Design, synthesis, and evaluation of novel bistrifluoromethyl-based hydrazones as dual inhibitors of acetylcholinesterase and carbonic anhydrase enzymes for Alzheimer's disease.

In this project, non-sulfonamide bistrifluoromethyl-derived hydrazide-hydrazones were synthesized as multi-target-directed ligands to treat Alzheimer's disease and then, the novel derivatives were characterized by diverse spectral methods. Acetylcholinesterase (AChE), and human carbonic anhydrase (hCA) inhibitory qualifications of these compounds were determined. The reported compounds (2a-y) were determined to be effective inhibitors of the hCA I, hCA II and AChE enzymes with Ki values in the range of 1.130 ± 0.15-5.440 ± 0.93 µM for hCA I, 0.894 ± 0.05-6.647 ± 1.35 µM for hCA II, and 0.196 ± 0.03-4.222 ± 1.04 µM for AChE. In silico studies were also performed to illuminate the binding interactions.

Novel imidazo[2,1-b]thiazole-based anticancer agents as potential focal adhesion kinase inhibitors: Synthesis, in silico and in vitro evaluation.

The purpose of this study was to synthesize imidazo[2,1-b]thiazole derivatives, characterize them with spectroscopical techniques and investigate for cytotoxic and apoptotic effects on glioma C6 cancer cell line. The in vitro anticancer activities were also investigated against focal adhesion kinase. Most of the compounds, particularly the derivatives carrying 3-oxo-1-tiya-4-azaspiro[4.5]decane moiety, exhibited higher or comparable activities in comparison with the reference drug, cisplatin. Compounds with methyl, propyl, phenyl moieties at the eighth and second position of the spirothiazolidinone ring showed high FAK inhibitory activities. In addition, molecular docking studies shed light on the binding modes of the synthesized compounds. The critical interactions with amino acid residues located in the active site were revealed. The results obtained from both biological assay data and computational results might provide insight into developing new inhibitors against focal adhesion kinase.

Antioxidant activity of novel imidazo[2,1-b]thiazole derivatives: Design, synthesis, biological evaluation, molecular docking study and in silico ADME prediction.

A series of novel oxo-hydrazone and spirocondensed-thiazolidine derivatives of imidazo[2,1-b]thiazole were synthesized and evaluated for their antioxidant activity. The antioxidant activity of 18 newly synthesized compounds and 12 previously reported compounds bearing similar scaffold, were evaluated by three different methods: inhibition of FeCl3/ascorbate system-induced lipid peroxidation of lecithin liposome (anti-LPO), scavenging activity against ABTS radical and Ferric Reducing Antioxidant Power (FRAP) activity. 4h, 5h, and 6h displayed the highest anti-LPO and ABTS radical removal activity. Also, in FRAP analysis, 4i and 4a displayed the best activity. In addition to the in vitro analysis, docking studies targeting the active site of Human peroxiredoxin 5 (PDB ID: 1HD2) were employed to explore the possible interactions of these compounds with the receptor. Structure-activity relationships, as well as virtual ADME studies, were carried out and a relationship between biological, electronic, and physicochemical qualifications of the target compounds was determined.

Design and synthesis of novel Imidazo[2,1-b]thiazole derivatives as potent antiviral and antimycobacterial agents.

A series of novel acyl-hydrazone (4a-d) and spirothiazolidinone (5a-d, 6a-d) derivatives of imidazo[2,1-b]thiazole were synthesized and evaluated for their antiviral and antimycobacterial activity. The antituberculosis activity was evaluated by using the Microplate Alamar Blue Assay and the antiviral activity was evaluated against diverse viruses in mammalian cell cultures. According to the biological activity studies of the compounds, 5a-c displayed hope promising antitubercular activity, 6d was found as potent for Coxsackie B4 virus, 5d was found as effective against Feline corona and Feline herpes viruses. Consequently, the obtained results displayed that, 5a-d and 6d present a leading structure for future drug development due to its straightforward synthesis and relevant bioactivity.

Synthesis and Aldose Reductase Inhibitory Effect of Some New Hydrazinecarbothioamides and 4-Thiazolidinones Bearing an Imidazo[2,1-b]Thiazole Moiety.

