Novel synthesis of hydrazide-hydrazone derivatives and their utilization in the synthesis of coumarin, pyridine, thiazole and thiophene derivatives with antitumor activity

Anti-hepatocellular carcinoma activities of novel hydrazone derivatives via downregulation of interleukin-6

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related morbidity worldwide. Sorafenib is a first-line drug for the treatment of HCC, however, it is reported to cause serious adverse effects and may lead to resistance in many patients. In this study, 20 hydrazone derivatives incorporating triazoles, pyrazolone, pyrrole, pyrrolidine, imidazoline, quinazoline, and oxadiazine moieties were designed, synthesized, and characterized. In addition to molecular docking and in silico ADME study, the cytotoxic activity of the synthesized compounds was evaluated against the human hepatocellular cancer cell line (HepG2) and liver mesenchymal stem cells as a normal cell line. The antitumor activities of the derivatives against sorafenib were compared. Of the 20 synthesized compounds, compound 16 demonstrated potential as a potent anti-HCC drug candidate through downregulation of interleukin 6 which reduces inflammation and tumorigenesis with a strong binding interaction and bioavailability.

Synthesis and in silico studies of certain benzo[f]quinoline-based heterocycles as antitumor agents

A series of benzoquinoline-employing heterocycles was synthesized by treating 3-chlorobenzo[f]quinoline-2-carbaldehyde with N-phenyl-3-methylpyrazolone, 4-aminoacetophenone, 1,2-diaminoethane, and 2-cyanoethanohydrazide. Also, pyridine, chromene, α,β-unsaturated nitrile, thiosemicarbazone, and 1,2-bis-aryl hydrazine derivatives were prepared from the cyanoethanohydrazone obtained. The DFT calculations and experiment outcomes were consistent. In vitro screening of their antiproliferative efficacy was examined against HCT116 and MCF7 cancer cell lines. The pyrazolone 2 and cyanoethanohydrazone 5 derivatives exhibited the most potency, which was demonstrated by their molecular docking towards the CDK-5 enzyme. The binding energies of compounds 2 and 5 were - 6.6320 kcal/mol (with RMSD of 0.9477 Å) and - 6.5696 kcal/mol (with RMSD of 1.4889 Å), respectively, which were near to that of co-crystallized ligand (EFP). This implies a notably strong binding affinity towards the CDK-5 enzyme. Thus, pyrazolone derivative 2 would be considered a promising candidate for further optimization to develop new chemotherapeutic agents. In addition, the ADME (absorption, distribution, metabolism, and excretion) analyses displayed its desirable drug-likeness and oral bioavailability properties.

Utility of sulfachloropyridazine in the synthesis of novel anticancer agents as antiangiogenic and apoptotic inducers

In a search for new anticancer agents with better activity and selectivity, the present work described the synthesis of several new series of sulfachloropyridazine hybrids with thiocarbamates 3a-e, thioureids 4a-h, 5a-e and 4-substituted sulfachloropyridazines 6a, b, 7a, b and 8. The synthesized compounds were screened in vitro against a panel of 60 cancer cell lines in one dose assay. The most potent derivatives 3a, 3c, 4c, 4d, 5e, 7a and 7b were tested for their antiangiogenic activity by measuring their ability to inhibit VEGFR-2. The most potent compounds in VEGFR-2 inhibitory assay were further evaluated for their ability to inhibit PDGFR. In addition, the ability of 4c compound to inhibit cell migration on HUVEC cells and cell cycle effect on UO-31 cells has been studied. The pro-apoptotic effect of compound 4c was studied by the evaluation of caspase-3, Bax and BCl-2. Alternatively, the IC50 of compounds 3a, 3c, 4c, 5e, 7a and 7b against certain human cancer cell lines were determined. Re-evaluation in combination with γ-radiation was carried out for compounds 4c, 5e and 7b to study the possible synergistic effect on cytotoxicity. Docking studies of the most active compounds were performed to give insights into the binding mode within VEGFR-2 active site.

Coumarin as an Elite Scaffold in Anti-Breast Cancer Drug Development: Design Strategies, Mechanistic Insights, and Structure-Activity Relationships

Breast cancer is the most common cancer among women. Currently, it poses a significant threat to the healthcare system due to the emerging resistance and toxicity of available drug candidates in clinical practice, thus generating an urgent need for the development of new potent and safer anti-breast cancer drug candidates. Coumarin (chromone-2-one) is an elite ring system widely distributed among natural products and possesses a broad range of pharmacological properties. The unique distribution and pharmacological efficacy of coumarins attract natural product hunters, resulting in the identification of numerous natural coumarins from different natural sources in the last three decades, especially those with anti-breast cancer properties. Inspired by this, numerous synthetic derivatives based on coumarins have been developed by medicinal chemists all around the globe, showing promising anti-breast cancer efficacy. This review is primarily focused on the development of coumarin-inspired anti-breast cancer agents in the last three decades, especially highlighting design strategies, mechanistic insights, and their structure-activity relationship. Natural coumarins having anti-breast cancer efficacy are also briefly highlighted. This review will act as a guideline for researchers and medicinal chemists in designing optimum coumarin-based potent and safer anti-breast cancer agents.

