In vitro and in silico antimalarial activity of 2-(2-hydrazinyl)thiazole derivatives

Identification of 3-[(4-Acetylphenyl)(4-Phenylthiazol-2-Yl)Amino]Propanoic Acid Derivatives as Promising Scaffolds for the Development of Novel Anticancer Candidates Targeting SIRT2 and EGFR

Background: A series of novel polysubstituted thiazole derivatives were synthesized, and their antiproliferative properties were evaluated using both 2D and 3D lung cancer models. Methods: The compounds were obtained via esterification, oximation, hydrazinolysis, and condensation reactions. Results: Structure-activity relationship analysis revealed that the antiproliferative activity was structure-dependent. Notably, oxime derivatives 21 and 22, along with carbohydrazides 25 and 26, exhibited low micromolar activity that was significantly greater than that of cisplatin (p < 0.005), a standard chemotherapeutic agent. These compounds demonstrated potent, antiproliferative activity against H69 small-cell lung carcinoma cells, as well as anthracycline-resistant H69AR cells. Moreover, compounds 21, 22, 25, and 26 effectively induced cell death in A549 agarose-based 3D spheroids, further supporting their potential therapeutic application. The in silico studies proposed that compound 22 is able to interact with human SIRT2 and EGFR via conserved amino acid residues. Conclusions: The ability of these thiazole derivatives to target both drug-sensitive and drug-resistant lung cancer models highlights their promise as scaffolds for further optimization and preclinical development. Future studies will focus on structural modifications to enhance potency, selectivity, and pharmacokinetic properties, paving the way for the development of novel thiazole-based antiproliferative agents.

Synthesis, antibacterial activity, in silico ADMET prediction, docking, and molecular dynamics studies of substituted phenyl and furan ring containing thiazole Schiff base derivatives

This study synthesized eighteen phenyl and furan rings containing thiazole Schiff base derivatives 2(a-r) in five series, and spectral analyses confirmed their structures. The in vitro antibacterial activities of the synthesized analogs against two gram-positive and two gram-negative bacteria were evaluated by disk diffusion technique. Compounds (2d) and (2n) produced prominently high zone of inhibition with 48.3 ±  0.6 mm and 45.3 ±  0.6 mm against B. subtilis, respectively, compared to standard ceftriaxone (20.0 ±  1.0 mm). However, the antibacterial potency of the compounds with furan ring was more notable than that of phenyl ring-containing derivatives. Molecular docking and dynamic study were performed based on the wet lab outcomes of (2d) and (2n), where both derivatives remained in the binding site of the receptors during the whole simulation time with RMSD and RMSF values below 2 nm. In silico ADMET prediction studies of the synthesized compounds validated their oral bioavailability. A more detailed study of the quantitative structure-activity relationship is required to predict structural modification on bioactivity and MD simulation to understand their therapeutic potential and pharmacokinetics.

Novel ethyl 2-hydrazineylidenethiazolidin-5-ylidene acetate clubbed with coumarinylthiazolyl pyrazole system as potential VEGFR-2 inhibitors and apoptosis inducer: synthesis, cytotoxic evaluation, cell cycle, autophagy, in silico ADMET and molecular docking studies

Novel derivatives of ethyl 3-substituted-2-{4-oxo-2-(2-((3-(2-oxo-2H-chromen-3-yl)-1-(4-phenylthiazol-2-yl)-1H-pyrazol-4-yl)methylene)hydrazineyl)thiazol-5(4H)-ylidene}acetate (5a-h) were synthesized and assessed for their cytotoxic potential against the liver cancer cell lines Huh-7 and HepG-2. Among these, compounds 5d and 5g demonstrated notable antiproliferative effects, which were benchmarked against the standard drug doxorubicin. To further understand the mechanisms behind their antiproliferative activity, compounds 5d and 5g were investigated for their impact on the cell cycle and their ability to induce apoptosis. They were found to induce significant cellular cycle arrest at the G1 phase. Besides, they potentially enhanced the cellular late apoptosis and reduced the cellular viability. In consent with the apoptosis results, compounds 5d and 5g displayed significant potential autophagic induction against the studied cancer cell lines. Further, both compounds 5d and 5g showed strong interactions with the VEGFR-2 receptor when they were studied using molecular docking. The ADMET prediction indicated that these bioactive compounds have the potential to serve as effective to fight liver cancer.

