The synthesis and antiproliferative activities of new arylidene-hydrazinyl-thiazole derivatives

Synthesis of hydrazinylthiazole carboxylates: a mechanistic approach for treatment of diabetes and its complications

Aim: The deaths of thousands of people and millions affected by diabetes mellitus triggered us to look for alternative possible solutions to cure diabetes and its complications. Materials & methods: A series of hydrazinylthiazole carboxylates (3a-n) was prepared by cyclocondensation reaction of thiosemicarbazones with ethyl 2-chloroacetoacetate. These compounds were screened for antidiabetic potential through α-amylase inhibition, antiglycation and antioxidant assays. Results & conclusion: Most of the compounds exhibited a promising antidiabetic property. Compounds 3e and 3h showed excellent α-amylase and glycation inhibition properties. The hemolytic assay indicated that all compounds are biocompatible. Docking studies carried out on α-amylase target showed correlation between in vitro inhibition and binding energy.

Visiblelight-induced ternary electron donor-acceptor complex enabled synthesis of 2-(2-hydrazinyl) thiazole derivatives and the assessment of their antioxidant and antidiabetic therapeutic potential

A mild and eco-friendly visible-light-induced synthesis of 2-(2-hydrazinyl) thiazole from readily accessible thiosemicarbazide, carbonyl, and phenacyl bromide in the absence of a metal catalyst and/or any extrinsic photosensitizer is reported. This approach only requires a source of visible light and a green solvent at room temperature to produce the medicinally privileged scaffolds of hydrazinyl-thiazole derivatives in good to outstanding yields. Experimental studies support the in situ formation of a visible-light-absorbing, photosensitized colored ternary EDA complex. The next step is to prepare a pair of radicals in an excited state, which makes it easier to prepare thiazole derivatives through a SET and PCET process. DFT calculations additionally supported the mechanistic analysis of the course of the reaction. The antioxidant and antidiabetic properties of some of the compounds in the synthesized library were tested in vitro. All the investigated compounds demonstrated appreciable antioxidant activity, as evidenced by the reducing power experiment and the IC₅₀ values of the DPPH radical scavenging experiment. Furthermore, the IC₅₀ values for 4c, 4d, and 4g also demonstrated a strong α-amylase inhibitory effect.

4-[Bis(thiazol-2-ylamino)methyl]phenol

We have designed and synthesized novel bis-thiazole derivative. A 4-[bis(thiazol-2-ylamino)methyl]phenol was efficiently prepared in 71% yield by the reaction of 2-aminothiazole with 4-hydroxybenzaldehyde in ethanol for 24 h. The structure of newly obtained compound was characterized by 1H, 13C NMR and mass spectrometry. Bis-thiazole derivative exhibits high tyrosinase inhibitory activity with an IC50 value of 29.71 μM. This inhibitory activity is 2.4 times higher than that of activity of kojic acid (IC50 72.27 µM) and almost 13 times higher than that of ascorbic acid (IC50 385.6 µM). Obtained data suggest that the presented compound may be a leading candidate for a tyrosinase inhibitor.

Spectrofluorimetric and Computational Investigation of New Phthalimide Derivatives towards Human Neutrophil Elastase Inhibition and Antiproliferative Activity

Herein, nine phthalimide-based thiazoles (4a-4i) were synthesized and investigated as new human neutrophil elastase (HNE) inhibitors using spectrofluorimetric and computational methods. The most active compounds containing 4-trifluoromethyl (4c), 4-naphthyl (4e) and 2,4,6-trichloro (4h) substituents in the phenyl ring exhibited high HNE inhibitory activity with IC₅₀ values of 12.98-16.62 µM. Additionally, compound 4c exhibited mixed mechanism of action. Computational investigation provided a consistent picture of the ligand-receptor pattern of inter-actions, common for the whole considered group of compounds. Moreover, compounds 4b, 4c, 4d and 4f showed high antiproliferative activity against human cancer cells lines MV4-11, and A549 with IC₅₀ values of 8.21 to 25.57 µM. Additionally, compound 4g showed high activity against MDA-MB-231 and UMUC-3 with IC₅₀ values of 9.66 and 19.81 µM, respectively. Spectrophotometric analysis showed that the most active compound 4c demonstrated high stability under physiological conditions.

