Axxam Collections

When selecting a compound collection for screening purposes, quality and diversity are both key features for success and
hallmarks of our libraries, consisting of a total of approximatively 426.000 small molecules.

These innovative libraries have been assembled by incorporating compounds with structural and molecular properties suitable for hit discovery and hit-to-lead programs, avoiding unwanted reactive chemical groups, frequent hitters, toxicophores, aggregators and other undesirables. The goal was to ensure that the resulting screening hits be readily tractable starting points for further optimization.

The AXXDiversity library consists of around 349.000 chosen small molecules whose selection was built on our broad screening expertise, with significant input given by our team of medicinal and computational chemists.

The collection consists of four independent screening sets, with no overlap, accessible separately or in combination according to your project’s needs.


Discovery set

  • Around 180.000 molecules
  • Mean of 15 analogues for each chemotype
  • Provides structure–activity relationship (SAR) information

ExplorerPLUS set

  • Approximately 98.000 molecules
  • High coverage of structural diversity (enriched unique scaffolds)
  • Ideal for novel peripheral and central targets

ExplorerFAST set

  • Around 24.000 molecules
  • High chemical tractability, carefully assessed by our medicinal chemists
  • sp3-rich non-flat screening compounds

ExplorerCNS set

  • Around 35.000 singletons
  • Characterized by optimized MPO scores (higher probability of blood-brain barrier or cellular permeability)
  • Ideal for CNS and intracellular targets

Probe set

  • Approximately 12.000 decorated fragment-like compounds
  • Characterized by low molecular weight
  • For an easy exploration of ligand-target interactions

The compound selection has been driven by quality and structural diversity from a trusted commercial source. The AXXDiversity is available for screening at Axxam, where several measurement technologies are available (including luminescence, fluorescence intensity, time-resolved fluorescence (TR-FRET), high-content screen, and electrophysiology), or as “screening ready plates” in 384- or 1536-well format for client’s in-house activities.

The Symegold library is accessible for screening at our facility thanks to the strategic alliance with Symeres, a leading contract research organization offering innovative medicinal, synthetic and development chemistry, as well as ADME-Tox among its services.


The Symegold collection is composed of approximatively  74.000 lead-like compounds synthesized at Symeres as part of the European Lead Factory (ELF) IMI-2 consortium, using state-of-the-art parallel synthesis and purification platforms. The library covers a lead-like diversity space not available in existing commercial libraries. The design criteria for preparing this novel and unique compound collection were based on diverse lead-like properties and structural novelty, using Symeres proprietary, rigid, sp3-rich scaffolds synthesized in house via innovative chemistries.

A small molecule compound collection specifically designed to bind RNA is available. This collection is suitable to initiate discovery programs aimed at finding RNA splicing modulators and RNA-protein interaction modulators.

  • Around 2.000 drug-like and lead-like compounds
  • High novelty & chemical diversity
  • Optimal starting point for MedChem programs
Axxam MPO score
Molecular weight
RNA-targeting library distribution

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