Design, Synthesis, Anti-Cancer, Anti-Inflammatory and In Silico Studies of 3-Substituted-2-Oxindole Derivatives

This study focuses on the design and synthesis of 3-substituted-2-oxindole derivatives aimed at developing dual-active molecules with anti-cancer and anti-inflammatory properties. The molecules were designed with diverse structural and functional features while adhering to Lipinski, Veber, and Leeson criteria. Physicochemical properties were assessed using SWISSADME to ensure drug-likeness and favourable pharmacokinetics. Multistep synthetic procedures were employed for molecule synthesis. In vitro evaluations confirmed the dual activity of the derivatives, with specific emphasis on the significance of dialkyl aminomethyl substitutions for potency against various cell lines. 4 a exhibited GI50 value 3.00E-05 against MDA-MB-231, 4 b has shown GI50 value 2E-05 against MDA-MB-231, 4 c has shown GI50 value 6E-05 against VERO, 4 d has shown GI50 value 8E-05 each against both the MDA-MB-231 and MCF-7 and 4 e has shown GI50 values 2E-05 and 5E-05 each against both the MCF-7 and VERO. The analysis indicates that compounds 3 c (71.19 %), 3 e (66.84 %), and 3 g (63.04 %) exhibited significant anti-inflammatory activity. Additionally, in silico binding free energy analysis and interaction studies revealed significant correlations between in vitro and computational data, identifying compounds 4 d, 4 e, 3 b, 3 i, and 3 e as promising candidates. Key residues such as Glu917, Cys919, Lys920, Glu850, Lys838, and Asp1046 were found to play critical roles in ligand binding and kinase inhibition, providing valuable insights for designing potent VEGFR2 inhibitors. The Quantum Mechanics-based Independent Gradient Model analysis further highlighted the electronic interaction landscape, showing larger attractive peaks and higher electron density gradients for compounds 4 d and 4 e compared to Sunitinib, suggesting stronger and more diverse attractive forces. These findings support the potential of these compounds for further development and optimization in anticancer drug design.

Evaluation of novel synthesized thiazole derivatives as potential aromatase inhibitors against breast cancer

Background: 4-Methylacetophenone is used in the preparation of starting materials, 4-methylphenacyle bromide (2) and 4-methylacetophenone thiosemicarbazole (3). Results: Several novel 2,4-disubstituted-1,3-thiazole analogues were obtained via the treatment of starting materials with 4-methylphenacyl bromide, acetyl chloride, aromatic aldehydes and bromination providing thiazole derivatives 5-8 respectively. Conclusion: Compounds 5-8 were investigated for their cytotoxic activity on MCF-7 and normal breast cells. Active compounds were found and in contrast to staurosporine, compound 8 displayed the most potent cytotoxic action that showed a strong inhibitory effect (aromatase) and (protein tyrosine kinase) enzymes, proving that the novel thiazole derivatives promoted the effective anticancer drug candidates.

A Review on Synthetic Thiazole Derivatives as an Antimalarial Agent

BACKGROUND

Thiazole is a widely studied core structure in heterocyclic chemistry and has proven to be a valuable scaffold in medicinal chemistry. The presence of thiazole in both naturally occurring and synthetic pharmacologically active compounds demonstrates the adaptability of these derivatives.

METHODS

The current study attempted to review and compile the contributions of numerous researchers over the last 20 years to the medicinal importance of these scaffolds, with a primary focus on antimalarial activity. The review is based on an extensive search of PubMed, Google Scholar, Elsevier, and other renowned journal sites for a thorough literature survey involving various research and review articles.

RESULTS

A comprehensive review of the antimalarial activity of the thiazole scaffold revealed potential therapeutic targets in Plasmodium species. Furthermore, the correlation of structure-activity-relationship (SAR) studies from various articles suggests that the thiazole ring has therapeutic potential.

CONCLUSION

This article intends to point researchers in the right direction for developing potential thiazole-based compounds as antimalarial agents in the future.

Indolyl-4H-Chromene Derivatives as Antibacterial Agents: Synthesis, in Vitro and in Silico Studies

