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A series of novel 2-alkythio-4-chloro-N-[imino-(heteroaryl)methyl]benzenesulfonamide derivatives, 8–24, were synthesized in the reaction of the N-(benzenesulfonyl)cyanamide potassium salts 1–7 with the appropriate mercaptoheterocycles. All the synthesized compounds were evaluated for their anticancer activity in HeLa, HCT-116 and MCF-7 cell lines. The most promising compounds, 11–13, molecular hybrids containing benzenesulfonamide and imidazole moieties, selectively showed a high cytotoxic effect in HeLa cancer cells (IC50: 6–7 μM) and exhibited about three times less cytotoxicity against the non-tumor cell line HaCaT cells (IC50: 18–20 μM). It was found that the anti-proliferative effects of 11, 12 and 13 were associated with their ability to induce apoptosis in HeLa cells. The compounds increased the early apoptotic population of cells, elevated the percentage of cells in the sub-G1 phase of the cell cycle and induced apoptosis through caspase activation in HeLa cells. For the most active compounds, susceptibility to undergo first-phase oxidation reactions in human liver microsomes was assessed. The results of the in vitro metabolic stability experiments indicated values of the factor t½ for 11–13 in the range of 9.1–20.3 min and suggested the hypothetical oxidation of these compounds to sulfenic and subsequently sulfinic acids as metabolites.

In the search for new compounds with antitumor activity, new potential anticancer agents were designed as molecular hybrids containing the structures of a triazine ring and a sulfonamide fragment. Applying the synthesis in solution, a base of new sulfonamide derivatives

The untypical course of reaction between chalcones and benzenesulfonylaminoguanidines led to the new 3-(2-alkylthio-4-chloro-5-methylbenzenesulfonyl)-2-(1-phenyl-3-arylprop-2-enylideneamino)guanidine derivatives 8–33. The new compounds were tested in vitro for their impact on the growth of breast cancer cells MCF-7, cervical cancer cells HeLa and colon cancer cells HCT-116 by MTT assay. The results revealed that the activity of derivatives is strongly related to the presence of hydroxy group in the benzene ring at the 3-arylpropylidene fragment. The most cytotoxic compounds 20 and 24 displayed mean IC50 values of 12.8 and 12.7 μM, respectively, against three tested cell lines and were almost 3- and 4-fold more active toward MCF-7 and HCT-116 when compared with non-malignant HaCaT cells. Furthermore, compound 24 induced apoptosis in cancer cells and caused a decrease of mitochondrial membrane potential as well as an increase of cells in sub-G1 phase in contrast to its inactive analog 31. The strongest activity against the most sensitive HCT-116 cell line was found for compound 30 (IC50 = 8 μM), which was 11-fold more effective in the growth inhibition of HCT-116 cells than those of HaCaT cells. Based on this fact, the new derivatives may be promising leading structures for the search for agents for the treatment of colon cancer.

A series of novel 2-[(4-amino-6-R2-1,3,5-triazin-2-yl)methylthio]-4-chloro-5-methyl-N-(5-R1-1H-benzo[d]imidazol-2(3H)-ylidene)benzenesulfonamides 6&ndash, 49 was synthesized by the reaction of 5-substituted ethyl 2-{5-R1-2-[N-(5-chloro-1H-benzo[d]imidazol-2(3H)-ylidene)sulfamoyl]-4-methylphenylthio}acetate with appropriate biguanide hydrochlorides. The most active compounds, 22 and 46, showed significant cytotoxic activity and selectivity against colon (HCT-116), breast (MCF-7) and cervical cancer (HeLa) cell lines (IC50: 7&ndash, 11 &micro, M, 15&ndash, 24 &micro, M and 11&ndash, 18 &micro, M), respectively. Further QSAR (Quantitative Structure&ndash, Activity Relationships) studies on the cytotoxic activity of investigated compounds toward HCT-116, MCF-7 and HeLa were performed by using different topological (2D) and conformational (3D) molecular descriptors based on the stepwise multiple linear regression technique (MLR). The QSAR studies allowed us to make three statistically significant and predictive models for them. Moreover, the molecular docking studies were carried out to evaluate the possible binding mode of the most active compounds, 22 and 46, within the active site of the MDM2 protein.

