In silico design, synthesis and antitubercular activity of novel 2-acylhydrazono-5-arylmethylene-4-thiazolidinones as enoyl-acyl carrier protein reductase inhibitors.

Mycobacteria regulate the synthesis of mycolic acid through the fatty acid synthase system type 1 (FAS I) and the fatty acid synthase system type-2 (FAS-II). Because mammalian cells exclusively utilize the FAS-I enzyme system for fatty acid production, targeting the FAS-II enzyme system could serve as a specific approach for developing selective antimycobacterial drugs. Enoyl-acyl carrier protein reductase enzyme (MtInhA), part of the FAS-II enzyme system, contains the NADH cofactor in its active site and reduces the intermediate. Molecular docking studies were performed on an in-house database (∼2200 compounds). For this study, five different crystal structures of MtInhA (PDB Code: 4TZK, 4BQP, 4D0S, 4BGE, 4BII) were used due to rotamer difference, mutation and the presence of cofactors. Molecular dynamics simulations (250 ns) were performed for the novel 2-acylhydrazono-5-arylmethylene-4-thiazolidinones derivatives selected by molecular docking studies. Twenty-three compounds selected by in silico methods were synthesized. Antitubercular activity and MtInhA enzyme inhibition studies were performed for compounds whose structures were elucidated by IR,1H-NMR,13C-NMR, HSQC, HMBC, MS and elemental analysis.Communicated by Ramaswamy H. Sarma.

Thiosemicarbazone-benzene Sulfonamide Derivatives as Human Carbonic Anhydrases Inhibitors: Synthesis, Characterization, and In silico Studies.

INTRODUCTION: Carbonic anhydrases (CAs) are widespread metalloenzymes with the core function of catalyzing the interconversion of CO2 and HCO3-. Targeting these enzymes using selective inhibitors has emerged as a promising approach for the development of novel therapeutic agents against multiple diseases. METHOD: A series of novel thiosemicarbazones-containing derivatives were synthesized, characterized, and tested for their inhibitory activity against pharmaceutically important human CA I (hCA I), II (hCA II), IX (hCA IX), and XII (hCA XII) using the single tail approach. RESULT: The compounds generally inhibited the isoenzymes at low nanomolar concentrations, with compound 6b having Ki values of 7.16, 0.31, 92.5, and 375 nM against hCA I, II, IX and XII, respectively. Compound 6e exhibited Ki values of 27.6, 0.34, 872, and 94.5 nM against hCA I, II, IX and XII, respectively. CONCLUSION: To rationalize the inhibition data, molecular docking studies were conducted, providing insight into the binding mechanisms, molecular interactions, and selectivity of the compounds towards the isoenzymes.

Novel 2-(hydrazinocarbonyl)-3-phenyl-1H-indole-5-sulfonamide based thiosemicarbazides as potent and selective inhibitors of tumor-associated human carbonic anhydrase IX and XII: Synthesis, cytotoxicity, and molecular modelling studies.

In the pursuit of discovering new selective carbonic anhydrase (CA, EC 4.2.1.1) inhibitors, a small collection of novel thiosemicarbazides (5a-5t) were designed and synthesized starting from 2-(hydrazinocarbonyl)-3-phenyl-1H-indole-5-sulfonamide which was evaluated as a potent inhibitor of different CA isoforms in a previous study. The newly synthesized compounds were examined against four human carbonic anhydrases (hCA), namely transmembrane tumor-related hCA IX/XII and cytosolic widespread off-targets hCA I/II. In enzyme inhibition assays, all nineteen compounds display up to ∼340-fold selectivity for hCA IX/XII over off-target isoforms hCA I/II. Four compounds have enzyme inhibition values (Ki) lower than 10 nM against tumor-associated isoforms hCA IX/XII including two compounds in the subnanomolar range (5r and 5s; hCA XII; Ki: 0.69 and 0.87 nM). The potential binding interactions of the most potent compounds against hCA IX and XII, compounds 5s and 5r, respectively, were investigated using ensemble docking and molecular dynamics studies. Cell viability assays using human colorectal adenocarcinoma cell line HT-29 and healthy skin fibroblasts CCD-86Sk show that compound 5e selectively inhibits HT-29 cancer cell proliferation (IC50: 53.32 ± 7.74 µM for HT-29; IC50: 74.64 ± 14.15 µM for CCD-986Sk). Finally, Western blot assays show that compounds 5e and 5r significantly reduce the expression of hCA XII in HT-29 cells. Moreover, 5e shows better cytotoxic activity in hypoxia compared to normoxic conditions. Altogether, the newly designed compounds show stronger inhibition of the tumor-associated hCA IX and XII isoforms and several tested compounds show selective cytotoxicity as well as downregulation of hCA XII expression.