OBJECTIVES: To synthesize and characterize 2-[[6-(4-bromophenyl)imidazo[2,1-b]thiazol-3-yl]acetyl]-N-alkyl/arylhydrazinecarbothioamide and 3-alkyl/aryl-2-[((6-(4-bromophenyl)imidazo[2,1-b]thiazol-3-yl)acetyl)hydrazono]-5-nonsubstituted/methyl-4-thiazolidinone derivatives and evaluate them for their aldose reductase (AR) inhibitory effect. MATERIALS AND METHODS: 2-[[6-(4-bromophenyl)imidazo[2,1-b]thiazol-3-yl]acetyl]-N-alkyl/arylhydrazinecarbothioamides (3a-f) and 3-alkyl/aryl-2-[((6-(4-bromophenyl)imidazo[2,1-b]thiazol-3-yl)acetyl)hydrazono]-5-nonsubstituted/methyl-4-thiazolidinones (4a-j) were synthesized from 2-[6-(4-bromophenyl)imidazo[2,1-b]thiazole-3-yl]acetohydrazide (2). Their structures were elucidated by elemental analyses and spectroscopic data. The synthesized compounds were tested for their ability to inhibit rat kidney AR. RESULTS: Among the synthesized compounds, 2-[[6-(4-bromophenyl)imidazo[2,1-b]thiazol-3-yl]acetyl]-N-benzoylhydrazinecarbothioamide (3d) showed the best AR inhibitory activity. CONCLUSION: The findings of this study indicate that the different derivatives of the compounds in this study may be considered interesting candidates for future research.

Antibacterial, Antitubercular and Antiviral Activity Evaluations of Some Arylidenehydrazide Derivatives Bearing Imidazo[2,1-b]thiazole Moiety.

OBJECTIVES: The aim of this study was to determine the probable antibacterial, antitubercular, and antiviral activities of some N2 -arylidene-(6-(4-chlorophenyl)imidazo[2,1-b]thiazol-3-yl) acetic acid hydrazides (3a-j). Further structural optimization of the identified lead structures can lead us to new more active potential antibacterial, antitubercular, and antiviral agents. MATERIALS AND METHODS: Antibacterial activities of the title compounds against Staphylococcus aureus ATCC 29213, Pseudomonas aeruginosa ATCC 27853 and Escherichia coli ATCC 25922. These molecules were also evaluated for their in vitro antitubercular activity against Mycobacterium tuberculosis H37Rv (ATCC 27294) using the BACTEC 460 radiometric system and BACTEC 12B medium. Moreover, all the compounds (3a-j) were also evaluated against some DNA and RNA viruses in Madin-Darby Canine Kidney, Crandell-Rees Feline Kidney (CRFK), Vero, human embryonic lung (HEL) and HeLa cells. RESULTS: Among the tested compounds, 3i displayed the highest efficacy against S. aureus and E. coli. Compound 3j, 5-nitro-2-furfurylidene derivative showed the highest antituberculosis activity (IC50: 6.16 µg/mL and IC90: 14.390 µg/mL). Compound 3i showed the most potent antiviral activity against feline corona virus in CRFK cell cultures (antiviral EC50: 7.5 µM and SI>13). Furthermore, compounds 3c and 3g displayed activity against herpes simplex virus-1 and vaccinia virus in HEL cell cultures (antiviral EC50 values of 9; 16 and 20; 14 µM, respectively). CONCLUSION: On the basis of aforementioned results, it can be conluded that imidazo[2,1-b]thiazole derivatives bearing hydrazone moieties serve as promising chemical probes to design therapeutic agents with antibacterial, antitubercular, and antiviral properties.

Synthesis and antiviral properties of novel indole-based thiosemicarbazides and 4-thiazolidinones.

A novel series of indolylthiosemicarbazides (6a-6g) and their cyclization products, 4-thiazolidinones (7a-7g), have been designed, synthesized and evaluated, in vitro, for their antiviral activity against a wide range of DNA and RNA viruses. Compounds 6a, 6b, 6c and 6d exhibited notable antiviral activity against Coxsackie B4 virus, at EC50 values ranging from 0.4 to 2.1 µg/mL. The selectivity index (ratio of cytotoxic to antivirally effective concentration) values of these compounds were between 9 and 56. Besides, 6b, 6c and 6d also inhibited the replication of two other RNA viruses, Sindbis virus and respiratory syncytial virus, although these EC50 values were higher compared to those noted for Coxsackie B4 virus. The SAR analysis indicated that keeping the free thiosemicarbazide moiety is crucial to obtain this antiviral activity, since the cyclization products (7a-7g) did not produce any antiviral effect.