A series of novel 2-[(4-amino-6-R2-1,3,5-triazin-2-yl)methylthio]-4-chloro-5-methyl-N-(5-R1-1H-benzo[d]imidazol-2(3H)-ylidene)benzenesulfonamides 6–49 was synthesized by the reaction of 5-substituted ethyl 2-{5-R1-2-[N-(5-chloro-1H-benzo[d]imidazol-2(3H)-ylidene)sulfamoyl]-4-methylphenylthio}acetate with appropriate biguanide hydrochlorides. The most active compounds, 22 and 46, showed significant cytotoxic activity and selectivity against colon (HCT-116), breast (MCF-7) and cervical cancer (HeLa) cell lines (IC50: 7–11 µM; 15–24 µM and 11–18 µM), respectively. Further QSAR (Quantitative Structure–Activity Relationships) studies on the cytotoxic activity of investigated compounds toward HCT-116, MCF-7 and HeLa were performed by using different topological (2D) and conformational (3D) molecular descriptors based on the stepwise multiple linear regression technique (MLR). The QSAR studies allowed us to make three statistically significant and predictive models for them. Moreover, the molecular docking studies were carried out to evaluate the possible binding mode of the most active compounds, 22 and 46, within the active site of the MDM2 protein.

To learn more about the structure&ndash, activity relationships of (E)-3-(5-styryl-1,3,4-oxadiazol-2-yl)benzenesulfonamide derivatives, which in our previous research displayed promising in vitro anticancer activity, we have synthesized a group of novel (E)-5-[(5-(2-arylvinyl)-1,3,4-oxadiazol-2-yl)]-4-chloro-2-R1-benzenesulfonamides 7-36 as well as (E)-4-[5-styryl1,3,4-oxadiazol-2-yl]benzenesulfonamides 47-50 and (E)-2-(2,4-dichlorophenyl)-5-(2-arylvinyl)-1,3,4-oxadiazols 51-55. All target derivatives were evaluated for their anticancer activity on HeLa, HCT-116, and MCF-7 human tumor cell lines. The obtained results were analyzed in order to explain the influence of a structure of the 2-aryl-vinyl substituent and benzenesulfonamide scaffold on the anti-tumor activity. Compound 31, bearing 5-nitrothiophene moiety, exhibited the most potent anticancer activity against the HCT-116, MCF-7, and HeLa cell lines, with IC50 values of 0.5, 4, and 4.5 &micro, M, respectively. Analysis of structure-activity relationship showed significant differences in activity depending on the substituent in position 3 of the benzenesulfonamide ring and indicated as the optimal meta position of the sulfonamide moiety relative to the oxadizole ring. In the next stage, chemometric analysis was performed basing on a set of computed molecular descriptors. Hierarchical cluster analysis was used to examine the internal structure of the obtained data and the quantitative structure&ndash, activity relationship (QSAR) analysis with multiple linear regression (MLR) method allowed for finding statistically significant models for predicting activity towards all three cancer cell lines.

The maize area in Poland, growing year by year, creates ideal conditions for the development of many pests. The most dangerous of them is the western corn rootworm Diabrotica virgifera Le Conte, which due to the specific way of feeding, causes very large crop losses. Until February 6, 2014, the pest had the status of a quarantine and invasive organism throughout the European Union, including Poland. The pest threat assessment was carried out in the years 2012-2013 in the area of two localities: Zopowa and Lubotyń (commune of Głubczyce and Kietrz), and then they were compared with monitoring research conducted by the State Plant Health and Seed Inspection in Głubczyce. The obtained results show, that the maize growing system had a significant impact on the occurrence of the pest. It has been found, that Diabrotica virgifera spreads faster in monoculture.