Novel 1,3-Thiazole Analogues with Potent Activity against Breast Cancer: A Design, Synthesis, In Vitro, and In Silico Study

Breast cancer is the most common cancer in women, responsible for over half a million deaths in 2020. Almost 75% of FDA-approved drugs are mainly nitrogen- and sulfur-containing heterocyclic compounds, implying the importance of such compounds in drug discovery. Among heterocycles, thiazole-based heterocyclic compounds have demonstrated a broad range of pharmacological activities. In the present study, a novel set of 1,3-thiazole derivatives was designed and synthesized based on the coupling of acetophenone derivatives, and phenacyl bromide was substituted as a key reaction step. The activity of synthesized compounds was screened against the proliferation of two breast cancer cell lines (MCF-7 and MDA-MB-231). Almost all compounds exhibited a considerable antiproliferative activity toward the breast cancer cells as compared to staurosporine, with no significant cytotoxicity toward the epithelial cells. Among the synthesized compounds, compound 4 exhibited the most potent antiproliferative activity, with an IC₅₀ of 5.73 and 12.15 µM toward MCF-7 and MDA-MB-231 cells, respectively, compared to staurosporine (IC₅₀ = 6.77 and 7.03 µM, respectively). Exploring the mechanistic insights responsible for the antiproliferative activity of compound 4 revealed that compound 4 possesses a significant inhibitory activity toward the vascular endothelial growth factor receptor-2 (VEGFR-2) with (IC₅₀ = 0.093 µM) compared to Sorafenib (IC₅₀ = 0.059 µM). Further, compound 4 showed the ability to induce programmed cell death by triggering apoptosis and necrosis in MCF-7 cells and to induce cell cycle arrest on MCF-7 cells at the G1 stage while decreasing the cellular population in the G2/M phase. Finally, detailed in silico molecular docking studies affirmed that this class of compounds possesses a considerable binding affinity toward VEGFR2 proteins. Overall, these results indicate that compound 4 could be a promising lead compound for developing potent anti-breast cancer compounds.

Phenolic Thiazoles with Antioxidant and Antiradical Activity. Synthesis, In Vitro Evaluation, Toxicity, Electrochemical Behavior, Quantum Studies and Antimicrobial Screening

Oxidative stress represents the underlying cause of many chronic diseases in human; therefore, the development of potent antioxidant compounds for preventing or treating such conditions is useful. Starting from the good antioxidant and antiradical properties identified for the previously reported Dihydroxy-Phenyl-Thiazol-Hydrazinium chloride (DPTH), we synthesized a congeneric series of phenolic thiazoles. The radical scavenging activity, and the antioxidant and chelation potential were assessed in vitro, a series of quantum descriptors were calculated, and the electrochemical behavior of the synthesized compounds was studied to evaluate the impact on the antioxidant and antiradical activities. In addition, their antibacterial and antifungal properties were evaluated against seven aerobic bacterial strains and a strain of C. albicans, and their cytotoxicity was assessed in vitro. Compounds 5a-b, 7a-b and 8a-b presented remarkable antioxidant and antiradical properties, and compounds 5a-b, 7a and 8a displayed good Cu⁺² chelating activity. Compounds 7a and 8a were very active against P. aeruginosa ATCC 27853 compared to norfloxacin, and proved less cytotoxic than ascorbic acid against the human keratinocyte cell line (HaCaT cells, CLS-300493). Several phenolic compounds from the synthesized series presented excellent antioxidant activity and notable anti-Pseudomonas potential.

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.

Phenanthrotriazine Derivatives Containing Arylidine Hydrazone Moieties as Novel Potential c-Met Inhibitors with Anticancer Effect

Cancer is the second cause of death in the world and the discovery of novel anticancer agents is of vital importance to provide better therapeutic options for cancer patients. In this study, a new series of 12 arylidene hydrazone phenanthrotriazine derivatives were designed, synthesized, and tested in-vitro for antiproliferative activity against three cancer cell lines including colorectal cancer (HT-29), breast cancer (MCF-7) and leukemia (MOLT-4) cells and also against Vero normal cells. The effect of derivatives on cell cycle and apoptosis induction were studied by flow cytometric propidium iodide/RNase assay and Hoechst 33258 staining, respectively, while docking analysis was used to investigate the interactions of synthesized derivatives with the c-Met receptor kinase domain. Some compounds showed considerable antiproliferative activity against tested cancer cells. The most potent derivative was 9k bearing pyrrole moiety with IC₅₀ values of 14.3, 4.7 and 1.7 µM against HT-29, MCF-7 and MOLT-4 cells, respectively, while it showed negligible activity against Vero normal cells (IC₅₀: 95.4 µM). Derivatives bearing 2-nitrophenyl (9g), 4-cyanophenyl (9j), pyrrole (9k), and thiophene (9l) moieties induced G0/G1 cell cycle arrest and also apoptosis at higher doses in MCF-7 cells. Docking study showed that the phenanthrotriazine backbone form H-bond interactions with Asn1209, while phenyl moieties of the pendants generate different hydrophobic interactions with the Asp1164 and Asp1231 residues of c-Met. In conclusion, phenanthrene 1,2,4-triazines, especially the ones with less influence on normal cells, may constitute promising compounds for the discovery of antiproliferative agents with potential c-Met inhibitory capacity.

