Search

The rapid increase in strains that are resistant to antibiotics requires new active compounds to be found whose mechanism of action on bacteria is different to those that are currently known. Of particular interest are compounds that occur in plants as secondary metabolites. The focus of this study concerns the examination of the effects of synthetic cinnamic acid derivatives, with 4-chloro-2-mercaptobenzenesulfonamide moiety on Enterococcus spp. with HLAR (high-level aminoglycoside resistance) and VRE (vancomycin-resistant Enterococcus) mechanisms. The minimum inhibitory concentration (MIC) values of the tested compounds were determined using the serial dilution method for Enterococcus spp. groups, and the most active compounds were as follows: 16d, 17c, 16a, 16c and 16f (2–4 µg/mL). These compounds, at a concentration of 4 × MIC, inhibited the biofilm formation of HLAR strains (70 to 94%). At concentrations of 2 × MIC and 4 × MIC, they also inhibited the growth of VRE strains (42 to 96%). The best effect produced on the formed biofilm was demonstrated by compound 16f (from 62% MIC concentration to 89% 4 × MIC concentration) on the tested HLAR strains. In vitro studies, using the peripheral blood of domestic sheep, demonstrated the stable bacteriostatic activity of the tested compounds against Enterococcus spp. The compounds 16a, 16c, 16d, 16f and 17c showed synergism and additivity with ampicillin, streptomycin, gentamicin and vancomycin against resistant strains of Enterococcus spp. The tested compounds, when combined, reduce the MIC for antibiotics by 800 to 10,000 times for HLAR strains and by 8 to 10,000 times for VRE strains. The MIC of the tested compounds, in combination with antibiotics, is reduced 2–16-fold for HLAR strains and 2–32-fold for VRE strains. These studies demonstrate the potential for the therapeutic use of synthetic, cinnamic acid derivatives, with 4-chloro-2-mercaptobenzenesulfonamide moiety, to work against clinical strains of Enterococcus spp.

Cinnamic acid is a plant metabolite with antimicrobial, anticancer, and antioxidant properties. Its synthetic derivatives are often more effective in vitro than parent compounds due to stronger biological activities. In our study, we synthesized ten new N–(4–chloro–2–mercapto–5–methylphenylsulfonyl)cinnamamide derivatives, containing two pharmacophore groups: cinnamic acid moiety and benzenesulfonamide. The antimicrobial activity of the obtained compounds was estimated using different types of Gram-positive and Gram-negative bacteria, fungus species of Candida albicans, as well as clinical strains. The compounds were evaluated on biofilm formation and biofilm formed by Staphylococcus clinical strains (methicillin–resistance S. aureus MRSA and methicillin–resistance coagulase–negative Staphylococcus MRCNS). Furthermore, blood bacteriostatic activity test was performed using S. aureus and S. epidermidis. In cytotoxic study, we performed in vitro hemolysis assay on domestic sheep peripheral blood and MTT [3–(4,5–dimethylthiazol–2–yl)–2,5–diphenyltetrazolium bromide] assay on human cervical HeLa, ovarian SKOV-3, and breast MCF-7 cancer cell lines. We also estimated antioxidant activity of ten compounds with 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′–azino–bis(3–ethylbenzthiazoline–6–sulfonic acid) (ABTS) assays. Our results showed a significant antimicrobial activity of the compounds. All of them were active on Staphylococcus and Enterococcus species (MIC was 1–4 µg/mL). The compounds 16d and 16e were the most active on staphylococci clinical strains and efficiently inhibited the biofilm formation and biofilm already formed by the clinical staphylococci. Moreover, the hemolytic properties of the tested compounds occurred in higher quantities (>32.5 µg/mL) than the concentrations that inhibited both the growth of bacteria in the blood and the formation and growth of biofilm. The results of MTT assay showed that compounds 16c, 16d, 17a, and 17d demonstrated the best activity on the cancer cells (the IC50 values were below 10 µg/mL). Compound 16f was the least active on the cancer cells (IC50 was > 60 µg/mL). Antiradical tests revealed that compounds 16f and 17d had the strongest antioxidant properties within the tested group (IC50 was 310.50 ± 0.73 and 574.41 ± 1.34 µg/mL in DPPH, respectively, and 597.53 ± 1.3 and 419.18 ± 2.72 µg/mL in ABTS assay, respectively). Our study showed that the obtained cinnamamide derivatives can be used as potential antimicrobial therapeutic agents.

