Eco-Friendly Synthesis, Characterization and Biological Evaluation of Some Novel Pyrazolines Containing Thiazole Moiety as Potential Anticancer and Antimicrobial Agents

Insight into the therapeutic potential of pyrazole-thiazole hybrids: A comprehensive review

Several pyrazole-thiazole hybrids featuring two potentially bioactive pharmacophores with or without linker have been synthesized using the molecular hybridization approach as target structures by medicinal chemists to modulate multiple drug targets simultaneously. The presented review aims to provide an overview of the diversified and wide array of pharmacological activities of these hybrids bestowing anticancer, antifungal, antibacterial, analgesic, anti-inflammatory, antioxidant, antitubercular, antiviral, antiparasitic, and miscellaneous activities. The structure-activity relationships and potential mechanism of action are also reviewed to shed light on the development of more effective and biotargeted candidates. This review focuses on the latest research advances in the biological profile of pyrazole-thiazole hybrids reported from 2015 to the present, providing medicinal researchers with a comprehensive platform to rationally design and develop more promising pyrazole-thiazole hybrids.

Synthesis and Molecular Docking of Curcumin-Derived Pyrazole-Thiazole Hybrids as Potent α-Glucosidase Inhibitors

α-Glucosidase inhibitors are critical for diabetes management, with pyrazoles and thiazoles emerging as effective options. This research highlights curcumin-based pyrazole-thiazole hybrids as potential inhibitors, synthesizing derivatives and evaluating their inhibitory capabilities. The study involved the synthesis of novel compounds using hydrazonoyl halides, confirmed through elemental and spectral analyses. The synthesized derivatives exhibited significant α-glucosidase inhibition, with IC50 values ranging from 3.37±0.25 to 16.35±0.37 μM. Among them, compound 7e demonstrated the strongest inhibition at 3.37±0.25 μM, outperforming the standard drug acarbose (IC50=5.36±0.31 μM). In silico assessments and molecular docking using AutoDock Vina revealed strong interactions, particularly with compounds 7b, 7e, 7f, and 7g, indicating their potential as stable and effective inhibitors. The results suggest that the synthesized pyrazole-thiazole hybrids hold promise as novel therapeutic agents for diabetes, warranting further exploration of their substituent effects for optimized inhibitor design.

New pyrazole-pyridazine hybrids as selective COX-2 inhibitors: design, synthesis, molecular docking, in silico studies and investigation of their anti-inflammatory potential by evaluation of TNF-α, IL-6, PGE-2 and NO in LPS-induced RAW264.7 macrophages

Hybrid-based design has gained significant interest in the development of novel active substances with anti-inflammatory properties. In this study, two series of new pyrazole-pyridazine-based hybrids, 5a-f and 6a-f, were designed and synthesized. Molecules containing pyrazole and pyridazine pharmacophores in a single molecule, each with a unique mechanism of action and different pharmacological characteristics, are believed to exert higher biological activity. The cell viability of all compounds was evaluated using MTT assay in LPS-induced RAW264.7 macrophages. In vitro COX-1 and COX-2 inhibition assays were performed for the investigation of the anti-inflammatory activity of target compounds. Trimethoxy derivatives 5f and 6f were the most active candidates, demonstrating higher COX-2 inhibitory action than celecoxib, with IC50 values of 1.50 and 1.15 μM, respectively. Bromo derivative 6e demonstrated a COX-2 inhibitory activity comparable to celecoxib. Further, the ability of compounds 5f, 6e, and 6f to inhibit the generation of specific pro-inflammatory cytokines and mediators, including nitric oxide (NO), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and prostaglandin-E2 (PGE-2), in RAW264.7 macrophages stimulated by LPS was also estimated. Compounds 5f and 6f demonstrated the most potent activity. Morover, according to the investigation using molecular modeling studies, derivatives 5f and 6f showed respectable binding affinity towards the COX-2 active site compared to the reference ligand. Moreover, the ADME parameters, physicochemical characteristics, pharmacokinetic characteristics, and l of the most potent compounds were also computed.

