Screening against fragment libraries rather than drug-like molecules has become increasingly popular as an integral part of many drug discovery programmes.
Large molecules (MW>300)
Large library (10⁶ compounds)
Less diverse hits
High affinity (1-10 µm)
Small molecules (MW<300)
Small library (10³ fragments)
Low affinity (<100 µM)
ComInnex Fragment Library
Success depends on the quality of the fragment library, and this is where ComInnex had a chance to enter the market. The take-off point was to cover the part of the fragment’s chemical space which is not covered by present vendors yet. A study conducted by Chris Swain compared the physchem properties (e.g size, shape, HBA, HBD and lipophilicity) of commercial fragments and that of actual fragment hits. They found that fragment hits have lower molecular weight, they contain a greater proportion of ionisable groups and aromatic rings than the commercial fragments. This difference might come from the fact that the long-used rule of 3 is now outworn. Most of the vendor libraries are redundant in representing experimental binding pharmacophores. The coverage of validated binding pharmacophores is limited.
- design and synthesis of a diverse fragment set
- our technology enabled chemistry led us to unique fragments (~1100 compounds)
- has the desired physchem parameters: MW ≤ 250; 1≤LogP≤3; 1≤HBA≤4; 1≤HBD≤2
- falls into the chemical space uncovered by vendors
- the most diverse pharmacophore subset covering the whole pharmacophore space (96 compounds) has been selected and sold on plate
- analogues of eventual hits are also available in a form of a small library or a virtual library of hundreds of analogous compounds for screening
Keserű’s Heterocyclic Electrophilic Fragment Library
Our Fraglyte-type compounds library was developed by György Keserű and his team. This set includes 84 five- and six-membered nitrogen-containing small heterocycles with electrophilic warheads which can target cysteines in peptides. The members of our specific fragment library can bind not only to binding site with non-covalent interactions but also can react with the cysteine group near to binding site with covalent interactions helping the substances in positioning more precisely.