Cancer is a disease that has spread widely throughout the world and requires the development of new anticancer drugs. Curing cancer is a complicated process as the drugs that are used target human cells and cells that have undergone genetic changes and are dividing at a quick and uncontrolled rate. Thus, there is a constant need to develop alternative or synergistic anticancer agents with minimal side effects. One of the important strategies in the search for chemotherapeutics is the approach based on combining fragments of known drugs in one molecule, leading to structures or “hit” structures. The conjugation of two pharmacophores into a molecular hybrid aims at achieving a synergistic effect with increased efficacy compared to the starting compounds. The aim of the work was to synthesize new N-substituted N′-(2-methylthio-4-chloro-5-methylbenzenesulfonyl)guanidines with potential anticancer activity, designed as molecular hybrids containing fragments of chalcone and 4-chloro-5-methyl-2-methylthiobenzenesulfonamide. Cytotoxic activity of the compounds was evaluated in the MTT test against three human tumor cell lines: breast cancer (MCF-7), colon cancer (HCT-116), and cervical cancer (HeLa). It has been shown that all sulfonamides are highly active against breast and colon cancer cell lines (IC50: 2.5–5 μM). Additionally, in tests carried out on the non-cancer human keratinocyte cell line (HaCaT), it was proved that the tested compounds showed higher cytotoxicity against cancer cells compared to healthy cells. Cytotoxic activity in the HeLa cell line ranged from values of IC50 from 5 to 17 μM.

During our research of biological activity of different N-aryl-4-substututed-pyridine-3-sulfonamides, we have found that compounds bearing a N-(quinolin-8-yl) substituent possess a significant anti-tumor activity. Mechanisms of anticancer activity of N-(quinoline)sulfonamide derivatives were reported to be inhibitors of the NF-κB pathway. Nuclear factor NF-κB regulates expression of genes that control cell proliferation and cell survival; thus, it is considered a potential molecular target for the prevention and treatment of cancer. Based on this information, we decided to synthesize and evaluate a series of 4-amino-N-(quinolin-8-yl)pyridine-3-sulfonamides, which contain both a 8-amonoquinolin group and a pyridine-3-sulfonamide scaffold. Target compounds were obtained in a multistep reaction starting from 4-hydroxypyridine, and their structure was confirmed using the spectroscopic methods: IR, 1H NMR, and elemental analysis (C, H, N). Synthesized compounds were tested using a tetrazolium (MTT) cell viability assay towards their effect on growth of three human cancer cell lines (colon cancer HCT-116, breast cancer MCF-7 and cervical cancer HeLa) and on the noncancerous keratinocyte cell line HaCaT. Cell viability was measured after 72 h of incubation with the tested compound in five concentrations (1–100 μM). All compounds show very high activity compared to cisplatin against cancer cells lines (IC50 = 4–43 μM), and a selectivity relative to HaCaT cells.

