Synthesis, in vitro antiproliferative activity, and in silico studies of fused tricyclic coumarin sulfonate derivatives

Anticancer mechanism of coumarin-based derivatives

The structural motif of coumarins is related with various biological activities and pharmacological properties. Both natural coumarin extracted from various plants or a new coumarin derivative synthesized by modification of the basic structure of coumarin, in vitro experiments showed that coumarins are a promising class of anti-tumor agents with high selectivity. Cancer is a complex and multifaceted group of diseases characterized by the uncontrolled and abnormal growth of cells in the body. This review focuses on the anticancer mechanism of various coumarins synthesized and isolated in more than a decade. Isopentenyloxycoumarins inhibit angiogenesis by reducing CCl2 chemokine levels. Ferulin C is a potent colchicine-binding agent that destabilizes microtubules, exhibiting antiproliferative and anti-metastatic effects in breast cancer cells through PAK1 and PAK2-mediated signaling. Trimers of triphenylethylene-coumarin hybrids demonstrated significant proliferation inhibition in HeLa, A549, K562, and MCF-7 cell lines. Platinum(IV) complexes with 4-hydroxycoumarin have the potential for high genotoxicity against tumor cells, inducing apoptosis in SKOV-3 cells by up-regulating caspase 3 and caspase 9 expression. Derivatives of 3-benzyl coumarin seco-B-ring induce apoptosis, mediated through the PI3K/Akt/mTOR signaling pathway. Sesquiterpene coumarins inhibit the efflux pump of multidrug resistance-associated protein. Coumarin imidazolyl derivatives inhibit the aromatase enzyme, a major contributor to estrogen overproduction in estrogen-dependent breast cancer.

Arylcoumarin and novel biscoumarin derivatives as potent inhibitors of human glutathione S-transferase

A series of arylcoumarin derivatives and two novel biscoumarin derivatives were investigated for their human recombinant glutathione S-transferase P1-1 (GSTP1-1) enzyme inhibitory activities for the first time. 4-(3,4-Dihydroxyphenyl)-6,7-dihydroxycoumarin (compound 24) was observed to be the most active coumarin derivative (IC50: 0.14 µM). The inhibition was found to be time-dependent and irreversible. Hypothetical binding modes of the ten most active compounds were calculated by molecular docking. Ligand efficiency indices (LEI) were estimated to better understand the binding performance of the coumarin derivatives. Extensive structure-activity relationship studies showed that hydroxy substitution on both the coumarin and the aryl ring enhanced the biological activity and the position of hydroxy group on the coumarin ring is critical for the binding pose and the activity. Top three ligands were subjected to molecular dynamics simulations and MM/PBSA for further investigation. Binding mode of compound 24 suggested that its high inhibitory activity might be attributed to its position between Tyr7 and the cofactor, glutathione (GS-DNB). Exhibiting favorable druglikeness profiles and pharmacokinetics based on ADME studies, compound 5 and 24 can be considered as potential drug leads in future studies for further development.Communicated by Ramaswamy H. Sarma.

Design and synthesis of new adamantyl derivatives as promising antiproliferative agents

A series of adamantyl carboxamide derivatives containing sulfonate or sulfonamide moiety were designed as multitargeted inhibitors of ectonucleotide pyrophosphatases/phosphodiesterases (NPPs) and carbonic anhydrases (CAs). The target compounds were investigated for their antiproliferative activity against NCI-60 cancer cell lines panel. Three main series composed of 3- and 4-aminophenol, 4-aminoaniline, and 5-hydroxyindole scaffolds were designed based on a lead compound (A). Compounds 1e (benzenesulfonyl) and 1i (4-fluorobenzenesulfonyl) of 4-aminophenol backbone exhibited the most promising antiproliferative activity. Both compounds exhibited a broad-spectrum and potent inhibition against all the nine tested cancer subtypes. Both compounds showed nanomolar IC50 values over several cancer cell lines that belong to leukemia and colon cancer such as K-562, RPMI-8226, SR, COLO 205, HCT-116, HCT-15, HT29, KM12, and SW-620 cell lines. Compounds 1e and 1i induced apoptosis in K-562 leukemia cells in a dose-dependent manner. Compound 1i showed the highest cytotoxic activity with IC50 value of 200 nM against HT29 cell line. In addition, compounds 1e and 1i were tested against normal breast cells (HME1) and normal skin fibroblast cells (F180) and the results revealed that the compounds are safe toward normal cells compared to cancers cells. Enzymatic assays against NPP1-3 and carbonic anhydrases II, IX, and XII were performed to investigate the possible molecular target(s) of compounds 1e and 1i. Furthermore, a molecular docking study was performed to predict the binding modes of compounds 1e and 1i in the active site of the most sensitive enzymes subtypes.

