Changes in the Sensitivity of MCF-7 and MCF-7/DX Breast Cancer Cells to Cytostatic in the Presence of Metformin.

Multidrug resistance is a serious problem in modern medicine and the reason for the failure of various therapies. A particularly important problem is the occurrence of multidrug resistance in cancer therapies which affects many cancer patients. Observations on the effect of metformin-a well-known hypoglycemic drug used in the treatment of type 2 diabetes-on cancer cells indicate the possibility of an interaction of this substance with drugs already used and, as a result, an increase in the sensitivity of cancer cells to cytostatics. The aim of this study was to evaluate the effect of metformin on the occurrence of multidrug resistance of breast cancer cells. The MCF-7-sensitive cell line and the MCF-7/DX cytostatic-resistant cell line were used for this study. WST-1 and LDH assays were used to evaluate the effects of metformin and doxorubicin on cell proliferation and viability. The effect of metformin on increasing the sensitivity of MCF-7 and MCF-7/DX cells to doxorubicin was evaluated in an MDR test. The participation of metformin in increasing the sensitivity of resistant cells to the effect of the cytostatic (doxorubicin) has been demonstrated.

Synthesis, Docking, and Machine Learning Studies of Some Novel Quinolinesulfonamides-Triazole Hybrids with Anticancer Activity.

In the presented work, a series of 22 hybrids of 8-quinolinesulfonamide and 1,4-disubstituted triazole with antiproliferative activity were designed and synthesised. The title compounds were designed using molecular modelling techniques. For this purpose, machine-learning, molecular docking, and molecular dynamics methods were used. Calculations of the pharmacokinetic parameters (connected with absorption, distribution, metabolism, excretion, and toxicity) of the hybrids were also performed. The new compounds were synthesised via a copper-catalysed azide-alkyne cycloaddition reaction (CuAAC). 8-N-Methyl-N-{[1-(7-chloroquinolin-4-yl)-1H-1,2,3-triazol-4-yl]methyl}quinolinesulfonamide was identified in in silico studies as a potential strong inhibitor of Rho-associated protein kinase and as a compound that has an appropriate pharmacokinetic profile. The results obtained from in vitro experiments confirm the cytotoxicity of derivative 9b in four selected cancer cell lines and the lack of cytotoxicity of this derivative towards normal cells. The results obtained from silico and in vitro experiments indicate that the introduction of another quinolinyl fragment into the inhibitor molecule may have a significant impact on increasing the level of cytotoxicity toward cancer cells and indicate a further direction for future research in order to find new substances suitable for clinical applications in cancer treatment.

Towards Anticancer and Antibacterial Agents: Design and Synthesis of 1,2,3-Triazol-quinobenzothiazine Derivatives.

In this paper, we describe a new method for synthesizing hybrid combinations of 1,2,3-triazoles with a tetracyclic quinobenzothiazinium system. The developed approach allowed for the production of a series of new azaphenothiazine derivatives with the 1,2,3-triazole system in different positions of the benzene ring. In practice, the methodology consists of the reaction of triazole aniline derivatives with thioquinanthrenediinium bis-chloride. The structure of the products was determined by 1H-NMR, 13C-NMR spectroscopy, and HR-MS spectrometry, respectively. Moreover, the spatial structure of the molecule and the arrangement of molecules in the crystal (unit cell) were determined by X-ray crystallography. The anticancer activity profiles of the synthesized compounds were tested in vitro against human cancer cells of the A549, SNB-19, and T47D lines and the normal NHDF cell line. Additional tests of antibacterial activity against methicillin-sensitive and methicillin-resistant staphylococci, vancomycin-sensitive and vancomycin-resistant enterococci, and two mycobacterial strains were also performed. In fact, the dependence of anticancer and antibacterial activity on the substituent type and its position in the quinobenzothiazinium system was observed. Furthermore, the distance-guided property evaluation was performed using principal component analysis (PCA) and hierarchical clustering analysis (HCA) on the pool of the calculated descriptors. Finally, the theoretically approximated partition coefficients (clogP) were (inter-)correlated with each other and cross-compared with the empirically specified logPTLC parameters.