Tropinone-Derived Alkaloids as Potent Anticancer Agents: Synthesis, Tyrosinase Inhibition, Mechanism of Action, DFT Calculation, and Molecular Docking Studies

A new series of hybrid compounds with tropinone and thiazole rings in the structure was designed and synthesized as potential anticancer agents. They were tested against human multiple myeloma (RPMI 8226), lung carcinoma (A549), breast adenocarcinoma (MDA-MB-231), and mouse skin melanoma (B16-F10) cell lines. Toxicity was tested on human normal skin fibroblasts (HSF) and normal colon fibroblasts (CCD-18Co). The growth inhibition mechanism of the most active derivative was analyzed through investigation of its effect on the distribution of cell cycle phases and ability to induce apoptosis and necrosis in RPMI 8226 and A549 cancer cells. The tyrosinase inhibitory potential was assessed, followed by molecular docking studies. Compounds 3a–3h show high anticancer activity against MDA-MB-231 and B16-F10 cell lines with IC₅₀ values of 1.51–3.03 µM. Moreover, the cytotoxic activity of the investigated compounds against HSF and CCD-18Co cells was 8–70 times lower than against the cancer cells or no toxicity was shown in our tests, with derivative 3a being particularly successful. The mechanism of action of compound 3a in RPMI 8226 cell was shown to be through induction of cell death through apoptosis. The derivatives show ability to inhibit the tyrosinase activity with a mixed mechanism of inhibition. The final molecular docking results showed for IC₅₀ distinct correlation with experiment.

Novel molecular discovery of promising amidine-based thiazole analogues as potent dual Matrix Metalloproteinase-2 and 9 inhibitors: Anticancer activity data with prominent cell cycle arrest and DNA fragmentation analysis effects

Thiazole derivatives are known to possess various biological activities such as antiparasitic, antifungal, antimicrobial and antiproliferative activities. Matrix metalloproteinases (MMPs) are important protease target involved in tumor progression including angiogenesis, tissue invasion, and migration. Therefore, MMPs have also been reported as potential diagnostic and prognostic biomarkers in many types of cancer. Herein, new aryl thiazoles were synthesized and evaluated for their anticancer effects on a panel of cancer cell lines including the invasive MDA-MB-231 line. Some of these compounds showed IC₅₀ values in the submicromolar range in anti-proliferative assays. In order to examine the relationship between their anticancer activity and MMPs targets, the compounds were evaluated for their inhibitory effects on MMP-2 and 9. That data obtained revealed that most of these compounds were potent dual MMP-2/9 inhibitors at nanomolar concentrations. Among these, 2-(1-(2-(2-((E)-4-iodobenzylidene)hydrazineyl)-4-methylthiazol-5-yl)ethylidene)hydrazine-1-carboximidamide (4a) was the most potent non-selective dual MMP-2/9 inhibitor with inhibitory concentrations of 56 and 38 nM respectively. When compound 4a was tested in an MDA-MB-231, HCT-116, MCF-7 model, it effectively inhibited tumor growth, strongly induced cancer cell apoptosis, inhibit cell migration, and suppressed cell cycle progression leading to DNA fragmentation. Taken together, the results of our studies indicate that the newly discovered thiazole-based MMP-2/9 inhibitors have significant potential for anticancer treatment.

Hydrazine clubbed 1,3-thiazoles as potent urease inhibitors: design, synthesis and molecular docking studies

Synthesis of a novel series of hydrazine clubbed 1,3-thiazoles (5a-m) has been described by reacting hydrazine-1-carbothioamides (3a-k) with α-chloro- or bromo-acetophenones (4a-d) in refluxing ethanol in good to excellent yields (65-86%). Structural confirmation was based upon spectroscopic techniques such as ¹H-NMR, ¹³C-NMR, FT-IR and mass spectrometry. The biological application of these motifs has been demonstrated in terms of their strong urease inhibition activity. The results of in vitro study revealed that all the compounds are the potent inhibitors of urease. The IC₅₀ (ranging in between 110 and 440 nM) values were higher as compared to that of standard, i.e., thiourea (IC₅₀ = 490 ± 10 nM). The synthesized compounds were docked at the active sites of the Jack bean urease enzyme in order to explore the possible binding interactions of enzyme-ligand complexes; the results reinforced the in vitro biological activity results.

Structural Properties and Catalytic Activity of Binary Poly (vinyl alcohol)/Al2O3 Nanocomposite Film for Synthesis of Thiazoles

A solution casting technique was applied to prepare a binary poly (vinyl alcohol)/Al2O3 nanocomposite. The structural properties of nanocomposite were investigated using Fourier-transform infrared spectra, field emission scanning electron microscope, energy dispersive X-ray analyses, and X-ray diffraction. The hybrid PVA/Al2O3 film exhibited a conspicuous catalytic performance for synthesis of thiazole derivatives under mild reaction conditions. Moreover, the optimization of catalytic efficiency and reusability of this nanocomposite have been investigated.