Synthesis and in vitro assessment of anticholinesterase and antioxidant properties of triazineamide derivatives

Aim: Cholinesterase inhibitors and radical scavengers have been recognized as powerful symptomatic anti-Alzheimer's disease agents. Hence, the present study aimed to develop new triazineamides as potent anticholinesterase and antioxidant agents. Methods: Triazineamide (7a-i) derivatives were synthesized using cyanuric chloride via nucleophilic substitution followed by condensation. Ellman assay, 2,2-azinobis(3-ethylbenzthiazoline-6-sulfonic acid) radical scavenging assay and molecular docking studies with Autodock 4.2.3 program were conducted. Results: Triazineamide 7c was assessed as a potent, selective and mixed-type dual inhibitor of acetylcholinesterase, with and IC₅₀ of 5.306 ± 0.002 μM, by binding simultaneously with the catalytic active and peripheral anionic sites of acetylcholinesterase, and it had strong 2,2-azinobis(3-ethylbenzthiazoline-6-sulfonic acid) radical scavenging abilities. Conclusion: These results suggest that triazineamides may be of interest to establish a structural basis for new anti-Alzheimer's disease agents.

Synthesis, characterization, DFT and molecular docking studies of acetone O-((2,5-dichlorophenyl)sulfonyl) oxime

Acetone O-((2,5-dichlorophenyl)sulfonyl) oxime was prepared from 2,5-dichlorophenylsulfonyl chloride and acetone oxime using triethylamine. The compound was characterized using 1H NMR and 13C NMR spectra. Molecular docking was performed with the compound and cholinesterase enzymes. The average affinity of the compound with the acetylcholinesterase and butyrylcholinesterase was calculated at −7.46 ± 0.14 and −6.70 ± 0.00 kcal/mol, respectively. The density functional theory method was also used to complement the experimental study. The findings of this work might be useful towards the applications of the compound studied.

Coumarins and Gastrointestinal Cancer: A New Therapeutic Option?

Cancers of the gastrointestinal (GI) tract are often life-threatening malignancies, which can be a severe burden to the health care system. Globally, the mortality rate from gastrointestinal tumors has been increasing due to the lack of adequate diagnostic, prognostic, and therapeutic measures to combat these tumors. Coumarin is a natural product with remarkable antitumor activity, and it is widely found in various natural plant sources. Researchers have explored coumarin and its related derivatives to investigate their antitumor activity, and the potential molecular mechanisms involved. These mechanisms include hormone antagonists, alkylating agents, inhibitors of angiogenesis, inhibitors of topoisomerase, inducers of apoptosis, agents with antimitotic activity, telomerase inhibitors, inhibitors of human carbonic anhydrase, as well as other potential mechanisms. Consequently, drug design and discovery scientists and medicinal chemists have collaborated to identify new coumarin-related agents in order to produce more effective antitumor drugs against GI cancers. Herein, we summarize the therapeutic effects of coumarin and its derivatives against GI cancer.

An Overview of Coumarin as a Versatile and Readily Accessible Scaffold with Broad-Ranging Biological Activities

Privileged structures have been widely used as an effective template for the research and discovery of high value chemicals. Coumarin is a simple scaffold widespread in Nature and it can be found in a considerable number of plants as well as in some fungi and bacteria. In the last years, these natural compounds have been gaining an increasing attention from the scientific community for their wide range of biological activities, mainly due to their ability to interact with diverse enzymes and receptors in living organisms. In addition, coumarin nucleus has proved to be easily synthetized and decorated, giving the possibility of designing new coumarin-based compounds and investigating their potential in the treatment of various diseases. The versatility of coumarin scaffold finds applications not only in medicinal chemistry but also in the agrochemical field as well as in the cosmetic and fragrances industry. This review is intended to be a critical overview on coumarins, comprehensive of natural sources, metabolites, biological evaluations and synthetic approaches.