Design, Synthesis and Biological Evaluation of Quinoline-8-Sulfonamides as Inhibitors of the Tumor Cell-Specific M2 Isoform of Pyruvate Kinase: Preliminary Study.

Cancer cells need to carefully regulate their metabolism to keep them growing and dividing under the influence of different nutrients and oxygen levels. Muscle isoform 2 of pyruvate kinase (PKM2) is a key glycolytic enzyme involved in the generation of ATP and is critical for cancer metabolism. PKM2 is expressed in many human tumors and is regulated by complex mechanisms that promote tumor growth and proliferation. Therefore, it is considered an attractive therapeutic target for modulating tumor metabolism. Various modulators regulate PKM2, shifting it between highly active and less active states. In the presented work, a series of 8-quinolinesulfonamide derivatives of PKM2 modulators were designed using molecular docking and molecular dynamics techniques. New compounds were synthesized using the copper-catalyzed azide-alkyne cycloaddition (CuAAC) reaction. Compound 9a was identified in in silico studies as a potent modulator of muscle isoform 2 of pyruvate kinase. The results obtained from in vitro experiments confirmed the ability of compound 9a to reduce the intracellular pyruvate level in A549 lung cancer cells with simultaneous impact on cancer cell viability and cell-cycle phase distribution. Moreover, compound 9a exhibited more cytotoxicity on cancer cells than normal cells, pointing to high selectivity in the mode of action. These findings indicate that the introduction of another quinolinyl fragment to the modulator molecule may have a significant impact on pyruvate levels in cancer cells and provides further directions for future research to find novel analogs suitable for clinical applications in cancer treatment.

Design, Synthesis and Antimicrobial Properties of New Tetracyclic Quinobenzothiazine Derivatives.

A new method for modifying the structure of tetracyclic quinobenzothiazinium derivatives has been developed, allowing introduction of various substituents at different positions of the benzene ring. The method consists of reacting appropriate aniline derivatives with 5,12-(dimethyl)thioquinantrenediinium bis-chloride. A series of new quinobenzothiazine derivatives was obtained with propyl, allyl, propargyl and benzyl substituents in 9, 10 and 11 positions, respectively. The structure of the obtained compounds was analyzed by 1H and 13C NMR (HSQC, HMBC) and X-ray analysis. All the compounds were tested against reference strains Staphylococcus aureus ATCC 29213 and Enterococcus faecalis ATCC 29212, and representatives of multidrug-resistant clinical isolates of methicillin-resistant S. aureus (MRSA) and vancomycin-resistant E. faecalis (VRE). In addition, all the compounds were evaluated in vitro against Mycobacterium smegmatis ATCC 700084 and M. marinum CAMP 5644. 9-Benzyloxy-5-methyl-12H-quino [3,4-b][1,4]benzothiazinium chloride (6j), 9-propoxy-5-methyl-12H-quino[3,4-b][1,4]benzothiazinium chloride (6a) and 9-allyloxy-5-methyl-12H-quino[3,4-b][1,4]benzothiazinium chloride (6d) demonstrated high activity against the entire tested microbial spectrum. The activities of the compounds were comparable with oxacillin, tetracycline and ciprofloxacinagainst staphylococcal strains and with rifampicin against both mycobacterial strains. Compound 6j had a significant effect on the inhibition of bacterial respiration as demonstrated by the MTT assay. The compounds showed not only bacteriostatic activity, but also bactericidal activity. Preliminary in vitro cytotoxicity screening of the compounds performed using normal human dermal fibroblasts (NHDF) proved that the tested compounds showed an insignificant cytotoxic effect on human cells (IC50 > 37 µM), making these compounds interesting for further investigation. Moreover, the intermolecular similarity of novel compounds was analyzed in the multidimensional space (mDS) of the structure/property-related in silico descriptors by means of principal component analysis (PCA) and hierarchical clustering analysis (HCA), respectively. The distance-oriented structure/property distribution was related with the experimental lipophilic data.