In this study, indolyl-4H-chromene derivatives are designed and synthesised using an eco-friendly multicomponent one-pot synthesis using benzaldehydes, nitroketene N, S-acetals, and indoles combine with InCl3 , a Lewis acid catalyst, and ethanol, an environmentally acceptable solvent. Due to antibiotic resistance, assessed these Indolyl-4H-chromene derivatives for their in vitro antibacterial activity against Gram-positive and Gram-negative bacteria, including Streptococcus pyogenes, Staphylococcus aureus, Clostridium pyrogenes, Bacillus subtilis, Escherichia coli, and Pseudomonas aeruginosa, using the agar well diffusion method and Minimum Inhibition Concentration (MIC) assay. Three compounds, 4-(1H-indol-3-yl)-6-methoxy-N-methyl-3-nitro-4H-chromen-2-amine, 4-(1H-indol-3-yl)-3-nitro-N-phenyl-4H-chromen-2-amine and 4-(6-Fluoro-1H-Indol-3-yl)-N-methyl-3-nitro-4H-chromen-2-amine showed better zone of inhibition (mm) and Minimum Inhibition Concentration (MIC) values of 10 μg/mL to 25 μg/mL against all bacterial types. The Ki values of 278.60 nM and 2.21 nM for compound 4-(1H-indol-3-yl)-3-nitro-N-phenyl-4H-chromen-2-amine showed improved interactions with DNA gyrase B and topoIV ParE's ATP binding sites in in silico studies.

In silico ADMET prediction, evaluation of cytotoxicity in mouse splenocytes and preliminary evaluation of in vitro antimalarial activity of 4-(4-chlorophenyl)thiazole compounds

In this work, an in silico study and evaluation of the cytotoxicity of 4-(4-chlorophenyl)thiazole compounds against mouse splenocytes and the chloroquine-sensitive Plasmodium falciparum 3D7 strain are reported. The in silico results showed that the compounds have important pharmacokinetic properties for compounds with potential drug candidates. Regarding cytotoxicity assays against splenocytes, the compounds have low cytotoxicity. In addition, they were able to promote activation of these cells by increasing nitric oxide production without promoting cell death. Finally, they were able to promote cell proliferation. Regarding the in vitro anti-P. falciparum activity assays, it was observed that the compounds were able to inhibit the parasite's growth, presenting IC50 values ​​ranging from 0.79 to greater than 10 µM. These results are promising when compared to chloroquine. Therefore, this study showed that 4-(4-chlorophenyl)thiazole compounds are promising candidates for antimalarials.

A new synthetic approach to cyclic ureas through carbonylation using di-tert-butyl dicarbonate (boc anhydride) via one pot strategy

A new approach has been successfully employed to synthesize cyclic ureas via carbonylation, utilizing Boc anhydride and employing K2CO3 as a base along with N,N-dimethylformamide as the solvent. Remarkably high yields were achieved using K2CO3 in conjunction with (Boc)2O, enabling the streamlined preparation of benzimidazolones and 2-benzoxazolones within a single reaction vessel. Significantly, this approach obviates the necessity for using any dangerous reagents, rendering it environmentally friendly, and its key benefit lies in being a metal-free system. The method stands out for its efficiency, concise pathway, optimization from readily accessible starting materials, and ease of execution. The resulting benzimidazolones and 2-benzoxazolones were thoroughly characterized using techniques including LCMS, 1H NMR, and 13C NMR.

Synthesis, Antioxidant, and Antifungal Activities of β-Ionone Thiazolylhydrazone Derivatives and Their Application in Anti-Browning of Freshly Cut Potato

In order to develop a new type of antioxidants with high efficiency, a series of β-ionone thiazolylhydrazone derivatives were designed and synthesized from β-ionone, and their structures were characterized by 1H-NMR, 13C-NMR, FT-IR, and HR-MS. The antioxidant test in vitro indicated that most of the target compounds had high biological activity. Among them, compound 1k exhibited very strong DPPH (1,1-diphenyl-2-picrylhydrazyl radical)-scavenging activity with a half-maximal effective concentration (IC50) of 86.525 μM. Furthermore, in the ABTS (2,2-azinobis (3-ethylbenzothiazoline-6-sulfonate) diammonium salt)-scavenging experiment, compound 1m exhibited excellent activity with an IC50 of 65.408 μM. Their biological activities were significantly better than those of the positive control Trolox. These two compounds, which have good free-radical-scavenging activity in vitro, were used as representative compounds in the anti-browning experiment of fresh-cut potatoes. The results showed that 1k and 1m had the same anti-browning ability as kojic acid, and they were effective browning inhibitors. In addition, it is well known that microbial infection is one of the reasons for food oxidation. Therefore, we investigated the antifungal activity of 25 target compounds against eight plant fungi at a concentration of 125 mg/L. The results indicated that these compounds all have some antifungal activity and may become new potential fungicides. Notably, compound 1u showed the best inhibitory effect against Poria vaporaria, with an inhibition rate as high as 77.71%; it is expected to become the dominant structure for the development of new antifungal agents.

