Green Biocatalyst for Ultrasound-Assisted Thiazole Derivatives: Synthesis, Antibacterial Evaluation, and Docking Analysis.

The catalytic activity of chitosan (Cs) and grafted Cs led to the preparation of terephthalohydrazide Cs Schiff's base hydrogel (TCsSB), which was then investigated as an eco-friendly biocatalyst for synthesizing novel thiazole derivatives. TCsSB exhibited greater surface area and higher thermal stability compared to Cs, making it a promising eco-friendly biocatalyst. We synthesized two novel series of thiazoles via the reaction of 2-(2-oxo-1,2-diphenylethylidene) hydrazine-1-carbothioamide with various hydrazonoyl chlorides and 2-bromo-1-arylethan-1-ones, employing ultrasonic irradiation and using TCsSB as a catalyst. A comparative study between Cs and TCsSB revealed higher yields than TCsSB. The methodology offered advantages such as mild reaction conditions, quick reaction times, and high yields. TCsSB could be reused multiple times without a significant loss of potency. The chemical structures of the newly synthesized compounds were verified through IR, 1H NMR, 13C NMR, and MS analyses. Six synthesized compounds were assessed for their in vitro antibacterial effectiveness by establishing the minimum inhibitory concentration against four distinct bacterial strains. The docking analyses revealed favorable binding scores against several amino acids within the selected protein (PDB Code-1MBT) for these compounds, with compound 4c exhibiting particularly noteworthy binding properties. Additionally, the in silico ADME parameter estimation for all compounds indicated favorable pharmacological properties for these compounds.

Synthesis, DPPH Radical Scavenging, Cytotoxic Activity, and Apoptosis Induction Efficacy of Novel Thiazoles and Bis-thiazoles.

BACKGROUND: Heterocyclic materials-containing thiazoles exhibited incredible importance in pharmaceutical chemistry and drug design due to their extensive biological properties. METHODS: Synthesis of thiazoles and bis-thiazoles from the reaction of 2-((6-Nitrobenzo[ d][1,3]dioxol-5-yl)methylene)hydrazine-1-carbothioamide with hydrazonoyl chlorides in dioxane and in the existence of triethylamine as basic catalyst. The antioxidant, invitro anti-proliferative, and cytotoxicity efficacy of thiazoles and bis-thiazoles were measured. RESULTS: In this work, novel series of 5-methyl-2-(2-(-(6-nitrobenzo[d][1,3]dioxol-5-yl)methylene) hydrazinyl)-4-(aryldiazenyl)thiazoles (4a-f) were prepared via the reaction of hydrazonoyl chlorides 2a-f with 2-((6-nitrobenzo[d][1,3]dioxol-5-yl)methylene)hydrazine-1-carbothioamide (1) in dioxane and employing triethylamine as basic catalyst. Following the same procedure, bisthiazoles (6, 8, and 10) have been synthesized by utilizing bis-hydrazonoyl chlorides (5, 7, and 9) and carbothioamide 1 in a molar ratio (1:2), respectively. The distinctive features in the structure of isolated products were elucidated by spectroscopic tools and elemental analyses. The antioxidant, invitro anti-proliferative, cytotoxicity, and anti-cancer efficacy of thiazoles and bis-thiazoles were evaluated. Compounds 4d and 4f were the most potent antioxidant agents. Gene expression of apoptosis markers and fragmentation assay of DNA were assessed to explore the biochemical mechanism of synthesized products. Thiazoles significantly inhibited cell growth and proliferation more than bis-thiazoles. They induced apoptosis through induction of apoptotic gene expression P53 and downregulation of antiapoptotic gene expression Bcl-2. Moreover, they induced fragmentation of DNA in cancer cells, indicating that they could be employed as anticancer agents by inhibiting tumor growth and progression and can be considered effective compounds in the strategy of anti-cancer agents' discovery. CONCLUSION: Synthesis, DPPH Radical Scavenging, Cytotoxic activity, and Apoptosis Induction Efficacy based on Novel Thiazoles and Bis-thiazoles.

Design, Synthesis, and Biological Evaluations of Novel Azothiazoles Based on Thioamide.

Herein we studied the preparation of different thiazoles via the reaction of 2-(3,4-dimethoxybenzylidene)hydrazine-1-carbothioamide (1) with hydrazonoyl halides under base-catalyzed conditions. The reactions proceed through nucleophilic substitution attack at the halogen atom of the hydrazonoyl halides by the thiol nucleophile to form an S-alkylated intermediate. The latter intermediate undergoes cyclization by the loss of water to afford the final products. The structures of the azo compounds were confirmed by FTIR, MS, NMR, and elemental analyses. Indeed, the newly synthesized azo compounds were estimated for their potential anticancer activities by an MTT assay against different human cancer cells, such as lung adenocarcinoma (A549) and colorectal adenocarcinoma (DLD-1). The caspase-3 levels were also estimated using Western blotting and the dual staining technique to evaluate the potency of the titled compounds to promote apoptosis.