Hybrids of 1,4-Quinone with Quinoline Derivatives: Synthesis, Biological Activity, and Molecular Docking with DT-Diaphorase (NQO1).

Hybrids 1,4-quinone with quinoline were obtained by connecting two active structures through an oxygen atom. This strategy allows to obtain new compounds with a high biological activity and suitable bioavailability. Newly synthesized compounds were characterized by various spectroscopic methods. The enzymatic assay used showed that these compounds were a suitable DT-diaphorase (NQO1) substrates as evidenced by increasing enzymatic conversion rates relative to that of streptonigrin. Hybrids were tested in vitro against a panel of human cell lines including melanoma, breast, and lung cancers. They showed also a high cytotoxic activity depending on the type of 1,4-quinone moiety and the applied tumor cell lines. It was found that cytotoxic activity of the studied hybrids was increasing against the cell lines with higher NQO1 protein level, such as breast (MCF-7 and T47D) and lung (A549) cancers. Selected hybrids were tested for the transcriptional activity of the gene encoding a proliferation marker (H3 histone), cell cycle regulators (p53 and p21) and the apoptosis pathway (BCL-2 and BAX). The molecular docking was used to examine the probable interaction between the hybrids and NQO1 protein.

[Anti-cancer properties of dichloroacetate]. / Przeciwnowotworowe wlasciwosci dichlorooctanu.

One of the hallmarks of cancer cells is aerobic glycolysis (the Warburg effect). The effect of dichloroacetate (DCA) is to switch glucose metabolism (cellular respiration) to a more efficient process involving oxygen, reduce the production of lactic acid, activate the respiratory chain, change the potential of the mitochondrial membrane, and release pro-apoptotic mediators (cytochrome c and AIF) into the cytosol. As a result, the control over the mutated cells is improved, their sensitivity to various drugs or radiotherapy and their sensitivity to apoptosis increase. In the study the review of data on the mechanism of action of DCA on neoplastic cells was performed to indicate the side effects associated with the possible introduction of this compound to cancer therapy.

[A multidirectional effect of metformin]. / Molekularne podstawy wielokierunkowego dzialania metforminy.

Diabetes as chronic civilization disease, very often occurs together with health disorders. One of the basic pharmaceuticals commonly used in her therapy is metformin. Many other positive effects, not related to diabetes, have been observed in tatients treated with metformin for a long time. These are: positive changes in diagnostiic parameters, protection against cancer development, less frequent occurrence of other pathologies and diseases, increased sensitivity to selected drugs (e.g. cytostatics), delayed aging processes of organism. In addition to the molecular changes resulting in a hypoglycemic effect, the most common modifications of gene expression have been described, indicated as the basis for the anti-aging, anti-atherosclerotic and anticancer effects of this drug and its effect on melanogenesis or the nervous system. The results presented in the study are very promising, but most of them relate to experiments carried out in cell cultures or animals. The possibility of obtaining similar effects in humans requires much more research.

Towards Property Profiling: SYNTHESIS and SAR Probing of New Tetracyclic Diazaphenothiazine Analogues.

