Synthesis and bioactivity studies of 1-aryl-3-(2-hydroxyethylthio)-1-propanones

Benzimidazole derivatives as potent and isoform selective tumor-associated carbonic anhydrase IX/XII inhibitors

We describe the synthesis of a series of 2-arylbenzimidazole derivatives bearing sulfonamide functionality (4a-d, 7a-c and 10) as well as hydroxamic acid (15a-b), carboxylic acid (16a-b), carboxamide (17a-b) and boronic acid (22a-b and 26) functionalities, which act as human carbonic anhydrase (hCA, EC 4.2.1.1) inhibitors. The newly synthesized benzimidazole derivatives were evaluated against 4 physiologically relevant CA isoforms (hCA I, II, IX, and XII), and especially the sulfonamide-containing benzimidazoles demonstrated intriguing inhibitory activity against tumor associated CA IX and XII with K_I values in the range of 5.2-29.3 nM and 9.9-41.7 nM, respectively. Notably, compound 4c was the most potent and selective CA IX (K_I = 6.6 nM) and XII (K_I = 9.9 nM) inhibitor with a significant selectivity ratio over cytosolic CA I and II isoforms in the range of 3.4-25.2. In addition, compounds having hydroxamic acid (15a-b) or carboxylic acid (16a-b) functionalities resulted in greater selectivity ratios for CA IX/XII over CAI/II in the range of 4.1-121.5 although with K_I values in lower micromolar potency (K_Is = 0.36-0.85 μM for CA IX/XII).

Synthesis, cytotoxicities, and carbonic anhydrase inhibition potential of 6-(3-aryl-2-propenoyl)-2(3H)-benzoxazolones

In this study, new chalcone compounds having the chemical structure of 6-(3-aryl-2-propenoyl)-2(3H)-benzoxazolones (1-8) were synthesised and were characterised by 1H-NMR, 13 C-NMR, and HRMS spectra. Cytotoxic and carbonic anhydrase (CA) inhibitory effects of the compounds were investigated. Cytotoxicity results pointed out that compound 4, 6-[3-(4-trifluoromethylphenyl)-2-propenoyl]-3H-benzoxazol-2-one, showed the highest cytotoxicity (CC50) and potency-selectivity expression (PSE) value, and thus can be considered as a lead compound of this study. According to the CA inhibitory results, IC50 values of the compounds 1-8 towards hCA I were in the range of 29.74-69.57 µM, while they were in the range of 18.14 - 48.46 µM towards hCA II isoenzyme. Ki values of the compounds 1-8 towards hCA I were in the range of 28.37 ± 6.63-70.58 ± 6.67 µM towards hCA I isoenzyme and they were in the range of 10.85 ± 2.14 - 37.96 ± 2.36 µM towards hCA II isoenzyme.

Synthesis, biological evaluation and in silico modelling studies of 1,3,5-trisubstituted pyrazoles carrying benzenesulfonamide as potential anticancer agents and selective cancer-associated hCA IX isoenzyme inhibitors

Inhibition of carbonic anhydrases (CAs, EC 4.2.1.1) has clinical importance for the treatment of several diseases. They participate in crucial regulatory mechanisms for balancing intracellular and extracellular pH of the cells. Among CA isoforms, selective inhibition of hCA IX has been linked to decreasing of cell growth for both primary tumors and metastases. The discovery of novel CA inhibitors as anticancer drug candidates is a current topic in medicinal chemistry. 1,3,5-Trisubstituted pyrazoles carrying benzenesulfonamide were evaluated against physiologically abundant cytosolic hCA I and hCA II and trans-membrane, tumor-associated hCA IX isoforms by a stopped-flow CO2 hydrase method. Their in vitro cytotoxicities were screened against human oral squamous cell carcinoma (OSCC) cell lines (HSC-2) and human mesenchymal normal oral cells (HGF) via 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT) test. Compounds 6, 8, 9, 11, and 12 showed low nanomolar hCA II inhibitory potency with Ki < 10 nM, whereas compounds 9 and 12 displayed Ki < 10 nM against hCA IX isoenzyme when compared with reference Acetazolamide (AZA). Compound 9, 4-(3-(hydrazinecarbonyl)-5-(4-nitrophenyl)-1H-pyrazol-1-yl)benzenesulfonamide, can be considered as the most selective hCA IX inhibitor over off-target cytosolic isoenzymes hCA I and hCA II with the lowest Ki value of 2.3 nM and selectivity ratios of 3217 (hCA I/hCA IX) and 3.9 (hCA II/hCA IX). Isoform selectivity profiles were also discussed using in silico modelling. Cytotoxicity results pointed out that compounds 5 (CC50 = 37.7 μM) and 11 (CC50 = 58.1 μM) can be considered as lead cytotoxic compounds since they were more cytotoxic than 5-Fluorouracil (5-FU) and Methotrexate (MTX).