Synthesis, In vitro and In silico Studies of Novel Bis-triazolopyridopyrimidines from Curcumin Analogues as Potential Aromatase Agents

Breast cancer remains a major global health issue, particularly affecting women and contributing significantly to mortality rates. Current treatments for estrogen receptor-positive breast cancers, such as aromatase inhibitors, are effective but often come with side effects and resistance issues. This study addresses these gaps by targeting aromatase, an enzyme crucial for estrogen synthesis, which plays a pivotal role in breast cancer progression. The innovative approach involves synthesizing novel bis-triazolopyridopyrimidines, designed to leverage the combined pharmacological benefits of pyridopyrimidine and 1,2,4-triazole structures, known for their potent aromatase inhibition and anti-cancer properties. These compounds were synthesized and characterized using 1H-NMR, 13C-NMR, and MS spectral analyses, and their anticancer efficacy was evaluated through MTT assays against MCF-7 breast cancer cell lines in vitro. Molecular docking analyses revealed strong binding energies with aromatase, particularly for compounds 5 b, 5 c, 10 a, and 10 b, indicating their potential as effective aromatase inhibitors. The study highlights these compounds as promising candidates for further development as therapeutic agents against breast cancer.

Development in the Synthesis of Bioactive Thiazole-Based Heterocyclic Hybrids Utilizing Phenacyl Bromide

Heterocyclic hybrid frameworks represent a burgeoning domain within the realms of drug discovery and medicinal chemistry, attracting considerable attention in recent years. Thiazole pharmacophore fragments, inherent in natural products such as peptide alkaloids, metabolites, and cyclopeptides, have demonstrated a broad spectrum of pharmacological potentials. Given their profound biological significance, a plethora of thiazole-based hybrids have been synthesized through the conjugation of thiazole moieties with bioactive pyrazole and pyrazoline fragments. This review systematically presents a compendium of robust methodologies for the synthesis of thiazole-linked hybrids, employing the (3 + 2) heterocyclization reaction, specifically the Hantzsch-thiazole synthesis, utilizing phenacyl bromide as the substrate. The strategic approach of molecular hybridization has markedly enhanced drug efficacy, mitigated resistance to multiple drugs, and minimized toxicity concerns. The resultant thiazole-linked hybrids exhibit a myriad of medicinal properties viz. anticancer, antibacterial, anticonvulsant, antifungal, antiviral, and antioxidant activities. This compilation of methodologies and insights serves as a valuable resource for medicinal chemists and researchers engaged in the design of novel thiazole-linked hybrids endowed with therapeutic attribute.

Synthesis, In Vitro Evaluation and Molecular Docking Studies of Novel Thiophenyl Thiazolyl-Pyridine Hybrids as Potential Anticancer Agents

Many literature reports revealed the anticancer activity of pyridine and thiazole derivatives, especially in lung cancer. Therefore, a new series of thiazolyl pyridines linked with thiophene moiety via hydrazone group was prepared by one-pot multi-component reaction of (E)-1-(4-methyl-2-(2-(1-(thiophen-2-yl)ethylidene)hydrazinyl)thiazol-5-yl)ethanone with benzaldehyde derivatives and malononitrile in a good yield. Then, compound 5 and the thiazolyl pyridines were investigated for their in vitro anticancer activity against lung cancer (A549) cell line using MTT assay compared to doxorubicin as a reference drug. The structure of all the newly synthesized compounds was established based on spectroscopic data and elemental analyses. For better insight to investigate their mechanism of action on A549 cell line, docking studies were performed, targeting epidermal growth factor receptor (EGFR) tyrosine kinase. The results obtained revealed that the tested compounds displayed excellent anticancer activities against lung cancer cell line except 8c and 8f compared to reference drug. Based on the data obtained, it can be inferred that the novel compounds, as well as their key intermediate, compound 5, demonstrated potent anticancer activity against lung carcinoma by inhibiting EGFR.

Synthesis, Molecular Docking, and Dynamic Simulation Targeting Main Protease (Mpro) of New, Thiazole Clubbed Pyridine Scaffolds as Potential COVID-19 Inhibitors

Many biological activities of pyridine and thiazole derivatives have been reported, including antiviral activity and, more recently, as COVID-19 inhibitors. Thus, in this paper, we designed, synthesized, and characterized a novel series of N-aminothiazole-hydrazineethyl-pyridines, beginning with a N'-(1-(pyridine-3-yl)ethylidene)hydrazinecarbothiohydrazide derivative and various hydrazonoyl chlorides and phenacyl bromides. Their Schiff bases were prepared from the condensation of N-aminothiazole derivatives with 4-methoxybenzaldehyde. FTIR, MS, NMR, and elemental studies were used to identify new products. The binding energy for non-bonding interactions between the ligand (studied compounds) and receptor was determined using molecular docking against the SARS-CoV-2 main protease (PDB code: 6LU7). Finally, the best docked pose with highest binding energy (8a = -8.6 kcal/mol) was selected for further molecular dynamics (MD) simulation studies to verify the outcomes and comprehend the thermodynamic properties of the binding. Through additional in vitro and in vivo research on the newly synthesized chemicals, it is envisaged that the achieved results will represent a significant advancement in the fight against COVID-19.