Synthesis of flurbiprofen thiadiazole urea derivatives and assessment of biological activities and molecular docking studies.

Totally 15 novel flurbiprofen urea derivatives were synthesized bearing the thiadiazole ring. Their inhibition effects on tyrosinase were determined. 3c was found to be the strongest inhibitor with the IC50 value of 68.0 µM against tyrosinase. The enzyme inhibition types of the synthesized compounds were determined by examining the kinetic parameters. The inhibition type of 3c was determined as uncompetitive and the Ki value was calculated as 36.3 µM. Moreover, their cytotoxic effects on hepatocellular carcinoma (HepG2), colorectal carcinoma (HT-29), and melanoma (B16F10) cell lines were evaluated. According to the cytotoxicity results, 3l (IC50 = 14.11 µM) showed the highest cytotoxicity on the HT-29 cells, while 3o (IC50 = 4.22 µM) exhibited the strongest cytotoxic effect on HepG2 cell lines. Also, 3j (IC50 = 7.55 µM strongly affected B16F10. The effects of synthesized compounds on the healthy cell line were evaluated on the CCD-986Sk cell line. Molecular modelling studies have indicated the potential binding interactions of the uncompetitive inhibitor 3c with the enzyme-substrate complex.

Tail-Approach-Based Design and Synthesis of Coumarin-Monoterpenes as Carbonic Anhydrase Inhibitors and Anticancer Agents.

In this study, sixty novel coumarin-monoterpene compounds were synthesized in two series [thirty-two compounds (12-43) bearing a triazole ring in the first series, and twenty-eight compounds (44-71) bearing an alkyl chain in the second one]. Their inhibitory effects on the human carbonic anhydrase (hCA) isoforms I, II, IX, and XII and anticancer potentials were determined. All synthesized molecules selectively inhibited CA IX and XII. 23 and 42 were found to be the strongest inhibitors, with K i values of 1.9 nM against hCA IX. Also, 70 showed the highest inhibitory activity with a K i value of 4.9 nM against hCA XII. Moreover, their cytotoxic effects on colon adenocarcinoma (HT-29), prostate adenocarcinoma (PC-3), and breast adenocarcinoma (MCF-7) cell lines were evaluated. According to the cytotoxicity results, 14 (IC50 = 2.48 µM) and 63 (IC50 = 3.91 µM) exhibited the highest cytotoxicity on the MCF-7 cells, while 23 showed the strongest cytotoxic effect on both PC-3 (IC50 = 9.40 µM) and HT-29 (IC50 = 12.10 µM) cell lines. 14, 23, and 66 decreased CA IX and CA XII protein expression in HT-29 cells, while 23 and 66 showed the strongest reduction of both CA IX and CA XII in MCF-7 cells. All of the selected compounds increased total apoptosis in a concentration-dependent manner in HT-29 and MCF-7 cells. 14 has the strongest apoptotic effect in MCF-7 cells. 23 increased early apoptosis primarily, while 14 and 66 increased total apoptosis in HT-29. In addition, PI/Hoechst staining proves that apoptotic cells are increased in HT-29 with an effect of 14, 23, and 66. As a result of the modeling studies, it has been shown that only the open coumarin form of the compounds can interact directly with the active-site Zn2+ ion. It has been shown that coumarin-monoterpene structures with different alkyl and monoterpene groups both specifically inhibit CA IX and XII and exhibit specific cytotoxicity in different cell lines.

Design and synthesis of new heterocyclic compounds containing 5-[(1H-1,2,4-triazol-1-yl)methyl]-3H-1,2,4-triazole-3-thione structure as potent hEGFR inhibitors.