Promising Dual Anticancer and Antimetastatic Action by a Cu(II) Complex Derived from Acylhydrazone on Human Osteosarcoma Models

Osteosarcoma cancers are becoming more common in children and young adults, and existing treatments have low efficacy and a very high mortality rate, making it pressing to search for new chemotherapies with high efficacy and high selectivity index. Copper complexes have shown promise in the treatment of osteosarcoma. Here, we report the synthesis, characterization, and anticancer activity of [Cu(N-N-Fur)(NO3)(H2O)] complex where N-N-Fur is (E)-N'-(2-hydroxy-3-methoxybenzylidene)furan-2-carbohydrazide. The [Cu(N-N-Fur)(NO3)(H2O)] complex was characterized via X-ray diffraction and electron spin resonance (ESR), displaying a copper center in a nearly squared pyramid environment with the nitrate ligand acting as a fifth ligand in the coordination sphere. We observed that [Cu(N-N-Fur)(NO3)(H2O)] binds to DNA in an intercalative manner. Anticancer activity on the MG-63 cell line was evaluated in osteosarcoma monolayer (IC50 2D: 1.1 ± 0.1 μM) and spheroids (IC50 3D: 16.3 ± 3.1 μM). Selectivity assays using nontumoral fibroblast (L929 cell line) showed that [Cu(N-N-Fur)(NO3)(H2O)] has selectivity index value of 2.3 compared to cis-diamminedichloroplatinum(II) (CDDP) (SI = 0.3). Additionally, flow cytometry studies demonstrated that [Cu(N-N-Fur)(NO3)(H2O)] inhibits cell proliferation and conveys cells to apoptosis. Cell viability studies of MG-63 spheroids (IC50 = 16.3 ± 3.1 μM) showed that its IC50 value is 4 times lower than for CDDP (IC50 = 65 ± 6 μM). Besides, we found that cell death events mainly occurred in the center region of the spheroids, indicating efficient transport to the microtumor. Lastly, the complex showed dose-dependent reductions in spheroid cell migration from 7.5 to 20 μM, indicating both anticancer and antimetastatic effects.

Synthesis of oxamide-hydrazone hybrid derivatives as potential anticancer agents

Background and purpose

Considering various studies implying anticancer activity of the hydrazone and oxamide derivatives through different mechanisms such as kinases and calpain inhibition, herein, we report the synthesis, characterization, and evaluation of the antiproliferative effect of a series of hydrazones bearing oxamide moiety compounds (7a-7n) against a panel of cancer cell lines to explore a novel and promising anticancer agent (7k).

Experimental approach

Chemical structures of the synthesized compounds were confirmed by FTIR, ¹H-NMR, ¹³C-NMR, and mass spectra. The antiproliferative activity and cell cycle progression of the target compound were investigated using the MTT assay and flow cytometry.

Findings/Results

Compound 7k with 2-hydroxybenzylidene structure was found to have a significant in vitro anti-proliferative influence on MDA-MB-231 (human adenocarcinoma breast cancer) and 4T1 (mouse mammary tumor) cells as the model of triple-negative breast cancer, with the IC50-72h values of 7.73 ± 1.05 and 1.82 ± 1.14 μM, respectively. Following 72-h incubation with compound 7k, it caused MDA-MB-231 cell death through G1/S cell cycle arrest at high concentrations (12 and 16 μM).

Conclusion and implications

Conclusively, this study for the first time reports the anti-proliferative efficacy of compound 7k possessing 2-hydroxyphenyl moiety, which may serve as a potent candidate in triple-negative breast cancer treatment.

Synthesis of Acyl Hydrazides via a Radical Chemistry of Azocarboxylic tert-Butyl Esters

A new chemistry of azo compounds, that is, addition of free radicals generated in situ to access various acyl hydrazides, has been developed. The protocol provides a novel strategy for the synthesis of valuable acyl hydrazides. The transformation features mild reaction conditions, good tolerance of functional groups, and a broad substrate scope. In view of the importance of acyl hydrazides in functional materials and medicinal chemistry, this approach would find broad applications.