Synthesis, biological screening and in silico studies of new N-phenyl-4-(1,3-diaryl-1H-pyrazol-4-yl)thiazol-2-amine derivatives as potential antifungal and antitubercular agents

A new series of N-aryl-4-(1,3-diaryl-1H-pyrazol-4-yl)thiazol-2-amine, (8a-x) have been synthesized by a cyclo-condensation reaction of 2-bromo-1-(1,3-diphenyl-1H-pyrazol-4-yl)ethanone (6a-f) with N-aryl thiourea, (7a-d). The structure of newly synthesized N-aryl-4-(1,3-diaryl-1H-pyrazol-4-yl)thiazol-2-amine, (8a-x) derivatives was analyzed by ¹H NMR, ¹³C NMR and Mass spectral analysis. The compounds 8a-x were screened for in vitro antimicrobial activity against Escherichia coli, Proteus mirabilis, Bacillus subtilis, Staphylococcus aureus, Candida albicans and Aspergillus niger. and antitubercular activity against M. tuberculosis H37Rv strain. Among the twenty-four pyrazolyl-thiazole derivatives, six compounds 8a, 8b, 8j, 8n, 8o and 8s showed good activity against S. aureus. Against A. niger, all synthesized derivatives showed good antifungal activity. Fifteen pyrazolyl-thiazole derivatives 8a, 8f, 8g, 8h, 8j, 8k, 8n, 8o, 8p, 8q, 8r, 8s, 8t, 8w and 8x showed good antitubercular activity with MIC 1.80-7.34 μM (0.8-3.12 μg/mL), these derivatives have showed more activity than the drugs isoniazid and ethambutol. The active compounds were further screened for cytotoxicity activity against the mouse embryonic fibroblast cells (3t3l1) cell lines at 12.5 and 25 μg/mL concentrations and found less or non-cytotoxicity. To know the plausible mode of action, the synthesized pyrazolyl-thiazole derivatives were studied for pharmacokinetics, toxicity profiles and binding interactions along with an in-depth analysis of structural dynamics and integrity using prolonged molecular dynamics (MD) simulation. The compounds have shown significant docking scores in the range of -7.98 to -5.52 and -9.44 to -7.2 kcal/mol with the M. tuberculosis enoyl reductase (M. tb. InhA) and C. albicans sterol 14-α demethylase (C. ab. CYP51), respectively. Thus, the significant antifungal and antitubercular activity of N-aryl-4-(1,3-diaryl-1H-pyrazol-4-yl)thiazol-2-amine, (8a-x) derivatives incited that, these scaffolds could assist in the development of lead compounds to treat fungal and antitubercular infections.

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.

Novel hybrids of quinoline with pyrazolylchalcones as potential antimalarial agents: Synthesis, biological evaluation, molecular docking and ADME prediction

A novel series of pyrazolyl chalcones containing quinoline scaffold, 5 a-v has been synthesized by Claisen Schimdt condensation of aromatic acetophenone with 1-(4-methylquinolin-2-yl)-3-aryl-1H-pyrazole-4-carbaldehyde in quantitative yield. The compounds were characterized using IR, NMR, MS and elemental analysis. An E-configuration about CC ethylenic bond was determined using ¹H NMR spectroscopy. These compounds exhibited significant antimalarial potential against CQ-sensitive and CQ-resistant strain of Plasmodium falciparum. Structure activity relationship has also been established based on outcomes of in vitro schizont inhibition assay. Compound 5u, (Z)-3-(1-(4-methylquinolin-2-yl)-3-p-tolyl-1H-pyrazol-4-yl)-1-p-tolylprop-2-en-1-one, was found to be the most potent among the series of synthetic analogues. In vivo, it demonstrated significant parasitemia suppression of 78.01% at a dose of 200 mg/kg against P. berghei in infected mice without any mortality in 7 days. In silico molecular docking study revealed that this compound 5u bound to the active site of cysteine protease falcipain-2 enzyme. Furthermore, in silico ADME studies, were also performed and physicochemical qualifications of the title compounds were determined. The biological outcomes of newer heterocyclic compounds may pave the new paths for researchers in development of potential antimalarial agents.

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.