EGFR is one of the important mediators of the signaling cascade that determines key roles in various biological processes such as growth, differentiation, metabolism and apoptosis in the cell in response to external and internal stimuli. In recent years, it has been proven that although this enzyme activity is tightly regulated in normal cells, if the enzyme activity cannot be controlled, it can lead to malignancy. EGFR is also considered a prominent macromolecule in targeted cancer chemotherapy. For this purpose, a comprehensive modeling studies were conducted against EGFR protein and novel molecules containing 5-[(1H-1,2,4-triazol-1-yl)methyl]-3H-1,2,4-triazole-3-thione structure were suggested to be synthesized. Among the synthesized molecules, compounds 7c, 8c, 8f and 8g were determined to have significant IC50 values. Compound 8g was found to have the IC50 value closest to the very well-known EGFR inhibitor Gefitinib with its noncompetitive inhibition form. Ki value of compound 8g was calculated as 0.00232 µM.Communicated by Ramaswamy H. Sarma.

Anti-SARS-CoV-2 and cytotoxic activity of two marine alkaloids from green alga Caulerpa cylindracea Sonder in the Dardanelles.

Caulerpa cylindracea Sonder is a green alga belonging to the Caulerpaceae family. This is the first chemical investigation of C. cylindracea in the Dardanelles which resulted in the isolation of four compounds, caulerpin (1), monomethyl caulerpinate (2), beta-sitosterol (3), and palmitic acid (4). Their structures were elucidated by spectroscopic analyses including 1D- and 2D NMR and mass. The isolated compounds 1 and 2 were tested against the SARS-CoV-2 viral targets spike protein and main protease (3CL) enzyme, and both compounds significantly inhibit the interaction of spike protein and ACE2, while the main protease activity was not significantly reduced. Docking studies suggested that compounds 1 and 2 may bind to the ACE2 binding pocket on spike, and compound 2 may also bind to an allosteric site on spike. As such, these compounds may inhibit the spike-ACE2 complex formation competitively and/or allosterically and have the potential to be used against SARS-CoV-2 virus infection. In addition, compounds 1 and 2 showed at least two-fold higher cytotoxicity against breast cancer cell lines MCF7 and MDA-MB-231 compared to the CCD fibroblast control cell line.

Azole-Based Compounds That Are Active against Candida Biofilm: In Vitro, In Vivo and In Silico Studies.

Fungal pathogens, including Candida spp., Aspergillus spp. and dermatophytes, cause more than a billion human infections every year. A large library of imidazole- and triazole-based compounds were in vitro screened for their antifungal activity against C. albicans, C. glabrata, C. krusei, A. fumigatus and dermatophytes, such as Microsporum gypseum, Trichophyton rubrum and Trichophyton mentagrophytes. The imidazole carbamate 12 emerged as the most active compound, showing a valuable antifungal activity against C. glabrata (MIC 1−16 µg/mL) and C. krusei (MIC 4−24 µg/mL). No activity against A. fumigatus or the dermatophytes was observed among all the tested compounds. The compound 12 inhibited the formation of C. albicans, C. glabrata and C. krusei biofilms and reduced the mature Candida biofilm. In the Galleria mellonella larvae, 12 showed a significant reduction in the Candida infection, together with a lack of toxicity at the concentration used to activate its antifungal activity. Moreover, the in silico prediction of the putative targets revealed that the concurrent presence of the imidazole core, the carbamate and the p-chlorophenyl is important for providing a strong affinity for lanosterol 14α-demethylase (CgCYP51a1) and the fungal carbonic anhydrase (CgNce103), the S-enantiomer being more productive in these interactions.

Thiosemicarbazide-Substituted Coumarins as Selective Inhibitors of the Tumor Associated Human Carbonic Anhydrases IX and XII.

A novel series of thiosemicarbazide-substituted coumarins was synthesized and the inhibitory effects against four physiologically relevant carbonic anhydrase isoforms I, II, IX and XII showed selective activities on the tumor-associated IX and XII isozymes. Molecular modeling studies on selected compounds 14a and 22a were performed. The binding modes of such compounds were determined assuming their enzymatically active structures (i.e., cinnamic acid) in the thermodynamically favored, and not previously explored, E geometry. Molecular modelling suggests multiple interactions within the enzymatic cavity and may explain the high potency and selectivity reported for the hCAs IX and XII.

