaceutical researchers demand.

Steric constraint drives peptide stability. The gem-dimethyl groups of penicillamine introduce significant steric hindrance that restricts backbone conformation and can enhance proteolytic stability. Any impurity in Fmoc-L-Pen(Acm)-OH will compromise your peptide's purity and activity. Our analytical release protocol includes HPLC purity verification (≥96%), optical rotation confirmation, and identity testing—because peptide quality begins with the building block.

Acm protection enables selective disulfide formation. The Acm-protected thiol of Fmoc-L-Pen(Acm)-OH is stable throughout SPPS and can be selectively deprotected after peptide assembly. This enables the synthesis of complex disulfide-rich peptides with multiple orthogonal protecting groups. Our documentation supports your method development and validation efforts.

Documentation that supports your work. Every shipment includes a Certificate of Analysis (COA) with batch-specific HPLC purity, optical rotation data, and chromatographic traceability. Custom quality agreements are available upon request.

Flexible supply across all scales. Cosperpharm supplies Fmoc-L-Pen(Acm)-OH from 1g–50g for research, to 100g–500g for process development, to kilogram-scale for commercial manufacturing. R&D samples ship within 5–7 business days; bulk orders ship within 2–3 weeks.

Technical support from peptide chemistry experts. Our team has extensive experience with penicillamine-containing peptides and can advise on coupling conditions, deprotection strategies, and disulfide bond formation protocols.

Global reach with transparent pricing. Cosperpharm ships worldwide with full customs documentation. Volume discounts apply at larger scales.

Product Advantages

Sterically Hindered Penicillamine Building Block

Fmoc-L-Pen(Acm)-OH introduces L-penicillamine (β,β-dimethylcysteine) into peptide sequences. The gem-dimethyl groups create significant steric hindrance that restricts peptide backbone conformation, enhancing proteolytic stability and potentially improving target binding affinity.

Orthogonal Thiol Protection with Acm

The acetamidomethyl (Acm) group of Fmoc-L-Pen(Acm)-OH provides orthogonal protection for the thiol functionality. The Acm group is stable under standard Fmoc SPPS conditions (piperidine deprotection, TFA cleavage) and can be selectively removed using mercuric acetate or iodine to reveal the free thiol for disulfide bond formation—enabling the synthesis of complex disulfide-rich peptides.

Standard Fmoc SPPS Compatibility

Fmoc-L-Pen(Acm)-OH is fully compatible with standard Fmoc solid-phase peptide synthesis protocols. The Fmoc group enables selective deprotection with piperidine, while the Acm-protected thiol remains intact throughout chain assembly and cleavage.

High Purity with Full Characterization

Cosperpharm supplies Fmoc-L-Pen(Acm)-OH with ≥96% HPLC purity, confirmed optical rotation ([α]²⁵D = −4 ± 2° in methanol), and full analytical characterization. Each batch is released with a comprehensive COA.

Product Quality Assurance

Cosperpharm has established a comprehensive quality assurance system for Fmoc-L-Pen(Acm)-OH:

Thorough analytical characterization. Each batch undergoes HPLC purity verification (≥96.0% with full chromatographic traceability), optical rotation confirmation ([α]²⁵D = −4 ± 2° in methanol), appearance verification (white solid), and identity confirmation.

Full batch traceability with retention samples. From raw material procurement through synthesis and final packaging, every step is fully documented and traceable. Each batch receives a unique lot number.

Documentation ready for regulatory submission. Every shipment includes a Certificate of Analysis (COA) with batch-specific purity and characterization data and a Material Safety Data Sheet (SDS). Custom quality agreements are available upon request.

Customer-initiated quality audits. Qualified customers are welcome to audit Cosperpharm's manufacturing, quality control, and documentation facilities.

Contact Us

Need Fmoc-L-Pen(Acm)-OH for your disulfide-rich peptide project? Cosperpharm is your source for high-quality protected amino acids. Contact us today for pricing, availability, or technical support—we're here to help.