Synthesis, Biological Activity and Molecular Docking Studies of Novel Nicotinic Acid Derivatives

In our research, we used nicotinic acid as a starting compound, which was subjected to a series of condensation reactions with appropriate aldehydes. As a result of these reactions, we were able to obtain a series of twelve acylhydrazones, two of which showed promising activity against Gram-positive bacteria (MIC = 1.95-15.62 µg/mL), especially against Staphylococcus epidermidis ATCC 12228 (MIC = 1.95 µg/mL). Moreover, the activity of compound 13 against the Staphylococcus aureus ATCC 43300 strain, i.e., the MRSA strain, was MIC = 7.81 µg/mL. Then, we subjected the entire series of acylhydrazones to a cyclization reaction in the acetic anhydride, thanks to which we were able to obtain twelve new 3-acetyl-2,5-disubstituted-1,3,4-oxadiazoline derivatives. Obtained 1,3,4-oxadiazolines were also tested for antimicrobial activity. The results showed high activity of compound 25 with a 5-nitrofuran substituent, which was active against all tested strains. The most promising activity of this compound was found against Gram-positive bacteria, in particular against Bacillus subtilis ATCC 6633 and Staphylococcus aureus ATCC 6538 (MIC = 7.81 µg/mL) and ATCC 43300 MRSA strains (MIC = 15.62 µg/mL). Importantly, the best performing compounds did not show cytotoxicity against normal cell lines. It seems practical to use some of these compounds or their derivatives in the future in the prevention and treatment of infections caused by some pathogenic or opportunistic microorganisms.

Synthesis of Substituted -N-(5-((7-Methyl-2-Oxo-2H-Chromen-4-yl)- Methyl)-1,3,4-Thiadiazol-2-yl)-Benzamide Derivatives Using TBTU as Coupling Agent and their Evaluation for Anti Tubercular Activity

Abstract:

Tuberculosis remains a highly infectious disease across the world. In the identification of new antitubercular agents, coumarin clubbed thiadiazole amides have been synthesized and evaluated for in vitro antitubercular activity. Owing to the growing concern of chemicals and their impact on the environment, greener and faster reaction conditions needed to be incorporated. Therefore, we used TBTU as a coupling reagent for efficient and facile synthesis of substituted-N-(5-((7-methyl-2-oxo-2Hchromes- 4-yl)-methyl)-1,3, 4-thiadiazol-2-yl)-benzamide 4a-j with good yields up to 95% in mild reaction conditions. All the synthesized compounds were evaluated in vitro for anti-tubercular activity against the H37Rv strain of M. tuberculosis. Compounds 4c, 4d, and 4f were found active at 12.5 μg/mL against M. tb H37Rv. Electron withdrawing substituents present on aromatic side chains showed promising anti-tubercular activity.

Human estrogen receptor α antagonists, part 2: Synthesis driven by rational design, in vitro antiproliferative, and in vivo anticancer evaluation of innovative coumarin-related antiestrogens as breast cancer suppressants

New twelve in silico designed coumarin-based ERα antagonists, namely 3DQ-1a to 3DQ-1е, were synthesized and confirmed as selective ERα antagonists, showing potencies ranging from single-digit nanomolar to picomolar. The hits were confirmed as selective estrogen receptor modulators and validated as antiproliferative agents using MCF-7 breast cancer cell lines exerting from picomolar to low nanomolar potency, at the same time showing no agonistic activity within endometrial cell lines. Their mechanism of action was inspected and revealed to be through the inhibition of the Raf-1/MAPK/ERK signal transduction pathway, preventing hormone-mediated gene expression on either genomic direct or genomic indirect level, and stopping the MCF-7 cells proliferation at G₀/G₁ phase. In vivo experiments, by means of the per os administration to female Wistar rats with pre-induced breast cancer, distinguished six derivatives, 3DQ-4a, 3DQ-2a, 3DQ-1a, 3DQ-1b, 3DQ-2b, and 3DQ-3b, showing remarkable potency as tumor suppressors endowed with optimal pharmacokinetic profiles and no significant histopathological profiles. The presented data indicate the new compounds as potential candidates to be submitted in clinical trials for breast cancer therapy.

Quinoline–hydrazone hybrids as dual mutant EGFR inhibitors with promising metallic nanoparticle loading: rationalized design, synthesis, biological investigation and computational studies

A novel quinoline–hydrazone hybrid induced apoptosis in MCF-7 cells through dual mutant EGFR inhibition with promising metallic nanoparticle loading.

Expedition of sulfur-containing heterocyclic derivatives as cytotoxic agents in medicinal chemistry: A decade update

This review article proposes a comprehensive report of the design strategies engaged in the development of various sulfur-bearing cytotoxic agents. The outcomes of various studies depict that the sulfur heterocyclic framework is a fundamental structure in diverse synthetic analogs representing a myriad scope of therapeutic activities. A number of five-, six- and seven-membered sulfur-containing heterocyclic scaffolds, such as thiazoles, thiadiazoles, thiazolidinediones, thiophenes, thiopyrans, benzothiazoles, benzothiophenes, thienopyrimidines, simple and modified phenothiazines, and thiazepines have been discussed. The subsequent studies of the derivatives unveiled their cytotoxic effects through multiple mechanisms (viz. inhibition of tyrosine kinases, topoisomerase I and II, tubulin, COX, DNA synthesis, and PI3K/Akt and Raf/MEK/ERK signaling pathways), and several others. Thus, our concise illustration explains the design strategy and anticancer potential of these five- and six-membered sulfur-containing heterocyclic molecules along with a brief outline on seven-membered sulfur heterocycles. The thorough assessment of antiproliferative activities with the reference drug allows a proficient assessment of the structure-activity relationships (SARs) of the diversely synthesized molecules of the series.