New 1H-indole-2,3-dione 3-thiosemicarbazones with 3-sulfamoylphenyl moiety as selective carbonic anhydrase inhibitors.

1-Methyl/ethyl/benzyl-5-(un)substituted 1H-indole-2,3-diones (2, 3, and 4) were synthesized by reaction of 5-(un)substituted 1H-indole-2,3-diones (1) with methyl iodide, ethyl chloride, and benzyl bromide. (3-Sulfamoylphenyl)isothiocyanate (6) was obtained by the treatment of 3-aminobenzenesulfonamide (5) with thiophosgene. Compound 6 was reacted with hydrazine to yield 4-(3-sulfamoylphenyl)thiosemicarbazide (7). Novel 1-(un)substituted/methyl/ethyl/benzyl-5-(un)substituted 1H-indole-2,3-dione 3-[4-(3-sulfamoylphenyl)thiosemicarbazone] derivatives (8-11) were prepared by condensation of 7 and 1-4. The structures of the synthesized compounds were confirmed by elemental analysis and spectral data. Inhibition of the widely distributed cytosolic off-targets human carbonic anhydrases (hCAs) I and II, and two tumor-associated membrane-bound isoforms (hCAs IX and XII), by 8-11 was investigated. The hCA II inhibitory effects of all tested compounds were in the subnanomolar to low nanomolar levels (Ki = 0.32-83.3 nM), and generally high selectivity for hCA II isoenzyme over hCA I, IX, and XII isoenzymes was observed. The strongest inhibitors of hCA II, 1-benzyl-5-(trifluoromethoxy)-substituted 11c (Ki = 0.32 nM) and 1-ethyl-5-chloro-substituted 10e (Ki = 0.35 nM), were docked within the enzyme active site. Molecular modeling studies with the most effective hCA IX and XII inhibitors were also carried out.

Mandelic acid-based spirothiazolidinones targeting M. tuberculosis: Synthesis, in vitro and in silico investigations.

A series of new spirothiazolidinone derivatives with a mandelic acid moiety were synthesized and subsequently tested in growth inhibition assays against Mycobacterium tuberculosis strain H37Rv. Compound 16 displayed the highest inhibition value of 98% at lower than 6.25 µg/mL concentration. A single crystal X-ray analysis was conducted on this compound to confirm the structure and determine its absolute configuration. Afterwards, reverse docking and molecular dynamics simulations of this specific stereoisomer were performed against a selection of 10 putative targets of M. tuberculosis to suggest possible mechanisms of action. Our results suggest HadAB, Pks13, DprE1, FadD32 and InhA as possible target proteins for the observed antimycobacterial activity of compound 16.

New Pyridinium Salt Derivatives of 2-(Hydrazinocarbonyl)-3-phenyl-1H-indole-5- sulfonamide as Selective Inhibitors of Tumour-Related Human Carbonic Anhydrase Isoforms IX and XII.

BACKGROUND: The positively charged membrane impermeant sulfonamides were evaluated as a remarkable class of carbonic anhydrase inhibitors (CAIs) previously. Without affecting the human carbonic anhydrase (hCA), cytosolic isoforms hCA I and II, inhibition of two membrane-associated isoforms hCA IX and XII especially overexpressed in hypoxic tumour cells, makes the pyridinium salt derivatives potent promising therapeutic agents. OBJECTIVE: A novel series of tri, tetra, and cyclo-substituted pyridinium salt derivatives of the lead compound 2- (hydrazinocarbonyl)-3-phenyl-1H-indole-5-sulfonamide has been prepared by using sixteen different pyrylium salts, for the search of selective inhibitors of transmembrane tumour-associated human carbonic anhydrase hCA IX and XII. METHODS: Molecular modeling studies were carried out to understand and rationalize the in vitro enzyme inhibition data. RESULTS: Six of the new compounds showed good inhibitory profiles with low nanomolar range (< 100 nM) against hCA IX/XII, and compound 5 showed excellent potency with Ki values lower than 10 nM. In addition, molecular modelling studies have presented the possible binding modes of the ligands. CONCLUSION: Most of the compounds displayed potent inhibitory activity against the tumor-associated hCA IX and XII in the low nanomolar range and selectivity over the off-targeted isoforms hCA I and II. Due to their cationic structure and membrane-impermeant behavior, it is also expected to maximize the selectivity over cytosolic isoforms hCA I/II while inhibiting tumor overexpressed isoforms hCA XI/XII of new compounds in in vivo conditions.