Structure- and ligand-based drug design methods for the modeling of antimalarial agents: a review of updates from 2012 onwards

Malaria still persists as one of the deadliest infectious disease having a huge morbidity and mortality affecting the higher population of the world. Structure and ligand-based drug design methods like molecular docking and MD simulations, pharmacophore modeling, QSAR and virtual screening are widely used to perceive the accordant correlation between the antimalarial activity and property of the compounds to design novel dominant and discriminant molecules. These modeling methods will speed-up antimalarial drug discovery, selection of better drug candidates for synthesis and to achieve potent and safer drugs. In this work, we have extensively reviewed the literature pertaining to the use and applications of various ligand and structure-based computational methods for the design of antimalarial agents. Different classes of molecules are discussed along with their target interactions pattern, which is responsible for antimalarial activity. Communicated by Ramaswamy H. Sarma.

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.

Corrosion Mitigation Performance of N80 Steel in 5% Sulfamic Acid Medium by Applying Novel Tetrahydro-1,2,4-triazines Including Triazene Moieties: Electrochemical and Theoretical Approaches

We observed our newly developed tetrahydro-1,2,4-triazines, including triazene moieties (THTA), namely, 6-((1E)-1-((2E)-(4-(((Z)-1-(2,4-diphenyl-2,3,4,5-tetrahydro-1,2,4-triazin-5-yl) ethylidene) triaz-1-en-1-yl)piperazin-1-yl) triaz-2-en-1-ylidene) ethyl)-2,4-diphenyl-2,3,4,5-tetrahydro-1,2,4-triazine (THTA-I), and 1-((E)-((E)-1-(2,4-diphenyl-2,3,4,5-tetrahydro-1,2,4-triazin-6-yl) ethylidene) triaz-1-en-1-yl) naphthalen-2-ol (THTA-II), as effective inhibitors for the corrosion protection of N80 carbon steel metal in 5% sulfamic acid as the corrosive medium via electrochemical approaches such as potentiodynamic polarization and electrochemical impedance spectroscopy. Furthermore, the tested steel exterior was monitored using X-ray photoelectron spectroscopy after the treatment with the investigated components to verify the establishment of the adsorbed shielding film. The investigated compounds acted as mixed-type inhibitors, as shown by Tafel diagrams. The compounds considered obey the Langmuir adsorption isotherm, and their adsorption on the steel surface was chemisorption. When the tested inhibitors were added, the double-layer capacitances, which can be determined by the adsorption of the tested inhibitors on N80 steel specimens, decreased compared with that of the blank solution. At 10^-4 M, the inhibitory efficacy of THTA-I and THTA-II achieved maximum values of 88.5 and 86.5%, respectively. Density-functional theory computations and Monte-Carlo simulation were applied to determine the adsorption attributes and inhibition mechanism through the studied components. Furthermore, the investigated inhibitors were considered to adsorb on the Fe (1 1 0) surface. The adsorption energy was then measured on steel specimens.

Thiazole: A Versatile Standalone Moiety Contributing to the Development of Various Drugs and Biologically Active Agents

For many decades, the thiazole moiety has been an important heterocycle in the world of chemistry. The thiazole ring consists of sulfur and nitrogen in such a fashion that the pi (π) electrons are free to move from one bond to other bonds rendering aromatic ring properties. On account of its aromaticity, the ring has many reactive positions where donor–acceptor, nucleophilic, oxidation reactions, etc., may take place. Molecules containing a thiazole ring, when entering physiological systems, behave unpredictably and reset the system differently. These molecules may activate/stop the biochemical pathways and enzymes or stimulate/block the receptors in the biological systems. Therefore, medicinal chemists have been focusing their efforts on thiazole-bearing compounds in order to develop novel therapeutic agents for a variety of pathological conditions. This review attempts to inform the readers on three major classes of thiazole-bearing molecules: Thiazoles as treatment drugs, thiazoles in clinical trials, and thiazoles in preclinical and developmental stages. A compilation of preclinical and developmental thiazole-bearing molecules is presented, focusing on their brief synthetic description and preclinical studies relating to structure-based activity analysis. The authors expect that the current review may succeed in drawing the attention of medicinal chemists to finding new leads, which may later be translated into new drugs.