Synthesis and Molecular Docking of Some Novel 3-Thiazolyl-Coumarins as Inhibitors of VEGFR-2 Kinase

One crucial strategy for the treatment of breast cancer involves focusing on the Vascular Endothelial Growth Factor Receptor (VEGFR-2) signaling system. Consequently, the development of new (VEGFR-2) inhibitors is of the utmost importance. In this study, novel 3-thiazolhydrazinylcoumarins were designed and synthesized via the reaction of phenylazoacetylcoumarin with various hydrazonoyl halides and α-bromoketones. By using elemental and spectral analysis data (IR, ¹H-NMR, ¹³C-NMR, and Mass), the ascribed structures for all newly synthesized compounds were clarified, and the mechanisms underlying their formation were delineated. The molecular docking studies of the resulting 6-(phenyldiazenyl)-2H-chromen-2-one (3, 6a-e, 10a-c and 12a-c) derivatives were assessed against VEGFR-2 and demonstrated comparable activities to that of Sorafenib (approved medicine) with compounds 6d and 6b showing the highest binding scores (-9.900 and -9.819 kcal/mol, respectively). The cytotoxicity of the most active thiazole derivatives 6d, 6b, 6c, 10c and 10a were investigated for their human breast cancer (MCF-7) cell line and normal cell line LLC-Mk2 using MTT assay and Sorafenib as the reference drug. The results revealed that compounds 6d and 6b exhibited greater anticancer activities (IC₅₀ = 10.5 ± 0.71 and 11.2 ± 0.80 μM, respectively) than the Sorafenib reference drug (IC₅₀ = 5.10 ± 0.49 μM). Therefore, the present study demonstrated that thiazolyl coumarins are potential (VEGFR-2) inhibitors and pave the way for the synthesis of additional libraries based on the reported scaffold, which could eventually lead to the development of efficient treatment for breast cancer.

Synthesis, Molecular Docking Study, and Cytotoxicity Evaluation of Some Novel 1,3,4-Thiadiazole as Well as 1,3-Thiazole Derivatives Bearing a Pyridine Moiety

Pyridine, 1,3,4-thiadiazole, and 1,3-thiazole derivatives have various biological activities, such as antimicrobial, analgesic, anticonvulsant, and antitubercular, as well as other anticipated biological properties, including anticancer activity. The starting 1-(3-cyano-4,6-dimethyl-2-oxopyridin-1(2H)-yl)-3-phenylthiourea (2) was prepared and reacted with various hydrazonoyl halides 3a–h, α-haloketones 5a–d, 3-chloropentane-2,4-dione 7a and ethyl 2-chloro-3-oxobutanoate 7b, which afforded the 3-aryl-5-substituted 1,3,4-thiadiazoles 4a–h, 3-phenyl-4-arylthiazoles 6a–d and the 4-methyl-3- phenyl-5-substituted thiazoles 8a,b, respectively. The structures of the synthesized products were confirmed by spectral data. All of the compounds also showed remarkable anticancer activity against the cell line of human colon carcinoma (HTC-116) as well as hepatocellular carcinoma (HepG-2) compared with the Harmine as a reference under in vitro condition. 1,3,4-Thiadiazole 4h was found to be most promising and an excellent performer against both cancer cell lines (IC₅₀ = 2.03 ± 0.72 and 2.17 ± 0.83 µM, respectively), better than the reference drug (IC₅₀ = 2.40 ± 0.12 and 2.54 ± 0.82 µM, respectively). In order to check the binding modes of the above thiadiazole derivatives, molecular docking studies were performed that established a binding site with EGFR TK.

