Mariangela Ceruso

Design, synthesis and evaluation of N-substituted saccharin derivatives as selective inhibitors of tumor-associated carbonic anhydrase XII

A series of N-alkylated saccharin derivatives were synthesized and tested for the inhibition of four different isoforms of human carbonic anhydrase (CA, EC 4. 2.1.1): the transmembrane tumor-associated CA IX and XII, and the cytosolic CA I and II. Most of the reported derivatives inhibited CA XII in the nanomolar/low micromolar range, hCA IX with KIs ranging between 11 and 390 nM, whereas they were inactive against both CA I (KIs >50 μM) and II (K(I)s ranging between 39.1 nM and 50 μM). Since CA I and II are off-targets of antitumor carbonic anhydrase inhibitors (CAIs), the obtained results represent an encouraging achievement for the development of new anticancer candidates without the common side effects of non-selective CAIs. Moreover, the lack of an explicit zinc binding function on these inhibitors opens the way towards the exploration of novel mechanisms of inhibition that could explain the high selectivity of these compounds for the inhibition of the transmembrane, tumor-associated isoforms over the cytosolic ones.

Carbonic anhydrase inhibitors: Synthesis, molecular docking, cytotoxic and inhibition of the human carbonic anhydrase isoforms I, II, IX, XII with novel benzenesulfonamides incorporating pyrrole, pyrrolopyrimidine and fused pyrrolopyrimidine moieties

A series of novel pyrroles, pyrrolopyrimidines, pyrazolopyrrolopyrimidine, triazolopyrrolopyrimidines, tetrazolopyrrolopyrimidine, triazinopyrrolopyrimidines and pyrrolopyrimidotriazepines bearing the biologically active benzenesulfonamide moiety were synthesized by using pyrrole-o-amino-carbonitrile as key intermediate. All the synthesized compounds were evaluated for their in vitro carbonic anhydrase (CA, EC 4.2.1.1) inhibitory effects against the human (h) isoforms hCA I, II, IX and XII. Among the tested derivatives, compounds 16, 18 and 20-24 showed potent activity as inhibitors for the tumor associated transmembrane isoforms (hCA IX and XII) in the nanomolar and subnanomolar range, with high selectivity. All compounds underwent cytotoxic activity assays on human breast cancer cell line (MCF-7) showing effective activity, comparable to that of the clinically used drug doxorubicin.

Salen and tetrahydrosalen derivatives act as effective inhibitors of the tumor-associated carbonic anhydrase XII—A new scaffold for designing isoform-selective inhibitors

Salen and tetrahydrosalen derivatives possess metal-chelating properties and have been used as ligands in organic synthesis and as scaffolds for developing therapeutic agents. Fourteen such compounds were synthesized in order to explore their ability to inhibit the zinc enzyme carbonic anhydrase (CA, EC 4.2.1.1). Human (h) isoforms hCA I, hCA II, hCA IX and hCA XII were included in the investigation. Several aliphatic and aromatic spacers were introduced between the two chelating groups from salen/tetrahydrosalen in order to explore a diverse chemical space for designing CA inhibitors, which incorporate both phenol and polyamine fragments in their molecule. Some of these compounds showed CA inhibitory activity in the low micromolar-nanomolar range and a pronounced selectivity for inhibiting an isoform over-expressed in hypoxic tumors, hCA XII, over hCA I, II and IX.

Overexpression of the transmembrane carbonic anhydrase isoforms IX and XII in the inflamed synovium

Abstract Juvenile idiopathic arthritis (JIA) is the most common form of chronic rheumatic disease affecting children worldwide, with some features similar to adult rheumatoid arthritis (RA). In the present study, we aim at investigating novel markers that will allow in the future for tailored, more personalized treatment strategies. Hence, taking notice of several reports proving the role of local acidosis as a causal link between inflammatory diseases and related pain, and the involvement of several carbonic anhydrases (CA, EC 4.2.1.1) isoforms in articular diseases, we evaluated in JIA patients the expression of these metalloenzymes. We identified that JIA patients show high levels of active CA IX and XII isoforms. Our results represent the first evidence of the identification of these enzymes as potential therapeutic targets and development of novel innovative therapies for arthritis, also considering that the two isoforms are validated antitumor targets.

Inhibition studies of quinazoline-sulfonamide derivatives against the γ-CA (PgiCA) from the pathogenic bacterium, Porphyromonas gingivalis

Abstract Carbonic anhydrases (CAs, EC 4.2.1.1) began to be investigated in detail in pathogenic bacteria, in the search for antibiotics with a novel mechanism of action, since it has been demonstrated that in many bacteria CAs are essential for the life cycle of the organism. The presence of CAs in pathogenic bacteria allows the development of anti-infectives with a new mechanism of action, less explored to date. Here, novel quinazoline derivatives crowned with sulfonamide functionality at position-2 were tested for their ability to inhibit the bacterial γ-CA (PgiCA), identified in the genome of Porphyromonas gingivalis. Six compounds were highly effective, nanomolar inhibitors of the pathogenic enzyme γ-PgCA. Three of them were also highly effective sub-nanomolar inhibitors of the cytosolic human isoform II (hCAII). The best γ-PgCA inhibitor was compound 8c, with a KI of 3.53 nM and selectivity ratio of 24.5 and 24.8 against hCA I and hCA II, respectively. Many of these new compounds showed a high selectivity for bacterial enzyme respect to the mammalian CA isoforms (hCAI and hCAII). These results suggest that sulfonamides with quinazoline scaffold could be considered as suitable candidates for further derivatization to better understand the role of bacterial CAs in pathogenesis.

