Synthesis and biological evaluation of novel 1,3,4-thiadiazole derivatives as possible anticancer agents

The synthesis of new N-(5-substituted-1,3,4-thiadiazol-2-yl)-2-[(5-(substituted amino)-1,3,4-thiadiazol-2-yl)thio]acetamide derivatives and investigation of their anticancer activities were the aims of this work. All the new compounds’ structures were elucidated by elemental analyses, IR, 1H NMR, 13C NMR and MS spectral data. Anticancer activity studies of the compounds were evaluated against MCF-7 and A549 tumor cell lines. In addition, with the purpose of determining the selectivity of cytotoxic activities, the most active compound was screened against a healthy NIH3T3 cell line (mouse embryonic fibroblast cells). Among the tested compounds, compound 4y (N-(5-ethyl-1,3,4-thiadiazol-2-yl)-2-((5-(p-tolylamino)-1,3,4-thiadiazol-2-yl)thio)acetamide), showed promising cytotoxic activity against MCF7 cancer cell with an IC50 value of 0.084 ± 0.020 mmol L–1 and against A549 cancer cell with IC50 value of 0.034 ± 0.008 mmol L–1, compared with cisplatin. The aromatase inhibitory activity was evaluated for compound 4y on MCF-7 cell line showing promising activity with IC50 of 0.062 ± 0.004 mmol L–1

Synthesis of 2-(5-(2-((5-(Cyclohexylamino)-1,3,4-Thiadiazol-2-yl)thio)ethyl)-1,3,4-Oxadiazol-2-yl) Derivatives and Their Antimicrobial Activity

The rate of invasive fungal infections has increased since the 1980s, particularly in the vast populace of immunocompromised patients as well as those hospitalized with serious underlying disease [1]. [...

Synthesis and Anticandidal Activity of New Imidazole Derivatives

During the last few years, there has been an increased awareness of morbidity and mortality related to invasive and systemic fungal disease because of resistant fungi and immunocompromised infections, for instance, AIDS. [...

Synthesis and AChE Inhibitory Activity of Novel Thiazolylhydrazone Derivatives

Alzheimer’s disease (AD) is the most common of the degenerative brain diseases and is described together with the impairment of cognitive function. Patients with AD lose the capability to code new memories, and life conditions are extremely difficult. The development of new drugs in this area continues at a great pace. A novel series of thiazole-piperazine hybrids, aimed against Alzheimer’s disease (AD), have been synthesized. The structure identification of synthesized compounds was elucidated by 1HNMR, 13C-NMR, and LCMSMS spectroscopic methods. The inhibitory potential of the synthesized compounds on cholinesterase enzymes was investigated. The compounds 3a, 3c and 3i showed significant inhibitory activity on the acetylcholinesterase (AChE) enzyme. On the other hand, none of the compounds showed significant inhibitory activity on the butyrylcholinesterase (BChE) enzyme. In addition to enzyme inhibition studies, enzyme kinetic studies were performed to observe the effects of the most active inhibitor compounds on the substrate–enzyme relationship. In addition to in vitro tests, docking studies also indicated that compound 3c potentially acts as a dual binding site AChE inhibitor

Synthesis and Anticandidal Activity Evaluation of New Benzimidazole-Thiazole Derivatives

Azole-based antifungal agents constitute one of the important classes of antifungal drugs. Hence, in the present work, 12 new benzimidazole-thiazole derivatives 3a–3l were synthesized to evaluate their anticandidal activity against C. albicans, C. glabrata, C. krusei, and C. parapsilopsis. The structures of the newly synthesized compounds 3a–3l were confirmed by IR, 1H-NMR, 13C-NMR, and ESI-MS spectroscopic methods. ADME parameters of synthesized compounds 3a–3l were predicted by an in-slico study and it was determined that all synthesized compounds may have a good pharmacokinetic profile. In the anticandidal activity studies, compounds 3c and 3d were found to be the most active compounds against all Candida species. In addition, cytoxicity studies showed that these compounds are nontoxic with a IC50 value higher than 500 µg/mL. The effect of compounds 3c and 3d on the ergosterol level of C. albicans was determined by an LC-MS-MS method. It was observed that both compounds cause a decrease in the ergosterol level. A molecular docking study including binding modes of 3c to lanosterol 14α-demethylase (CYP51), a key enzyme in ergosterol biosynthesis, was performed to elucidate the mechanism of the antifungal action. The docking studies revealed that there is a strong interaction between CYP51 and the most active compound 3c

Design and Synthesis of New Benzothiazole Compounds as Selective hMAO-B Inhibitors

In the current work a new class of novel benzothiazole-hydrazone derivatives was designed and synthesized as hMAO-B inhibitors. Structures of the obtained compounds (3a–3j) were characterized by IR, 1H-NMR, 13C-NMR, and HRMS spectroscopic methods. The inhibitory activity of compounds (3a–3j) against hMAO-A and hMAO-B enzymes was evaluated by using an in vitro fluorometric method. According to activity results, some of the synthesized compounds displayed selective and significant hMAO-B enzyme inhibitor activity. Compound 3e was the most active derivative in the series with an IC50 value of 0.060 µM. Furthermore, cytotoxicity of compound 3e was investigated and found to be non-cytotoxic. Absorption, distribution, metabolism, and excretion (ADME) and blood-brain barrier (BBB) permeability predictions were performed for all compounds. It was determined that these compounds may have a good pharmacokinetic profiles. Bınding modes between the most active compound 3e and the hMAO-B enzyme were analyzed by docking studies. It was observed that there is a strong interaction between compound 3e and enzyme active site

