Design, Synthesis, Computational Studies, and Anti-Proliferative Evaluation of Novel Ethacrynic Acid Derivatives Containing Nitrogen Heterocycle, Urea, and Thiourea Moieties as Anticancer Agents.

In the present work, the synthesis of new ethacrynic acid (EA) derivatives containing nitrogen heterocyclic, urea, or thiourea moieties via efficient and practical synthetic procedures was reported. The synthesised compounds were screened for their anti-proliferative activity against two different cancer cell lines, namely, HL60 (promyelocytic leukaemia) and HCT116 (human colon carcinoma). The results of the in vitro tests reveal that compounds 1-3, 10, 16(a-c), and 17 exhibit potent anti-proliferative activity against the HL60 cell line, with values of the percentage of cell viability ranging from 20 to 35% at 1 µM of the drug and IC50 values between 2.37 µM and 0.86 µM. Compounds 2 and 10 showed a very interesting anti-proliferative activity of 28 and 48% at 1 µM, respectively, against HCT116. Two PyTAP-based fluorescent EA analogues were also synthesised and tested, showing good anti-proliferative activity. A test on the drug-likeness properties in silico of all the synthetised compounds was performed in order to understand the mechanism of action of the most active compounds. A molecular docking study was conducted on two human proteins, namely, glutathione S-transferase P1-1 (pdb:2GSS) and caspase-3 (pdb:4AU8) as target enzymes. The docking results show that compounds 2 and 3 exhibit significant binding modes with these enzymes. This finding provides a potential strategy towards developing anticancer agents, and most of the synthesised and newly designed compounds show good drug-like properties.

Improvement of the Chemical Reactivity of Michael Acceptor of Ethacrynic Acid Correlates with Antiproliferative Activities.

The present study aims to report the design, synthesis, and biological activity of new ethacrynic acid (EA) analogs (6-10) obtained by the double modulation of the carboxylic acid moiety and the aromatic ring with the aim to increase the chemical reactivity of Michael acceptor of EA. All obtained compounds were characterized by 1H and 13C NMR, IR, and high-resolution mass spectrometry. The antiproliferative activity was evaluated in vitro using MMT test, in a first step, against HL60 cell line and in a second step, on a panel of human cancer cell lines such as HCT116, A549, MCF7, PC3, U87-MG, and SKOV3, and normal cell line MRC5 in comparison with positive control doxorubicin. Among all the tested compounds, the product 8 containing a propargyl and a hydroxyl groups, allowing an intramolecular hydrogen bond with the keto group of EA, exhibited a pronounced and selective activity in a nanomolar range against HL60, A549, PC3, and MCF7 with IC50 values of 15, 41.2, 68.7, and 61.5 nM, respectively. Compound 8 also showed a good selectivity index (SI) against HL60 and moderate SI against the other three human cancer cells (A549, PC3, and MCF7). The study of the structure-activity relationship showed that both modifications of the carboxylic group and the introduction of an intramolecular hydrogen bond are highly required to improve the antiproliferative activities. The molecular modeling studies of compound 8 revealed that it favorably binds to the glutathione S-transferase active site, which may explain its interesting anticancer activity. These new compounds have potential to be developed as novel therapeutic agents against various cancer types.

Synthesis, Anticancer Activities and Molecular Docking Studies of a Novel Class of 2-Phenyl-5,6,7,8-tetrahydroimidazo [1,2-b]pyridazine Derivatives Bearing Sulfonamides.

In the present study, new 2-phenyl-5,6,7,8-tetrahydroimidazo [1,2-b]pyridazines bearing sulfonamides were synthesized, characterized and evaluated for their anticancer activities. The structures of these derivatives were elucidated by 1H NMR, 13C NMR, infrared and high-resolution mass spectrometry for further validation of the target compound structures. The anticancer activities of the new molecules were evaluated against five human cancer cell lines, including A-549, Hs-683, MCF-7, SK-MEL-28 and B16-F10 cell lines using 5-fluorouracil and etoposide as the reference drugs. Among the tested compounds, 4e and 4f exhibited excellent activities in the same range of the positive controls, 5-fluorouracil and etoposide, against MCF-7 and SK-MEL-28 cancer cell lines, with IC50 values ranging from 1 to 10 µM. The molecular docking studies of 4e and 4f showed a strong binding with some kinases, which are linked to MCF-7 and SK-MEL-28 cancer cell lines.