A new series of 2-alkylthio-N-(quinazolin-2-yl)benzenesulfonamide derivatives have been synthesized and evaluated in vitro for their antiproliferative activity by MTT assay against cancer cell lines HCT-116, MCF-7, and HeLa as well as the NCI-60 human tumor cell lines screen. In NCI screen, three compounds inhibited approximately 50% growth of RPMI-8226 and A549/ATCC cell lines. The mean of IC50 calculated in MTT assays for three tested cell lines was about 45 μM for four compounds. The QSAR allowed finding statistically significant OPLS models for HeLa cell line. Metabolic stability in vitro studies indicated favorable and unfavorable structural elements. The good metabolic stability, with t1/2 higher than 40 min, was observed for three derivatives, which together with their antiproliferative activity and good ADMET profile, makes them good leading structures for further research.

A bstract A series of new N'-(2-alkylthio-4-chloro-5-methylbenzenesulfonyl)-1-(5-phenyl-1H-pyrazol-1-yl)amidine derivatives have been synthesized and evaluated in vitro by MTT assays for their antiproliferative activity against cell lines of colon cancer HCT-116, cervical cancer HeLa and breast cancer MCF-7. The studied compounds display selective activity mainly against HCT-116 and HeLa cells. Thus, five compounds show selective cytotoxic effect against HCT-116 (IC50 = 3–10 μM) and HeLa (IC50 = 7 μM). Importantly, the noticed values of IC50 for four compounds are almost 4-fold lower for HeLa than non-malignant HaCaT cells. More-in-depth biological research revealed that the treatment of HCT-116 and HeLa with active compound resulted in increased numbers of cells in sub-G1 phase in a time dependent manner, while non-active derivative does not influence cell cycle. Metabolic stability assays using liver microsomes and NADPH provide important information on compounds susceptibility to phase 1 biotransformation reactions.

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.

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.

Rising resistance of pathogenic bacteria reduces the options of treating hospital and non-hospital bacterial infections. There is a need to search for newer chemotherapies that will show antimicrobial ability against planktonic cells as well as bacterial biofilms. We have synthesized a series of N-(2-arylmethylthio-4-chloro-5-methylbenzenesulfonyl)amides, namely, molecular hybrids, which include a 2-mercaptobenzenosulfonamide fragment and either cinnamic or cyclohexylpropionic acid residues. The antimicrobial activity of compounds 8‒17 was evaluated on Gram-positive, Gram-negative bacteria and fungal species. Experiments took into account investigation of antibacterial activity against planktonic cells as well as biofilms. Compounds 8‒17 showed high bacteriostatic activity against staphylococci, with the most active molecules 10 and 16 presenting low MIC values of 4&ndash, 8 &mu, g/mL against reference methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-sensitive S. aureus (MSSA) strains as well as clinical isolates. Compounds 10 and 16 also showed an ability to inhibit biofilms formed by MRSA and MSSA. The potential of 10 and 16 as antibiofilm agents was supported by cytotoxicity assays that indicated no cytotoxic effect either on normal cells of human keratinocytes or on human cancer cells, including cervical, colon, and breast cancer lines.

A new series of N-(aryl/heteroaryl)-2-chlorobenzenesulfonamide derivatives 4-21 have been synthesized, and evaluated at the National Cancer Institute (USA) for their in vitro activities against a panel of 60 different human cancer cell lines. Among them, compounds 16, 20 and 21 exhibited remarkable cytotoxic activity against numerous human cancer cell lines. We found that sulfonamide derivative 21 appeared to be more selective than compounds 16 and 20. In comparison to compounds 16 and 20 it showed higher cytotoxic activity against A549 non-small cell lung adenocarcinoma and HCT-116 colon carcinoma cells and was less toxic to HEK-293 human embryonic kidney cells and HaCaT immortalized human keratinocytes. Treatment of A549 and HCT-116 cells with compound 21 resulted in the G0/G1-cell cycle arrest with a concomitant increase in p53 and p21 protein levels. Moreover, compound 21 led to ATP depletion and disruption of the mitochondrial membrane potential in both studied cell lines. Our results suggest that 2,4-dichloro-N-(quinolin-8-yl and/or 1H-indazol-7-yl)benzenesulfonamides serve as novel promising anticancer agents.