Synthesis of New Thiazole Clubbed Imidazo[2,1-b]thiazole Hybrid as Antimycobacterial Agents.

AIMS: The study aims to synthesize bioactive hybrid pharmacophores (thiazole ring and imidazo[2,1-b]thiazole system) by incorporating them into one biological assessment molecular system. BACKGROUND: A literature survey revealed that various imidazo[2,1-b]thiazoles, thiazoles, and hydrazones have powerful antimycobacterial activity. OBJECTIVE: This study demonstrates the effectiveness of molecular hybridization and the scope for imidazo[2,1-b]thiazole-hydrazone-thiazoles to develop as promising antimycobacterial agents. METHODS: Several imidazo[2,1-b]thiazole-hydrazine-thiazoles 5a-g, 7a,b, 9a,b, 11a,b, 13, and 15a,b were generated using a molecular hybridization strategy and assessed against Mycobacterium tuberculosis (ATCC 25618) for their in vitro antituberculous activity. RESULTS: Derivative 7b (MIC = 0.98 µg/mL) has shown the most promising antimycobacterial activity among the series tested. Brief structure-activity relationship studies found that the thiazole of chlorophenyl or pyridine, or coumarin had a significant relation with the antimycobacterial activity. CONCLUSION: The promising antimycobacterial activity of compound 7b compared with the reference drug suggests that this compound may contribute as a lead compound in the search for new potential antimycobacterial agents.

One-Pot Synthesis of Novel Thiazoles as Potential Anti-Cancer Agents.

BACKGROUND: Thiazole and thiosemicarbazone derivatives are known to have potential anticancer activity with a mechanism of action related to inhibition of matrix metallo-proteinases, kinases and anti-apoptotic BCL2 family proteins. MATERIALS AND METHODS: A novel three series of 5-(1-(2-(thiazol-2-yl)hydrazono)ethyl)thiazole derivatives were prepared in a one-pot three-component reaction using 2-(2-benzylidene hydrazinyl)-4-methylthiazole as a starting precursor. MS, IR, 1H-NMR and 13C-NMR were used to elucidate the structures of the synthesized compounds. Most of the synthesized products were evaluated for their in vitro anticancer screening against HCT-116, HT-29 and HepG2 using the MTT colorimetric assay. RESULTS: The results indicated that compounds 4c, 4d and 8c showed growth inhibition activity against HCT-116 with IC50 values of 3.80 ± 0.80, 3.65 ± 0.90 and 3.16 ± 0.90 µM, respectively, compared to harmine (IC50 = 2.40 ± 0.12 µM) and cisplatin (IC50 = 5.18 ± 0.94 µM) reference drugs. Also, compounds 8c, 4d and 4c showed promising IC50 values of 3.47 ± 0.79, 4.13 ± 0.51 and 7.24 ± 0.62 µM, respectively, against the more resistant human colorectal cancer (HT-29) cell line compared with harmine (IC50 = 4.59 ± 0.67 µM) and cisplatin (IC50 = 11.68 ± 1.54 µM). On the other hand, compounds 4d, 4c, 8c and 11c were the most active (IC50 values of 2.31± 0.43, 2.94 ± 0.62, 4.57 ± 0.85 and 9.86 ± 0.78 µM, respectively) against the hepatocellular carcinoma (HepG2) cell line compared with harmine (IC50 = 2.54 ± 0.82 µM) and cisplatin (IC50 = 41 ± 0.63 µM). The study also suggested that the mechanism of the anticancer action exerted by the most active compounds (4c, 4d and 8c) inside HCT-116 cells was apoptosis through the Bcl-2 family. CONCLUSION: Thiazole scaffolds 4c, 4d and 8c showed anticancer activities in the micromolar range and are appropriate as a candidate for cancer treatment.

Efficient Methods for the Synthesis of Novel Arylazothiazoles Based on Acetylferrocene or Adamantane.