Antiproliferative activity of cycloalkanecarboxamide derivatives possessing sulfonate or sulfamate moiety

A series of cycloalkanecarboxamide-containing sulfonate and sulfamate derivatives were prepared, and their antiproliferative activity was tested against NCI-60 cancer cell lines panel. Compound 1f possessing cyclohexyl and p-(tert-butyl)benzenesulfonate moieties was the most active among all the target compounds. It exerted broad-spectrum anticancer activity against all the nine cancer types involved in the NCI-60 panel. Additionally, compound 1g containing cyclohexyl and p-fluorobenzenesulfonate moieties was the most potent against HT29 colon cancer cell line (IC₅₀ = 4.73 µM) with selectivity index more than 4.23 towards HT29 than normal fibroblasts. It exerts its antiproliferative activity against HT29 through the induction of apoptosis (increasing caspase 3/7 activity) but not necrosis. Structure-activity relationship studies are presented in detail.

Translational role of natural coumarins and their derivatives as anticancer agents

Natural coumarins and their derivatives isolated from various plants or microorganisms have inherent antioxidant, antibacterial, antifungal, antiviral and anticancer properties among many biological activities. Some of these coumarins and their derivatives lead to self-programmed cancer cell death (apoptosis) via different mechanisms, which will be discussed. The link between bacterial and viral infections to cancer compels us to highlight fascinating reports from coumarin isolation from microorganisms; comment on the recent bioavailability studies of natural or derived coumarins; and discuss our perspectives with respect to bioisosterism in coumarins, p-glycoprotein inhibition and covalent modification, and bioprobes. Overall, this review hopes to stimulate and offer in particular medicinal chemists and the reader in general an outlook on natural coumarins and their derivatives with potential for cancer therapy.

Selective COX-2 inhibitors as anticancer agents: a patent review (2014-2018)

INTRODUCTION

COX-2 is a key enzyme in the process of prostaglandins (PGs) synthesis. The products of this enzyme could play a major role as the mediators of the inflammatory response and some other medical states such as cancer. The design and synthesis of novel selective COX-2 inhibitors have always been attractive to researchers. This review discusses the structures of novel COX-2 inhibitors synthesized during the last five years and describes their efficacy as anticancer agents.

AREAS COVERED

It is well established that COX-2 is overexpressed in many different cancers and treatment with selective COX-2 inhibitors could relieve their symptoms and limit their adverse sequences.

EXPERT OPINION

The diversity of selective COX-2 inhibitors is mainly related to the types of scaffolds. Monocyclic, bicyclic, tricyclic, and acyclic scaffolds with different pharmacological effects and toxicological profiles could be found in the family of selective COX-2 inhibitors. The great interest of the researchers in this field is due to the importance of selective COX-2 inhibitors as a relatively safe and effective set of compounds which could present different properties such as antirheumatic, anti-inflammatory, antiplatelet, anti-Alzheimer's disease, anti-Parkinson's disease, and anticancer.

Benzophenone Esters and Sulfonates: Synthesis and their Potential as Antiinflammatory Agents

BACKGROUND

Inflammation is a biological rejoinder of vascular tissues against destructive agents e.g. irritants, damaged cell or pathogens. During inflammation, respiratory burst occurs by activated phagocytes which help to destroy invading pathogens. Phagocytic cells such as neutrophils and macrophages are one of the major sources of reactive oxygen species (ROS) and nitric oxide (NO). Normally, the redox environment is maintained by various antioxidant defense systems, however, these reactive oxygen species may be destructive and can lead to various pathological conditions.

METHODS

Benzophenone esters and sulfonates (1-18) were synthesized through one pot synthesis by reacting 4-hydroxy benzophenone either different benzoyl chloride or sulfonyl chloride. These synthetic compounds were evaluated for their in vitro immunosuppressive potential on two parameters of innate immune response including inhibition of intracellular reactive oxygen species (ROS) and nitric oxide (NO). ROS were induced in polymorphonuclear leukocytes (PMNs) isolated from human whole blood by serum opsonized zymosan stimulation, whereas NO were produced in J774.2 cells by lipopolysachharides (LPS) stimulation. Moreover, cytotoxicity of compounds was also determined using NIH-3T3 fibroblast cells (ATCC, Manassas, USA) was evaluated by using the standard MTT colorimetric assay.

