Biotech R&D group developed a non-standard modified peptide from concept to gram-scale in 9 weeks
A pre-clinical biotech R&D group needed a custom-modified peptide combining a non-natural amino acid, intramolecular disulfide bridging, and N-terminal acetylation. The development workflow ran from concept brief to validated gram-scale material in 9 weeks.
Published April 30, 2026 · Anonymized customer story
Concept → pilot batch delivery
5 weeks
Concept → commercial-scale
9 weeks
Measured HPLC purity
≥99.1%
Modifications handled
3 concurrent (Dmt + S-S + Ac)
Challenge
The R&D group was developing a research tool for a specific receptor-pharmacology question and needed a peptide with three modifications that most catalog SPPS providers don't handle in combination: a non-natural Dmt residue (analogous to the Dmt in the SS-31 family), an intramolecular disulfide bridge between positions 3 and 9, and an N-terminal acetyl cap. The lab had received several quotes from other suppliers ranging from "we can do two of the three" to "we don't handle Dmt in combination with disulfide cyclization." The Head of Chemistry needed a supplier that could handle the full modification stack on a research-program timeline.
Approach
PeptideXpo's R&D team confirmed all three modifications were within the routine SPPS scope of our facility and quoted a pilot synthesis at 200 mg gram-scale. Pilot synthesis used Fmoc-protected Dmt building blocks, controlled oxidative folding for the disulfide bridge (under conditions that favoured the intramolecular over intermolecular scrambled isomer), and acetyl-anhydride capping at the N-terminus. The released-batch documentation included HPLC at ≥99.1% measured purity, ESI mass spec confirming the modified mass (Dmt +28 Da vs natural Tyr, disulfide -2 Da vs reduced linear, acetyl +42 Da vs free amine, three diagnostic offsets), and LC-MS/MS sequence verification covering both arms of the disulfide-bridged molecule.
Outcome
Pilot batch landed in the buyer's lab 5 weeks from signed brief. Commercial scale-up to 5 g ran in parallel with the buyer's pharmacology validation work, with the 5 g batch delivered at week 9 total. The custom synthesis route is now locked for repeat orders and the buyer's R&D program has continued ordering against quarterly forecast without re-validation overhead.
“Three concurrent modifications, Dmt plus disulfide plus N-acetyl, wasn't something we could find at any other SPPS shop on our timeline. The diagnostic-offset mass-spec validation, where all three modifications produce a distinct mass shift, was exactly the analytical evidence we needed to take the batch into our pharmacology work without an additional re-validation step.”