Synthetic and Medicinal Perspective of Fused-Thiazoles as Anticancer Agents

BACKGROUND

Cancer is second leading disease after cardiovascular disease. Presently, Chemotherapy, Radiotherapy and use of chemicals are some treatments available these days. Thiazole and its hybrid compounds extensively used scaffolds in drug designing and development of novel anticancer agents due to their wide pharmacological profiles. Fused thiazole scaffold containing drugs are available in market as a promising group of anticancer agents.

METHODS

The detailed study has been done using different database that focused on potent thiazole hybrid compounds with anticancer activity. The literature included in this review is focused on novel fused thiazole derivatives exhibiting anticancer potency in last decade.

RESULTS

Literature suggested that thiazoles and its fused and linked congener serve excellent pharmacological profile as an anticancer agent. Various synthetic strategies for fused thiazole are also summarized in this article. Novel thiazole and its fused congener showed anticancer activity against various cancer cell lines.

INTERPRETATION

Thiazole is a promising scaffold reported in literature with broad range of biological activities. This article covers the thiazole compounds fused with other carbocyclic/heterocycle including benzene, imidazole, pyridine, pyrimidine, quinoline, phenothiazine, thiopyrano, steroids, pyrrole etc. with anticancer activity from last decades. Several inhibitors for breast cancer, colon cancer, melanoma cancer, ovarian cancer, tubulin cancer etc. were reported in this review. Thus, this review will definitely aid to develop a lead for the new selective anticancer agents in future.

Molecular Docking and Biophysical Studies for Antiproliferative Assessment of Synthetic Pyrazolo-Pyrimidinones Tethered with Hydrazide-Hydrazones

Chemotherapy represents the most applied approach to cancer treatment. Owing to the frequent onset of chemoresistance and tumor relapses, there is an urgent need to discover novel and more effective anticancer drugs. In the search for therapeutic alternatives to treat the cancer disease, a series of hybrid pyrazolo[3,4-d]pyrimidin-4(5H)-ones tethered with hydrazide-hydrazones, 5a-h, was synthesized from condensation reaction of pyrazolopyrimidinone-hydrazide 4 with a series of arylaldehydes in ethanol, in acid catalysis. In vitro assessment of antiproliferative effects against MCF-7 breast cancer cells, unveiled that 5a, 5e, 5g, and 5h were the most effective compounds of the series and exerted their cytotoxic activity through apoptosis induction and G0/G1 phase cell-cycle arrest. To explore their mechanism at a molecular level, 5a, 5e, 5g, and 5h were evaluated for their binding interactions with two well-known anticancer targets, namely the epidermal growth factor receptor (EGFR) and the G-quadruplex DNA structures. Molecular docking simulations highlighted high binding affinity of 5a, 5e, 5g, and 5h towards EGFR. Circular dichroism (CD) experiments suggested 5a as a stabilizer agent of the G-quadruplex from the Kirsten ras (KRAS) oncogene promoter. In the light of these findings, we propose the pyrazolo-pyrimidinone scaffold bearing a hydrazide-hydrazone moiety as a lead skeleton for designing novel anticancer compounds.

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.

Antimicrobial and cytotoxic activities of isoniazid connected menthone derivatives and their investigation of clinical pathogens causing infectious disease

BACKGROUND

This work is development of new molecules of isoniazid derivatives as dealing with potential of antimicrobial activity against clinical pathogens causing infectious disease. Antimicrobial of novel Mannich base derivatives can be achieved via one-pot synthesis in green chemistry approach. This method offers efficient, mild reaction conditions and high yields. In this study, totally 12 compounds (1a-l) was prepared and screened for cytotoxic and antimicrobial activities.

MATERIALS AND METHODS

Newly synthesised compounds were conformed via FT- IR, ¹H, and ¹³C NMR (Nuclear Magnetic Resonance), and mass spectra analysis. All compounds were checked antibacterial activity against gram-positive bacteria of Enterococcus faecalis, Staphylococcus aureus and gram-negative bacteria of Pseudomonas aeruginosa, Klebsiella pneumoniae and Escherichia coli. All compounds were checked against antifungal activity against Aspergillus fumigatus, Candida albicans, Cryptococcus neoformans, Aspergillus niger, and Microsporum audouinii. All compounds were screened for cytotoxic activity against the MCF-7 (Michigan Cancer Foundation-7) cancer cell line.

