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Estradiol dimers (EDs) possess significant anticancer activity by targeting tubulin dynamics. In this study, we synthesised 12 EDs variants via copper-catalysed azide-alkyne cycloaddition (CuAAC) reaction, focusing on structural modifications within the aromatic bridge connecting two estradiol moieties. In vitro testing of these EDs revealed a marked improvement in selectivity towards cancerous cells, particularly for ED1-8. The most active compounds, ED3 (IC 50  = 0.38 μM in CCRF-CEM) and ED5 (IC 50  = 0.71 μM in CCRF-CEM) demonstrated cytotoxic effects superior to 2-methoxyestradiol (IC 50  = 1.61 μM in CCRF-CEM) and exhibited anti-angiogenic properties in an endothelial cell tube-formation model. Cell-based experiments and in vitro assays revealed that EDs interfere with mitotic spindle assembly. Additionally, we proposed an in silico model illustrating the probable binding modes of ED3 and ED5, suggesting that dimers with a simple linker and a single substituent on the aromatic central ring possess enhanced characteristics compared to more complex dimers.

A series of triterpenoid pyrones was synthesized and subsequently modified to introduce phthalimide or phthalate moieties into the triterpenoid skeleton. These compounds underwent in vitro cytotoxicity screening, revealing that a subset of six compounds exhibited potent activity, with IC 50 values in the low micromolar range. Further biological evaluations, including Annexin V and propidium iodide staining experiment revealed, that all compounds induce selective apoptosis in cancer cells. Measurements of mitochondrial potential, cell cycle analysis, and the expression of pro- and anti-apoptotic proteins confirmed, that apoptosis was mediated via the mitochondrial pathway. These findings were further supported by cell cycle modulation and DNA/RNA synthesis studies, which indicated a significant increase in cell accumulation in the G0/G1 phase and a marked reduction in S-phase cells, alongside a substantial inhibition of DNA synthesis. The activation of caspase-3 and the cleavage of PARP, coupled with a decrease in the expression of Bcl-2 and Bcl-XL proteins, underscored the induction of apoptosis through the mitochondrial pathway. Given their high activity and pronounced effect on mitochondria function, trifluoromethyl pyrones 1f and 2f, and dihydrophthalimide 2h have been selected for further development., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

Microtubule dynamic is exceptionally sensitive to modulation by small-molecule ligands. Our previous work presented the preparation of microtubule-targeting estradiol dimer (ED) with anticancer activity. In the present study, we explore the effect of selected linkers on the biological activity of the dimer. The linkers were designed as five-atom chains with carbon, nitrogen or oxygen in their centre. In addition, the central nitrogen was modified by a benzyl group with hydroxy or methoxy substituents and one derivative possessed an extended linker length. Thirteen new dimers were subjected to cytotoxicity assay and cell cycle profiling. Dimers containing linker with benzyl moiety substituted with one or more methoxy groups and longer branched ones were found inactive, whereas other structures had comparable efficacy as the original ED (e.g. D1 with IC 50  = 1.53 µM). Cell cycle analysis and immunofluorescence proved the interference of dimers with microtubule assembly and mitosis. The proposed in silico model and calculated binding free energy by the MM-PBSA method were closely correlated with in vitro tubulin assembly assay., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)