BACKGROUND: Hydrazonoyl halides are convenient for the synthesis of arylazothiazoles. MATERIALS AND METHODS: A series of novel arylazothiazoles were efficiently synthesized from the reaction of hydrazonoyl chlorides with 2-(adamantan-2-ylidene)hydrazinecarbothioamide or 2-(ferrocenyl-1-ylidene)hydrazinecarbo-- thioamide in dioxane used as an aprotic solvent because of its lower toxicity and higher boiling point (101 °C) and triethylamine at reflux. The reaction mechanistic pathway proceeded by the nucleophilic substitution reaction by the elimination of hydrogen chloride to give thiohydrazonates as intermediate, which in situ undergo intramolecular cyclization and loss of water molecule to afford the final product of novel arylazothiazoles. This method is simple with good yield and excellent purities. RESULTS AND DISCUSSION: The synthetic schemes for the final products are proposed and discussed. The chemical structures of the final products were identified by different techniques, such as elemental analysis, Fourier-transform infrared spectroscopy (FT-IR), nuclear magnetic resonance (NMR), and mass spectrometry (MS). CONCLUSION: In this article, we prepared arylazothiazoles from the reaction of 2-(adamantan-2-ylidene)hydrazinecarbothioamide or 2-(ferrocenyl-1-ylidene)hydrazinecarbothioamide with hydrazonoyl halides.

Design, efficient synthesis and molecular docking of some novel thiazolyl-pyrazole derivatives as anticancer agents.

Pyrazoles, thiazoles and fused thiazoles have been reported to possess many biological activities. 3-Methyl-5-oxo-4-(2-arylhydrazono)-4,5-dihydro-1H-pyrazole-1-carbothioamides 3a,b (obtained from the reaction of ethyl 3-oxo-2-(2-arylhydrazono)butanoates 1a,b with thiosemicarbazide) could be transformed into a variety of thiazolyl-pyrazole derivatives 6a-h, 10a-c, 15a-c, 17, 19 and 21 via their reaction with a diversity hydrazonoyl chlorides as well as bromoacetyl derivatives. Moreover, the computational studies were carried out for all new compounds. The results indicated that five compounds showed promising binding affinities (10a: - 3.4 kcal/mol, 6d: - 3.0 kcal/mol, 15a: - 2.2 kcal/mol, 3a: - 1.6 kcal/mol, and 21: - 1.3 kcal/mol) against the active site of the epidermal growth factor receptor kinase (EGFR). The cytotoxicity of the potent products 3a, 6d, 10a, 15a, and 21 was examined against human liver carcinoma cell line (HepG-2) and revealed activities close to Doxorubicin standard drug. There was an understanding between the benefits of restricting affinities and the data obtained from the practical anticancer screening of the tested compounds.

Synthesis and Biological Evaluation of Bisthiazoles and Polythiazoles.

Small heterocyclic compounds containing nitrogen and sulfur atoms, such as thiazole derivatives, represent a significant class of organic azoles that exhibit promising bioactivities and have a great potential in medicinal and agricultural fields. A convenient and high-yielding synthetic approach for a range of organic molecules is presented. The nuclease-like activities of compounds were studied with the aid of E. coli AB1157 DNA and agarose gel electrophoresis. The antioxidant evaluation of the compounds was carried out with different antioxidant techniques, such as ABTS and NO scavenging efficiency. The antibacterial behavior was evaluated against various bacterial strains, both Gram-positive and -negative, and the minimum inhibitory concentration (MIC) values of these compounds were determined. The antiproliferative activities and IC50 values of the synthesized organic molecules compounds against HEPG-2, MCF-7, and HCT-116 cell lines were evaluated.

New Route Synthesis of Thiadiazoles, Bisthiadiazoles, Thiadiazolotriazines, and Pyrazolothiadiazoles Based on Hydrazonoyl Halides and Dihydrazinylthiadiazole.

Synthesis and characterization of new thiadiazoles, bisthiadiazoles from the reaction of mono- and di-hydrazonoyl halides with various hydrazinecarbodithioate derivatives were studied. Treatment of hydrazonoyl halides with 2,5-dihydrazinyl-1,3,4-thiadiazole afforded new bistriazines containing thiadiazole; we also examined the reaction of 2,5-dihydrazinyl-1,3,4-thiadiazole with active methylene compounds to afford new pyrazoles containing thiadiazole compounds. The new synthesized compounds were identified by elemental analysis and various spectral data (Fourier transform infrared spectroscopy, mass spectrometry, 1H and 13C nuclear magnetic resonance).

Synthesis of novel triazoles, tetrazine, thiadiazoles and their biological activities.

An expedient synthesis of novel triazoles, tetrazine and thiadiazoles, using conveniently accessible and commercially available starting materials has been achieved. The synthesized compounds were characterized by spectroscopic and elemental analyses, and screened for their antibacterial activities against four different strains, namely E. coli, P. aeruginosa, S. aureus and B. megaterium. In particular, the compounds 5, 24 and 26h exhibited excellent antibacterial activities compared to the reference antibiotic. To get further insight about their behavior, these compounds were tested for their antioxidant activities via SOD-like activity, DPPH free radical scavenging activity, ABST and NO, which showed promising results. Furthermore, these compounds effectively promoted the cleavage of genomic DNA as well, in the absence of any external additives.