RESULT

The compound 1g was highly (MIC: 0.25 μg/mL) active against gram-negative bacterial of P. aeruginosa, whereas other compounds 1e and 1h were more active (MIC: 2 μg/mL) in K. pneumoniae and also 1g (MIC: 2 μg/mL) was more active in E. faecalis than standard ciprofloxacin. Antifungal screening, the compound 1b was highly active (MIC: 0.25 μg/mL) against C. albicance,1g (MIC: 2 μg/mL) and 1h (MIC: 4 μg/mL) was significant of active against A. fumigatus, and the compound 1c (MIC: 4 μg/mL) was extremely active in M. audouinii than clotrimazole. Compound 1g (GI₅₀ = 0.01 μM) exhibited high activity against the MCF-7 cell line, while 1b (GI₅₀ = 0.02 μM) was equipotent active compared with standard doxorubicin.

CONCLUSION

A novel set of isoniazid derivatives (1a-l) and 1h were synthesized and screened for antimicrobial and cytotoxic activities. We found some highly active molecules, which are evidencing to be a potential treatment of bacterial and fungal infection candidates.

Coumarin hybrid derivatives as promising leads to treat tuberculosis: Recent developments and critical aspects of structural design to exhibit anti-tubercular activity

Tuberculosis (TB) is a highly contagious airborne disease with nearly 25% of the world's population infected with it. Challenges such as multi drug resistant TB (MDR-TB), extensive drug resistant TB (XDR-TB) and in rare cases totally drug resistant TB (TDR-TB) emphasizes the critical and urgent need in developing novel TB drugs. Moreover, the prolonged and multi drug treatment regime suffers a major drawback due to high toxicity and vulnerability in TB patients. This calls for intensified research efforts in identifying novel molecular scaffolds which can combat these issues with minimal side effects. In this pursuit, researchers have screened many bio-active molecules among which coumarin have been identified as promising candidates for TB drug discovery and development. Coumarins are naturally occurring compounds known for their low toxicity and varied biological activity. The biological spectrum of coumarin has intrigued medicinal researchers to investigate coumarin scaffolds for their relevance as anti-TB drugs. In this review we focus on the recent developments of coumarin and its critical aspects of structural design required to exhibit anti-tubercular (anti-TB) activity. The information provided will help medicinal chemists to design and identify newer molecular analogs for TB treatment and also broadens the scope of exploring future generation potent yet safer coumarin based anti-TB agents.

Novel Derivatives of 4-Methyl-1,2,3-Thiadiazole-5-Carboxylic Acid Hydrazide: Synthesis, Lipophilicity, and In Vitro Antimicrobial Activity Screening

Bacterial infections, especially those caused by strains resistant to commonly used antibiotics and chemotherapeutics, are still a current threat to public health. Therefore, the search for new molecules with potential antimicrobial activity is an important research goal. In this article, we present the synthesis and evaluation of the in vitro antimicrobial activity of a series of 15 new derivatives of 4-methyl-1,2,3-thiadiazole-5-carboxylic acid. The potential antimicrobial effect of the new compounds was observed mainly against Gram-positive bacteria. Compound 15, with the 5-nitro-2-furoyl moiety, showed the highest bioactivity: minimum inhibitory concentration (MIC) = 1.95–15.62 µg/mL and minimum bactericidal concentration (MBC)/MIC = 1–4 µg/mL.

Synthesis, Crystal Structure, Spectroscopic Characterization, DFT Calculations and Cytotoxicity Assays of a New Cu(II) Complex with an Acylhydrazone Ligand Derived from Thiophene

A new Cu(II) complex is synthetized by the reaction of copper nitrate and a N-acylhydrazone ligand obtained from the condensation of o-vanillin and 2-thiophecarbohydrazide (H2L). The solid-state structure of [Cu(HL)(H2O)](NO3)·H2O, or CuHL for simplicity, was determined by X-ray diffraction. In the cationic complex, the copper center is in a nearly squared planar environment with the nitrate interacting as a counterion. CuHL was characterized by spectroscopic techniques, including solid-state FTIR, Raman, electron paramagnetic resonance (EPR) and diffuse reflectance and solution UV-Vis electronic spectroscopy. Calculations based on the density functional theory (DFT) assisted the interpretation and assignment of the spectroscopic data. The complex does not show relevant antioxidant activity evaluated by the radical cation of 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) method, being even less active than the free ligand as a radical quencher. Cytotoxicity assays of CuHL against three human tumor cell lines, namely MG-63, A549 and HT-29, revealed an important enhancement of the effectiveness as compared with both the ligand and the free metal ion. Moreover, its cytotoxic effect was remarkably stronger than that of the reference metallodrug cisplatin in all cancer cell lines tested, a promissory result in the search for new metallodrugs of essential transition metals.