A series of new tertiary phenothiazine derivatives containing a quinoline and a pyridine fragment was synthesized by the reaction of 1-methyl-3-benzoylthio-4-butylthioquinolinium chloride with 3-aminopyridine derivatives bearing various substituents on the pyridine ring. The direction and mechanism of the cyclization reaction of intermediates with the structure of 1-methyl-4-(3-pyridyl)aminoquinolinium-3-thiolate was related to the substituents in the 2- and 4-pyridine position. The structures of the compounds were analyzed using 1H, 13C NMR (COSY, HSQC, HMBC) and X-ray analysis, respectively. Moreover, the antiproliferative activity against tumor cells (A549, T47D, SNB-19) and a normal cell line (NHDF) was tested. The antibacterial screening of all the compounds was conducted against the reference and quality control strain Staphylococcus aureus ATCC 29213, three clinical isolates of methicillin-resistant S. aureus (MRSA). In silico computation of the intermolecular similarity was performed using principal component analysis (PCA) and hierarchical clustering analysis (HCA) on the pool of structure/property-related descriptors calculated for the novel tetracyclic diazaphenothiazine derivatives. The distance-oriented property evaluation was correlated with the experimental anticancer activities and empirical lipophilicity as well. The quantitative shape-based comparison was conducted using the CoMSA method in order to indicate the potentially valid steric, electronic and lipophilic properties. Finally, the numerical sampling of similarity-related activity landscape (SALI) provided a subtle picture of the SAR trends.

Molecular Structure, In Vitro Anticancer Study and Molecular Docking of New Phosphate Derivatives of Betulin.

A series of 30-diethylphosphate derivatives of betulin were synthesized and evaluated for their in vitro cytotoxic activity against human cancer cell lines, such as amelanotic melanoma (C-32), glioblastoma (SNB-19), and two lines of breast cancer (T47D, MDA-MB-231). The molecular structure and activities of the new compounds were also compared with their 29-phosphonate analogs. Compounds 7a and 7b showed the highest activity against C-32 and SNB-19 cell lines. The IC50 values for 7a were 2.15 and 0.91 µM, and, for 7b, they were 0.76 and 0.8 µM for the C-32 and SNB-19 lines, respectively. The most potent compounds, 7a and 7b, were tested for their effects on markers of apoptosis, such as H3, TP53, BAX, and BCL-2. For the whole series of phosphate derivatives, a lipophilicity study was performed, and the ADME parameters were calculated. The most active products were docked to the active site of the EGFR protein. The relative binding affinity of selected phosphate betulin derivatives toward EGFR was compared with standard erlotinib on the basis of ChemScore and KDEEP score. Positively, all derivatives docked inside the cavity and showed significant interactions. Moreover, a molecular dynamics study also reveals that ligands 7a,b form stable complexes and the plateau phase started after 7 ns.

Design, synthesis and biological activity of 1,4-quinone moiety attached to betulin derivatives as potent DT-diaphorase substrate.

In this research, betulin derivatives were bonded to the 1,4-quinone fragment by triazole linker. Furthermore, the enzymatic assay used has shown that these compounds are a good DT-diaphorase (NQO1) substrates as evidenced by increasing enzymatic conversion rates relative to that of streptonigrin. The anticancer activities of the hybrids were tested against a panel of human cell lines, like: melanoma, ovarian, breast, colon, and lung cancers. The structure-activity relationship showed that the activity depends on the type of 1,4-quinone moiety and the tumor cell lines used. It was also found that the anticancer effects were increasing against the cell line with higher NQO1 protein level, like: breast (T47D, MCF-7), colon (Caco-2), and lung (A549) cancers. The transcriptional activity of the gene encoding a proliferation marker (H3 histone), cell cycle regulators (p53 and p21) and apoptosis pathway (BCL-2 and BAX) for selected compounds were determined. The molecular docking study was carried out to examine the interaction between the hybrids and NQO1 enzyme. The computational simulation showed that the type of the 1,4-quinone moiety influences location of the compound in the active site of the enzyme. It is worth noting that the study of new hybrids of betulin as substrate for NQO1 protein may lead to new medical therapeutic applications in the future.

Structural and spectral characterisation of 2-amino-2H-[1,2,3]triazolo[4,5-g]quinoline-4,9-dione polymorphs. Cytotoxic activity and molecular docking study with NQO1 enzyme.