Aryl/heteroarylsulfonamides are an important group of compounds with different directions of biological activity. The number of literature reports on the antibacterial activity of sulfonamides is steadily increasing, bringing a lot of interesting data on the diverse structures and mechanisms of their pharmacological action. The presented research joins the stream of the search for new hybrid molecules being created as a result of the combination of various pharmacophores with interesting biological profiles. Particular attention was paid to their antibacterial activity. The new compounds were designed and obtained based on the structure of the pharmacophore group of 4-chlorobenzenesulfonamide functionalized in the 2-position on sulfur atom, and the structure of chalcone. Taking into account the previous results of our own research and the available literature data, new N-(4-chloro-2-arylmethylthio-5-methylphenylsulfonyl)cinnamamide derivatives were designed and synthesized, which have pharmacophore groups in their structure, such as: 1-naphthylmethylthio and 6-chloropiperonylthio. Preliminary microbiological analysis was performed using TLC-bioautography. The expected antibacterial activity of the obtained compounds was confirmed inin vitrotests against Gram-positive bacteria: S. aureus, S. epimermidis, E. hirae, E. faecalis, and B. subtilis. In the next stage, the microbiological activity of selected compounds against clinical strains MRSA, CNS, and MRSE was also tested. The derivatives’ activity against bacterial biofilm and hemolytic activity on the peripheral blood of domestic sheep were also tested.

Our previous research proved that benzenesulfonylguanidine derivatives display significant cytotoxic activity against human cancer cells. Here, we describe new 1-(2-alkylthio-4-chloro-5-methylbenzenesulfonyl)guanidines with cytotoxic activity against HCT-116 and MCF-7 cells. The planned derivatives were obtained by a two-step synthesis. The starting substrates were 1-(2-alkylthio-4-chloro-5-methyl)benzenesulfonyl)-3-aminoguanidines 1–4, which were transformed into 1-(2-alkylthio-4-chloro-5-methylbenzenesulfonyl)-3-[(2-chloroacetyl)amino]guanidines 5–8 by a reaction with chloroacetyl chloride. In the next step, the derivatives 5–8 were reacted with potassium thiocyanate, yielding 1-(2-alkylthio-4-chloro-5-methylbenzenesulfonyl)-3-(2-imino-4-oxothiazolidine-3-yl)guanidines 9–12. The synthesized derivatives 5–12 were evaluated in vitro by MTT assays for their activity against three human cancer cell lines: colon cancer HCT-116, breast cancer MCF-7, and cervical cancer HeLa. The activity against non-cancerous human epidermal keratinocyte line HaCaT was also examined. The data indicate that compounds 5–8 inhibit the growth of cancer cells more strongly than derivatives 9–12. The selective cytotoxic effect against HCT-116 cells was found for benzenesulfonylguanidine 6 containing a 2-(trifluoromethyl)benzylthio group at position two of the benzenesulfonyl scaffold. The IC50 value was 13 μM, while IC50 for HaCaT cells, it was 48 μM. Good selectivity was also observed for compound 7, with a 2-chloromethylbenzylthio substituent, against HCT-116 and MCF-7 cells (IC50 = 12 and 19 μM, respectively, for HCT-116 and MCF-7 cells, IC50 = 47 μM for HaCaT cells). Among compounds 9–12, only compound 9 showed moderate but selective cytotoxicity against MCF-7 cells, with IC50 = 18 μM compared with IC50 = 54 μM for HaCaT cells.

Sulfonamides are a classic group of chemotherapeutic drugs with a broad spectrum of pharmacological action, including anticancer activity. In this work, reversed-phase high-performance liquid chromatography and biomimetic chromatography were applied to characterize the lipophilicity of sulfonamide derivatives with proven anticancer activities against human colon cancer. Chromatographically determined lipophilicity parameters were compared with obtained logP, employing various computational approaches. Similarities and dissimilarities between experimental and computational logP were studied using principal component analysis, cluster analysis, and the sum of ranking differences. Furthermore, quantitative structure–retention relationship modeling was applied to understand the influences of sulfonamide’s molecular properties on lipophilicity and affinity to phospholipids.