In this work, a large set of betulinic acid derivatives modified with various aromatic substituents at the position C-3 were prepared via Suzuki-Myiaura cross-coupling. All compounds were tested for their in vitro cytotoxic activity in 8 cancer and 2 healthy cell lines. Derivatives 6h, 6i, and 6o had the lowest IC 50 in the CCRF-CEM cell line (0.69-4.0 μM) and had high selectivity. In addition, 6h and 6i also showed significant activity in daunorubicin-resistant CEM and taxol-resistant K562 cell lines; therefore, they were selected for the evaluation of the mechanism of action. First, the effect of 6h, 6i, and 6o on cell death induction was studied. To our surprise, we have not detected almost any apoptotic cells, even following a long-time exposure of CCRF-CEM cells to the compounds. On the other hand, a dramatic cell number decrease was observed, proportional to the time of the compound's exposure. Based on this data it was concluded that the effect of compounds is cytostatic rather than cytotoxic, which was further confirmed by subsequent studies of the impact of 6h, 6i, and 6o on the cell cycle. Detailed cell cycle analysis revealed a block in the G1 phase accompanied by reduced expression of phosphorylated forms of the RB protein as well as cyclin A protein. Evaluation of the pharmacological properties of the most promising compounds revealed their high stability in the presence of phosphate buffer, human plasma, and microsomes and limited permeability determined using permeability through artificial membrane (PAMPA) and cell permeability assay: Caco-2 and MDCK-MDR1 cell lines. Compounds 6h, 6i, and 6o were selected for further drug development; their cytostatic effect may be advantageous in this process since we expect fewer non-specific interactions and toxicity than in highly cytotoxic compounds. In addition, the activity of 6h and 6i against resistant CEM-DNR and K562-TAX leukemic cell lines makes them promising as a possible future alternative to currently used therapies., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Masson SAS. All rights reserved.)

A set of fifteen triterpenoid pyrazines and pyridines was prepared from parent triterpenoid 3-oxoderivatives (betulonic acid, dihydrobetulonic acid, oleanonic acid, moronic acid, ursonic acid, heterobetulonic acid, and allobetulone). Cytotoxicity of all compounds was tested in eight cancer and two non-cancer cell lines. Evaluation of the structure-activity relationships revealed that the triterpenoid core determined whether the final molecule is active or not, while the heterocycle is able to increase the activity and modulate the specificity. Five compounds (1b, 1c, 2b, 2c, and 8) were found to be preferentially and highly cytotoxic (IC 50  ≈ 1 μM) against leukemic cancer cell lines (CCRF-CEM, K562, CEM-DNR, or K562-TAX). Surprisingly, compounds 1c, 2b, and 2c are 10-fold more active in multidrug-resistant leukemia cells (CEM-DNR and K562-TAX) than in their non-resistant analogs (CCRF-CEM and K562). Pharmacological parameters were measured for the most promising candidates and two types of prodrugs were synthesized: 1) Sugar-containing conjugates, most of which had improved cell penetration and retained high cytotoxicity in the CCRF-CEM cell line, unfortunately, they lost the selectivity against resistant cells. 2) Medoxomil derivatives, among which compounds 26-28 gained activities of IC 50 0.026-0.043 μM against K562 cells. Compounds 1b, 8, 21, 22, 23, and 24 were selected for the evaluation of the mechanism of action based on their highest cytotoxicity against CCRF-CEM cell line. Several experiments showed that the majority of them cause apoptosis via the mitochondrial pathway. Compounds 1b, 8, and 21 inhibit growth and disintegrate spheroid cultures of HCT116 and HeLa cells, which would be important for the treatment of solid tumors. In summary, compounds 1b, 1c, 2b, 2c, 24, and 26-28 are highly and selectively cytotoxic against cancer cell lines and were selected for future in vivo tests and further development of anticancer drugs., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Masson SAS. All rights reserved.)

A set of new substituted dienes were synthesized from betulinic acid by its oxidation to 30-oxobetulinic acid followed by the Wittig reaction. Cytotoxicity of all compounds was tested in vitro in eight cancer cell lines and two noncancer fibroblasts. Almost all dienes were more cytotoxic than betulinic acid. Compounds 4.22, 4.30, 4.33, 4.39 had IC 50 below 5 μmol/L; 4.22 and 4.39 were selected for studies of the mechanism of action. Cell cycle analysis revealed an increase in the number of apoptotic cells at 5 × IC 50 concentration, where activation of irreversible changes leading to cell death can be expected. Both 4.22 and 4.39 led to the accumulation of cells in the G0/G1 phase with partial inhibition of DNA/RNA synthesis at 1 × IC 50 and almost complete inhibition at 5 × IC 50 . Interestingly, compound 4.39 at 5 × IC 50 caused the accumulation of cells in the S phase. Higher concentrations of tested drugs probably inhibit more off-targets than lower concentrations. Mechanisms disrupting cellular metabolism can induce the accumulation of cells in the S phase. Both compounds 4.22 and 4.39 trigger selective apoptosis in cancer cells via intrinsic pathway, which we have demonstrated by changes in the expression of the crucial apoptosis-related protein. Pharmacological parameters of derivative 4.22 were superior to 4.39, therefore 4.22 was the finally selected candidate for the development of anticancer drug., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier Masson SAS. All rights reserved.)

Carbonic anhydrase IX (CA IX) is a transmembrane enzyme overexpressed in hypoxic tumors, where it plays an important role in tumor progression. Specific CA IX inhibitors potentially could serve as anti-cancer drugs. We designed a series of sulfonamide inhibitors containing carborane clusters based on prior structural knowledge of carborane binding into the enzyme active site. Two types of carborane clusters, 12-vertex dicarba-closo-dodecaborane and 11-vertex 7,8-dicarba-nido-undecaborate (dicarbollide), were connected to a sulfonamide moiety via aliphatic linkers of varying lengths (1-4 carbon atoms; n = 1-4). In vitro testing of CA inhibitory potencies revealed that the optimal linker length for selective inhibition of CA IX was n = 3. A 1-sulfamidopropyl-1,2-dicarba-closo-dodecaborane (3) emerged as the strongest CA IX inhibitor from this series, with a K i value of 0.5 nM and roughly 1230-fold selectivity towards CA IX over CA II. X-ray studies of 3 yielded structural insights into their binding modes within the CA IX active site. Compound 3 exhibited moderate cytotoxicity against cancer cell lines and primary cell lines in 2D cultures. Cytotoxicity towards multicellular spheroids was also observed. Moreover, 3 significantly lowered the amount of CA IX on the cell surface both in 2D cultures and spheroids and facilitated penetration of doxorubicin. Although 3 had only a moderate effect on tumor size in mice, we observed favorable ADME properties and pharmacokinetics in mice, and preferential presence in brain over serum., Competing Interests: Declaration of competing interest The authors declare the following competing financial interest(s): B. G., J. B., V. S., J. H., P. D., M. H., and P. R. are inventors of a United States Patent, Pat. No. 9,290,529 B2, issued on Mar. 22, 2016, that covers the title compounds., (Copyright © 2020 Elsevier Masson SAS. All rights reserved.)

A series of 19 synthetic alkyl and thioalkyl glycosides derived from d-mannose, d-glucose and d-galactose and having C 10 -C 16 aglycone were investigated for cytotoxic activity against 7 human cancer and 2 non-tumor cell lines as well as for antimicrobial potential on 12 bacterial and yeast strains. The most potent compounds were found to be tetradecyl and hexadecyl β-d-galactopyranosides (18, 19), which showed the best cytotoxicity and therapeutic index against CCRF-CEM cancer cell line. Similar cytotoxic activity showed hexadecyl α-d-mannopyranoside (5) but it also inhibited non-tumor cell lines. Because these two galactosides (18, 19) were inactive against all tested bacteria and yeast strains, they could be a target-specific for eukaryotic cells. On the other hand, β-D-glucopyranosides with tetradecyl (11) and hexadecyl (12) aglycone inhibited only Gram-positive bacterial strain Enterococcus faecalis. The studied glycosides induce changes in the lipid bilayer thickness and lateral phase separation at high concentration, as derived from SAXS experiments on POPC model membranes. In general, glucosides and galactosides exhibit more specific properties. Those with longer aglycone show high cytotoxicity and therefore, they are more promising candidates for cancer cell line targeted inhibition., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

A series of pentamethinium salts with benzothiazolium and indolium side units comprising one or two positive charges were designed and synthesized to determine the relationships among the molecular structure, charge density, affinity to sulfated polysaccharides, and biological activity. Firstly, it was found that the affinity of the pentamethinium salts to sulfated polysaccharides correlated with their biological activity. Secondly, the side heteroaromates displayed a strong effect on the cytotoxicity and selectivity towards cancer cells. Finally, doubly charged pentamethinium salts possessing benzothiazolium side units exhibited remarkably high efficacy against a taxol-resistant cancer cell line., (Copyright © 2018. Published by Elsevier Inc.)

Background: Hypoxia is a prominent feature of solid tumors, dramatically remodeling microtubule structures and cellular pathways and contributing to paclitaxel resistance. Peloruside A (PLA), a microtubule-targeting agent, has shown promising anti-tumor effects in preclinical studies. Although it has a similar mode of action to paclitaxel, it binds to a distinct site on β-tubulin that differs from the classical taxane site. In this study, we examined the unexplored effects of PLA in hypoxia-conditioned colorectal HCT116 cancer cells., Methods: Cytotoxicity of PLA was determined by cell proliferation assay. The effects of a pre-exposure to hypoxia on PLA-induced cell cycle alterations and apoptosis were examined by flow cytometry, time-lapse imaging, and western blot analysis of selected markers. The hypoxia effect on stabilization of microtubules by PLA was monitored by an intracellular tubulin polymerization assay., Results: Our findings show that the cytotoxicity of PLA is not altered in hypoxia-conditioned cells compared to paclitaxel and vincristine. Furthermore, hypoxia does not alter PLA-induced microtubule stabilization nor the multinucleation of cells. PLA causes cyclin B1 and G2/M accumulation followed by apoptosis., Conclusions: The cellular and molecular effects of PLA have been determined in normoxic conditions, but there are no reports of PLA effects in hypoxic cells. Our findings reveal that hypoxia preconditioning does not alter the sensitivity of HCT116 to PLA., General Significance: These data report on the cellular and molecular effects of PLA in hypoxia-conditioned cells for the first time, and will encourage further exploration of PLA as a promising anti-tumor agent., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Two isomeric series of new thieno-fused 7-deazapurine ribonucleosides (derived from 4-substituted thieno[2',3':4,5]pyrrolo[2,3-d]pyrimidines and thieno[3',2':4,5]pyrrolo[2,3-d]pyrimidines) were synthesized by a sequence involving Negishi coupling of 4,6-dichloropyrimidine with iodothiophenes, nucleophilic azidation, and cyclization of tetrazolopyrimidines, followed by glycosylation and cross-couplings or nucleophilic substitutions at position 4. Most nucleosides (from both isomeric series) exerted low micromolar or submicromolar in vitro cytostatic activities against a broad panel of cancer and leukemia cell lines and some antiviral activity against HCV. The most active were the 6-methoxy, 6-methylsulfanyl, and 6-methyl derivatives, which were highly active to cancer cells and less toxic or nontoxic to fibroblasts.

Spheroid cultures of cancer cells reproduce the spatial dimension-induced in vivo tumor traits more effectively than the conventional two-dimensional cell cultures. With growing interest in spheroids for high-throughput screening (HTS) assays, there is an increasing demand for cost-effective miniaturization of reproducible spheroids in microtiter plates (MPs). However, well-to-well variability in spheroid size, shape, and growth is a frequently encountered problem with almost every culture method that has prevented the transfer of spheroids to the HTS platform. This variability partly arises due to increased susceptibility of MPs to edge effects and evaporation-induced changes in the growth of spheroids. In this study, we examined the effect of evaporation on the reproducibility of spheroids of tumor and nontumor cell lines in 384-well plates, and show that culture conditions that prevent evaporation-induced medium loss result in the formation of uniform spheroids across the plate. Additionally, we also present a few technical improvements to increase the scalability of the liquid-overlay spheroid culturing technique in MPs, together with a simple software routine for the quantification of spheroid size. We believe that these cost-effective improvements will aid in further improvement of spheroid cultures for HTS drug discovery., (© 2016 Society for Laboratory Automation and Screening.)

7-(2-Thienyl)-7-deazaadenosine (AB61) showed nanomolar cytotoxic activities against various cancer cell lines but only mild (micromolar) activities against normal fibroblasts. The selectivity of AB61 was found to be due to inefficient phosphorylation of AB61 in normal fibroblasts. The phosphorylation of AB61 in the leukemic CCRF-CEM cell line proceeds well and it was shown that AB61 is incorporated into both DNA and RNA, preferentially as a ribonucleotide. It was further confirmed that a triphosphate of AB61 is a substrate for both RNA and DNA polymerases in enzymatic assays. Gene expression analysis suggests that AB61 affects DNA damage pathways and protein translation/folding machinery. Indeed, formation of large 53BP1 foci was observed in nuclei of AB61-treated U2OS-GFP-53BP1 cells indicating DNA damage. Random incorporation of AB61 into RNA blocked its translation in an in vitro assay and reduction of reporter protein expression was also observed in mice after 4-hour treatment with AB61. AB61 also significantly reduced tumor volume in mice bearing SK-OV-3, BT-549, and HT-29 xenografts. The results indicate that AB61 is a promising compound with unique mechanism of action and deserves further development as an anticancer agent. Mol Cancer Ther; 15(5); 922-37. ©2016 AACR., (©2016 American Association for Cancer Research.)

The synthesis and biological activity profiling of a large series of diverse pyrrolo[2,3-d]pyrimidine 4'-C-methylribonucleosides bearing an (het)aryl group at position 4 or 5 is reported as well as the synthesis of several phosphoramidate prodrugs. These compounds are 4'-C-methyl derivatives of previously reported cytostatic hetaryl-7-deazapurine ribonucleosides. The synthesis is based on glycosylation of halogenated 7-deazapurine bases with 1,2-di-O-acetyl-3,5-di-O-benzyl-4-C-methyl-β-d-ribofuranose followed by cross-coupling and nucleophilic substitution reactions. The final compounds showed low cytotoxicity and several derivatives exerted antiviral activity against HCV or Dengue viruses at micromolar concentrations., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

We report design and synthesis of set of novel anticancer agents based on caffeine-hydrazones bearing 2-hydroxyaryl- or 2-N-heteroaryl moiety. Anticancer activity evaluation using seven cancer cell lines and two non-malignant cell lines demonstrated that several derivatives display significant anticancer activity and great selectivity index toward T-lymphoblastic leukaemia cells. In general, hydrazones bearing 2-N-heteroaryl moiety are more active and selective than those with 2-hydroxyaryl moiety. Tested compounds exhibit dose-dependent inhibition of both RNA and DNA synthesis, with some exceptions. Antimicrobial activities were tested on set of twelve bacterial and yeast strains, however prepared compounds were not active, suggesting for a molecular target specific for eukaryotic cells., (Copyright © 2015 Elsevier Inc. All rights reserved.)

We report the design and synthesis of novel anticancer agents based on bis-hydrazones separated by a rigid Tröger's base skeleton. This novel approach combines a biologically active moiety (hydrazone) with this scaffold (Tröger's base) to construct DNA intercalators. Evaluation of the anticancer activity of these agents using seven cancer cell lines and two healthy cell lines found that several derivatives had potent anticancer activity and excellent selectivity indexes toward cancer cells. The antimicrobial activities were tested on a set of thirteen bacterial stains, but the prepared compounds were not active. Complexation studies using biologically important metal ions demonstrated that these compounds are able to bind Cu(2+), Fe(3+), Co(2+), Ni(2+) and Zn(2+). DNA intercalation studies showed that the compounds themselves do not interact with DNA, but their metallocomplexes do interact, most likely via intercalation into DNA., (Copyright © 2015. Published by Elsevier Ltd.)

A number of 5-alkoxymethyluracil analogues were synthesized to evaluate their cytotoxic activity. 5-Alkoxymethyluracil derivatives 1 were prepared via known nucleophilic substitution of 5-chloromethyluracil 5 and subsequently transformed to their corresponding nucleosides 2. All prepared compounds were submitted to cytotoxic activity testing against drug sensitive and drug resistant leukaemia cells and solid tumour derived cell lines. In addition, the cytotoxic activity of 5-alkoxymethyluracil analogues 1 and 2 was compared with the previously published 5-[alkoxy(4-nitrophenyl)methyl]uracil analogues 3 and 4. Extensive structure-cytotoxic activity relationship studies are reported., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

The synthesis and anticancer activity evaluation of new quinazoline alkaloids rutaecarpine and evodiamine semisynthetic derivatives and their molecular hybrids with lupinine moiety is described. Newly synthesized compounds were elucidated based on elemental analyses and spectral data (1H and 13C NMR). Anticancer cytotoxicity was studied toward some cell lines of lung cancer, T-lymphoblastic leukemia, colon cancer, myeloid leukemia, and osteosarcoma. Among the tested compounds, the highest activity with a specific sensitivity profile toward the Leukemia cell lines CCRF-CEM and K-562 was demonstrated by the starting compound evodiamine. Structural modifications of the studied quinazoline alkaloids did not lead to the improvement of anticancer activity. [ABSTRACT FROM AUTHOR]

This work describes the synthesis of 8-iodoimidazo[1,2- c]pyrimidin-5(6 H)-one 2 from 5-iodocytosine 1. This compound was subjected to Suzuki with aryl and heteroarylboronic acids. After optimization, 10 products 3a, 3b, 3c, 3d, 3e, 3f, 3g, 3h, 3i, 3j were obtained in good yields 61-90%. Cytotoxic activity of all new products was evaluated on seven tumor cell lines including resistant variants and on normal human fibroblasts. Two derivatives showed promising and good therapeutic index in the case of 3h. [ABSTRACT FROM AUTHOR]

Abstract: Large series of O-alkyl derivatives (methyl and benzyl) of silybin and 2,3-dehydrosilybin was prepared. Selective alkylation of the silybin molecule was systematically investigated. For the first time we present here, for example, preparation of 19-nor-2,3-dehydrosilybin. All prepared silybin/2,3-dehydrosilybin derivatives were tested for cytotoxicity on a panel of drugs sensitive against multidrug resistant cell lines and the ability to inhibit P-glycoprotein mediated efflux activity. We have identified effective and relatively non-cytotoxic inhibitors of P-gp derived from 2,3-dehydrosilybin. Some of them were more effective inhibitors at concentrations lower than a standard P-gp efflux inhibitor cyclosporin A. Another group of 2,3-dehydrosilybin derivatives also had better inhibitory effects on P-gp efflux but a cytotoxicity comparable with that of parent 2,3-dehydrosilybin. Structural requirements for improving inhibitory activity and reducing toxicity of 2,3-dehydrosilybin were established. Effect of E-ring substitution as well as an influence of the substituent size at the C-7-OH position of A-ring on P-gp-inhibitory activity was evaluated for the first time in this study. [Copyright &y& Elsevier]

Cytokinin ribosides (N 6 -substituted adenosines) have demonstrated anticancer activity in various cultured cell lines, several xenografts and even a small clinical trial. Effects of kinetin riboside, N 6 -benzyladenosine (BAR) and N 6 -isopentenyladenosine on various parameters related to apoptosis have also been reported, but not directly compared with those of the highly active naturally occurring aromatic cytokinins oTR ( ortho -topolin riboside) and 2OH3MeOBAR (N 6 -(2-hydroxy-3-methoxybenzyl)adenosine). Here we show that 2OH3MeOBAR is the most active cytokinin riboside studied to date (median, 1st quartile, 3rd quartile and range of GI50 in tests with the NCI60 cell panel: 0.19, 0.10, 0.43 and 0.02 to 15.7 μM, respectively) and it differs from other cytokinins by inducing cell death without causing pronounced ATP depletion. Analysis of NCI60 test data suggests that its activity is independent of p53 status. Further we demonstrate that its 5′-monophosphate, the dominant cancer cell metabolite, inhibits the candidate oncogene DNPH1. Synthesis, purification, HPLC-MS identification and HPLC-UV quantification of 2OH3MeOBAR metabolites are also reported. [ABSTRACT FROM AUTHOR]