RESULTS

All compounds inhibited the production of ROS at various extent among which compounds 2, 5, 6, 8, 10, 13 and 16 were found to be the potent inhibitors of ROS with IC50 values ranging between (1.0 - 2.2 µg/mL) as compared to ibuprofen (IC50 = 2.5 ± 0.6 µg/mL) as the standard drug. Compounds 2, 7, 11, 13, 14 and 18 showed good inhibition of NO production with % inhibition values ranging between (63.6% - 76.7%) at concentration of 25 µg/mL as compared to NG-monomethyl-Larginine (L-NMMA 65.6 ± 1.1 µg/mL) as the standard. All other derivatives showed moderate to low level of inhibition on both tested parameters. Cytotoxicity activity also showed nontoxicity of synthetic compounds. Structures of all the synthetic compounds were confirmed through 1H-NMR, 13C-NMR, EI-MS and HREI-MS spectroscopic techniques.

CONCLUSION

Compounds 2 and 13 were found to be good dual antiinflammatory (ROS and NO) agent. However, compounds 5, 6, 8, 10 and 16 were found to be selectively active for ROS inhibitory studies. Compounds 7, 11, 14 and 18 were discriminatory active at NO inhibition assay. These initial findings of antiinflammatory activity concluded that these compounds might have the potential to develop a novel non-steroidal antiinflammatory drugs (NSAIDs), non-acidic antiinflammatory agent. Most active compounds 2, 5-8, 10, 13, 14 and 16 showed nontoxicity of synthetic compounds.

A comparative experimental and theoretical investigation of hydrogen-bond, halogen-bond and π–π interactions in the solid-state supramolecular assembly of 2- and 4-formylphenyl arylsulfonates

To explore the operational role of noncovalent interactions in supramolecular architectures with designed topologies, a series of solid-state structures of 2- and 4-formylphenyl 4-substituted benzenesulfonates was investigated. The compounds are 2-formylphenyl 4-methylbenzenesulfonate, C14H12O4S, 3a, 2-formylphenyl 4-chlorobenzenesulfonate, C13H9ClO4S, 3b, 2-formylphenyl 4-bromobenzenesulfonate, C13H9BrO4S, 3c, 4-formylphenyl 4-methylbenzenesulfonate, C14H12O4S, 4a, 4-formylphenyl 4-chlorobenzenesulfonate, 4b, C13H9ClO4S, and 4-formylphenyl 4-bromobenzenesulfonate, C13H9BrO4S, 4c. The title compounds were synthesized under basic conditions from salicylaldehyde/4-hydroxybenzaldehydes and various aryl sulfonyl chlorides. Remarkably, halogen-bonding interactions are found to be important to rationalize the solid-state crystal structures. In particular, the formation of O...X (X = Cl and Br) and type I X...X halogen-bonding interactions have been analyzed by means of density functional theory (DFT) calculations and characterized using Bader's theory of `atoms in molecules' and molecular electrostatic potential (MEP) surfaces, confirming the relevance and stabilizing nature of these interactions. They have been compared to antiparallel π-stacking interactions that are formed between the arylsulfonates.

Novel hydrazide-hydrazone and amide substituted coumarin derivatives: Synthesis, cytotoxicity screening, microarray, radiolabeling and in vivo pharmacokinetic studies

The current work presents the synthesis and biological evaluation of new series of coumarin hydrazide-hydrazone derivatives that showed in vitro broad spectrum antitumor activities against resistant pancreatic carcinoma (Panc-1), hepatocellular carcinoma (HepG2) and leukemia (CCRF) cell lines using doxorubicin as reference standard. Bromocoumarin hydrazide-hydrazone derivative (BCHHD) 11b showed excellent anticancer activity against all tested cancer cell lines. Enzyme assays showed that BCHHD 11b induced apoptosis due to activation of caspases 3/7. Moreover, 11b inhibited GST and CYP3A4 in a dose dependent manner and the induced cell death could be attributed to metabolic inhibition. Moreover, 11b microarray analysis showed significant up- and down-regulation of many genes in the treated cells related to apoptosis, cell cycle, tumor growth and suppressor genes. All of the above presents BCHHD 11b as a potent anticancer agent able to overcome drug resistance. In addition, compound 11b was able to serve as a chemical carrier for ^99mTc and the in vivo biodistribution study of ^99mTc-11b complex revealed a remarkable targeting ability of ^99mTc into solid tumor showing that ^99mTc-11b might be used as a promising radiopharmaceutical imaging agent for cancer.

