Synthesis and cytotoxicity of methyl-4,8-dihydrobenzo[1,2-b:5,4-b']dithiophene-4,8-dione derivatives

A Review on Anticancer Activities of Thiophene and Its Analogs

Cancer is the world's second-largest cause of mortality and one of the biggest global health concerns. The prevalence and mortality rates of cancer remain high despite significant progress in cancer therapy. The search for more effective, as well as less toxic treatment methods for cancer, is at the focus of current studies. Thiophene and its derivatives have surged as an influential scaffold, which, because of their appreciable diversity in biological activities, has drawn the concerned interest of the researchers in the field of medicinal chemistry. By the affluent introduction of its derivatives, which have antioxidant, anti-inflammatory, antimicrobial, and anticancer activities, the adaptability of the thiophene moiety has been displayed. The nature and positioning of the substitutions significantly impacted thiophene moiety activity. This decent array in the living response account about this moiety has picked plentiful researcher's consideration to inquire about it to its peculiar potential across certain activities. In the field of cancer therapy against different cancer cells, the structure-activity relationship for each of the derivatives showed an excellent understanding of thiophene moiety. Information from the various articles revealed the key role of thiophene moiety and its derivatives to develop the vital lead compound. The essential anticancer mechanisms identified include inhibition of the topoisomerase, inhibition of tyrosine kinase, tubulin interaction and apoptosis induction through the activation of reactive oxygen species. This review is an endeavor to promote the anticancer potential of the derivatives, whether having thiophene or condensed thiophene as a core moiety or as a substituent that can lead in the future to synthesize varieties of chemotherapeutic entities in the field of cancer treatment.

Hydrogen bonded-extended lanthanide coordination polymers decorated with 2,3-thiophenedicarboxylate and oxalate: synthesis, structures, and properties

Five new LnCPs decorated with H₂tdc and oxalate mixed ligands exhibit a 2D sql layer structure, then the 2D layers are further linked by intermolecule hydrogen bonds to form a 3D supramolecular network with sxb topology.

The structural diversity and photoluminescent properties of cadmium thiophenedicarboxylate coordination polymers

Two series of Cd(ii) CPs based on two positional isomeric thiophenedicarboxylic acids and N-donor ligands have been synthesized. Moreover, the thermal stability and photoluminescence properties of these complexes are investigated.

Discovery and development of natural product-derived chemotherapeutic agents based on a medicinal chemistry approach

Medicinal plants have long been an excellent source of pharmaceutical agents. Accordingly, the long-term objectives of the author's research program are to discover and design new chemotherapeutic agents based on plant-derived compound leads by using a medicinal chemistry approach, which is a combination of chemistry and biology. Different examples of promising bioactive natural products and their synthetic analogues, including sesquiterpene lactones, quassinoids, naphthoquinones, phenylquinolones, dithiophenediones, neo-tanshinlactone, tylophorine, suksdorfin, DCK, and DCP, will be presented with respect to their discovery and preclinical development as potential clinical trial candidates. Research approaches include bioactivity- or mechanism of action-directed isolation and characterization of active compounds, rational drug design-based modification and analogue synthesis, and structure-activity relationship and mechanism of action studies. Current clinical trial agents discovered by the Natural Products Research Laboratories, University of North Carolina, include bevirimat (dimethyl succinyl betulinic acid), which is now in phase IIb trials for treating AIDS. Bevirimat is also the first in a new class of HIV drug candidates called "maturation inhibitors". In addition, an etoposide analogue, GL-331, progressed to anticancer phase II clinical trials, and the curcumin analogue JC-9 is in phase II clinical trials for treating acne and in development for trials against prostate cancer. The discovery and development of these clinical trial candidates will also be discussed.

2-(1-Hydroxethyl)-4,8-dihydrobenzo[1,2-b:5,4-b']dithiophene-4,8-dione (BTP-11) enhances the ATRA-induced differentiation in human leukemia HL-60 cells

2-(1-Hydroxethyl)-4,8-dihydrobenzo[1,2-b:5,4-b']dithiophene-4,8-dione (BTP-11) is a potent enhancer for all-trans retinoic acid (ATRA)-induced differentiation in HL-60 cells. Combination of BTP-11 and ATRA cut down the concentration of ATRA significantly, and that BTP-11 promoted the progression of ATRA-induced into the terminal granulocytic differentiation. Further, Western blot analysis revealed that combination of BTP-11 and ATRA decreased cyclin D/CDK4 and increased C/EBPvarepsilon protein expression to arrest the cells into G0/G1 phase leading to granulocytic maturation. These results confirmed that BTP-11 is a potent enhancer for ATRA-induced differentiation of HL-60 cells, and the great developmental potential of BTP-11 will be expected.