Click-tailed coumarins with potent and selective inhibitory action against the tumor-associated carbonic anhydrases IX and XII.

Coumarins behave as inhibitors of the metalloenzyme carbonic anhydrase (CA, EC 4.2.1.1) with a mechanism of inhibition distinct from other classes of inhibitors. A series of 7-substituted coumarins incorporating aryl-triazole moieties were prepared by click chemistry procedures starting from 7-hydroxycoumarin or 4-methyl-7-aminocoumarin. The panel of new compounds was assayed for the inhibition of the cytosolic, widespread human (h) isoforms hCA I and II, and the transmembrane, tumor-associated ones hCA IX and XII. Most of the coumarins were weak inhibitors or did not inhibit significantly hCA I and II, but showed low nanomolar inhibitory action against the transmembrane isoforms (K(I) of 14.3-34.4 nM against hCA IX and of 4.7-37.8 nM against hCA XII). Since many hypoxic tumors overexpress hCA IX/XII, and as these targets were recently validated for obtaining antitumor/antimetastatic agents, with one inhibitor in Phase I clinical trials, the present findings constitute an interesting extension to the knowledge of non-sulfonamide, selective inhibitors of CA isoforms involved in serious pathologies.

Sulfonamides incorporating fluorine and 1,3,5-triazine moieties are effective inhibitors of three β-class carbonic anhydrases from Mycobacterium tuberculosis.

Abstract A new series of fluorine containing 1,3,5-triazinyl sulfonamide derivatives obtained from cyanuric fluoride, sulfanilamide/4-aminoethylbenzenesulfonamide followed and incorporating also amin0, amino alcohol and amino acid moieties have been investigated as inhibitors of three β-carbonic anhydrases (CAs, EC 4.2.1.1) from the bacterial pathogen Mycobacterium tuberculosis, mtCA1 (Rv1284), mtCA 2 (Rv3588c) and mtCA 3 (Rv3273). All three enzymes were efficiently inhibited by these sulfonamides with KI values in the nanomolar or submicromolar range, depending on the substitution of one or both fluorine atoms at the 1,3,5-triazine ring. As some of these enzymes are crucial for the life cycle of this bacterium, the class of β-CA inhibitors reported in this study may lead to antimycobacterial agents with a different mechanism of action compared to the clinically used such drugs for which the pathogen developed extensive drug resistance.

7-Aryl-triazolyl-substituted sulfocoumarins are potent, selective inhibitors of the tumor-associated carbonic anhydrase IX and XII

Abstract Sulfocoumarins behave as interesting inhibitors of the metalloenzyme carbonic anhydrase (CA, EC 4.2.1.1). Here, we report a new series of 7-substituted derivatives which were obtained by the click chemistry approach from 7-propargyloxy-sulfocoumarin and aryl azides incorporating halogens, hydroxy, methoxy and carboxyl moieties in their molecules. The new compounds were screened for the inhibition on four physiologically relevant human CA (hCA) isoforms, the cytosolic hCA I and II and the transmembrane tumor-associated hCA IX and XII. The new compounds did not inhibit the cytosolic isoforms but were low nanomolar inhibitors of the tumor-associated ones hCA IX and XII.

Amido/ureidosubstituted benzenesulfonamides-isatin conjugates as low nanomolar/subnanomolar inhibitors of the tumor-associated carbonic anhydrase isoform XII

By using a molecular hybridization approach, two series of amido/ureidosubstituted benzenesulfonamides incorporating substituted-isatin moieties were synthesized. The prepared derivatives were in vitro evaluated for their inhibitory activity against human carbonic anhydrase (hCA, EC 4.2.1.1) I, II (cytosolic) and IX, XII (transmembrane, tumor-associated) isoforms. All these isoforms were inhibited in variable degrees by the sulfonamides reported here. hCA I was inhibited with KIs in the range of 7.9-894 nM, hCA II in the range of 7.5-1645 nM (with one compound having a KI > 10 μM); hCA IX in the range of 5.0-240 nM, whereas hCA XII in the range of 0.47-2.83 nM. As all these isoforms are involved in various pathologies, in which their inhibition can be exploited therapeutically, the derivatives reported here may represent interesting extensions to the field of CA inhibitors of the sulfonamide type.

Novel sulfonamides bearing pyrrole and pyrrolopyrimidine moieties as carbonic anhydrase inhibitors: Synthesis, cytotoxic activity and molecular modeling.

Novel pyrrole and pyrrolopyrimidine scaffold-based sulfonamides were designed and synthesized. The carbonic anhydrase (CA) inhibition ability of all derivatives was assessed against the human (h) cytosolic isoforms hCA I and II and the transmembrane, tumor-associated isoforms hCA IX and XII. Some of these sulfonamides were 6-8 fold more potent than the reference drug acetazolamide (AZA, Ki = 5.7 nM)) against hCA XII showing subnanomolar activity. The in vitro cytotoxicity of these derivatives was evaluated against MCF-7, where some derivatives were more cytotoxic than doxorubicin (IC50 = 8.02 μM) displaying IC50 values between 6.46 and 7.56 μM. Docking of these sulfonamides with CA XII was performed and their binding modes were comparable with that of AZA.