Depending on temperature, the 2-amino-2H-[1,2,3]triazolo[4,5-g]quinoline-4,9-dione forms two polymorphic structures, which differ in the spatial arrangement of the amine group. Both polymorphs were investigated using different experimental methods as well as various quantum chemical calculations in order to characterise their molecular structures. We used X-ray diffraction, FT-IR and NMR (solid-state and liquid) methods supplemented by the density functional theory (DFT) calculations, molecular electrostatic potential (MEP) and molecular orbital (HOMO, LUMO) analyses. It was found that the arrangement of the amine group affected the crystal structure, formation of H-bonds, the amine and carbonyl vibration bands in the FT-IR spectra, chemical shift of amine group in 15N CP/MAS NMR and chemical shift of amine protons in 1H NMR spectra. Both polymorphs were tested on anticancer activity against a panel of human cancer cell lines. Comparing the activity of both compounds showed that activity against MCF-7, MDA-MB-231 and Caco-2 lines depend on the arrangement of the amine group. Moreover, both polymorphs exhibited the highest activity against cell line with high NQO1 protein level, such as: A549, MCF-7 and Caco-2. The molecular docking was used to examine the probable interaction between the ligand of the tested polymorphs and the NQO1 enzyme. The analysis showed that ligands formed a hydrophobic interaction with tryptophan (Trp105), phenylalanine (Phe126 and Phe178) and tyrosine (Tyr 126).

Design, Synthesis, and Structural Characterization of Novel Diazaphenothiazines with 1,2,3-Triazole Substituents as Promising Antiproliferative Agents.

A series of novel 1,2,3-triazole-diazphenothiazine hybrids was designed, synthesized, and evaluated for anticancer activity against four selected human tumor cell lines (SNB-19, Caco-2, A549, and MDA-MB231). The majority of the synthesized compounds exhibited significant potent activity against the investigated cell lines. Among them, compounds 1d and 4c showed excellent broad spectrum anticancer activity, with IC50 values ranging from 0.25 to 4.66 µM and 0.25 to 6.25 µM, respectively. The most promising compound 1d, possessing low cytotoxicity against normal human fibroblasts NHFF, was used for gene expression analysis using reverse transcription-quantitative real-time PCR (RT-qPCR). The expression of H3, TP53, CDKN1A, BCL-2, and BAX genes revealed that these compounds inhibited the proliferation in all cells (H3) and activated mitochondrial events of apoptosis (BAX/BCL-2).

10H-1,9-diazaphenothiazine and its 10-derivatives: synthesis, characterisation and biological evaluation as potential anticancer agents.

10H-1,9-diazaphenothiazine was obtained in the sulphurisation reaction of diphenylamine with elemental sulphur and transformed into new 10-substituted derivatives, containing alkyl and dialkylaminoalkyl groups at the thiazine nitrogen atom. The 1,9-diazaphenothiazine ring system was identified with advanced 1H and 13C NMR techniques (COSY, NOESY, HSQC and HMBC) and confirmed by X-ray diffraction analysis of the methyl derivative. The compounds exhibited significant anticancer activities against the human glioblastoma SNB-19, melanoma C-32 and breast cancer MDA-MB-231 cell lines. The most active 1,9-diazaphenothiazines were the derivatives with the propynyl and N, N-diethylaminoethyl groups being more potent than cisplatin. For those two compounds, the expression of H3, TP53, CDKN1A, BCL-2 and BAX genes was detected by the RT-QPCR method. The proteome profiling study showed the most probable compound action on SNB-19 cells through the intrinsic mitochondrial pathway of apoptosis. The 1,9-diazaphenotiazine system seems to be more potent than known isomeric ones (1,6-diaza-, 1,8-diaza-, 2,7-diaza- and 3,6-diazaphenothiazine).

Betulin-1,4-quinone hybrids: Synthesis, anticancer activity and molecular docking study with NQO1 enzyme.