Pyridine appended 2-hydrazinylthiazole derivatives: design, synthesis, in vitro and in silico antimycobacterial studies

An array of pyridine appended 2-hydrazinylthiazole derivatives has been synthesized to discover novel chemotherapeutic agents for Mycobacterium tuberculosis (Mtb). The drug-likeness of pyridine appended 2-hydrazinylthiazole derivatives was validated using the Lipinski and Veber rules. The designed thiazole molecules have been synthesized through Hantzsch thiazole methodologies. The in vitro antimycobacterial studies have been conducted using Luciferase reporter phage (LRP) assay. Out of thirty pyridine appended 2-hydrazinylthiazole derivatives, the compounds 2b, 3b, 5b, and 8b have exhibited good antimycobacterial activity against Mtb, an H37Rv strain with the minimum inhibitory concentration in the range of 6.40–7.14 μM. In addition, in vitro cytotoxicity of active molecules has been observed against Human Embryonic Kidney Cell lines (HEK293t) using MTT assay. The compounds 3b and 8b are nontoxic and their cell viability is 87% and 96.71% respectively. The in silico analyses of the pyridine appended 2-hydrazinylthiazole derivatives have been studied to find the mode of binding of the active compounds with KasA protein of Mtb. The active compounds showed a strong binding score (−5.27 to −6.23 kcal mol⁻¹).

Thirty novel pyridine-appended 2-hydrazinylthiazole derivatives have been synthesized and tested for their antimycobacterial activity against Mictrobactrium tuberculosis, H37Rv strain.

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.

The newly synthesized thiazole derivatives as potential antifungal compounds against Candida albicans

Abstract

Recently, the occurrence of candidiasis has increased dramatically, especially in immunocompromised patients. Additionally, their treatment is often ineffective due to the resistance of yeasts to antimycotics. Therefore, there is a need to search for new antifungals. A series of nine newly synthesized thiazole derivatives containing the cyclopropane system, showing promising activity against Candida spp., has been further investigated. We decided to verify their antifungal activity towards clinical Candida albicans isolated from the oral cavity of patients with hematological malignancies and investigate the mode of action on fungal cell, the effect of combination with the selected antimycotics, toxicity to erythrocytes, and lipophilicity. These studies were performed by the broth microdilution method, test with sorbitol and ergosterol, checkerboard technique, erythrocyte lysis assay, and reversed phase thin-layer chromatography, respectively. All derivatives showed very strong activity (similar and even higher than nystatin) against all C. albicans isolates with minimal inhibitory concentration (MIC) = 0.008–7.81 µg/mL Their mechanism of action may be related to action within the fungal cell wall structure and/or within the cell membrane. The interactions between the derivatives and the selected antimycotics (nystatin, chlorhexidine, and thymol) showed additive effect only in the case of combination some of them and thymol. The erythrocyte lysis assay confirmed the low cytotoxicity of these compounds as compared to nystatin. The high lipophilicity of the derivatives was related with their high antifungal activity. The present studies confirm that the studied thiazole derivatives containing the cyclopropane system appear to be a very promising group of compounds in treatment of infections caused by C. albicans. However, this requires further studies in vivo.

Key points

• The newly thiazoles showed high antifungal activity and some of them — additive effect in combination with thymol.

• Their mode of action may be related with the influence on the structure of the fungal cell wall and/or the cell membrane.

• The low cytotoxicity against erythrocytes and high lipophilicity of these derivatives are their additional good properties.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s00253-021-11477-7.

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.

Neto JDB, de Abreu FC, Figueiredo IM, Carinhanha C. Santos J, Pessoa CDÓ, da Silva-Júnior EF, de Araújo-Júnior JX, M. de Aquino T. Synthesis of hybrids thiazole–quinoline, thiazole–indole and their analogs: in vitro anti-proliferative effects on cancer cell lines, DNA binding properties and molecular modeling

A quinoline–thiazole hybrid was synthesized, which showed cytotoxicity against the HL-60 cell line. Electrochemical and spectroscopic experiments suggested DNA as the biological target.

Dual active 1, 4-dihydropyridine derivatives: Design, green synthesis and in vitro anti-cancer and anti-oxidant studies

The present work describes the design of 1,4-dihydropyridines (1,4-DHPs) with diverse variations in structural and functional groups. The physico-chemical properties and drug-like molecule nature evaluations were carried out using SWISSADME. A simple, economical, eco-friendly, water-mediated and Para-Toluene sulfonic acid catalysed multicomponent and one-pot synthetic method from nitroketene N, S- acetals (NMSM) and corresponding aldehydes has been developed. All compounds (6a-u and 13a-h) were subjected to in vitro assays against two important human cancer cell lines Viz. are Laryngeal carcinoma (Hep2) and Lung adenocarcinoma (A549) cells. The reduction level of DPPH (%) used to evaluate the anti-oxidant properties. The 1,4-DHP derivatives, 6o, 6u and 6l displayed the potent anti-cancer activity with IC₅₀ value of 10 µM, 14 µM and 10 µM against the Hep2 and 8 µM, 9 µM and 50 µM against the A549 cells. Similarly, the anti-oxidant properties of 6o, 6l and 6u at a standard concentration of 50 µg, are found to be 70.12%, 63.90% and 59.57% respectively favours the 1,4-DHP derivatives dual activity potentials. The compounds, 6o and 6l found to be equivalent with standard drug, Doxorubicin.

