Benzoxaboroles as Efficient Inhibitors of the β-Carbonic Anhydrases from Pathogenic Fungi: Activity and Modeling Study

A series of 6-substituted benzoxaboroles were investigated as inhibitors of the beta-class carbonic anhydrase from three pathogenic fungi (Cryptococcus neoformans, Candida glabrata, and Malassezia globosa). Independently from the nature of the substituents on the phenyl of the urea/thiourea group, all reported derivatives showed nanomolar inhibitory activities against Can2 and CgNce103 vs micromolar inhibition against MgCA. Selectivity over human CA I and CA II was noticed. The observed structure-activity relationship trends have been rationalized by modeling study of selected compounds into the active site of Can2 and MgCA. The present letter demonstrates that benzoxaborole chemotype may offer interesting opportunities for the inhibition of beta-CA from pathogenic fungi and for the development of antifungal agents with a new mechanism of action.