Betulin-1,4-quinone hybrids were obtain by connecting two active structures with a linker. This strategy allows for obtaining compounds showing a high biological activity and better bioavailability. In this research, synthesis, anticancer activity and molecular docking study of betulin-1,4-quinone hybrids are presented. Newly synthesized compounds were characterized by 1H, 13C NMR, IR and HR-MS. Hybrids were tested in vitro against a panel of human cell lines including glioblastoma, melanoma, breast and lung cancer. They showed a high cytotoxic activity depending on the type of 1,4-quinone moiety and the applied tumor cell lines. It was found that cytotoxic activities of the studied hybrids were increasing against the cell line with higher NQO1 protein level, like melanoma (C-32), breast (MCF-7) and lung (A-549) cancer. Selected hybrids were tested on the transcriptional activity of the gene encoding a proliferation marker (H3 histone), a cell cycle regulators (p53 and p21) and an apoptosis pathway (BCL-2 and BAX). The obtained results suggested that the tested compounds caused a mitochondrial apoptosis pathway in A549 and MCF-7 cell lines. The molecular docking was used to examine the probable interaction between the hybrids and human NAD[P]H-quinone oxidoreductase (NQO1) protein. The computational studies showed that the type of the 1,4-quinone moiety affected the location of the compound in the active site of the enzyme. Moreover, it was shown that an interaction of 1,4-quinone fragment with the hydrophobic matrix of the active site near Tyr128, Phe178, Trp105 and FAD cofactor could explain the observed increase of TP53 gene expression.

Evaluation of angularly condensed diquinothiazines as potential anticancer agents.

We present efficient synthesis of isomeric types of angularly fused diquinothiazines in the reactions of 2,2'-dichloro-3,3'-diquinolinyl disulfide and diquinodithiin with 3-, 5-, 6- and 8-aminoquinolines. The pentacyclic diquinothiazine ring systems were identified as diquino[3,2-b;3',4'-e][1,4]thiazine, diquino[3,2-b;5',6'-e][1,4]thiazine, diquino[3,2-b;6',5'-e][1,4]thiazine and diquino[3,2-b;8',7'-e][1,4]thiazine with advanced two-dimensional 1H and 13C NMR techniques (COSY, ROESY, HSQC and HMBC) of N-methyl derivatives. The identification of pentacyclic ring system was confirmed by X-ray diffraction analysis of selected N-alkyl derivatives. The X-ray analysis revealed different spatial structures of the ring system (planar and folded). NH-diquinothiazines were further transformed into N-alkyl and N-dialkylaminoalkyl derivatives. Most of diquinothiazines exhibited significant cancer cell growth inhibition against the human glioblastoma SNB-19, colorectal carcinoma Caco-2, breast cancer MDA-MB-231 and lung cancer A549 cell lines with the IC50 values < 3 µM. This anti-proliferative activity was found to be more than for cisplatin. The most promising compound, 7-dimethylaminopropyldiquino[3,2-b;6',5'-e]thiazine, was used for gene expression analysis by reverse transcription-quantitative real-time PCR (RT-QPCR) method. The expression of H3, TP53, CDKN1A, BCL-2 and BAX genes revealed that this compound inhibited the proliferation in all cells (H3) and activated mitochondrial events of apoptosis (BAX/BCL-2) in two cancer cell lines (SNB-19 and Caco-2).

Synthesis, Anticancer Activity, and Apoptosis Induction of Novel 3,6-Diazaphenothiazines.

New 10-substituted derivatives of 3,6-diazaphenothiazine, containing the triple bond linker terminated with tertiary cyclic and acyclic amine groups, were synthesized and screened for their anticancer action. The compounds exhibited varied anticancer activities against human glioblastoma SNB-19, melanoma C-32, and breast cancer MDA-MB231 cell lines, depending on the nature of the substituents. The most active 3,6-diazaphenothiazine, 4, was the derivative with the N,N-diethylamino-2-butynyl substituent against glioblastoma SNB-19, and was ten times more potent than cisplatin. For this compound, the expression of H3, TP53, CDKN1A, BCL-2, and BAX genes was detected by the RT-qPCR method. The gene expression ratio BAX/BCL-2 indicated the induction of mitochondrial apoptosis in cancer cell lines. The transformation of the propynyl substituent into amino-2-butynyl can be a method applicable to the search for more anticancer-active azaphenothiazines.