Cell differentiation enhancement by hydrophilic derivatives of 4,8-dihydrobenzo[1,2-b:5,4-b']dithiophene-4,8-diones in HL-60 leukemia cells

Among five carboxamide derivatives (13-17), N-(2-dimethylaminoethyl)-4,8-dihydrobenzo[1,2-b:5,4-b']dithiophene-4,8-dione-2-carboxamide (13) showed the greatest enhancement of all-trans retinoid acid (ATRA)-induced differentiation in HL-60 cells, inducing nearly complete differentiation at a concentration of 0.02microM. On the other hand, 2-hydroxymethyl-4,8-dihydrobenzo[1,2-b:5,4-b']dithiophene-4,8-dione (2) and 2-(1-hydroxylethyl)-4,8-dihydrobenzo[1,2-b:5,4-b']dithiophene-4,8-dione (18) exhibited excellent and equally potent differentiation effects on HL-60 cells. To improve their water solubility, ester-type hydrophilic prodrugs (23-26) were also synthesized. Compounds 13 and 23-26 are identified in this paper as new anti-leukemic drug candidates.

A QSAR review on melanoma toxicity

Melanoma is one of the most aggressive forms of skin cancer and is currently attracting our attention particularly in the area of quantitative structure-activity relationships (QSAR). In the present review, an attempt has been made to collect the data for different sets of compounds and to discuss their toxicities toward melanoma cells by the formulation of a total number of 36 QSAR.

Benzodithiophenes Potentiate Differentiation of Acute Promyelocytic Leukemia Cells by Lowering the Threshold for Ligand-Mediated Corepressor/Coactivator Exchange with Retinoic Acid Receptor α and Enhancing Changes in all-trans-Retinoic Acid–Regulated Gene Expression

Differentiation induction is an effective therapy for acute promyelocytic leukemia (APL), which dramatically responds to all-trans-retinoic acid (ATRA). Recent studies have indicated that combinatorial use of retinoid and nonretinoid compounds, such as histone deacetylase inhibitors, arsenics, and PKA agonists, has higher therapeutic value in this disease and potentially in other malignancies. In a screen of 370 compounds, we identified benzodithiophene analogues as potent enhancers of ATRA-induced APL cell differentiation. These effects were not associated with changes in global histone acetylation and, for the most potent compounds, were exerted at very low nanomolar concentrations, and were paralleled by enhancement of some, but not all, ATRA-modulated gene expressions. Investigating the mechanism underlying the effects of these drugs on ATRA-induced APL cell differentiation, we have shown that benzodithiophenes enhance ATRA-mediated dissociation and association of corepressor N-CoR and coactivator p300 acetyltransferase, respectively, with retinoic acid receptor (RAR) alpha proteins. These data suggest that benzodithiophenes act at the level of receptor activation, possibly by affecting posttranslational modification of the receptor (and/or coregulators), thus leading to an enhancement in ATRA-mediated effects on gene expression and APL cell differentiation. Given the specificities of these low benzodithiophene concentrations for PML-RARalpha and RARalpha, these drugs may be useful for combinatorial differentiation therapy of APL and possibly other acute myelogenous leukemia subtypes in which the overall ATRA signaling is suppressed.