Synthesis, anti-TB activities, and molecular docking studies of 4-(1,2,3-triazoyl)arylmethanone derivatives.

Infectious diseases such as tuberculosis (TB) are leading causes of human death. Antibiotics are effective molecules to combat bacterial infections by affecting the processes required for bacterial cell growth and proliferation. The development of new antibiotics has become an important issue as overdosed or incorrect use of antibiotic lead to the development of antibiotic resistance. In this study, a new series of 4-(1,2,3-triazoyl)arylmethanone derivatives has been synthesized using the one-pot Copper-​Catalyzed Oxidative Cross-​Dehydrogenative Coupling​/Oxidative Cycloaddition strategy to overcome the aforementioned problems. New compounds were characterized by using spectroscopic techniques (1 H, 13 C-APT-NMR, FT-IR, and HRMS-TOF). In vitro antimycobacterial activities of the arylmethanone derivatives against the Mycobacterium tuberculosis H37 Rv standard strain were examined using the resazurin microplate method in the presence of streptomycin and rifampycin as standard medicines. Bioactive assays demonstrated promising results that some of the synthesized 4-(1,2,3-triazoyl)arylmethanone derivatives exhibited good anti-TB activities. Notably, compounds 6b, 6f, and 6g gave the most potent efficiency with minimum inhibitory concentration values of 4 µg/ml (12.8, 11.7, and 12.8 µΜ, respectively). Among the synthesized compounds, the cytotoxicity measurements of the 6b, 6f, 6g, 6d, and 6v derivatives were screened and it was found that the 6f derivative did not show any cytotoxicity. Molecular docking analyses are utilized to identify the binding mode and the key interactions between target compounds and the ligand-binding site of M. tuberculosis enoyl-acyl carrier protein reductase enzyme (MtInhA, EC 1.3.1.9). The docking results were in agreement with the in vitro results, which confirm the synthesized ligands bind to MtInha with moderate to low affinity.

The neutralization effect of montelukast on SARS-CoV-2 is shown by multiscale in silico simulations and combined in vitro studies.

Small molecule inhibitors have previously been investigated in different studies as possible therapeutics in the treatment of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). In the current drug repurposing study, we identified the leukotriene (D4) receptor antagonist montelukast as a novel agent that simultaneously targets two important drug targets of SARS-CoV-2. We initially demonstrated the dual inhibition profile of montelukast through multiscale molecular modeling studies. Next, we characterized its effect on both targets by different in vitro experiments including the enzyme (main protease) inhibition-based assay, surface plasmon resonance (SPR) spectroscopy, pseudovirus neutralization on HEK293T/hACE2+TMPRSS2, and virus neutralization assay using xCELLigence MP real-time cell analyzer. Our integrated in silico and in vitro results confirmed the dual potential effect of montelukast both on the main protease enzyme inhibition and virus entry into the host cell (spike/ACE2). The virus neutralization assay results showed that SARS-CoV-2 virus activity was delayed with montelukast for 20 h on the infected cells. The rapid use of new small molecules in the pandemic is very important today. Montelukast, whose pharmacokinetic and pharmacodynamic properties are very well characterized and has been widely used in the treatment of asthma since 1998, should urgently be completed in clinical phase studies and, if its effect is proved in clinical phase studies, it should be used against coronavirus disease 2019 (COVID-19).

New azolyl-derivatives as multitargeting agents against breast cancer and fungal infections: synthesis, biological evaluation and docking study.

Nonsteroidal aromatase inhibitors (NSAIs) are well-established drugs for the therapy of breast cancer. However, they display some serious side effects, and their efficacy can be compromised by the development of chemoresistance. Previously, we have reported different indazole-based carbamates and piperidine-sulphonamides as potent aromatase inhibitors. Starting from the most promising compounds, here we have synthesised new indazole and triazole derivatives and evaluated their biological activity as potential dual agents, targeting both the aromatase and the inducible nitric oxide synthase, being this last dysregulated in breast cancer. Furthermore, selected compounds were evaluated as antiproliferative and cytotoxic agents in the MCF-7 cell line. Moreover, considering the therapeutic diversity of azole-based compounds, all the synthesized compounds were also evaluated as antifungals on different Candida strains. A docking study, as well as molecular dynamics simulation, were carried out to shed light on the binding mode of the most interesting compound into the different target enzymes catalytic sites.

