Nested Chemical Library™ (NCL)

NCLOur Nested Chemical Library™ (NCL) technology is a novel hit and lead finding method for rational drug design of kinase inhibitors. The NCL relies on a systematically built knowledge base, integrating our experience accumulated in the field of kinase inhibitory chemistry over the past 20 years.

The concept of NCL is aimed to:

  • include the best published clinically and preclinically relevant kinase inhibitors
  • continuously increase chemical diversity: more than 110 core structures, more than 600 scaffolds
  • have inhibitors against an increasing number of kinases (more than 160 validated targets)
  • continuously improve, update and extend
    • small focused libraries around hits
    • several thousands of proprietary structures

Using NCL for a large series of kinase targets and even for cellular targets of infectious diseases or cancer, the hit-rates were always above 3-5%.

Based on our unique NCL we can perform pharmacophore model generation, scaffold hopping for novel patentable hits and hit to lead optimization.

We offer:

  • More than 17000 chemical entities (continuously growing)
  • Quality controlled 5 mM DMSO stock solutions (on request we can prepare different stock concentrations)
  • We provide You with the samples on requested plate format
  • Structures of hit compounds will be revealed (max. 2%)

Chemical Validation Library (CVL)

We use or provide our Chemical Validation Library for in vitro or in vivo target validation.

Given the discrepancy of employing molecular biological tools for target validation which affect an entire protein rather than just its activity, and the subsequent generation of pharmacological agents which modulate the activity of kinase rather than affecting the whole kinase protein, we have chosen a strategy to validate potentially novel kinase targets with tools which are as close as possible to the final product, a pharmacologically active agent.

This strategy is called chemical validation and relies on a representative collection of more than 400 proven kinase inhibitors; i.e., a kinase-based compound library. In that setting, a novel kinase target of interest is screened against this collection and the hits from one or more chemical series are determined.

Subsequently, these hits are employed in a cellular model combined with a direct cellular kinase assay. Provided that the hits show activity in the cell-free and in both cellular assays, the kinase of interest is considered validated while the tool inhibitors have already proven its druggability.

Extended Validation Library (EVL)

We use or provide our Extended Validation Library (EVL), a library containing more than 2000 compounds totally around our CVL, when beside the chemical validation of the kinase of interest, hit finding becomes important as well, but no robust screening assay is available.

This library contains the CVL and the closest patentable analogues around it, which makes this library the optimal choice for hit finding, when only limited experiments can be performed.

Master Library (ML)

The Master Library includes novel compounds and analog structures around the CVL and EVL, extended with an additional ~15.000 compounds. New potential hit molecules are filtered by their ADMET (Adsorption, Distribution, Metabolism, Excretion, Toxicity) properties, druglikeness and patentability. Typically, novel and potential kinase targets can be validated chemically by using the CVL compounds and then, if a robust assay is available, the Master Library compounds shall be tested in a biochemical assay for activity against the kinase of interest. The selected and active inhibitors of a particular kinase are applied to therapeutically relevant cellular assays, in order to confirm the role of the kinase activity in this biological model. Based on the biochemical assay data, pharmacophore models can be generated to select or design novel patentable leads.

Availability and characterization of the NCL


The compounds are available in solid form (for each compound minimum a few milligrams are available) or in DMSO solution (5 mM, 96 or 368 Well plates)


  • 3 months -20°C in DMSO, 6 months -80°C in DMSO
  • 12 months in +4°C in solid form


  • no known or potential toxicopores are present in the library compounds


  • MW of 83.8% of the compounds is < 500
  • calculated logP of 76.5% of the compounds is <5
  • TPSA of 97.4% of the compounds is <140
  • TPSA of 66.5% of the compounds is <90
  • % of compounds passing Ro3: 92.8
  • % of compounds passing Ro5: 67.0

3D complexity

  • % of compounds containing 0 chiral centers: 84
  • % of compounds containing 1 chiral centre: 12
  • % of compounds containing more chiral centers: 4

As part of the NCL we have developed thematic sublibraries, such as the Allosteric Library (AL) based on published allosteric enzyme and allosteric modulatory compounds. The Allosteric Library inhibitory library contains more than 2000 compounds. In addition, we have developed the Tool Compound Library (TCL) which contains more than 300 modified kinase inhibitors which can be chemically bound to other compounds (e.g. to dyes) or resin columns. This allows various utilization of the modified kinase inhibitors, such as determination of slow binding kinetics, target profile determination with affinity chromatography and targeted delivery.

If you have any further questions, please do not hesitate to contact us: