Synthesis and biological evaluation of thiazolidine-2,4-dione and 2,4-thione derivatives as inhibitors of translation initiation

Anticancer Drug Discovery By Structure-Based Repositioning Approach

Despite the tremendous progress that has occurred in recent years in cell biology and oncology, in chemical, physical and computer sciences, the disease cancer has continued as the major cause of death globally. Research organizations, academic institutions and pharmaceutical companies invest huge amounts of money in the discovery and development of new anticancer drugs. Though much effort is continuing and whatever available approaches are being attempted, the success of bringing one effective drug into the market has been uncertain. To overcome problems associated with drug discovery, several approaches are being attempted. One such approach has been the use of known, approved and marketed drugs to screen these for new indications, which have gained considerable interest. This approach is known in different terms as "drug repositioning or drug repurposing." Drug repositioning refers to the structure modification of the active molecule by synthesis, in vitro/ in vivo screening and in silico computational applications where macromolecular structure-based drug design (SBDD) is employed. In this perspective, we aimed to focus on the application of repositioning or repurposing of essential drug moieties present in drugs that are already used for the treatment of some diseases such as diabetes, human immunodeficiency virus (HIV) infection and inflammation as anticancer agents. This review thus covers the available literature where molecular modeling of drugs/enzyme inhibitors through SBDD is reported for antidiabetics, anti-HIV and inflammatory diseases, which are structurally modified and screened for anticancer activity using respective cell lines.

Synthesis, In Vitro Anticancer, Anti-Inflammatory and DNA Binding Activity of Thiazolidinedione Derivatives

BACKGROUND

Cancer is the second leading cause of mortality worldwide. Despite several advances made in the treatment strategies, the cure for cancer remains still a challenge. Currently used treatment modalities pose several side effects and remain ineffective in the later stages. Thiazolidinediones (TZDs) have been shown to possess anti-cancer activity in several in vitro models.

OBJECTIVES

The objective of this study was to assess the effect of novel synthesized thiazolidinedione derivatives on three selected cancer cell lines viz., human breast adenocarcinoma cell line (MCF-7), lung adenocarcinoma (A549) and colorectal carcinoma (HT29). This study also aimed to evaluate the anti-inflammatory and DNA binding activity of the synthesized derivatives.

METHODS

The synthesized thiazolidinedione derivatives were screened for their in vitro anti-cancer activity on the human breast adenocarcinoma cell line (MCF-7), lung adenocarcinoma (A549) and colorectal carcinoma (HT29) using the Methyl Thaizolyl Tetrazolium (MTT) Assay. They were also evaluated for in vitro antiinflammatory activity using albumin denaturation method, DNA binding activity and hemocompatibility.

RESULTS

Compounds 5a, 5b, 5d, 6c and 6d showed IC50 of 30.19, 41.56, 65.97, 60.16 and 50.41μM respectively on breast adenocarcinoma (MCF-7), IC50 of 49.75, 51.42, 65.43, 61.94 and 56.80μM on lung adenocarcinoma (A549) and 38.11, 45.58, 71.24, 53.15 and 51.25μM on colorectal carcinoma (HT29). In the hemolysis assay, compounds 5a and 5b were found to be nontoxic and nonhemolytic to human erythrocytes. Five compounds possessed significant anticancer and anti-inflammatory activity. Three of them are Mannich bases, whereas the remaining two are aryl acyl derivatives.

CONCLUSION

The in vitro results (anticancer and anti-inflammatory) showed that the 4-chloro anilinomethyl substitution at third position and thiophenoethenyl at the fifth position of thiozolidinedione (5a) emerged as the most effective derivative on all the tested cancer cell lines. A higher DNA binding affinity of the test compounds was also found.

Environmentally Friendly Approach to Knoevenagel Condensation of Rhodanine in Choline Chloride: Urea Deep Eutectic Solvent and QSAR Studies on Their Antioxidant Activity

A series of rhodanine derivatives was synthesized in the Knoevenagel condensation of rhodanine and different aldehydes using choline chloride:urea (1:2) deep eutectic solvent. This environmentally friendly and catalyst free approach was very effective in the condensation of rhodanine with commercially available aldehydes, as well as the ones synthesized in our laboratory. All rhodanine derivatives were subjected to 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) scavenging activity investigation and quantitative structure-activity relationship (QSAR) studies were performed to elucidate their structure-activity relationship. The best multiple linear QSAR model demonstrate a stability in the internal validation and Y-randomization (R² = 0.81; F = 24.225; Q²loo = 0.72; R²Yscr = 0.148). Sphericity of the molecule, ratio of symmetric atoms enhanced atomic mass along the principle axes in regard to total number of atoms in molecule, and 3D distribution of the atoms higher electronegativity (O, N, and S) in molecules are important characteristic for antioxidant ability of rhodanine derivatives. Molecular docking studies were carried out in order to explain in silico antioxidant studies, a specific protein tyrosine kinase (2HCK). The binding interactions of the most active compound have shown strong hydrogen bonding and van der Waals interactions with the target protein.

5-Ene-4-thiazolidinones - An efficient tool in medicinal chemistry

The presented review is an attempt to summarize a huge volume of data on 5-ene-4-thiazolidinones being a widely studied class of small molecules used in modern organic and medicinal chemistry. The manuscript covers approaches to the synthesis of 5-ene-4-thiazolidinone derivatives: modification of the C5 position of the basic core; synthesis of the target compounds in the one-pot or multistage reactions or transformation of other related heterocycles. The most prominent pharmacological profiles of 5-ene derivatives of different 4-thiazolidinone subtypes belonging to hit-, lead-compounds, drug-candidates and drugs as well as the most studied targets have been discussed. Currently target compounds (especially 5-en-rhodanines) are assigned as frequent hitters or pan-assay interference compounds (PAINS) within high-throughput screening campaigns. Nevertheless, the crucial impact of the presence/nature of C5 substituent (namely 5-ene) on the pharmacological effects of 5-ene-4-thiazolidinones was confirmed by the numerous listed findings from the original articles. The main directions for active 5-ene-4-thiazolidinones optimization have been shown: i) complication of the fragment in the C5 position; ii) introduction of the substituents in the N3 position (especially fragments with carboxylic group or its derivatives); iii) annealing in complex heterocyclic systems; iv) combination with other pharmacologically attractive fragments within hybrid pharmacophore approach. Moreover, the utilization of 5-ene-4-thiazolidinones in the synthesis of complex compounds with potent pharmacological application is described. The chemical transformations cover mainly the reactions which involve the exocyclic double bond in C5 position of the main core and correspond to the abovementioned direction of the 5-ene-4-thiazolidinone modification.

Synthesis and anticancer activity of novel quinazolinone-based rhodanines

Background

Rhodanines and quinazolinones have been reported to possess various pharmacological activities.

Results

A novel series of twenty quinazolinone-based rhodanines were synthesized via Knoevenagel condensation between 4-[3-(substitutedphenyl)-3,4-dihydro-4-oxoquinazolin-2-yl)methoxy]substituted-benzaldehydes and rhodanine. Elemental and spectral analysis were used to confirm structures of the newly synthesized compounds. The newly synthesized compounds were biologically evaluated for in vitro cytotoxic activity against the human fibrosarcoma cell line HT-1080 as a preliminary screen using the MTT assay.

Conclusions

All the target compounds were active, displaying IC₅₀ values roughly in the range of 10–60 µM. Structure–activity relationship study revealed that bulky, hydrophobic, and electron withdrawing substituents at the para-position of the quinazolinone 3-phenyl ring as well as methoxy substitution on the central benzene ring, enhance cytotoxic activity. The four most cytotoxic compounds namely, 45, 43, 47, and 37 were further tested against two human leukemia cell lines namely, HL-60 and K-562 and showed cytotoxic activity in the low micromolar range with compound 45 being the most active, having IC₅₀ values of 1.2 and 1.5 μM, respectively. Interestingly, all four compounds were devoid of cytotoxicity against normal human fibroblasts strain AG01523, indicating that the synthesized rhodanines may be selectively toxic against cancer cells. Mechanistic studies revealed that the most cytotoxic target compounds exhibit pro-apoptotic activity and trigger oxidative stress in cancer cells.

Synthesis of thiazolidine-2,4-dione derivatives: anticancer, antimicrobial and DNA cleavage studies

In the search of efficient anticancer agents, here, new 5-(4-alkylbenzyledene)thiazolidine-2,4-dione derivatives (5a-g) have been successfully synthesized and characterized and are evaluated for anticancer and antimicrobial activities using DNA cleavage studies. In vitro studies on anticancer activity of compound 5d (NSC: 768619/1) was done against the full panel of 60 human tumor cell lines. The five-level dose activity results revealed that, the compound 5d was active against all the cell lines, it has shown potential activity against leukemia SR (GI₅₀: 2.04 μM), non-small cell lung cancer NCI-H522 (GI₅₀: 1.36 μM), colon cancer COLO 205 (GI₅₀: 1.64 μM), CNS cancer SF-539 (GI₅₀: 1.87 μM), melanoma SK-MEL-2 (GI₅₀: 1.64 μM), ovarian cancer OVCAR-3 (GI₅₀: 1.87 μM), renal cancer RXF 393 (GI₅₀: 1.15 μM), prostate cancer PC-3 (GI₅₀: 1.90 μM), and breast cancer MDA-MB-468(GI₅₀: 1.11 μM). DNA cleavage studies revealed that at 50 μg/mL concentration, partial DNA digestion was observed and when the concentration is increasing to threefold (150 μg/mL), complete linear DNA digestion and partial supercoiled DNA digestion was observed. Further antimicrobial studies indicate that all the synthesized compounds except compound 5a possess prominent activity against all the screened microbial species. This study throws a ray of light in the field of anticancer drugs.

Design, synthesis, molecular modeling and biological evaluation of novel 1H-pyrazolo[3,4-b]pyridine derivatives as potential anticancer agents

In trying to develop new anticancer agents, a series of 1H-pyrazolo[3,4-b]pyridine derivatives was designed and synthesized. Fifteen compounds were evaluated in vitro for their anti-proliferative activity against HePG-2, MCF-7, HCT-116, and PC-3 cell lines. Additionally, DNA binding affinity of the synthesized derivatives was investigated as a potential mechanism for the anticancer activity using DNA/methyl green assay and association constants assay. Compounds 19, 20, 21, 24 and 25 exhibited good activity against the four cancer cells comparable to that of doxorubicin. Interestingly, DNA binding assay results were in agreement with that of the cytotoxicity assays where the most potent anticancer compounds showed good DNA binding affinity comparable to that of doxorubicin and daunorubicin. Furthermore, a molecular docking of the tested compounds was carried out to investigate their binding pattern with the prospective target, DNA (PDB-code: 152d).

Small molecule adenosine 5'-monophosphate activated protein kinase (AMPK) modulators and human diseases

Adenosine 5'-monophosphate activated protein kinase (AMPK) is a master sensor of cellular energy status that plays a key role in the regulation of whole-body energy homeostasis. AMPK is a serine/threonine kinase that is activated by upstream kinases LKB1, CaMKKβ, and Tak1, among others. AMPK exists as αβγ trimeric complexes that are allosterically regulated by AMP, ADP, and ATP. Dysregulation of AMPK has been implicated in a number of metabolic diseases including type 2 diabetes mellitus and obesity. Recent studies have associated roles of AMPK with the development of cancer and neurological disorders, making it a potential therapeutic target to treat human diseases. This review focuses on the structure and function of AMPK, its role in human diseases, and its direct substrates and provides a brief synopsis of key AMPK modulators and their relevance in human diseases.

Synthesis and biological evaluation of new rhodanine analogues bearing 2-chloroquinoline and benzo[h]quinoline scaffolds as anticancer agents

Several rhodanine derivatives (9-39) were synthesized for evaluation of their potential as anticancer agents. Villsmeier cyclization to synthesize aza-aromatic aldehydes, rhodanine derivatives preparation and Knoevenagel type of condensation between the rhodanines and aza-aromatic aldehydes are key steps used for the synthesis of 31 compounds. In vitro antiproliferative activity of the synthesized rhodanine derivatives (9-39) was studied on a panel of six human tumor cell lines viz. HGC, MNK-74, MCF-7, MDAMB-231, DU-145 and PC-3 cell lines. Some of the compounds were capable of inhibiting the proliferation of cancer cell lines at a micromolar concentration. Six compounds are found to be potent against HGC cell lines; compound 15 is found to be active against HGC - Gastric, MCF7 - Breast Cancer and DU145 - Prostate Cancer cell lines; compound 39 is potent against MNK-74; four compounds are found to be potent against MCF-7 cell lines; three compounds are active against MDAMB-231; nine compounds are found to be potent against DU-145; three compounds are active against PC-3 cell lines. These compounds constitute a promising starting point for the development of novel and more potent anticancer agents in future.

New 5-ylidene rhodanine derivatives based on the dispacamide A model

A practical approach for the preparation of (5Z) 5-ylidene rhodanine derivatives bearing the (4,5-dihalogeno-pyrrol-2-yl)carbamoyl fragment of dispacamide A is reported. The new compounds were obtained in good yields (19-88 %) by Knoevenagel condensation according to a solution-phase microwave dielectric heating protocol in the presence of organic bases (piperidine, TEA, and AcONa) from a set of N-substituted rhodanines 2(a-i). The ten synthetic products 3(a-j) have been synthesized with a Z-geometry about their exocyclic double bond and the structure of one of these compounds (3) was confirmed by a single X-ray diffraction analysis. The new (5Z) 5-ylidene rhodanine derivatives 3(a-j) were tested against eight protein kinases.

Synthesis of 5-arylidene-2-amino-4-azolones and evaluation of their anticancer activity

Series of novel 5-arylidene-2-arylaminothiazol-4(5H)-ones and 2-aryl(benzyl)amino-1H-imidazol-4(5H)-ones were synthesized from appropriate 2-alkylthioazol-4-ones using nucleophilic substitution in position 2 by various anilines and benzylamines and Knoevenagel reaction. X-ray structural studies of 22 revealed the structure to be intermediate between amino and imino tautomeric forms. All the target compounds were evaluated for the anticancer activity in vitro in standard National Cancer Institute 60 cancer cell lines assay. Majority of compounds showed significant antitumor cytotoxicity effect at micromolar and submicromolar level (Mean LogGI50 ranges -5.77 to -4.35). Some of the most potent compounds, namely 10 and 13, possessed selectively high effect on all leukemia cell lines at submicromolar level (Mean LogGI50 [leukemia lines], respectively, -6.41 and -6.29), which are probably associated with immunosuppressive activity. Individual cancer cell lines sensitivity to synthesized compounds and SAR studies are discussed. COMPARE analysis allowed to disclose probable modes of anticancer action for synthesized compounds, in particular showed number of high correlations with activity patterns of alkylating agents (PCC approximately 0.606-0.731).

Expression, purification and characterization of recombinant mouse translation initiation factor eIF4E as a dihydrofolate reductase (DHFR) fusion protein

One of the earliest steps in translation initiation is recognition of the mRNA cap structure (m7GpppX) by the initiation factor eIF4E. Studies of interactions between purified eIF4E and its binding partners provide important information for understanding mechanisms underlying translational control in normal and cancer cells. Numerous impediments of the available methods used for eIF4E purification led us to develop a novel methodology for obtaining fractions of eIF4E free from undesired by-products. Herein we report methods for bacterial expression of eIF4E tagged with mutant dihydrofolate reductase (DHFR) followed by isolation and purification of the DHFR-eIF4E protein by using affinity and anion exchange chromatography. Fluorescence quenching experiments indicated the cap-analog, 7MeGTP, bound to DHFR-eIF4E and eIF4E with a dissociation constant (K(d)) of 6+/-5 and 10+/-3 nM, respectively. Recombinant eIF4E and DHFR-eIF4E were both shown to significantly enhance in vitro translation in dose dependent manner by 75% at 0.5 microM. Nevertheless increased concentrations of eIF4E and DHFR-eIF4E significantly inhibited translation in a dose dependent manner by a maximum at 2 microM of 60% and 90%, respectively. Thus, we have demonstrated that we have developed an expression system for fully functional recombinant eIF4E. We have also shown that the fusion protein DHFR-eIF4E is functional and thus may be useful for cell based affinity tag studies with fluorescently labeled trimethoprim analogs.

Synthesis, polymerization ability, nonlinear optical properties of methacrylic monomers and polymers with benzylidene moiety

New methacrylic monomers, their polymers with benzylidene fragment were synthesized. Structures of all compounds were determined by HNMR, UV- spectroscopies. The third order nonlinear optical properties of oxazolone, thiazolidinone and thiohydantoin containing compounds were investigated in solutions using degenerate four wave mixing (DFWM) method at 532 nm.

New 5-substituted thiazolo[3,2-b][1,2,4]triazol-6-ones: synthesis and anticancer evaluation

Following [2+3]-cyclocondensation reaction of 1,2,4-triazole-3(5)-thiol with N-arylmaleimides or with monochloroacetic acid and oxocompounds, N-(R-phenyl)-(6-oxo-5,6-dihydro[1,3]thiazol[3,2-b][1,2,4]triazol-5-yl)acetamides (1-5) and 5-ylidene-[1,3]thiazolo[3,2-b][1,2,4]triazol-6-ones (6-11) were synthesized as possible anticancer agents. Anticancer activity evaluation on the full panel of nearly 60 human cancer cell lines showed that synthesized compounds displayed this kind of activity on renal cancer, leukemia, colon cancer, breast cancer and melanoma cell lines. It was shown that 5-ylidene-[1,3]thiazolo[3,2-b][1,2,4]triazol-6-ones are characterized with more potent anticancer activity than respective amides. The structures of the compounds were determined by (1)H NMR, (13)C NMR and X-ray analysis.

Anticancer thiopyrano[2,3-d][1,3]thiazol-2-ones with norbornane moiety. Synthesis, cytotoxicity, physico-chemical properties, and computational studies

A series of novel 9-substituted-3,7-dithia-5-azatetracyclo[9.2.1.0(2,10).0(4,8)]tetradecen-4(8)-ones-6 have been synthesized by a stereoselective hetero-Diels-Alder reaction of 5-ylidene-4-thioxo-2-thiazolidone derivatives with norbornene-2. All the compounds have been evaluated for antitumor activity in in vitro human tumor cell lines, and 10 of them possessed significant and selective cytotoxicity (MGM logGI50 approximately -4.17 to -4.98, for individual cell lines logGI50 up to -8). COMPARE analyses of differential growth inhibition patterns of compounds at the GI50 level showed high correlations with some of the antitubulin agents. The lipophilicity of the compounds was studied by RP-TLC and found to correlate well with calculated logP values. Docking and structure-activity relationship studies produced seven QSAR models with 2 or 3 variables, with correlation coefficients r2>0.9 and leave-one-out cross-validation correlation coefficients, q2>0.8.

Synthesis and biological evaluation of rhodanine derivatives as PRL-3 inhibitors

A series of rhodanine derivatives was synthesized and evaluated for their ability to inhibit PRL-3. Benzylidene rhodanine derivative showed good biological activity, while compound 5e was the most active in this series exhibiting an IC50 value of 0.9 microM in vitro and showed a reduced invasion in cell-based assay.

In vitro antiproliferative activity against human colon cancer cell lines of representative 4-thiazolidinones. Part I

The characterization of two cyclooxygenase isoforms (COX), the rate-limiting enzyme for the synthesis of prostaglandins (PGs) from arachidonic acid, has allowed the development of COX-2 selective inhibitors as non-steroidal anti-inflammatory drugs (NSAIDs) with significant gastric tolerability. However, PGs are also important in cancer pathogenesis. Thus, there is an increasing interest in studying COX-2 inhibitors as potential drugs aimed at the prevention and treatment of cancer, especially colorectal cancer. The purpose of this study was to determine the inhibitory effects of some representative 4-thiazolidinones, already widely investigated as potential NSAIDs, on the growth of five human colon carcinoma cell lines with a different COX-2 expression, and to correlate them with COX-2 inhibitory properties. Our results preliminarily revealed that 2-phenylimino derivative 3 and 2,4-thiazolidindione 4 were the most active compounds. In particular, 3 mainly inhibited the HT29 cell line characterized by a high COX-2 expression, whereas 4 showed antiproliferative properties on all tested cell lines, suggesting molecular targets other than COX-2 inhibition.

Synthesis and evaluation of potential inhibitors of eIF4E cap binding to 7-methyl GTP

Cap-dependent translation is initiated by the binding of eIF4E to capped mRNA (m(7)GpppN). We have prepared a small library of 7-methyl guanosine nucleoside and nucleotide analogs and evaluated their ability to inhibit eIF4E binding to 7-methyl GTP with a competitive eIF4E binding immunoassay. 5'-H-Phosphonate derivatives in which the 2'- and 3'-riboside hydroxyls were tethered together by an isopropylidene group were shown to be a new class of inhibitors of eIF4E binding to capped mRNA.