Synthesis and bioactivities of pyrazoline benzensulfonamides as carbonic anhydrase and acetylcholinesterase inhibitors with low cytotoxicity

4-(3-Substitutedphenyl-5-polymethoxyphenyl-4,5-dihydro-1H-pyrazol-1-yl)benzenesulfonamides (9-16) were synthesized and their chemical structures were elucidated by 1H NMR, 13C NMR, and HRMS. The compounds designed include pyrazoline and sulfonamide pharmacophores in a single molecule by hibrit molecule approach which is a useful technique in medicinal chemistry in designing new compounds with potent activity for the desired several bioactivities. Inhibition potency of the sulfonamides were evaluated against human CA isoenzymes (hCA IandhCA II) and acetylcholinesterase (AChE) enzyme and also their cytotoxicities were investigated towards oral squamous cancer cell carcinoma (OSCC) cell lines (Ca9-22, HSC-2, HSC-3, and HSC-4) and non-tumor cells (HGF, HPLF, and HPC). Cytosolic hCA I and hCA II isoenzymes were inhibited by the sulfonamide derivatives (9-16) and Ki values were found in the range of 27.9 ± 3.2-74.3 ± 28.9 nM and 27.4 ± 1.4-54.5 ± 11.6 nM, respectively. AChE enzyme was strongly inhibited by the sulfonamide derivatives with Ki values in the range of 37.7 ± 14.4-89.2 ± 30.2 nM The CC50 values of the compounds were found between 15 and 200 µM towards OSCC malign cell lines. Their tumor selectivities were also calculated with two ways. Compound's selectivities towards cancer cell line were found generally low, except compounds bearing 3,4-dimethoxyphenyl 14 (TS1 = 1.3, TS2 = 1.4) and 10 (TS2 = 1.4). All sulfonamide derivatives studied here can be considered as good candidates to develop novel CAs or AChE inhibitor candidates based on the enzyme inhibition potencies with their low cytotoxicity and tumor selectivity.

Probing the mechanism of thermally driven thiol-Michael dynamic covalent chemistry

The thermally driven exchange of thiol-Michael adducts is investigated, elucidating the underlying mechanism of this dynamic covalent process.

Microwave-assisted synthesis and bioevaluation of new sulfonamides

In this study, 4-[5-(4-hydroxyphenyl)-3-aryl-4,5-dihydro-1H-pyrazol-1-yl]benzenesulfonamide derivatives (8-14) were synthesized for the first time by microwave irradiation and their chemical structures were confirmed by ¹H NMR, ¹³C NMR and HRMS. Cytotoxic activities and inhibitory effects on carbonic anhydrase I and II isoenzymes of the compounds were investigated. The compounds 9 (PSE = 4.2), 12 (PSE = 4.1) and 13 (PSE = 3.9) with the highest potency selectivity expression (PSE) values in cytotoxicity experiments and the compounds 13 (Ki = 3.73 ± 0.91 nM toward hCA I) and 14 (Ki = 3.85 ± 0.57 nM toward hCA II) with the lowest Ki values in CA inhibition studies can be considered as leader compounds for further studies.