Synthesis and Biological Activity of Hydrazones and Derivatives: A Review

Hydrazones and their derivatives are very important compounds in medicinal chemistry due to their reported biological activity for the treatment of several diseases, like Alzheimer's, cancer, inflammation, and leishmaniasis. However, most of the investigations on hydrazones available in literature today are directed to the synthesis of these molecules with little discussion available on their biological activities. With the purpose of bringing lights into this issue, we performed a revision of the literature and wrote this review based on some of the most current research reports of hydrazones and derivatives, making it clear that the synthesis of these molecules can lead to new drug prototypes. Our goal is to encourage more studies focused on the synthesis and evaluation of new hydrazones, as a contribution to the development of potential new drugs for the treatment of various diseases.

Synthesis, in vitro safety and antioxidant activity of new pyrrole hydrazones

Six new N-pyrrolylhydrazide hydrazones were synthesized under micro synthesis conditions, assuring about 59-93 % yield, low harmful emissions and reagent economy. The structures of the new compounds were elucidated by melting points, TLC characteristics, IR, 1H and 13C NMR spectral data followed by MS data. The purity of the obtained compounds was proven by the corresponding elemental analyses. "Lipinski's rule of five" parameters were applied for preliminary evaluation of the pharmacokinetic properties of the target molecules. The initial in vitro safety screening for cytotoxicity (on HepG2 cells) and hemocompatibility (hemolysis assay) showed good safety of the new compounds, where ethyl 5-(4-bromophenyl)-1-(1-(2-(4-hydroxy-3-methoxybenzylidene)-hydrazineyl)-1-oxo-3-phenylpropan-2-yl)-2-methyl-1H-pyr-role-3-carboxylate (4d) and ethyl 5-(4-bromophenyl)-1-(1-(2-(2-hydroxybenzylidene)hydrazineyl)-1-oxo-3-phenylpropan--2-yl)-2-methyl-1H-pyrrole-3-carboxylate (4a) were the least toxic. The antioxidant activity in terms of radical scavenging activity (DPPH test) and reducing ability (ABTS) was also evaluated. The antioxidant protective potential of the compounds was next determined in different in vitro cellular-based models, revealing compounds 4d and 3 [ethyl 5-(4-bromophenyl)-1-(1-hydrazineyl-1-oxo-3-phenylpropan-2-yl)-2-methyl-1H-pyrrole-3-carboxylate] as the most promising compounds, with 4d having better safety profile.

Synthesis of Tetrahydrobenzo[b]thiophene-3-carbohydrazide Derivatives as Potential Anti-cancer Agents and Pim-1 Kinase Inhibitors

BACKGROUND

Tetrahydrobenzo[b]thiophene derivatives are well known to be biologically active compounds and many of them occupy a wide range of anticancer agent drugs.

OBJECTIVE

One of the main aim of this work was to synthesize target molecules not only possessing anti-tumor activities but also kinase inhibitors. To achieve this goal, our strategy was to synthesize a series of 4,5,6,7- tetrahydrobenzo[b]thiophene-3-carbohydrazide derivatives using cyclohexan-1,4-dione and cyanoacetylhydrazine to give the 2-amino-6-oxo-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carbohydrazide (3) as the key starting material for many heterocyclization reactions.

METHODS

Compound 3 was reacted with some aryldiazonium salts and the products were cyclised when reacted with either malononitrile or ethyl cyanoacetate. Thiazole derivatives were also obtained through the reaction of compound 3 with phenylisothiocyanate followed by heterocyclization with α-halocarbonyl derivatives. Pyrazole, triazole and pyran derivatives were also obtained.

RESULTS

The compounds obtained in this work were evaluated for their in-vitro cytotoxic activity against c-Met kinase, and the six typical cancer cell lines (A549, H460, HT-29, MKN-45, U87MG, and SMMC-7721). The results of anti-proliferative evaluations and c-Met kinase, Pim-1 kinse inhibitions revealed that some compounds showed high activities.

CONCLUSION

The most promising compounds 5b, 5c, 7c, 7d, 11b, 14a, 16b, 18b, 19, 21a, 23c, 23d and 23i against c-Met kinase were further investigated against the five tyrosin kinases (c-Kit, Flt-3, VEGFR-2, EGFR, and PDGFR). Compounds 5b, 5c, 7d, 7e, 11b, 11c, 16c, 16d, 18c, 19, 23e, 23k and 23m were selected to examine their Pim-1 kinase inhibitions activity where compounds 7d, 7e, 11b, 11c, 16d, 18c and 23e showed high activities. All of the synthesized compounds have no impaired effect toward the VERO normal cell line.