The two β-carbonic anhydrases (CAs, EC 4.2.1.1) from the pathogenic bacterium Brucella suis, BsuCA1 and BsuCA2, were investigated for their inhibition profile with a series of pyridine-3-sulphonamide derivatives incorporating 4-hetaryl moieties. BsuCA1 was effectively inhibited by these sulphonamides with inhibition constants ranging between 34 and 624 nM. BsuCA2 was less sensitive to these inhibitors, with KIs in the range of 62 nM - > 10 µM. The nature of the 4-substituent present on the pyridine ring was the main factor influencing the inhibitory profile against both isoforms, with 4-halogenophenylpiperazin-1-yl and 3,4,5-trisubstituted-pyrazol-1-yl derivatives showing the most effective inhibition. Some of these sulphonamides were most effective bacterial CA than human (h) CA I and II inhibitors, making them selective for the prokaryotic enzymes. Investigation of bacterial CA inhibitors may be relevant for finding antibiotics with a new mechanism of action compared to the clinically used agents for which substantial drug resistance emerged.

In this work, a target-based drug screening method is proposed exploiting the synergy effect of ligand-based and structure-based computer-assisted drug design. The new method provides great flexibility in drug design and drug candidates with considerably lower risk in an efficient manner. As a model system, 45 sulphonamides (33 training, 12 testing ligands) in complex with carbonic anhydrase IX were used for development of quantitative structure-activity-lipophilicity (property)-relationships (QSPRs). For each ligand, nearly 5,000 molecular descriptors were calculated, while lipophilicity (logkw) and inhibitory activity (logKi) were used as drug properties. Genetic algorithm-partial least squares (GA-PLS) provided a QSPR model with high prediction capability employing only seven molecular descriptors. As a proof-of-concept, optimal drug structure was obtained by inverting the model with respect to reference drug properties. 3509 ligands were ranked accordingly. Top 10 ligands were further validated through molecular docking. Large-scale MD simulations were performed to test the stability of structures of selected ligands obtained through docking complemented with biophysical experiments.

A series of new 3-amino-6-chloro-7-(azol-2 or 5-yl)-1,1-dioxo-1,4,2-benzodithiazine derivatives 5a–j have been synthesized and evaluated in vitro for their antiproliferative activity at the U.S. National Cancer Institute. The most active compound 5h showed significant cytotoxic effects against ovarian (OVCAR-3) and breast (MDA-MB-468) cancer (10% and 47% cancer cell death, respectively) as well as a good selectivity toward prostate (DU-145), colon (SW-620) and renal (TK-10) cancer cell lines. To obtain a deeper insight into the structure-activity relationships of the new compounds 5a–j QSAR studies have been applied. Theoretical calculations allowed the identification of molecular descriptors belonging to the RDF (RDF055p and RDF145m in the MOLT-4 and UO-31 QSAR models, respectively) and 3D-MorSE (Mor32m and Mor16e for MOLT-4 and UO-31 QSAR models) descriptor classes. Based on these data, QSAR models with good robustness and predictive ability have been obtained.

A series of novel N-acyl-4-chloro-5-methyl-2-(R1-methylthio)benzenesulfonamides 18–47 have been synthesized by the reaction of N-[4-chloro-5-methyl-2-(R1-methylthio) benzenesulfonyl]cyanamide potassium salts with appropriate carboxylic acids. Some of them showed anticancer activity toward the human cancer cell lines MCF-7, HCT-116 and HeLa, with the growth percentages (GPs) in the range from 7% to 46%. Quantitative structure-activity relationship (QSAR) studies on the cytotoxic activity of N-acylsulfonamides toward MCF-7, HCT-116 and HeLa were performed by using topological, ring and charge descriptors based on the stepwise multiple linear regression technique (MLR). The QSAR studies revealed three predictive and statistically significant models for the investigated compounds. The results obtained with these models indicated that the anticancer activity of N-acylsulfonamides depends on topological distances, number of ring system, maximum positive charge and number of atom-centered fragments. The metabolic stability of the selected compounds had been evaluated on pooled human liver microsomes and NADPH, both R1 and R2 substituents of the N-acylsulfonamides simultaneously affected them.