Synthesis and Molecular Docking Study of New Thiazole Derivatives as Potential Tubulin Polymerization Inhibitors

A new series of 2,4-disubstituted thiazole derivatives containing 4-(3,4,5-trimethoxyphenyl) moiety was synthesized and evaluated for their potential anticancer activity as tubulin polymerization inhibitors. All designed compounds were screened for cytotoxic activity against four human cancer cell lines, namely, HepG2, MCF-7, HCT116, and HeLa, using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide assay, with combretastatin A-4 as a reference drug. Compounds 5c, 6d, 7c, 8, and 9a,b showed superior activity against the tested cell lines, with IC₅₀ values ranging from 3.35 ± 0.2 to 18.69 ± 0.9 μM. Further investigation for the most active cytotoxic agents as tubulin polymerization inhibitors was also performed in order to explore the mechanism of their antiproliferative activity. The obtained results suggested that compounds 5c, 7c, and 9a remarkably inhibit tubulin polymerization, with IC₅₀ values of 2.95 ± 0.18, 2.00 ± 0.12, and 2.38 ± 0.14 μM, respectively, which exceeded that of the reference drug combretastatin A-4 (IC₅₀ 2.96 ± 0.18 μM). Molecular docking studies were also conducted to investigate the possible binding interactions between the targeted compounds and the tubulin active site. The interpretation of the results showed clearly that compounds 7c and 9a were identified as the most potent tubulin polymerization inhibitors with promising cytotoxic activity and excellent binding mode in the docking study.

Synthesis, Molecular Docking Study, and Cytotoxic Activity against MCF Cells of New Thiazole–Thiophene Scaffolds

Investigating novel compounds that may be useful in designing new, less toxic, selective, and potent breast anticancer agents is still the main challenge for medicinal chemists. Thus, in the present work, acetylthiophene was used as a building block to synthesize a novel series of thiazole-bearing thiophene derivatives. The structures of the synthesized compounds were elucidated based on elemental analysis and spectral measurements. The cytotoxic activities of the synthesized compounds were evaluated against MCF-7 tumor cells and compared to a cisplatin reference drug, and against the LLC-Mk2 normal cell line using the MTT assay, and the results revealed promising activities for compounds 4b and 13a. The active compounds were subjected to molecular modeling using MOE 2019, the pharmacokinetics were studied using SwissADME, and a toxicity radar was obtained from the biological screening data. The results obtained from the computational studies supported the results obtained from the anticancer biological studies.

Investigating ESIPT and donor-acceptor substituent effects on the photophysical and electrochemical properties of fluorescent 3,5-diaryl-substituted 1-phenyl-2-pyrazolines

This paper describes the synthesis, structural study, and evaluation of electrochemical and photophysical properties by UV-Vis absorption and fluorescence emission analysis (solution and solid-state) of a series of eight 3,5-aryl-substituted 1-phenyl-2-pyrazolines (5), where 3-aryl = 2-OH-C₆H₄ (5a-g) or Ph (5h), and 5-aryl = Ph (a, h), 1-naphthyl (b), 4-Br-C₆H₄ (c), 4-F-C₆H₄ (d), 4-OCH₃-C₆H₄(e), 4-NO₂-C₆H₄ (f), 4-(N(CH₃)₂)-C₆H₄(g). The UV-Vis absorption properties of 2-pyrazolines were evaluated in DCM, MeCN, AcOEt, EtOH, and DMSO as the solvent and showed a fluorescence shift for the polar aprotic solvents. The steady-state fluorescence emission exhibited a band in the blue region when excited at the least energetic transition of each compound, although the excited-state intramolecular proton (ESIPT) effect was not detected. In the solid state, compounds presented similar behavior regarding absorption and emission properties compared to the solution assays. With the electrochemical analyses performed for the synthesized 2-pyrazolines, it was possible to conclude that the redox potentials were influenced by the electronic and steric effects of the substituents on the aryl rings and, according to the electronic nature of the substituents, which electron-donating groups were favored. Finally, the TD-DFT analyses revealed that all compounds had delocalized electron density throughout the 2-pyrazolines unit and were not influenced by the substituent bonded at C-5. Nonetheless, LUMO orbital analysis showed that only derivatives 5b and 5f have this localized density over the substituents.

2,2-Dichloro-N-[5-[2-[3-(4-methoxyphenyl)-5-phenyl-3,4-dihydro-2H-pyrazol-2-yl]-2-oxoethyl]sulfanyl-1,3,4-thiadiazol-2-yl]acetamide

The pharmacophore hybridization approach is widely used for the design of drug-like small molecules with anticancer properties. In the present work, a “cost-effective” approach to the synthesis of the novel non-condensed pyrazoline-bearing hybrid molecule with 1,3,4-thiadiazole and dichloroacetic acid moieties is proposed. The 5-amino-1,3,4-thiadiazole-2-thiol was used as a starting reagent, and the synthetic strategy includes stepwise alkylation of the sulfur atom and acylation of the nitrogen atom to obtain the target title compound. The structure of the synthesized 2,2-dichloro-N-[5-[2-[3-(4-methoxyphenyl)-5-phenyl-3,4-dihydro-2H-pyrazol-2-yl]-2-oxoethyl]sulfanyl-1,3,4-thiadiazol-2-yl]acetamide (yield 90%) was confirmed by 1H, 13C, 2D NMR and LC-MS spectra. Anticancer activity in “60 lines screening” (NCI DTP protocol) was studied in vitro for the title compound.