Synthesis, Characterization, and Biologic Activity of New Acyl Hydrazides and 1,3,4-Oxadiazole Derivatives

Starting from isoniazid and carboxylic acids as precursors, thirteen new hydrazides and 1,3,4-oxadiazoles of 2-(4-substituted-phenoxymethyl)-benzoic acids were synthesized and characterized by appropriate means. Their biological properties were evaluated in terms of apoptosis, cell cycle blocking, and drug metabolism gene expression on HCT-8 and HT-29 cell lines. In vitro antimicrobial tests were performed by the microplate Alamar Blue assay for the anti-mycobacterial activities and an adapted agar disk diffusion technique for other non-tubercular bacterial strains. The best antibacterial activity (anti-Mycobacterium tuberculosis effects) was proved by 9. Compounds 7, 8, and 9 determined blocking of G1 phase. Compound 7 proved to be toxic, inducing apoptosis in 54% of cells after 72 h, an effect that can be predicted by the increased expression of mRNA caspases 3 and 7 after 24 h. The influence of compounds on gene expression of enzymes implicated in drug metabolism indicates that synthesized compounds could be metabolized via other pathways than NAT2, spanning adverse effects of isoniazid. Compound 9 had the best antibacterial activity, being used as a disinfectant agent. Compounds 7, 8, and 9, seemed to have antitumor potential. Further studies on the action mechanism of these compounds on the cell cycle may bring new information regarding their biological activity.

Malebari A, Khayyat AN, Mohamed MFA, Bokhtia RM, AlAwadh MA, Seliem IA, Asfour HZ, Alhakamy NA, Panda SS, AL-Mahmoudy AMM. In Vitro Antimycobacterial Activity and Physicochemical Characterization of Diaryl Ether Triclosan Analogues as Potential InhA Reductase Inhibitors

Two sets of diphenyl ether derivatives incorporating five-membered 1,3,4-oxadiazoles, and their open-chain aryl hydrazone analogs were synthesized in good yields. Most of the synthesized compounds showed promising in vitro antimycobacterial activity against Mycobacterium tuberculosis H37Rv. Three diphenyl ether derivatives, namely hydrazide 3, oxadiazole 4 and naphthylarylidene 8g exhibited pronounced activity with minimum inhibitory concentrations (MICs) of 0.61, 0.86 and 0.99 μg/mL, respectively compared to triclosan (10 μg/mL) and isoniazid (INH) (0.2 μg/mL). Compounds 3, 4, and 8g showed the InhA reductase enzyme inhibition with higher IC₅₀ values (3.28–4.23 µM) in comparison to triclosan (1.10 µM). Correlation between calculated physicochemical parameters and biological activity has been discussed which justifies a strong correlation with respect to the inhibition of InhA reductase enzyme. Molecular modeling and drug-likeness studies showed good agreement with the obtained biological evaluation. The structural and experimental information concerning these three InhA inhibitors will likely contribute to the lead optimization of new antibiotics for M. tuberculosis.

Synthesis, Molecular Docking Studies and Biological Evaluation of N-Acylarylhydrazones as Anti-Inflammatory Agents

In the present work a series of N'-arylidene-2-(benzamido)-3-(naphthalen-2-yl)acrylohydrazides were synthesized by refluxing the intermediate 2-(benzamido)-3-(naphthalen-2-yl)acrylohydrazide with various substituted benzaldehyde in the presence of glacial acetic acid. The intermediate 2-(benzamido)-3-(naphthalen-2-yl)acrylohydrazide 2 was prepared by stirring 4-((naphthalen-2-yl)methylene)-2-phenyloxazol-5(4H)-one with hydrazine hydrate in the presence of absolute ethanol. The chemical structures of the compounds were established by IR, ¹H NMR and mass spectral data. All the compounds were evaluated for anti-inflammatory (in vivo, in vitro) activity and performed docking against COX-2. The compounds 3a, 3c and 3o showed good inhibition of COX-2 in in vitro studies (0.75 μM, 0.5 μM and 0.7 μM as IC50, respectively). The compounds 3c, 3e and 3f were found to be more active than standard drug phenylbutazone at equidose. Molecular docking studies showed that compound 3 m exhibited good binding affinity against COX-2 with docking score 9.328 kcal/mol, when compared to the standard celecoxib.

