Background: Benzimidazole derivatives are promising compounds for the treatment of parasitic infections. The structure-activity relationships of 91 benzimidazoles with activity against Trichomonas vaginalis and Giardia intestinalis were analyzed using a novel activity landscape modeling approach.
Results: We identified two prominent cases of 'activity switches' and 'selectivity switches' where two R group substitutions in the benzimidazole scaffold completely invert the activity and selectivity pattern for T. vaginalis and G. intestinalis.
Conclusion: A chemoinformatic methodology was used to rapidly identify discrete structural changes around the central scaffold that are associated with large changes in biological activity for each parasite. The structure-activity relationships for the benzimidazole derivatives is smooth for both protozoan with few but markedly important activity cliffs.