Synthesis of new 1,2,4-triazole-(thio)semicarbazide hybrid molecules: Their tyrosinase inhibitor activities and molecular docking analysis.

Tyrosinase inhibition is very important in controlling melanin synthesis. If melanin synthesis is not controlled in metabolism, an unwanted increase in melanin synthesis occurs. As melanin plays a role in the formation of skin color, its unusual levels cause some skin disorders such as pregnancy scars, age spots, and especially skin cancer (melanoma). However, the tyrosinase activity is also related to Parkinson's disease and some neurodegenerative diseases. For all these reasons, the medicinal as well as the cosmetic industries focus on research on tyrosinase inhibitors for the treatment of skin disorders and some neurodegenerative diseases. In this study, 32 new 1,2,4-triazole-(thio)semicarbazide hybrid molecules (6a-p and 7a-p) were synthesized, starting from 4-amino-1-pentyl-3-phenyl-1H-1,2,4-triazole-5(4H)-one. These compounds were evaluated for their inhibitory activity against mushroom tyrosinase. The results indicated that 6h, 6m, 6n, and 6p exhibited the most effective inhibitory activity, with IC50 values of 0.00162 ± 0.0109, 0.00166 ± 0.0217, 0.00165 ± 0.019, and 0.00197 ± 0.0063 µM, respectively, compared with kojic acid as the reference drug (IC50 = 14.09 ± 0.02 µM). Also, molecular docking analyses were performed to suggest possible binding poses for the ligands. As a result, derivatives 6h, 6m, 6n, and 6p can be used as promising tyrosinase inhibitor candidates in the medicinal, cosmetics, or food industries.

Quinoline-sulfamoyl carbamates/sulfamide derivatives: Synthesis, cytotoxicity, carbonic anhydrase activity, and molecular modelling studies.

Carbonic anhydrase (CA) IX, and XII isoforms are known to be highly expressed in various human tissues and malignancies. CA IX is a prominent target for some cancers because it is overexpressed in hypoxic tumors and this overexpression leads to poor prognosis. Novel twenty-seven compounds in two series (sulfamoylcarbamate-based quinoline (2a-2o) and sulfamide-based quinoline (3a-3l)) were synthesized and characterized by means of IR, NMR, and mass spectra. Their inhibitory activities were evaluated against CA I, CA II, CA IX, and CA XII isoforms. 2-Phenylpropyl (N-(quinolin-8-yl)sulfamoyl)carbamate (2m) exhibited the highest hCA IX inhibition with the Ki of 0.5 µM. In addition, cytotoxic effects of the synthesized compounds on human colorectal adenocarcinoma (HT-29; HTB-38), human breast adenocarcinoma (MCF7; HTB-22), human prostate adenocarcinoma (PC3; CRL-1435) and human healthy skin fibroblast (CCD-986Sk; CRL-1947) cell lines were examined. The cytotoxicity results showed that 2j, 3a, 3e, 3f are most active compounds in all cell lines (HT-29, MCF7, PC3, and CCD-986Sk).

Carbonic Anhydrase Inhibitors Targeting Metabolism and Tumor Microenvironment.

The tumor microenvironment is crucial for the growth of cancer cells, triggering particular biochemical and physiological changes, which frequently influence the outcome of anticancer therapies. The biochemical rationale behind many of these phenomena resides in the activation of transcription factors such as hypoxia-inducible factor 1 and 2 (HIF-1/2). In turn, the HIF pathway activates a number of genes including those involved in glucose metabolism, angiogenesis, and pH regulation. Several carbonic anhydrase (CA, EC 4.2.1.1) isoforms, such as CA IX and XII, actively participate in these processes and were validated as antitumor/antimetastatic drug targets. Here, we review the field of CA inhibitors (CAIs), which selectively inhibit the cancer-associated CA isoforms. Particular focus was on the identification of lead compounds and various inhibitor classes, and the measurement of CA inhibitory on-/off-target effects. In addition, the preclinical data that resulted in the identification of SLC-0111, a sulfonamide in Phase Ib/II clinical trials for the treatment of hypoxic, advanced solid tumors, are detailed.