Recent preclinical studies point to muscarinic and GABAB receptors as novel therapeutic targets for the treatment of schizophrenia. This study was aimed to assess the role of muscarinic and GABAB receptor interactions in animal models of schizophrenia, using positive allosteric modulators (PAMs) of GABAB receptor (GS39783), muscarinic M4 (VU0152100) and M5 (VU0238429) receptor, and partial allosteric agonist of M1 receptor (VU0357017). DOI-induced head twitches, social interaction and novel object recognition tests were used as the models of schizophrenia. Analyses of DOI-induced increases in sEPSCs (spontaneous excitatory postsynaptic currents) were performed as complementary experiments to the DOI-induced head twitch studies. Haloperidol-induced catalepsy and the rotarod test were used to examine the adverse effects of the drugs. All three activators of muscarinic receptors were active in DOI-induced head twitches. When administered together with GS39783 in subeffective doses, only the co-administration of VU0152100 and GS39783 was effective. The combination also reduced the frequency but not the amplitude of DOI-induced sEPSCs. Neither VU0357017 nor VU0238429 were active in social interaction test when given alone, and also the combination of VU0152100 and GS39783 failed to reverse MK-801-induced deficits observed in this test. All muscarinic activators when administered alone or in combination with GS39783 reversed the MK-801-induced disruption of memory in the novel object recognition test, and their actions were blocked by specific antagonists. None of the tested compounds or their combinations influenced the motor coordination of the animals. The compounds had no effect on haloperidol-induced catalepsy and did not induce catalepsy when administered alone. Pharmacokinetic analysis confirmed lack of possible drug-drug interactions after combined administration of GS39783 with VU0357017 or VU0152100; however, when the drug was co-administered with VU0238429 its ability to pass the blood-brain barrier slightly decreased, suggesting potential drug-drug interactions. Our data show that modulation of cholinergic and GABAergic systems can potentially be beneficial in the treatment of the positive and cognitive symptoms of schizophrenia without inducing the adverse effects typical for presently used antipsychotics.

A series of N-(aryl/heteroaryl)-4-(1H-pyrrol-1-yl)benzenesulfonamides were synthesized from 4-amino-N-(aryl/heteroaryl)benzenesulfonamides and 2,5-dimethoxytetrahydrofuran. All the synthesized compounds were evaluated for their anticancer activity on HeLa, HCT-116, and MCF-7 human tumor cell lines. Compound 28, bearing 8-quinolinyl moiety, exhibited the most potent anticancer activity against the HCT-116, MCF-7, and HeLa cell lines, with IC50 values of 3, 5, and 7 µM, respectively. The apoptotic potential of the most active compound (28) was analyzed through various assays: phosphatidylserine translocation, cell cycle distribution, and caspase activation. Compound 28 promoted cell cycle arrest in G2/M phase in cancer cells, induced caspase activity, and increased the population of apoptotic cells. Relationships between structure and biological activity were determined by the QSAR (quantitative structure activity relationships) method. Analysis of quantitative structure activity relationships allowed us to generate OPLS (Orthogonal Projections to Latent Structure) models with verified predictive ability that point out key molecular descriptors influencing benzenosulfonamide’s activity.