A series of 80 7-(het)aryl-and 7-ethynyl-7-deazapurine ribonucleosidesbearing a methoxy, methylsulfanyl, methylamino, dimethylamino, methyl,or oxo group at position 6, or 2,6-disubstituted derivatives bearinga methyl or amino group at position 2, were prepared, and the biologicalactivity of the compounds was studied and compared with that of theparent 7-(het)aryl-7-deazaadenosine series. Several of the compounds,in particular 6-substituted 7-deazapurine derivatives bearing a furylor ethynyl group at position 7, were significantly cytotoxic at lownanomolar concentrations whereas most were much less potent or inactive.Promising activity was observed with some compounds against Mycobacterium bovis and also against hepatitis C virus ina replicon assay. [ABSTRACT FROM AUTHOR]

Novel analogues of (+)-varitriol have been synthesised via Julia-Kocienski olefination from γ-D-ribonolactone. Newly prepared compounds were screened for their in vitro cytotoxicity towards certain human tumours and NCI60 cancer cell line panel. [ABSTRACT FROM AUTHOR]

Abstract: Cytokinin ribosides (N6-substituted adenosine derivatives) have been shown to have anticancer activity both in vitro and in vivo. This study presents the first systematic analysis of the relationship between the chemical structure of cytokinins and their cytotoxic effects against a panel of human cancer cell lines with diverse histopathological origins. The results confirm the cytotoxic activity of N6-isopentenyladenosine, kinetin riboside, and N6-benzyladenosine and show that the spectrum of cell lines that are sensitive to these compounds and their tissues of origin are wider than previously reported. The first evidence that the hydroxylated aromatic cytokinins (ortho-, meta-, para-topolin riboside) and the isoprenoid cytokinin cis-zeatin riboside have cytotoxic activities is presented. Most cell lines in the panel showed greatest sensitivity to ortho-topolin riboside (IC50 =0.5–11.6μM). Cytokinin nucleotides, some synthesized for the first time in this study, were usually active in a similar concentration range to the corresponding ribosides. However, cytokinin free bases, 2-methylthio derivatives and both O- and N-glucosides showed little or no toxicity. Overall the study shows that structural requirements for cytotoxic activity of cytokinins against human cancer cell lines differ from the requirements for their activity in plant bioassays. The potent anticancer activity of ortho-topolin riboside (GI50 =0.07–84.60μM, 1st quartile=0.33μM, median=0.65μM, 3rd quartile=1.94μM) was confirmed using NCI60, a standard panel of 59 cell lines, originating from nine different tissues. Further, the activity pattern of oTR was distinctly different from those of standard anticancer drugs, suggesting that it has a unique mechanism of activity. In comparison with standard drugs, oTR showed exceptional cytotoxic activity against NCI60 cell lines with a mutated p53 tumour suppressor gene. oTR also exhibited significant anticancer activity against several tumour models in in vivo hollow fibre assays. [Copyright &y& Elsevier]

Abstract: A series of the 3,7-diaryl-5-(3,4,5-trimethoxyphenyl)pyrazolo[4,3-e][1,2,4]triazines (17a–20f) have been synthesized in five steps. The cytotoxic activity of all of the newly synthesized compounds has been tested in vitro against five cancer cell lines. Several compounds demonstrated significant broad cytotoxic activity in low micromolar range, while others were selectively active against lung adenocarcinoma cell line A549. [Copyright &y& Elsevier]