Synthesis and Biological Evaluation of Thiazolyl-Ethylidene Hydrazino-Thiazole Derivatives: A Novel Heterocyclic System

The reaction of 2-(1-(2-(2-(4-methoxybenzylidene)hydrazinyl)-4-methylthiazol-5-yl)ethylidene)hydrazinecarbothioamide with a range of hydrazonoyl chlorides and α-halo-compounds yielded three new series of thiazole derivatives. Chemical and physical techniques were used to analyze all newly prepared derivatives (1H-NMR, 13C-NMR, FT-IR and mass spectrometry). The potential antimicrobial and anticancer properties of the synthesized derivatives were investigated using various in vitro biological experiments. Most of the thiazole compounds tested were effective against Gram-positive and Gram-negative bacteria. In addition, a minimum inhibition concentration was determined for the antibiotic properties of the most active produced substances. The cytotoxic activities were tested on HepG-2 (liver carcinoma), HCT-116 (colorectal carcinoma) and MDA-MB-231 (breast carcinoma) cell lines in comparison with cisplatin reference drug and using colorimetric MTT assay. The results detected that compound 10c was the most potent against the three tested cell lines. Interestingly, when the tested compounds were evaluated for their toxicity against normal (MRC-5) cells, they exhibited low toxic effects indicating the safe use of most of them that may require further in vivo and pharmacological studies.

Microwave-Assisted One Pot Three-Component Synthesis of Novel Bioactive Thiazolyl-Pyridazinediones as Potential Antimicrobial Agents against Antibiotic-Resistant Bacteria

Pyridazine and thiazole derivatives have various biological activities such as antimicrobial, analgesic, anticancer, anticonvulsant, antitubercular and other anticipated biological properties. Chitosan can be used as heterogeneous phase transfer basic biocatalyst in heterocyclic syntheses. Novel 1-thiazolyl-pyridazinedione derivatives were prepared via multicomponent synthesis under microwave irradiation as ecofriendly energy source and using the eco-friendly naturally occurring chitosan basic catalyst with high/efficient yields and short reaction time. All the prepared compounds were fully characterized by spectroscopic methods, and their in vitro biological activities were investigated. The obtained results were compared with those of standard antibacterial/antifungal agents. DFT calculations and molecular docking studies were used to investigate the electronic properties and molecular interactions with specific microbial receptors.

Thiazole-Based Thiosemicarbazones: Synthesis, Cytotoxicity Evaluation and Molecular Docking Study

INTRODUCTION

Hybrid drug design has developed as a prime method for the development of novel anticancer therapies that can theoretically solve much of the pharmacokinetic disadvantages of traditional anticancer drugs. Thus a number of studies have indicated that thiazole-thiophene hybrids and their bis derivatives have important anticancer activity. Mammalian Rab7b protein is a member of the Rab GTPase protein family that controls the trafficking from endosomes to the TGN. Alteration in the Rab7b expression is implicated in differentiation of malignant cells, causing cancer.

METHODS

1-(4-Methyl-2-(2-(1-(thiophen-2-yl) ethylidene) hydrazinyl) thiazol-5-yl) ethanone was used as building block for synthesis of novel series of 5-(1-(2-(thiazol-2-yl) hydrazono) ethyl) thiazole derivatives. The bioactivities of the synthesized compounds were evaluated with respect to their antitumor activities against MCF-7 tumor cells using MTT assay. Computer-aided docking protocol was performed to study the possible molecular interactions between the newly synthetic thiazole compounds and the active binding site of the target protein Rab7b. Moreover, the in silico prediction of adsorption, distribution, metabolism, excretion (ADME) and toxicity (T) properties of synthesized compounds were carried out using admetSAR tool.

RESULTS

The results obtained showed that derivatives 9 and 11b have promising activity (IC50 = 14.6 ± 0.8 and 28.3 ± 1.5 µM, respectively) compared to Cisplatin (IC50 = 13.6 ± 0.9 µM). The molecular docking analysis reveals that the synthesized compounds are predicted to be fit into the binding site of the target Rab7b. In summary, the synthetic thiazole compounds 1-17 could be used as potent inhibitors as anticancer drugs.