Synthesis and Biological Evaluation of New Thiosemicarbazone Derivative Schiff Bases as Monoamine Oxidase Inhibitory Agents

Twenty-six novel thiosemicarbazone derivative B1–B26 were synthesized via condensation reactions between the corresponding thiosemicarbazides and aldehydes. The chemical characterization of the compounds was carried out by infrared (IR), mass (MS), proton and carbon nuclear magnetic resonance (1H- and 13C-NMR) spectroscopic analyses. The compounds were investigated for their monoamine oxidase A (MAO-A) and monoamine oxidase B (MAO-B) inhibitory activity and most of them were more potent against MAO-A enzyme when compared with MAO-B enzyme. N-Cyclohexyl-2-[4-[(4-chlorophenyl)thio]benzylidene]hydrazine-1-carbothioamide (B24) was the most active compound against MAO-A. The enzyme kinetics study revealed that compound B24 has a reversible and competitive mode of binding. Interaction modes between compound B24 and MAO-A were clarified by docking studies. In addition, the favourable absorption, distribution, metabolism, and excretion (ADME) properties and non-toxic nature of compound B24 make this compound a promising MAO-A inhibitor

Synthesis of Oxadiazole-Thiadiazole Hybrids and Their Anticandidal Activity

In the field of infection management, it is a major challenge to discover a potent and safe antifungal agent due to the emergence of resistant strains. Hence, the goal of this paper is to design and synthesize novel oxadiazole-thiadiazole hybrid compounds (6a–6s) and evaluate their antifungal activity. The structures of synthesized compounds were elucidated by various methods including FT-IR, 1H-NMR, 13C-NMR and HR-MS spectral data. Compounds were tested against four Candida species by broth microdilution assay. Compounds 6e, 6k and 6r, bearing a nitro group, showed significant antifungal activity against all fungi with minimum inhibitory concentration (MIC) in the range of 0.78–3.12 µg/mL. These compounds were also screened for their in vitro cytotoxic effects by MTT assay and detected as nontoxic at their active concentrations against Candida strains. To examine the effects of these compounds on ergosterol biosynthesis, the LC-MS-MS method, which is based on quantification of ergosterol level in C. krusei, was carried out. Finally, the most active molecule (6e) was docked in the active site of the lanosterol 14α-demethylase enzyme, and it was determined that there is a strong interaction between the compound and enzyme

Synthesis and biological evaluation of novel 1,3,4-thiadiazole derivatives as possible anticancer agents

The synthesis of new N-(5-substituted-1,3,4-thiadiazol-2-yl)-2-[(5-(substituted amino)-1,3,4-thiadiazol-2-yl)thio]acetamide derivatives and investigation of their anticancer activities were the aims of this work. All the new compounds’ structures were elucidated by elemental analyses, IR, 1H NMR, 13C NMR and MS spectral data. Anticancer activity studies of the compounds were evaluated against MCF-7 and A549 tumor cell lines. In addition, with the purpose of determining the selectivity of cytotoxic activities, the most active compound was screened against a noncancer NIH3T3 cell line (mouse embryonic fibroblast cells). Among the tested compounds, compound 4y (N-(5-ethyl-1,3,4-thiadiazol-2-yl)-2-((5-(p-tolylamino)-1,3,4-thiadiazol-2-yl)thio)acetamide), showed promising cytotoxic activity against MCF7 cancer cell with an IC50value of 0.084 ± 0.020 mmol L−1 and against A549 cancer cell with IC50 value of 0.034 ± 0.008 mmol L−1, compared with cisplatin. The aromatase inhibitory activity was evaluated for compound 4y on MCF-7 cell line showing promising activity with IC50 of 0.062 ± 0.004 mmol L−1

Design, Synthesis, In Vitro and In Silico Studies of New Thiazolylhydrazine-Piperazine Derivatives as Selective MAO-A Inhibitors

Monoamine oxidase (MAO) isoenzymes are very important drug targets among neurological disorders. Herein, novel series of thiazolylhydrazine-piperazine derivatives were designed, synthesized and evaluated for their MAO-A and -B inhibitory activity. The structures of the synthesized compounds were assigned using different spectroscopic techniques such as 1H-NMR, 13C-NMR and HRMS. Moreover, the prediction of ADME (Absorption, Distribution, Metabolism, Elimination) parameters for all of the compounds were performed using in silico method. According to the enzyme inhibition results, the synthesized compounds showed the selectivity against MAO-A enzyme inhibition. Compounds 3c, 3d and 3e displayed significant MAO-A inhibition potencies. Among them, compound 3e was found to be the most effective derivative with an IC50 value of 0.057 ± 0.002 µM. Moreover, it was seen that this compound has a more potent inhibition profile than the reference inhibitors moclobemide (IC50 = 6.061 ± 0.262 µM) and clorgiline (IC50 = 0.062 ± 0.002 µM). In addition, the enzyme kinetics were performed for compound 3e and it was determined that this compound had a competitive and reversible inhibition type. Molecular modeling studies aided in the understanding of the interaction modes between this compound and MAO-A. It was found that compound 3e had significant and important binding property