Peptide and Peptidomimetic Chemistry & Synthesis

From challenging linear sequences (15-20 mers) to macrocyclic/bicyclic and conjugation-ready peptides, Oxeltis delivers high-purity custom peptides through solid-phase peptide synthesis (SPPS), solution-phase, and hybrid strategies.

01 — WHAT MAKES US DIFFERENT

Peptides bridge chemistry and biology, offering unmatched selectivity and relevance as therapeutics, tools, and scaffolds. However, their synthesis, particularly with non-standard amino acids or macrocyclization, demands advanced expertise.

At Oxeltis, we specialize in custom peptide synthesis, tailoring Fmoc and Boc SPPS, solution-phase, and hybrid approaches to each sequence. Our PhD and MSc chemists leverage organic synthesis expertise to design robust, scalable routes and preempt challenges.

We adapt to the unpredictable: sequences evolve, biological feedback reshapes designs, and timelines shift. As your integrated scientific partner, we engage in SAR discussions, adjust strategies in real time, and deliver excellence, whether for a single peptide, SAR libraries, or scalable clinical routes.

Key differentiators

Full synthetic flexibility

SPPS (Fmoc/Boc), solution-phase, and hybrid convergent strategies, not a single-protocol facility

Genuine macrocyclization expertise

on-resin and in-solution cyclization, lactam formation, and RCM stapling via non-natural amino acid cross-links

PhD-level chemists

with fine organic synthesis background capable of tackling non-standard building blocks and novel structural motifs

Integrated consortium model

synthesized peptides flow directly into biological screening (Partex.AI Labs) and CADD-guided redesign (Molecular Forecaster)

02 — CAPABILITIES

What we can do for your peptide program

Each capability below directly addresses a recurring challenge in peptide synthesis for drug discovery programs.

Solid-Phase Peptide Synthesis (SPPS) Fmoc & Boc strategies

Expert selection of resin, coupling reagents, and deprotection conditions tailored to each sequence. Optimized coupling cycles to minimize epimerization, deletion sequences, and low-yield steps.

Solution-Phase Synthesis & Convergent Fragment Condensation

When solid-phase approaches reach their limits, we bring solution-phase strategies and convergent fragment condensation to the table.

Macrocyclization & Structural Constraint

Conformational control for enhanced selectivity, cell permeability, and proteolytic stability. Our capabilities include on-resin and in-solution macrocyclization, lactam cyclization, and ring-closing metathesis (RCM) for peptide stapling via non-natural amino acid cross-links.

Non-Proteinogenic & Non-Standard Building Blocks

Incorporation of D-amino acids, β-amino acids, N-methylated residues, and other non-canonical building blocks to improve proteolytic stability, tune pharmacology, or address specific SAR hypotheses. Custom building block synthesis where commercial sources are unavailable.

Conjugation-Ready Peptides

Sequences equipped with orthogonal reactive handles (azides, alkynes, maleimides, NHS esters, and more) for downstream conjugation to ADC payloads, fluorescent labels, PEG chains, or other functional modules, delivered with full analytical characterization of the functionalized peptide.

Analytical Rigor & Full Characterization

Every peptide delivered by Oxeltis is fully characterized by HPLC purity assessment, LC-MS, and NMR spectroscopy where required.

Equipment & technology highlights

SPPS synthesizer (Fmoc/Boc)
Hybrid SFC purification platform
LC-MS (analytical & preparative)
HRMS
NMR (¹H, ¹³C, ³¹P, ¹⁹F, ¹⁵N, 2D)
RCM / olefin metathesis
Chiral resolution by SFC

Need expert peptide chemistry capabilities for your program?

From a single challenging sequence to a full SAR library or IND-enabling batch, tell us about your project and we'll come back to you within 48 hours.