Novel triazoles of 3-acetylbetulin and betulone as anticancer agents.

The CuAAC reaction of azides and acetylenic triterpenes was used for synthesis of new triazoles of 3-acetylbetulin and betulone. The triazole derivatives were evaluated for their anticancer activity in vitro against amelanotic melanoma C-32, ductal carcinoma T47D and glioblastoma SNB-19 cell lines. 28-[1-(3'-Deoxythymidine-5'-yl)-1H-1,2,3-triazol-4-yl]carbonylbetulone 6e exhibited a significant IC50 value (0.17 µM) against the human glioblastoma SNB-19 cell line, an almost 5-fold higher potency while compared with reference cisplatin.

Synthesis and anticancer activity of multisubstituted purines and xanthines with one or two propynylthio and aminobutynylthio groups.

A synthesis of new 2,6-disubstituted and 2,6,8-trisubstituted 7-methylpurines as well as 8-substituted 3,7-dimethylxanthines containing a triple bond chain have been worked out. Purinethiones and xanthinethiones were converted into propynylthio derivatives, which were then further transformed via a Mannich reaction into aminobutynylthio derivatives (amine = pyrrolidine, piperidine, morpholine, and diethylamine). The products thus obtained represent various types of the purine and xanthine structure: 8-mono-, 2,6- and 6,8-dipropynylthio, 6- and 8-monoaminobutynylthio, 2,6- and 6,8-diaminobutynylthio derivatives. All of these compounds were tested for their anticancer activity against human glioblastoma SNB-19, human adenocarcinoma MDA-MB-231, and melanoma C-32 cell lines. The anticancer activity depends on the nature of the substituent and its localization in the purine and xanthine framework. Generally, compounds possessing two alkynylthio groups (propynylthio or aminobutynylthio) were more active than those possessing only one group. Some compounds exhibited stronger or similar anticancer activity to cisplatin. All compounds were also tested for their cytotoxic activity against normal human fibroblasts (HFF-1). The most promising anticancer compounds were found to be 2,6-dipropynylthio-7-methylpurine 4, 2-chloro-6,8-dipropynylthio-7-methylpurine 14, and 2-chloro-6,8-di(N-morpholinylbutynylthio)-7-methylpurine 15c acting selectively on glioblastoma SNB-19, melanoma C-32, and adenocarcinoma MDA-MB-231 with the IC50 = 0.07-4.08 µg/mL.

Novel Triazole Hybrids of Betulin: Synthesis and Biological Activity Profile.

Betulin derivatives containing a 1,2,3-triazole ring possess a wide spectrum of biological activities, including antiviral, anticancer, and antibacterial activity. A series of novel triazoles were prepared by the 1,3-dipolar cycloaddition reaction between the alkyne derivatives of betulin and organic azides. The chemical structures of the obtained compounds were defined by ¹H and 13C NMR, IR, and high-resolution mass spectrometry (HR-MS) analysis. The target triazoles were screened for their antiviral activity against DNA and RNA viruses. The cytotoxic activity of the obtained compounds 5a-k and 6a-h was determined using five human cancer cell lines (T47D, MCF-7, SNB-19, Colo-829, and C-32) by a WST-1 assay. The bistriazole 6b displayed a promising IC50 value (0.05 µM) against the human ductal carcinoma T47D (500-fold higher potency than cisplatin). The microdilution method was applied for an evaluation of the antimicrobial activity of all of the compounds. The triazole 5e containing a 3'-deoxythymidine-5'-yl moiety exhibited antibacterial activity against two gram-negative bacteria vz. Klebsiellapneumoniae and Escherichia coli (minimal inhibitory concentration (MIC) range of 0.95-1.95 µM).