Biological Evaluation of 2-aminothiazole Hybrid as Antimalarial and Antitrypanosomal Agents: Design and Synthesis

Background:

A series of 2-aminothiazole schiff’s bases (1-24) were synthesized and screened against a few neglected tropical disorders (NTDs). Compounds 12 and 14 were found to have antitrypanosidal activity, whereas compound 14 was found to be more effective than standard benznidazole. The antiplasmodial assay provided three specific and effective compounds (9, 12 and 24) than standard chloroquine. Compound (21) inhibited Leishmania infantum, almost similar to Miltefosine.

Methods:

All the compounds were subjected to cytotoxicity assay and none of the compounds were found to be cytotoxicity. Molecular docking simulations revealed that four compounds (1, 9, 12 and 21) were found to similarly occupy the hydrophobic active site of trans-2-enoyl acyl carrier protein reductase of P. falciparum (PfENR) as triclosan and outcomes were closely related to their anti-malarial potencies.

Results and Conclusion:

The screening results against T. cruzi, T. brucei, L. donovani, L. infantum, P. falciferum and cytotoxicity assays provided a few significant to most potent compounds; two variant class of NTDs.

An epigrammatic status of the 'azole'-based antimalarial drugs

The development of multidrug resistance in the malarial parasite has sabotaged majority of the eradication efforts by restraining the inhibition profile of first line as well as second line antimalarial drugs, thus necessitating the development of novel pharmaceutics constructed on appropriate scaffolds with superior potency against the drug-resistant and drug-susceptible Plasmodium parasite. Over the past decades, the infectious malarial parasite has developed resistance against most of the contemporary therapeutics, thus necessitating the rational development of novel approaches principally focused on MDR malaria. This review presents an epigrammatic collation of the epidemiology and the contemporary antimalarial therapeutics based on the 'azole' motif.

Benzo[b]thiophene-thiazoles as potent anti-Toxoplasma gondii agents: Design, synthesis, tyrosinase/tyrosine hydroxylase inhibitors, molecular docking study, and antioxidant activity

Synthesis and investigation of anti-Toxoplasma gondii activity of novel thiazoles containing benzo [b]thiophene moiety are presented. Among the derivatives, compound 3k with adamantyl group shows exceptionally high potency against Me49 strain with IC₅₀ (8.74 μM) value which is significantly lower than the activity of trimethoprim (IC₅₀ 39.23 μM). In addition, compounds 3a, 3b and 3k showed significant activity against RH strain (IC₅₀ 51.88-83.49 μM). The results of the cytotoxicity evaluation showed that Toxoplasma gondii growth was inhibited at non-cytotoxic concentrations for the mammalian L929 fibroblast (CC₃₀ ∼ 880 μM). The most active compound 3k showed tyrosinase inhibition effect, with IC₅₀ value of 328.5 μM. The binding energies calculated for compounds 3a-3e, 3k are strongly correlated with the experimentally determined values of tyrosinase inhibition activity. Moreover, the binding energies corresponding to the same ligands and calculated for both tyrosinase and tyrosine hydroxylase are also correlated with each other, suggesting that tyrosinase inhibitors may also have an inhibitory effect on tyrosine hydroxylase. Compounds 3j and 3k have also very strong antioxidant activity (IC₅₀ 15.9 and 15.5 μM), respectively, which is ten times higher than well-known antioxidant BHT.

Aryliodoazide Synthons: A Different Approach for Diversified Synthesis of 2-Aminothiazole, 1,3-Thiazole, and 1,3-Selenazole Scaffolds

Several straightforward and practical processes have been established for the construction of 2-aminothiazoles, 1,3-thiazoles and 1,3-selenazoles from aryliodoazides. These strategies successfully proceed with a wide spectrum of substituted thioamides and its derivatives producing the resulting five-membered heterocycles obtained in satisfactory yields. The unique features of these protocols are operational simplicity and highly functional group tolerance, which make them convenient and practical routes for the preparation of various libraries of 2-aminothiazoles, 1,3-thiazoles, and 1,3-selenazoles.