Tricyclic coumarin sulphonate derivatives with alkaline phosphatase inhibitory effects: in vitro and docking studies

Tissue-nonspecific alkaline phosphatase (TNAP) is an important isozyme of alkaline phosphatases, which plays different pivotal roles within the human body. Most importantly, it is responsible for maintaining the balanced ratio of phosphate and inorganic pyrophosphate, thus regulates the extracellular matrix calcification during bone formation and growth. The elevated level of TNAP has been linked to vascular calcification and end-stage renal diseases. Consequently, there is a need to search for highly potent and selective inhibitors of alkaline phosphatases (APs) for treatment of disorders associated with the over-expression of APs. Herein, a series of tricyclic coumarin sulphonate 1a-za with known antiproliferative activity, was evaluated for AP inhibition against human tissue nonspecific alkaline phosphatase (h-TNAP) and human intestinal alkaline phosphatase (h-IAP). The methylbenzenesulphonate derivative 1f (IC₅₀ = 0.38 ± 0.01 μM) was found to be the most active h-TNAP inhibitor. Another 4-fluorobenzenesulphonate derivative 1i (IC₅₀ = 0.45 ± 0.02 μM) was found as the strongest inhibitor of h-IAP. Some of the derivatives were also identified as highly selective inhibitors of APs. Detailed structure-activity relationship (SAR) was investigated to identify the functional groups responsible for the effective inhibition of AP isozymes. The study was also supported by the docking studies to rationalise the most possible binding site interactions of the identified inhibitors with the targeted enzymes.

Small hybrid heteroaromatics: resourceful biological tools in cancer research

Nowadays, hybrid drugs containing two or more covalently linked known potential pharmacophores are designed to simultaneously modulate multiple targets of multifactorial diseases to overcome the side effects associated with a single drug.

Synthesis of New Tricyclic and Tetracyclic Fused Coumarin Sulfonate Derivatives and Their Inhibitory Effects on LPS-Induced Nitric Oxide and PGE2 Productions in RAW 264.7 Macrophages: Part 2

The synthesis of a new series of 21 fused coumarin derivatives is described, and the biological evaluation of their in vitro antiinflammatory effects as inhibitors of lipopolysaccharide (LPS)-induced nitric oxide (NO) and prostaglandin E₂ (PGE₂ ) production in RAW 264.7 macrophages. The target compounds 1a-u were first tested for cytotoxicity to determine a non-toxic concentration for antiinflammatory screening, so that the inhibitory effects against NO and PGE₂ production would not be caused by cytotoxicity. Compounds 1f and 1p were the most active PGE₂ inhibitors with IC₅₀ values of 0.89 and 0.95 µM, respectively. Western blot and cell-free COX-2 screening showed that their effects were due to inhibition of both COX-2 protein expression and COX-2 enzyme activity. Their IC₅₀ values against the COX-2 enzyme were 0.67 and 0.85 µM, respectively, which is more potent than etoricoxib. The selectivity indexes of compounds 1f and 1p against COX-2 compared to COX-1 were 41.1 and 42.5, respectively. Compound 1f showed strong inhibitory effects at 5 µM concentration on COX-2 mRNA expression in LPS-induced RAW 264.7 macrophages. Moreover, the tricyclic compounds 1l and 1n as well as the tetracyclic analog 1u were the most potent NO inhibitors, with one-digit micromolar IC₅₀ values. They showed dose-dependent inhibition of inducible nitric oxide synthase (iNOS) protein expression. The tetracyclic derivative 1u was the most potent inhibitor of NO production. It also exhibited a strong inhibitory effect on iNOS mRNA expression in LPS-induced RAW 264.7 macrophages.

Synthesis and anticancer activity of 6-heteroarylcoumarins

A series of novel 7-hydroxy-8-methyl-coumarins with indole, pyrimidine, pyrazole, pyran, tetrazolo[1,5-a]pyrimidine, pyrimido[1,2-a]benzimidazol, 2-oxo-1,2-dihydropyridine and dihydropyrazolo[3,4-b]pyridine moieties at C6 position of heterocyclic core have been synthesized. Anticancer activity screening on NCI60 cell lines allowed identification of 6-(6-fluoro-1H-indol-2-yl)-7-hydroxy-4,8-dimethyl-2H-chromen-2-one (23) with the highest level of antimitotic activity with mean GI50/TGI values of 3.28/13.24 μM and certain sensitivity profile towards the Non-Small Cell Lung Cancer cell line НОР-92 (GI50/TGI/LC50 values 0.95/4.17/29.9 μM).