A series of novel 4-substituted-N-(phenylcarbamoyl)-3-pyridinesulfonamides 11–27 have been synthesized by the reaction of 4-substituted pyridine-3-sulfonamides 2–10 with the appropriate aryl isocyanates in presence of potassium carbonate. The in vitro anticancer activity of compounds 11, 12, 14–21 and 24–26 was evaluated at the U.S. National Cancer Institute and in light of the results, some structure-activity relationships were discussed. The most prominent compound, N-[(4-chlorophenyl)carbamoyl]-4-[4-(3,4-dichlorophenyl)piperazin-1-yl]pyridine-3-sulfonamide (21) has exhibited a good activity profile and selectivity toward the subpanels of leukemia, colon cancer and melanoma, with average GI50 values ranging from 13.6 to 14.9 µM.

A series of new 6-chloro-3-(2-arylmethylene-1-methylhydrazino)-1,4,2-benzodithiazine 1,1-dioxide derivatives were effectively synthesized from N-methyl-N-(6-chloro-1,1-dioxo-1,4,2-benzodithiazin-3-yl)hydrazines. The intermediate compounds as well as the products, were evaluated for their cytotoxic effects toward three human cancer cell lines. All compounds shown moderate or weak cytotoxic effects against the tested cancer cell lines, but selective cytotoxic effects were observed. Compound 16 exhibited the most potent cytotoxic activity against the HeLa cell line, with an IC50 value of 10 µM, while 14 was the most active against the MCF-7 and HCT-116 cell lines, affording IC50 values of 15 µM and 16 µM, respectively. The structure-activity relationship was evaluated based on QSAR methodology. The QSAR MCF-7 model indicated that natural charge on carbon atom C13 and energy of highest occupied molecular orbital (HOMO) are highly involved in cytotoxic activity against MCF-7 cell line. The cytotoxic activity of compounds against HCT-116 cell line is dependent on natural charge on carbon atom C13 and electrostatic charge on nitrogen atom N10. The obtained QSAR models could provide guidelines for further development of novel anticancer agents.

Pathogenic fungi are one of the main causes of hospital-related infections. Since conventional antifungals have become less effective because of the increasing fungal resistance to the standard drugs, the need for new agents is becoming urgent. Herein we report a synthesis of a series of novel N-[imino-(1-oxo-(1H)-phthalazin-2-yl)methyl]-benzenesulfonamide derivatives with in vitro activity against yeast-like fungi isolated from the oral cavity and respiratory tract of patients with candidiasis. These compounds were synthesized by the one-step or two-step reactions of 1-(2-alkylthiobenzensulfonyl)-2-aminoguanidines with the appropriate ortho-carbonyl benzoic acids. The biological study revealed that new derivatives have shown significant growth-inhibitory activity, superior or comparable, than those of the reference drug fluconazole. The most promising activities were observed against Candida albicans, with inhibition at least 1–3 (12.5%–37.5%) of the eight tested strains at the low MIC level of ≤6.2–25 µg/mL.

Candidiasis represent a serious threat for patients with altered immune responses. Therefore, we have undertaken the synthesis of compounds comprising a pyridine-3-sulfonamide scaffold and known antifungally active 1,2,4-triazole substituents. Thus a series of novel 4-substituted N-(5-amino-1H-1,2,4-triazol-3-yl)pyridine-3-sulfonamides have been synthesized by multistep reactions starting from 4-chloropyridine-3-sulfonamide via N′-cyano-N-[(4-substitutedpyridin-3-yl)sulfonyl]carbamimidothioates which were further converted with hydrazine hydrate to the corresponding 1,2,4-triazole derivatives 26–36. The final compounds were evaluated for antifungal activity against strains of the genera Candida, Geotrichum, Rhodotorula, and Saccharomycess isolated from patients with mycosis. Many of them show greater efficacy than fluconazole, mostly towards Candida albicans and Rhodotorula mucilaginosa species, with MIC values ≤ 25 µg/mL. A docking study of the most active compounds 26, 34 and 35 was performed showing the potential mode of binding to Candida albicans lanosterol 14α-demethylase. Also in vitro cytotoxicity of selected compounds have been evaluated on the NCI-60 cell line panel.