Novel Indole-Based Hydrazones as Potent Inhibitors of the α-class Carbonic Anhydrase from Pathogenic Bacterium Vibrio cholerae.

Due to the increasing resistance of currently used antimicrobial drugs, there is an urgent problem for the treatment of cholera disease, selective inhibition of the α-class carbonic anhydrases (CA, EC 4.2.1.1) from the pathogenic bacterium Vibrio cholerae (VcCA) presents an alternative therapeutic target. In this study, a series of hydrazone derivatives, carrying the 2-(hydrazinocarbonyl)-3-phenyl-1H-indole-5-sulfonamide scaffold, have been evaluated as inhibitors of the VcCA with molecular modeling studies. The results suggest that these compounds may bind to the active site of VcCA. To verify this, VcCA enzyme inhibition studies were performed and as predicted most of the tested compounds displayed potent inhibitory activities against VcCA with three compounds showing KI values lower than 30 nM. In addition, all these compounds showed selectivity for VcCA and the off-targets hCA I and II.

The Synthesis, Anticancer Activity, Structure-Activity Relationships and Molecular Modelling Studies of Novel Isoindole-1,3(2H)-dione Compounds Containing Different Functional Groups.

BACKGROUND: Isoindole-1,3(2H)-dione derivatives are known to have cytotoxic effects on many cancer cells. The anticancer activity of these compounds varies depending on the substituents attached to them. Therefore, the effect of substituents is very important when determining the anticancer activities of molecules. We have recently reported an example of the substituent effect. According to that work, the anticancer activity against HeLa, C6, and A549 cancer cell lines of isoindole- 1,3(2H)-dione compounds containing tert-butyldiphenylsilyl ether, azido, and hydroxyl groups was examined by our group. It was found that an isoindole-1,3(2H)-dione compound containing both tert-butyldiphenylsilyl ether group and azido groups showed higher anticancer activity than 5-fluorouracil and another isoindole-1,3(2H)- dione compound containing both azido and hydroxyl groups. After we discovered that tert-butyldiphenylsilyl ether group in the skeletal structure of isoindole-1,3(2H)-dione exhibits anticancer activity against HeLa, C6, and A549 cancer cell lines, we wanted to examine the anticancer activities of different silyl ether groups, i.e., OTMS, -OTBDPS, and -OTBDMS groups, and also -OH and -Br groups, by comparing them with each other according to the structure-activity relationship. METHODS: All of the synthesized compounds were characterized by 1H and 13C NMR spectra, IR spectroscopy, and mass spectra measurements. The IC50 values of these compounds were calculated for all cancer cell lines and compared with each other and cisplatin, which is a platinum-containing chemotherapeutic drug. Molecular modelling studies were carried out using the MOE software package. RESULTS: It was found that compounds 13 and 16, containing both silyl ether (-OTBDMS) and -Br groups, showed higher anticancer activity than cisplatin against both Caco-2 and MCF-7 cell lines. Compounds 20 and 23 showed anticancer activity in MCF-7 cells and compounds 8, 9, 20, and 23 in Caco-2 cells. While compounds 20 and 23 have only a silyl ether (-OTMS) group, compounds 8 and 9 have only a -OH group. Molecular modelling studies indicated that compounds 8 and 13, as well as their analogs, may bind to the active site of hRS6KB1 (pdb: 4l3j), compound 11 may bind to the active site of human mTOR (pdb: 4jt5) and additionally, compounds 10-17 are expected to be both mutagenic and reactive according to the mutagenicity and reactivity calculations. CONCLUSION: According to these results, the anticancer activities of isoindole-1,3(2H)-dione compounds (8 - 23) vary depending on the groups they contain and these groups affect each other's activities. Silyl ethers (-OTBDMS and -OTMS) and -OH and -Br groups in the skeletal structure of isoindole-1,3(2H)-dione can be regarded as anticancer agents. In this sense, compounds 13 and 16, containing both silyl ether (-OTBDMS) and - Br groups, may be regarded as alternative chemotherapeutic drugs. This work may lead to the synthesis of new isoindole-1,3(2H)-dione compounds containing different silyl ether groups and studies evaluating their anticancer activities or other biological properties.