CHEMBL3707564

Spectrophotometric Enzyme Assay: Compounds were evaluated in spectrophotometric enzyme assays using ChDHFR-TS and hDHFR. Inhibition constants (IC50) were measured (see Table 4). The lead compound, X, has an inhibition constant of 38 nM and modest selectivity (8-fold). All of the biphenyl compounds are more potent than the initial lead compound X and exhibit greater selectivity for the pathogenic enzyme. The most potent racemic compound, D(rac), a 5′-biphenyl derivative, is also the most selective of the racemic compounds (944-fold). The single R enantiomer of this 5′-biphenyl analog is the most potent (1.1 nM) and most selective (1273-fold) of all known compounds tested against the Cryptosporidium DHFR enzyme.