Synthesis and evaluation of a novel class of ethacrynic acid derivatives containing triazoles as potent anticancer agents.

For unmet clinical needs, a novel class of ethacrynic acid (EA) derivatives containing triazole moieties (3a-i and 8) were designed, synthesized and evaluated as new anticancer agents. The in vitro anti-proliferative activities were assessed first on HL60 cell line and in a second stage, the two selected compounds 3a and 3c were tested on a panel of human cancer cell lines (A549, MCF7, PC3, U87-MG, SKOV3 and HCT116) and on a normal cell line (MCR5). Compound3c exhibited very good antitumor activities with IC50 values of 20.2, 56.5 and 76.8 nM against A549, PC3 and U87-MG cell lines respectively, which is 2.8- and 1.3-fold more active than doxorubicin on A549 and U87-MG cancer cells, respectively. In addition, compound 3c displays a very good safety index (SI) of 82 fold for A549. Compound 3a showed also good IC50 values of 50 nM on both A549 and PC3 cells and lower selectivity compared to 3c for A549 and PC3 vs. MCR5 with SI of 33 and 18 fold, respectively. The measurement of mitochondrial membrane potential on HCT116 cells after treatments by either 3a or 3c showed that both compounds induced mitochondrial dysfunctions causing thus caspase-induced apoptosis.

Synthesis and biological evaluation of ethacrynic acid derivatives bearing sulfonamides as potent anti-cancer agents.

A series of ethacrynic acid (2-[2,3-dichloro-4-(2-methylidenebutanoyl)phenoxy]acetic acid) (EA, Edecrin) containing sulfonamides linked via three types of linkers namely 1,2-ethylenediamine, piperazine and 4-aminopiperidine was synthesized and subsequently evaluated in vitro against HL60 and HCT116 cancer cell lines. All the EA analogs, excluding 6a and 6c, showed anti-proliferative activity with IC50s in the micromolar range (less than 4 uM). Three derivatives 6b, 7b and 7e were selected for their interesting dual activity on HL60 cell line in order to be further evaluated against a panel of cancer cell lines (HCT116, A549, MCF7, PC3, U87-MG and SKOV3) as well as on MRC5 as a normal cell line. These compounds displayed IC50 values in nanomolar range against A549, MCF7, PC3 and HCT116 cell lines, deducing the discovery that piperazine or 4-aminopiperidine is the linker's best choice to develop EA analogs with highly potent anti-proliferative activities own up to 24 nM. Besides, in terms of selectivity, those linkers are more suitable offering safety ratios of up to 63.8.

"On Water" Palladium Catalyzed Direct Arylation of 1H-Indazole and 1H-7-Azaindazole.

The C3 direct arylation of 1H-indazole and 1H-7-azaindazole has been a significant challenge due to the lack of the reactivity at this position. In this paper, we describe a mild and an efficient synthesis of new series of C3-aryled 1H-indazoles and C3-aryled 1H-7-azaindazoles via a C3 direct arylation using water as solvent. On water, PPh3 was effective as a ligand along with a lower charge of the catalyst Pd(OAc)2 (5 mol%) at 100 °C, leading to C3-aryled 1H-indazoles or C3-aryled 1H-7-azaindazoles in moderate to good yields.

Design of new small molecules derived from indolin-2-one as potent TRKs inhibitors using a computer-aided drug design approach.