CONCLUSION

Promising anticancer activity of compounds 9 and 11 compared with cisplatin reference drug suggests that these ligands may contribute as lead compounds in search of new anticancer agents to combat chemo-resistance.

An Overview of the Synthesis and Antimicrobial, Antiprotozoal, and Antitumor Activity of Thiazole and Bisthiazole Derivatives

Thiazole, a five-membered heteroaromatic ring, is an important scaffold of a large number of synthetic compounds. Its diverse pharmacological activity is reflected in many clinically approved thiazole-containing molecules, with an extensive range of biological activities, such as antibacterial, antifungal, antiviral, antihelmintic, antitumor, and anti-inflammatory effects. Due to its significance in the field of medicinal chemistry, numerous biologically active thiazole and bisthiazole derivatives have been reported in the scientific literature. The current review provides an overview of different methods for the synthesis of thiazole and bisthiazole derivatives and describes various compounds bearing a thiazole and bisthiazole moiety possessing antibacterial, antifungal, antiprotozoal, and antitumor activity, encouraging further research on the discovery of thiazole-containing drugs.

Pyrazoline Hybrids as Promising Anticancer Agents: An Up-to-Date Overview

Pyrazolines are five-membered heterocycles possessing two adjacent nitrogens. They have attracted significant attention from organic and medicinal chemists due to their potent biological activities and the numerous possibilities for structural diversification. In the last decade, they have been intensively studied as targets for potential anticancer therapeutics, producing a steady yearly rise in the number of published research articles. Many pyrazoline derivatives have shown remarkable cytotoxic activities in the form of heterocyclic or non-heterocyclic based hybrids, such as with coumarins, triazoles, and steroids. The enormous amount of related literature in the last 5 years prompted us to collect all these published data from screening against cancer cell lines, or protein targets like EGFR and structure activity relationship studies. Therefore, in the present review, a comprehensive account of the compounds containing the pyrazoline nucleus will be provided. The chemical groups and the structural modifications responsible for the activity will be highlighted. Moreover, emphasis will be given on recent examples from the literature and on the work of research groups that have played a key role in the development of this field.

Recent advancements in the development of bioactive pyrazoline derivatives

Pyrazolines remain privileged heterocycles in drug discovery. 2-Pyrazoline scaffold has been proven as a ubiquitous motif which is present in a number of pharmacologically important drug molecules such as antipyrine, ramifenazone, ibipinabant, axitinib etc. They have been widely explored by the scientific community and are reported to possess wide spectrum of biological activities. For combating unprecedented diseases and worldwide increasing drug resistance, 2-pyrazoline has been tackled as a fascinating pharmacophore to generate new molecules with improved potency and lesser toxicity along with desired pharmacokinetic profile. This review aims to summarizes various recent advancements in the medicinal chemistry of pyrazoline based compounds with the following objectives: (1) To represent inclusive data on pyrazoline based marketed drugs as well as therapeutic candidates undergoing preclinical and clinical developments; (2) To discuss recent advances in the medicinal chemistry of pyrazoline derivatives with their numerous biological significances for the eradication of various diseases; (3) Summarizes structure-activity relationships (SAR) including in silico and mechanistic studies to afford ideas for the design and development of novel compounds with desired therapeutic implications.

New chalcone-type compounds and 2-pyrazoline derivatives: synthesis and caspase-dependent anticancer activity

Aim: There is a continuous and urgent need for new anticancer agents with novel structures and target selectivity. Methods & results: The anticancer activity of the prepared compounds was assessed against human lung (A549) and stomach (AGS) cancer cell lines and evaluated in the noncancer human lung fibroblast (MRC-5) cell line. 2-Pyrazolines were devoid of toxicity in all cell lines used, chalcones bearing a β-(benz)imidazole moiety being toxic toward AGS cell line. Mechanistic studies showed that these compounds trigger loss of cell viability and mitochondrial membrane potential, while eliciting morphological traits compatible with regulated cell death, which was ultimately shown to derive from caspase activation, specifically caspase-3. Conclusion: Chalcones 1-3 have been identified as new and promising anticancer agents toward the AGS cell line.

Recurrent π–π stacking motifs in three new 4,5-dihydropyrazolyl–thiazole–coumarin hybrids: X-ray characterization, Hirshfeld surface analysis and DFT calculations

Two different π–π stacking modes are described, studied and characterized in the crystal structures of 4,5-dihydropyrazolyl–thiazole–coumarin hybrids, including a partial aliphatic ring.