Benzylaminoethylureido-Tailed Benzenesulfonamides Show Potent Inhibitory Activity against Bacterial Carbonic Anhydrases

Recent developments of agents targeting Vibrio cholerae: patents and literature data

INTRODUCTION

Vibrio cholerae bacteria cause an infection characterized by acute diarrheal illness in the intestine. Cholera is sustained by people swallowing contaminated food or water. Even though symptoms can be mild, if untreated disease becomes severe and life-threatening, especially in low-income countries.

AREAS COVERED

After a description of the most recent literature on the pathophysiology of this infection, we searched for patents and literature articles following the PRISMA guidelines, filtering the results disclosed from 2020 to present. Moreover, some innovative molecular targets (e.g., carbonic anhydrases) and pathways to counteract this rising problem were also discussed in terms of design, structure-activity relationships and structural analyses.

EXPERT OPINION

This review aims to cover and analyze the most recent advances on the new druggable targets and bioactive compounds against this fastidious pathogen, overcoming the use of old antibiotics which currently suffer from high resistance rate.

Biochemical, structural, and computational studies of a γ-carbonic anhydrase from the pathogenic bacterium Burkholderia pseudomallei

•

Melioidosis is a severe disease caused Burkholderia pseudomallei.

•

γ-carbonic anhydrases (γ-CAs) have been recently introduced as novel antibacterial drug targets.

•

A new γ-CA from B. pseudomallei has been investigated by a multidisciplinary approach.

•

Obtained results provide an important starting point for developing new anti-melioidosis drugs.

Melioidosis is a severe disease caused by the highly pathogenic gram-negative bacterium Burkholderia pseudomallei. Several studies have highlighted the broad resistance of this pathogen to many antibiotics and pointed out the pivotal importance of improving the pharmacological arsenal against it. Since γ-carbonic anhydrases (γ-CAs) have been recently introduced as potential and novel antibacterial drug targets, in this paper, we report a detailed characterization of BpsγCA, a γ-CA from B. pseudomallei by a multidisciplinary approach. In particular, the enzyme was recombinantly produced and biochemically characterized. Its catalytic activity at different pH values was measured, the crystal structure was determined and theoretical pKa calculations were carried out. Results provided a snapshot of the enzyme active site and dissected the role of residues involved in the catalytic mechanism and ligand recognition. These findings are an important starting point for developing new anti-melioidosis drugs targeting BpsγCA.

Synthesis and biological evaluation of sulfonamide-based compounds as inhibitors of carbonic anhydrase from Vibrio cholerae

This study reports our continued efforts to identify inhibitors capable of targeting carbonic anhydrases (CAs) expressed in bacteria. Based on previously identified chemotypes, we designed and synthesized new analogs that were screened toward the α, β, and γ classes encoded in Vibrio cholerae (Vch). The K_i values measured in the stopped-flow hydrase assay revealed that very simple structural modifications might induce a relevant impact on the inhibitory effects as well as the selectivity profile over ubiquitous human isozymes (hCA I/II). Unfortunately, the best active VchCA inhibitors demonstrated a dramatic loss of hCA II selectivity when compared to previously reported compounds. Among the new series of sulfonamides, several molecules proved to be about sevenfold more potent against VchCAγ than the reference compound acetazolamide, thus furnishing new insights for further development of inhibitors targeting CAs expressed in bacteria.

One-Pot Procedure for the Synthesis of Asymmetric Substituted Ureido Benzene Sulfonamides as Effective Inhibitors of Carbonic Anhydrase Enzymes

We report a one-pot procedure for the synthesis of asymmetrical ureido-containing benzenesulfonamides based on in situ generation of the corresponding isocyanatobenezenesulfonamide species, which were trapped with the appropriate amines. A library of new compounds was generated and evaluated in vitro for their inhibition properties against a representative panel of the human (h) metalloenzymes carbonic anhydrases (EC 4.2.1.1), and the best performing compounds on the isozyme II (i.e., 7c, 9c, 11g, and 12c) were screened for their ability to reduce the intraocular pressure in glaucomatous rabbits. In addition, the binding modes of 7c, 11f, and 11g were assessed by means of X-ray crystallography.

Novel 1,3,5-Triazinyl Aminobenzenesulfonamides Incorporating Aminoalcohol, Aminochalcone and Aminostilbene Structural Motifs as Potent Anti-VRE Agents, and Carbonic Anhydrases I, II, VII, IX, and XII Inhibitors

A series of 1,3,5-triazinyl aminobenzenesulfonamides substituted by aminoalcohol, aminostilbene, and aminochalcone structural motifs was synthesized as potential human carbonic anhydrase (hCA) inhibitors. The compounds were evaluated on their inhibition of tumor-associated hCA IX and hCA XII, hCA VII isoenzyme present in the brain, and physiologically important hCA I and hCA II. While the test compounds had only a negligible effect on physiologically important isoenzymes, many of the studied compounds significantly affected the hCA IX isoenzyme. Several compounds showed activity against hCA XII; (E)-4-{2-[(4-[(2,3-dihydroxypropyl)amino]-6-[(4-styrylphenyl)amino]-1,3,5-triazin-2-yl)amino]ethyl}benzenesulfonamide (31) and (E)-4-{2-[(4-[(4-hydroxyphenyl)amino]-6-[(4-styrylphenyl)amino]-1,3,5-triazin-2-yl)amino]ethyl}benzenesulfonamide (32) were the most effective inhibitors with K_Is = 4.4 and 5.9 nM, respectively. In addition, the compounds were tested against vancomycin-resistant Enterococcus faecalis (VRE) isolates. (E)-4-[2-({4-[(4-cinnamoylphenyl)amino]-6-[(4-hydroxyphenyl)amino]-1,3,5-triazin-2-yl}amino)ethyl]benzenesulfonamide (21) (MIC = 26.33 µM) and derivative 32 (MIC range 13.80-55.20 µM) demonstrated the highest activity against all tested strains. The most active compounds were evaluated for their cytotoxicity against the Human Colorectal Tumor Cell Line (HCT116 p53 +/+). Only 4,4'-[(6-chloro-1,3,5-triazin-2,4-diyl)bis(iminomethylene)]dibenzenesulfonamide (7) and compound 32 demonstrated an IC₅₀ of ca. 6.5 μM; otherwise, the other selected derivatives did not show toxicity at concentrations up to 50 µM. The molecular modeling and docking of active compounds into various hCA isoenzymes, including bacterial carbonic anhydrase, specifically α-CA present in VRE, was performed to try to outline a possible mechanism of selective anti-VRE activity.