Thiosemicarbazone derivatives: Design, synthesis and in vitro antimalarial activity studies

Different types of thiosemicarbazone derivatives were designed and tested for their Drug-Like Molecular (DLM) nature by using Lipinski and Veber rules. Subsequently, compounds with DLM properties were synthesized and characterized by spectral methods. In vitro antimalarial activity studies of the synthesized thiosemicarbazone derivatives have been carried out against Plasmodium falciparum, 3D7 strain using fluorescence assay method and found that the compounds, (E)-2-(1-(4-fluorophenyl)ethylidene)hydrazine-1-carbothioamide (6), (E)-2-(1-(3-bromophenyl) ethylidene) hydrazine-1-carbothioamide (15) and (E)-2-(3,4,5-trimethoxybenzylidene) hydrazine-1-carbothioamide (29) showed notable antimalarial activity with EC₅₀ values of 13.54 μM, 15.83 μM and 14.52 μM respectively.

Design, synthesis, and pharmacology of some oxadiazole and hydroxypyrazoline hybrids bearing thiazoyl scaffold: antiproliferative activity, molecular docking and DNA binding studies

A series of oxadiazole (7a-l) and hydroxypyrazoline derivatives (8a-l) incorporating thiazole were synthesized and characterized by spectral analysis (¹H-NMR, ¹³C-NMR, Mass, and FT-IR). The synthesized compounds were screened for their in vitro cytotoxicity against MDA-MB231 and HT-29 human cell lines. Conjugates 7d, 7e, 7f, 7i, 7l, 8a, 8b, 8i and 8l exhibited significant antiproliferative activity on both MDA-MB231 and HT-29 cell lines. Flow cytometric analysis reveals that, 7i arrests both cells lines at Go/G1 phase whereas 8i induced G0/G1 arrest only in the HT-29 cells. Furthermore, Computational interaction studies of 7i and 8i exhibited its capacity of being a plausible CDK2 and BCL-2 inhibitor respectively. In addition, DNA binding of the synthesized compounds and DNA docking of 7i and 8i demonstrated the ability to interact with DNA. Compounds 7i and 8i causes' remarkable growth inhibition of MDA-MB231 and HT-29 cells but compound 8i was considerably effective against HT-29 cells. Overall these compounds can be practiced for further drug development.

Thiazole, thio and semicarbazone derivatives against tropical infective diseases: Chagas disease, human African trypanosomiasis (HAT), leishmaniasis, and malaria

Thiazole, thiosemicarbazone and semicarbazone moieties are privileged scaffolds (acting as primary pharmacophores) in many compounds that are useful to treat several diseases, mainly tropical infectious diseases. In this review article, we critically analyzed the contribution of these scaffolds to medicinal chemistry in the last five years, focusing on tropical infectious diseases, such as Chagas disease, human African trypanosomiasis (HAT), leishmaniasis, and malaria. We also present perspectives for their use in drug design in order to contribute to the development of new drugs.

Design, Synthesis and DFT/DNP Modeling Study of New 2-Amino-5-arylazothiazole Derivatives as Potential Antibacterial Agents

A new series of 2-amino-5-arylazothiazole derivatives has been designed and synthesized in 61–78% yields and screened as potential antibacterial drug candidates against the Gram negative bacterium Escherichia coli. The geometry of the title compounds were being studied using the Material Studio package and semi-core pseudopods calculations (dspp) were performed with the double numerica basis sets plus polarization functional (DNP) to predict the properties of materials using the hybrid FT/B3LYP method. Modeling calculations, especially the (E_H-E_L) difference and the energetic parameters revealed that some of the title compounds may be promising tools for further research work and the activity is structure dependent.

Synthesis, Characterization, and Molecular Docking of Novel bis‐thiazolyl Thienothiophene Derivatives as Promising Cytotoxic Antitumor Drug

A novel, facile reaction for the synthesis of series of bis‐thiazole derivatives has been developed from the reaction of the appropriate thiosemicarbazone derivatives and bis‐2‐bromoacetylthieno[2,3‐b]thiophene derivatives in ethanol under reflux. The structures of the newly synthesized products were established on the basis of spectral data (mass, IR, and 1H and 13C NMR) and elemental analyses. Fifteen compounds of the synthesized compounds were evaluated for their anticancer activity against human liver hepatocellular carcinoma cell line (HepG2). All compounds showed anticancer activity but differs in potency comparable with the reference drug Cisplatin. Moreover, molecular docking study using MOE software predicted the best binding mode between the most active compound 5o into the active site of human heat‐shock protein 90. The computational studies are confirming the results in biological activity.