Inhibition of sterol 14 α-demethylation of Candida albicans with NND-502, a novel optically active imidazole antimycotic agent

To investigate the mode of action of the newly synthesized optically active imidazole compound, NND-502, (-)-(E)-[4-(2,4-dichlorophenyl)-1,3-dithiolan-2-ylidene]-1 -imidazolylacetonitrile, its effect on ergosterol biosynthesis in cell-free extracts of Candida albicans was examined and compared with that of the (S)-enantiomer of NND-502 in addition to lanoconazole and bifonazole, both of which are clinically used for the treatment of dermatomycoses. NND-502 was found to interfere with ergosterol biosynthesis by inhibition of sterol 14α-demethylase, while no interference due to the (S)-enantiomer of NND-502 was found, indicating that the stereochemical orientation of the 2,4-dichlorophenyl group plays an important role in the interaction with the enzyme. In terms of drug concentration exerting 50% inhibition of ergosterol biosynthesis, NND-502 was 2.5 and 28 times more effective than that of lanoconazole and bifonazole, respectively.