Thiazole-containing compounds as therapeutic targets for cancer therapy

In the last few decades, considerable progress has been made in anticancer agents development, and several new anticancer agents of natural and synthetic origin have been produced. Among heterocyclic compounds, thiazole, a 5-membered unique heterocyclic motif containing sulphur and nitrogen atoms, serves as an essential core scaffold in several medicinally important compounds. Thiazole nucleus is a fundamental part of some clinically applied anticancer drugs, such as dasatinib, dabrafenib, ixabepilone, patellamide A, and epothilone. Recently, thiazole-containing compounds have been successfully developed as possible inhibitors of several biological targets, including enzyme-linked receptor(s) located on the cell membrane, (i.e., polymerase inhibitors) and the cell cycle (i.e., microtubular inhibitors). Moreover, these compounds have been proven to exhibit high effectiveness, potent anticancer activity, and less toxicity. This review presents current research on thiazoles and elucidates their biological importance in anticancer drug discovery. The findings may aid researchers in the rational design of more potent and bio-target specific anticancer drug molecules.

Synthesis, anticancer activity and mechanism of action of new thiazole derivatives

Thiazole derivatives are recognized to possess various biological activities as antiparasitic, antifungal, antimicrobial and antiproliferative. The present work reports the synthesis of 22 new substances belonging to two classes of compounds: thiosemicarbazones and thiazoles, with the purpose of developing new drugs that present high specificity for tumor cells and low toxicity to the organism. A cytotoxic screening was performed to evaluate the performance of the new derivatives in five tumor cell lines. Eight compounds were shown to be promising in at least three tumor cell lines. These compounds had their IC₅₀ determined within 72 h and the activity structure ratio was assessed. The effect of the best compounds on PBMC and hemolytic activity assay was then evaluated. The compound 1d was considered the most promising among the samples tested and its influence on cell cycle, DNA fragmentation and mitochondrial depolarization was evaluated.

Cytotoxicity and Antioxidant Potential of Novel 2-(2-((1H-indol-5yl)methylene)-hydrazinyl)-thiazole Derivatives

Newly synthesized 2-(2-((1H-indol-5yl)methylene)-hydrazinyl)-thiazole derivatives were evaluated for their in vitro cytotoxicity on two carcinoma cell lines A2780 and HeLa. Significant cytotoxic activity for 2-(2-((1H-indol-5-yl)methylene)hydrazinyl)-4-methylthiazole (1) and 2-(2-((1H-indol-5-yl)methylene)hydrazinyl)-4-phenylthiazole (3), on both A2780 [IC₅₀: 11.6 μM (1), and 12.4 μM (3)] and HeLa [IC₅₀: 22.4 μM (1) and 19.4μM (3)] cell lines is reported. Their antioxidant potential was evaluated by spectrophotometric method, using DPPH radical or Fe (TPTZ)³⁺ complex, and EPR spectroscopy, therefore the compounds 1 and 3 showed remarkable antioxidant activity simultaneously with a cytotoxic effect on A2780 and HeLa cell lines. Furthermore, based on theoretical quantum chemical calculation, the present study analyzed the chemoselectivity of the hydrogen extraction from the indolyl-hydrazinil-thiazoles in reaction with free radicals.

Synthesis, Anticancer Activity, and Genome Profiling of Thiazolo Arene Ruthenium Complexes

Sixteen hydrazinyl-thiazolo arene ruthenium complexes of the general formula [(η(6)-p-cymene)Ru(N,N'-hydrazinyl-thiazolo)Cl]Cl were synthesized. All complexes were tested in vitro for their antiproliferative activity on three tumor cell lines (HeLa, A2780, and A2780cisR) and on a noncancerous cell line (HFL-1). A superior cytotoxic activity of the ruthenium complexes as compared to cisplatin and oxaliplatin, on both cisplatin-sensitive and cisplatin resistant ovarian cancer cells, was observed. In addition, the biological activity of two selected derivatives was evaluated using microarray gene expression assay and ingenuity pathway analysis. p53 signaling was identified as an important pathway modulated by both arene ruthenium compounds. New activated molecules such as FAS, ZMAT3, PRMT2, BBC3/PUMA, and PDCD4, whose overexpressions are correlated with overcoming resistance to cisplatin therapy, were also identified as potential targets. Moreover, the arene ruthenium complexes can be used in association with cisplatin to prevent cisplatin resistance development and synergistically to induce cell death in ovarian cancer cells.