A series of N-(aryl/heteroaryl)-4-(1H-pyrrol-1-yl)benzenesulfonamides were synthesized from 4-amino-N-(aryl/heteroaryl)benzenesulfonamides and 2,5-dimethoxytetrahydrofuran. All the synthesized compounds were evaluated for their anticancer activity on HeLa, HCT-116, and MCF-7 human tumor cell lines. Compound 28, bearing 8-quinolinyl moiety, exhibited the most potent anticancer activity against the HCT-116, MCF-7, and HeLa cell lines, with IC50 values of 3, 5, and 7 µM, respectively. The apoptotic potential of the most active compound (28) was analyzed through various assays: phosphatidylserine translocation, cell cycle distribution, and caspase activation. Compound 28 promoted cell cycle arrest in G2/M phase in cancer cells, induced caspase activity, and increased the population of apoptotic cells. Relationships between structure and biological activity were determined by the QSAR (quantitative structure activity relationships) method. Analysis of quantitative structure activity relationships allowed us to generate OPLS (Orthogonal Projections to Latent Structure) models with verified predictive ability that point out key molecular descriptors influencing benzenosulfonamide’s activity.

Recent preclinical studies point to muscarinic and GABA

A new series of 2-alkylthio

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 novel 2-(2-arylmethylthio-4-chloro-5-methylbenzenesulfonyl)-1-(6-substituted-4-chloro-1,3,5-triazin-2-ylamino)guanidine derivatives 9–20 have been synthesized by substitution of chlorine atom at the 1,3,5-triazine ring in compounds 5–8 with 3- or 4-aminobenzenesulfonamide and 4-(aminomethyl)benzenesulfonamide hydrochloride. All the synthesized compounds were evaluated for their inhibitory activity toward hCA I, II, IX and XII as well as anticancer activity against HeLa, HCT-116 and MCF-7 human tumor cell lines. The investigated compounds showed weak inhibitory potency against the human CA I, while activity toward hCA II was differentiated and depended on structure of inhibitor (KI: 5.4–933.1 nM). Compounds containing the 4-sulfamoylphenyl moiety (9–12) exhibited the strongest inhibitory activity against hCA IX with KI values from 37.1 to 42.9 nM, as well as against hCA XII in range of 31–91.9 nM. The most promising compound 12 (KI = 41 nM) showed the highest selectivity toward hCA IX versus hCA I (hCA I/hCA IX = 18) and hCA II (hCA II/hCA IX = 4). Compound 12 displayed prominent cytotoxic effect selectively toward HeLa cancer cells (IC50 = 17 μM) and did not exhibit toxicity to the non-cancerous HaCaT cells. In silico analysis suggested that despite the lack of a single binding pose, the selective affinity is conferred by specific interactions with an arginine moiety, as well as better-defined binding modes within the active site.

The depletion of the conventional energy sources, as well as the degradation and pollution of the environment by the exploitation of fossil fuels caused the development of renewable energy sources (RES), including biomass. In Poland, biomass is the most popular renewable energy source, which is closely related to the obligations associated with the membership in the EU. Biomass is the oldest renewable energy source, and its potential, diversity and polymorphism place it over other sources. Besides, the improvement in its parameters, including an increase in its calorific value, resulted in increasing use of biomass as energy source. In the electric power industry biomass is applied in the process of co-combustion with coal. This process may contribute, inter alia, to the reduction in the emissions of carbon, nitrogen and sulfur oxides. The article presents the characteristics of the biomass burned in power boilers of one of the largest Polish power plants, located in Opole Province (Southern Poland). Besides, the impact of biomass on the installation of co-combustion, as well as the advantages and disadvantages of the co-combustion process not only in technological, but also environmental, economic and social aspects were described.