Tropomyosin receptor kinase (TRKs) enzymes are responsible for cancers associated with the neurotrophic tyrosine kinase receptor gene fusion and are identified as effective targets for anticancer drug discovery. A series of small-molecule indolin-2-one derivatives showed remarkable biological activity against TRKs enzymatic activity. These small molecules could have an excellent profile for pharmaceutical application in the treatment of cancers caused by TRKs activity. The aim of this study is to modify the structure of these molecules to obtain new molecules with improved TRK inhibitory activity and pharmacokinetic properties favorable to the design of new drugs. Based on these series, we carried out a 3D-QSAR study. As a result, robust and reliable CoMFA and CoMSIA models are developed and applied to the design of 11 new molecules. These new molecules have a biological activity superior to the most active molecule in the starting series. The eleven designed molecules are screened using drug-likeness, ADMET proprieties, molecular docking, and MM-GBSA filters. The results of this screening identified the T1, T3, and T4 molecules as the best candidates for strong inhibition of TRKs enzymatic activity. In addition, molecular dynamics simulations are performed for TRK free and complexed with ligands T1, T3, and T4 to evaluate the stability of ligand-protein complexes over the simulation time. On the other hand, we proposed experimental synthesis routes for these newly designed molecules. Finally, the designed molecules T1, T2, and T3 have great potential to become reliable candidates for the conception of new drug inhibitors of TRKs.Communicated by Ramaswamy H. Sarma.

Development of a new experimental NMR strategy for covalent cysteine protease inhibitors screening: toward enhanced drug discovery.

In the development of antiviral drugs, proteases and polymerases are among the most important targets. Cysteine proteases, also known as thiol proteases, catalyze the degradation of proteins by cleaving peptide bonds using the nucleophilic thiol group of cysteine. As part of our research, we are examining how cysteine, an essential amino acid found in the active site of the main protease (Mpro) enzyme in SARS-CoV-2, interacts with electrophilic groups present in ethacrynic acid (EA) and compounds 4, 6, and 8 to form sulfur-carbon bonds. Nuclear magnetic resonance (NMR) spectroscopy was used to monitor the reaction rate between cysteine and Michael acceptors. We found that the inhibitory activity of these compounds towards Mpro is correlated to their chemical reactivity toward cysteine. This approach may serve as a valuable tool in drug development for detecting potential covalent inhibitors of Mpro and other cysteine proteases.

Design, synthesis, in-vitro, in-silico, DFT and POM studies of a novel family of sulfonamides as potent anti-triple-negative breast cancer agents.

In this study, a new family of ethacrynic acid-sulfonamides and indazole-sulfonamides was synthesized and tested in vitro against MDA-MB-468 triple-negative breast cancer cells and PBMCs human peripheral blood mononuclear cells, using the MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay. The aim of this research is to discover novel compounds with potential therapeutic effects on breast cancer. The antiproliferative activity of these compounds showed a significant dose-dependent activity, with IC50 values ranging between 2.83 and 7.52 µM. The lead compounds 8 and 9 displayed similar IC50 values to paclitaxel with 2.83, 3.84 and 2.72 µM, respectively. This highlights the novelty and potential of these compounds as alternatives to current treatments. The binding properties of 8, 9, and paclitaxel with the active sites of the PARP1(Poly(ADP-ribose) polymérase 1) and EGFR (Epidermal growth factor receptor) proteins were analyzed by molecular docking methods showing, for PARP1 protein, binding affinities of -9.8 Kcal /mol, -10 Kcal /mol, and -9.4 Kcal /mol, respectively. While their binding affinities for EGFR protein are -7.5 Kcal/mol, -7.2 Kcal/mol and -6.9 Kcal/mol, respectively. Moreover, drug-likeness and ADMET (Absorption-distribution-metabolism-excretion-toxicity) analyses demonstrated that both molecules are orally bioavailable and have good pharmacokinetic and non-toxic profiles. DFT (Density functional theory) was also carried out on both compounds 8 and 9 additionally to POM (Petra/Osiris/Molinspiration) studies on all compounds. The outcomes of this study suggest that compounds 8 and 9 are promising candidates for further development as therapeutic agents against triple-negative breast cancer.