In a recent publication describing the leadlikeness and diversity of commercially available screening libraries, ChemBridge came out on top for both the number of leadlike compounds having immediate availability as well as offering the largest number of unique structures (Ref 1).
The cheminformatics team at Pyxis Discovery BV in Delft reported the results of their analysis performed on 45 commercial offerings totalling 5.3 million structures.
Of these 5.3 million only 12% were considered to be both unique and leadlike with ChemBridge’s EXPRESS-Pick™ collection leading the way with more than 220,000 leadlike structures comprising nearly 40,000 clusters; almost 63,000 of these structures were considered unique.
Independent of the above mentioned Pyxis Discovery study, ChemBridge had analyzed a new in-house designed library, NOVACore, using the same test conditions.
The resulting analysis showed that 90% (nearly 60,000 structures) of NOVACore Library was leadlike and 99.95% (more than 65,800 structures) was found to be unique.
The filters used by Pyxis Discovery were designed to differentiate between druglikeness and leadlikeness, the latter being the most preferable in ongoing drug discovery programs.
The filters included substructure filters, molecular weight, clogP, clogSw and rotatable bonds.
Leadlikeness is summarized by Pyxis Discovery as compounds having lower molecular weights than drug like compounds and are more polar while being less complex structurally (the lower molecular weight does allow exploration of the chemical space around the leadlike core).
Lead like compounds as compared to drug like structures will have on average 1 less ring structure, 2 fewer rotatable bonds, 1 less H-bond acceptor, and be 0.5-1 logP unit lower than the generally accepted metrics most commonly used for drug likeness as defined by the Lipinski Rules.
“This is all good news for research groups looking for more diverse, leadlike structures and ChemBridge can offer over 600,000 off the shelf compounds in either powder and/or solution formats.” said Reg Richardson, ChemBridge’s European sales representative.
"The results show that the work undertaken by ChemBridge in refining the structural and chemometric filters have worked positively to allow us to offer more leadlike structures, now favored by researchers, than any other small-molecule library provider.
The design effort put into NOVACore Library further reflects the capabilities ChemBridge has in understanding the current needs for lead-finding, and we expect this trend to progress further as we extend this collection."
Ref 1. Verheij, H.J., Leadlikeness and Structural Diversity of Synthetic Screening Libraries, Molecular Diversity, 10(3), 377-388, (2006).