Sulfonylureas have been commonly used since the 1950s as antihypoglycemic (e.g., tolbutamide, glipizide, glimepiride) and diuretics drugs (torasemide). Preclinical studies towards antineoplastic activity of sulfonyloureas led to recognize among them a group of diarylsulfonylureas (DSU) (e.g. LY-181984, Sulofenur and LY‑295501) with activity against a broad spectrum of syngeneic rodent solid tumors and human tumor xenografts [1]. Continuing our previous studies, in which we have shown a significant potential for antitumor activity of 1-(4-substituted pyridine-3-sulfonyl)-3-phenylureas [2], we have undertaken the synthesis and evaluation of cytostatic activity of novel series of N-{[4-(1,2,3-triazol)pyridin-3-yl]sulfonyl}urea derivatives. To provide easy functionalization of substituent at the position 4 of the pyridinesulfonamide scaffold, which have a significant influence on the antitumor activity [2.3], we started from 4-(2-propyn-1-ylthio/amino)pyridine-3-sulfonamides and, using the copper-catalyzed azide-alkyne cycloaddition (CuAAC), introduced 1,4-disubstituted 1,2,3-triazole ring. The primary sulfonamides thus obtained were next treated with various isocyanates to give a series of desired sulfonylurea derivatives. The structures of all compounds were confirmed with IR and NMR spectroscopy and elemental analyses. All compounds were submitted to test their effects on growth of human cancer cell lines: colon cancer HCT-116, breast cancer MCF-7 and cervical cancer HeLa. Cell viability was measured using MTT assay after 72 h of incubation with tested compound in concentration 1 – 100 μM. References: Pasello G, et al. Oncologist 2013; 18: 1118–1125. Szafranski K, Slawinski J. Molecules. 2015; 20; 12029–12044. Slawinski J, et al. Eur J Med Chem. 2013;69:701–10.

Benzenesulfonylguanidine derivatives have been known to inhibit growth of different types of human cancer cell lines. According to this fact, new compounds with structures based on benzenesulfonylguanidine scaffold and modified by important pharmacophores such as morpholine, 4-methylpiperazine or piperidine, have been designed and synthesized. The planned N-(2-mercaptobenzenesulfonyl)guanidine derivatives have been obtained by reaction of the appropriate N-(2-mercaptobenzenesulfonyl)cyanamide potassium salt with 1-aminopiperidine, 4-aminomorpholine or 1-amino-4-methylpiperazine; p-toluenesulfonic acid has been used as a protonating agent. The obtained compounds have been evaluated in MTT assay for an antiproliferative activity against human cancer cell lines HCT-116 (colon carcinoma), MCF-7 (breast cancer) and HeLa (cervical cancer). The results indicated that compounds containing the 4-methylpiperazine ring were the most potent growth inhibitors. The obtained IC50 values for these derivatives were lower than 35 μM against all tested cancer cell lines, with the best activity at level of IC50 ≤ 15 μM for compound with a methyl group at the position 5, and a (2-fluorophenyl)methylthio group at the position 2 of benzenesulfonyl scaffold. Moderate antiproliferative effect (IC50 ~ 40 μM) was observed for derivatives containing a piperidine residue. Compounds with a morpholine fragment, in contrast, did not show significant growth inhibition.

A series of new 2-(2-alkylthiobenzenesulfonyl)-3-(phenylprop-2-ynylideneamino)guanidine derivatives have been synthesized and evaluated in vitro by MTT assays for their antiproliferative activity against cell lines of colon cancer HCT-116, cervical cancer HeLa and breast cancer MCF-7. The obtained results indicated that these compounds display prominent cytotoxic effect. The best anticancer properties have been observed for derivatives 44 (IC 50 = 6–18 μM) and 45 (IC 50 = 8–14 μM). Very good results of antiproliferative assays have been also shown for compounds 26 , 36 , and 46 and noticeable anticancer profile has been found for set of derivatives 34 – 39 . Based on results of MTT assays the structure-activity relationships have been drawn. More in-depth biological research revealed that compounds 26 , 33 , 37 , 39 , 41 and 43 display cytotoxic effect only against cancer cells and do not inhibit the growth of non-malignant HaCaT cells. Furthermore, the novel series of derivatives have shown good metabolic stability, especially among the pharmacologically active compounds. To obtain a deeper insight into the molecular description of compounds activity the QSAR studies have been applied. Support vector machines (SVM) have been used to developed QSAR models for predicting the anti-proliferative activity of novel derivatives. The obtained SVM models have shown prognostic ability for HCT-116 and HeLa cell lines and as a result these models may be useful for further development of structurally similar derivatives with better biological properties.