A set of 15 new sulphonamide derivatives, presenting antitumor activity have been subjected to a metabolic stability study. The results showed that besides products of biotransformation, some additional peaks occurred in chromatograms. Tandem mass spectrometry revealed the same mass and fragmentation pathway, suggesting that geometric isomerization occurred. Thus, to support this hypothesis, quantitative structure-retention relationships were applied. Human liver microsomes were used as an in vitro model of metabolism. The biotransformation reactions were tracked by liquid chromatography assay and additionally, fragmentation mass spectra were recorded. In silico molecular modeling at a semi-empirical level was conducted as a starting point for molecular descriptor calculations. A quantitative structure-retention relationship model was built applying multiple linear regression based on selected three-dimensional descriptors. The studied compounds revealed high metabolic stability, with a tendency to form hydroxylated biotransformation products. However, significant chemical instability in conditions simulating human body fluids was noticed. According to literature and MS data geometrical isomerization was suggested. The developed in sillico model was able to describe the relationship between the geometry of isomer pairs and their chromatographic retention properties, thus it supported the hypothesis that the observed pairs of peaks are most likely geometric isomers. However, extensive structural investigations are needed to fully identify isomers' geometry. An effort to describe MS fragmentation pathways of novel chemical structures is often not enough to propose structures of potent metabolites and products of other chemical reactions that can be observed in compound solutions at early drug discovery studies. The results indicate that the relatively non-expensive and not time- and labor-consuming in sillico approach could be a good supportive tool assisting the identification of cis-trans isomers based on retention data. This methodology can be helpful during the structural identification of biotransformation and degradation products of new chemical entities--potential new drugs.

A series of novel 5-substituted 2-(arylmethylthio)-4-chloro-N-(5-aryl-1,2,4-triazin-3-yl) benzenesulfonamide derivatives 27–60 have been synthesized by the reaction of aminoguanidines with an appropriate phenylglyoxal hydrate in glacial acetic acid. A majority of the compounds showed cytotoxic activity toward the human cancer cell lines HCT-116, HeLa and MCF-7, with IC50 values below 100 μM. It was found that for the analogues 36–38 the naphthyl moiety contributed significantly to the anticancer activity. Cytometric analysis of translocation of phosphatidylserine as well as mitochondrial membrane potential and cell cycle revealed that the most active compounds 37 (HCT-116 and HeLa) and 46 (MCF-7) inhibited the proliferation of cells by increasing the number of apoptotic cells. Apoptotic-like, dose dependent changes in morphology of cell lines were also noticed after treatment with 37 and 46. Moreover, triazines 37 and 46 induced caspase activity in the HCT-116, HeLa and MCF-7 cell lines. Selected compounds were tested for metabolic stability in the presence of pooled human liver microsomes and NADPH, both R2 and Ar = 4-CF3-C6H4 moiety in 2-(R2-methylthio)-N-(5-aryl-1,2,4-triazin-3-yl)benzenesulfonamides simultaneously increased metabolic stability. The results pointed to 37 as a hit compound with a good cytotoxicity against HCT-116 (IC50 = 36 μM), HeLa (IC50 = 34 μM) cell lines, apoptosis-inducing activity and moderate metabolic stability.

A series of novel 3-/2,3-substituted pyrido[4,3-e][1,2,4]triazino[3,2-c][1,2,4]thiadiazine 6,6-dioxides 4–28 have been synthesized by the reaction of 3-amino-2-(4-thioxo-1,4-dihydropyridin-3-yl-sulfonyl)guanidine with either 2-oxoalkanoic acids and its esters, or phenylglyoxylic hydrates in glacial acetic acid. Some of them exhibited reasonable or moderate anticancer activity toward human cancer cell lines, HCT-116, MCF-7 and HeLa. The structure of this novel heterocyclic ring system was confirmed by 1D-NMR and 2D-NMR spectroscopic data including COSY, ROESY and HMBC, elemental analyses and MS spectrometry.