Benzodithiophenes Induce Differentiation and Apoptosis in Human Leukemia Cells

All-trans retinoic acid (ATRA) induces clinical remission in patients with t(15;17) acute promyelocytic leukemia (APL) carrying leukemogenic promyelocytic leukemia-retinoic acid receptor alpha (PML-RARalpha) fusion protein by overcoming PML-RARalpha transcriptional repression and inducing myeloid differentiation. To identify more potent chemical differentiation inducers, a screening assay was developed utilizing an ATRA-insensitive NB4 cell line (NB4-c) in which differentiation could be measured after 48 hours when primed with ATRA followed by other potential inducers. Over 300 cytostatic agents selected from the National Cancer Institute library were screened using this established method. Three compounds, NSC656243, NSC625748, and NSC144168, were identified to amplify ATRA-induced differentiation with acceptable cytotoxicity in NB4-c cells. In the absence of ATRA, these compounds also induced HL-60 and murine erythroleukemia cells to undergo partial differentiation. NSC656243, a benzodithiophene compound, was selected for further studies to examine the underlying mechanism of action. The differentiation effect of NSC656243 was associated with enhanced ATRA-mediated up-regulation of cell cycle regulatory proteins p21waf1 and p27kip1, retinoblastoma dephosphorylation, expression of RIG-E and RIG-G, and myelomonocytic differentiation-specific down-regulation of the myeloperoxidase (MPO) gene. Moreover, at 2- to 3-fold higher concentrations than those used to synergize with ATRA, NSC656243 induced apoptosis in NB4-c cells by reactive oxygen species-mediated pathways. The dual effects of benzodithiophenes (i.e., differentiation and apoptosis induction) support further development of these compounds as therapeutic agents for leukemia.

Photostability of 2-hydroxymethyl-4,8-dibenzo[1,2-b:5,4-b']dithiophene-4,8-dione (NSC 656240), a potential anticancer drug

Stability studies of 2-hydroxymethyl-4,8-dibenzo[1,2-B:5,4-b']dithiophene-4,8-dione (NSC 656240, dithiophene), a poorly water-soluble (approximately 5 microg/ml) potential anticancer drug are reported. Dithiophene stability turned out to be very sensitive to laboratory fluorescent lighting. The rate of photodegradation of dithiophene was studied in aqueous solutions at room temperature (approximately 25 degrees C) at various pH values, in MeOH, CH(3)CN, DMF, DMA, and in mixed nonbuffered aqueous/organic solutions. The aqueous pH-rate profile indicated no sensitivity to changing pH values. 1H NMR and LC/MS methods were used to characterize the degradation products. Dithiophene photodegradation in the presence of air followed an apparent autoxidation pathway with dithiophene-2-aldehyde and dithiophene-2-carboxylic acid as the major degradants. The structures were confirmed against authentic samples. Dithiophene photodegradation under anaerobic conditions followed an apparent disproportionation pathway with only one identified major product, dithiophene-2-aldehyde.

Pharmacogenomic analysis: correlating molecular substructure classes with microarray gene expression data

Genomic studies are producing large databases of molecular information on cancers and other cell and tissue types. Hence, we have the opportunity to link these accumulating data to the drug discovery processes. Our previous efforts at 'information-intensive' molecular pharmacology have focused on the relationship between patterns of gene expression and patterns of drug activity. In the present study, we take the process a step further-relating gene expression patterns, not just to the drugs as entities, but to approximately 27,000 substructures and other chemical features within the drugs. This coupling of genomic information with structure-based data mining can be used to identify classes of compounds for which detailed experimental structure-activity studies may be fruitful. Using a systematic substructure analysis coupled with statistical correlations of compound activity with differential gene expression, we have identified two subclasses of quinones whose patterns of activity in the National Cancer Institute's 60-cell line screening panel (NCI-60) correlate strongly with the expression patterns of particular genes: (i) The growth inhibitory patterns of an electron-withdrawing subclass of benzodithiophenedione-containing compounds over the NCI-60 are highly correlated with the expression patterns of Rab7 and other melanoma-specific genes; (ii) the inhibitory patterns of indolonaphthoquinone-containing compounds are highly correlated with the expression patterns of the hematopoietic lineage-specific gene HS1 and other leukemia genes. As illustrated by these proof-of-principle examples, we introduce here a set of conceptual tools and fluent computational methods for projecting directly from gene expression patterns to drug substructures and vice versa. The analysis is presented in terms of the NCI-60 cell lines and microarray-based gene expression patterns, but the concept and methods are broadly applicable to other large-scale pharmacogenomic database sets as well. The approach (SAT for Structure-Activity-Target) provides a systematic way to mine databases for the design of further structure-activity studies, particularly to aid in target and lead identification.