Inhibition of α-, β-, γ-, and δ-carbonic anhydrases from bacteria and diatoms with N′-aryl-N-hydroxy-ureas

The inhibition of α-, β-, γ-, and δ-class carbonic anhydrases (CAs, EC 4.2.1.1) from bacteria (Vibrio cholerae and Porphyromonas gingivalis) and diatoms (Thalassiosira weissflogii) with a panel of N’-aryl-N-hydroxy-ureas is reported. The α-/β-CAs from V. cholerae (VchCAα and VchCAβ) were effectively inhibited by some of these derivatives, with K(I)s in the range of 97.5 nM – 7.26 µM and 52.5 nM – 1.81 µM, respectively, whereas the γ-class enzyme VchCAγ was less sensitive to inhibition (K(I)s of 4.75 – 8.87 µM). The β-CA from the pathogenic bacterium Porphyromonas gingivalis (PgiCAβ) was not inhibited by these compounds (K(I)s > 10 µM) whereas the corresponding γ-class enzyme (PgiCAγ) was effectively inhibited (K(I)s of 59.8 nM – 6.42 µM). The δ-CA from the diatom Thalassiosira weissflogii (TweCAδ) showed effective inhibition with these derivatives (K(I)s of 33.3 nM – 8.74 µM). As most of these N-hydroxyureas are also ineffective as inhibitors of the human (h) widespread isoforms hCA I and II (K(I)s > 10 µM), this class of derivatives may lead to the development of CA inhibitors selective for bacterial/diatom enzymes over their human counterparts and thus to anti-infectives or agents with environmental applications.