Design, Synthesis and Antimicrobial Evaluation of 1,3,4‐Oxadiazole/1,2,4‐Triazole‐Substituted Thiophenes

The increasing level of antimicrobial resistance in pathogenic bacteria, together with the lack of new potential drug scaffolds in the pipeline, make the problem of infectious diseases a major public health concern. Thus, in this context, a novel series of 1,3,4‐oxadiazole‐substituted thiophenes (4 a–m) and 1,2,4‐triazole (6 a–m) substituted thiophene derivatives were synthesized. Characterization of all the synthesized derivatives was done by various spectroscopic techniques such as 1H NMR, 13C NMR spectroscopy and mass spectrometry, and evaluated for antimicrobial activity against various pathological strains using broth dilution and disc diffusion method. In particular, compound 6 e and 4 e exhibited significant inhibitory potential with MIC ranging from 2–7 μg mL−1 against S. aureus, B. subtilis, P. aeruginosa and E. coli. Additionally, compound 6 e was found to be highly potent against methicillin resistant S. aureus (MRSA; MIC=2 μg mL−1). Molecular docking studies were also performed to confer the possible mode of action and association studies indicate the binding of potent active compound with DHFR enzyme (Ka=2.10×103 M−1). Further, the mechanism of action has also been explored by atomic force microscopy (AFM), which reveals the bacterial cell wall deformity and cell wall rupturing that may lead to bacteria cell death. Additionally, in silico ADME prediction study suggested the drug like properties of active compounds.

Uses of cyclohexane-1,3-dione for the synthesis of 1,2,4-triazine derivatives as anti-proliferative agents and tyrosine kinases inhibitors

Tetrahydrobenzo[b]thiophene derivatives were well known to be biologically active compounds and many of them occupy a wide range as anticancer agent drugs. One of our main aim of this work was to synthesize target molecules not only possess anti-tumor activities but also kinase inhibitors. To achieve this goal, our strategy was to synthesize a series of novel 1,2,4-triazines as efficient anticancer drugs with low cytotoxicity and good bioavailability properties using cyclohexane-1,3-dione and 3-cyano-4,5,6,7-tetrahydrobenzo[b]thiophene-2-diazonium chloride to give the 2-(2-(2,6-dioxocyclohexylidene)hydrazinyl)-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carbonitrile (3) as the key starting material for many heterocyclization reactions. Compound 3 was reacted with phenylisothiocyanate to give the tetrahydrobenzo[e][1,2,4]triazine derivative 5 which reacted with hydrazines to give dihydrazone derivatives. In addition, it underwent multi-component reactions with aromatic aldehydes and either malononitrile or ethyl cyanoacetate in the presence of triethylamine or ammonium acetate to produce fused pyran and fused pyridine derivatives, respectively. Compounds obtained in this work were evaluated for their c-Met kinase inhibitory potency as well as in-vitro cytotoxic activity against the six typical cancer cell lines (A549, H460, HT-29, MKN-45, U87MG, and SMMC-7721). Molecular modeling studies were carried out for the most active compounds 5, 7a, 7b, 10c, 10e, 11c and 11f using Molecular Operating Environment (MOE) software. It was found that all the tested compounds displayed potent c-Met enzymatic activity with IC₅₀ values ranging from 0.24 to 9.36 nM. Ten of them (5, 7a, 7b, 10c, 10e, 10f, 11b, 11c, 11d and 11f) exhibited higher potency with IC₅₀ values less than 1.00 nM compared with foretinib (IC₅₀ = 1.16 nM). Also those compounds possessed moderate to strong cytotoxicity against the six tested cancer cell lines in the single-digit µM range. The synthesized compounds 5, 7a, 7b, 10c, 10e, 11c and 11f were fit on the active site of c-Met kinase, with almost the same binding pattern as foretinib and higher binding energy scores (from -16.38 to -18.21 kcal/mol) compared to foretinib (-16.37 kcal/mol). A series of novel 1,2,4-triazines were synthesized and displayed potent bioactivities, indicating that these compounds could be considered as a new lead for more investigation in the future.

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.

Development and validation of RP-HPLC method for stability evaluation of model hydrazone, containing a pyrrole ring

RP-HPLC method with UV detection was developed and validated for determination of the chemical stability and stability in close to physiological conditions of a model pyrrole hydrazone ethyl 5-(4-bromophenyl)-1-(1-(2-(4-hydroxy-3-methoxybenzylidene) hydrazineyl)-4-methyl-1-oxopentan-2-yl)-2-methyl-1H-pyrrole-3-carboxylate (D_5d), containing susceptible to hydrolysis hydrazone group. The evaluated substance was subjected to the influence of a variety of pH , representing the main physiological values of 37°C and corresponding pH values in the stomach (pH 2.0), blood (pH 7.4) and small intestine (pH 9.0). Chemical stability in a highly alkaline medium with a pH of 13.0 was also evaluated. The hydrazone I tested was found to be stable at pH 7.4 and pH 9.0 and 37 ° C and hydrolyzed under strong acidic (pH 2.0) and highly alkaline media (pH 13.0) and at the same temperature.The products of hydrolysis were identified to be the initial hydrazide and aldehyde, pointing the hydrazone group as most liable.

Synthesis, antiproliferative and apoptosis induction potential activities of novel bis(indolyl)hydrazide-hydrazone derivatives

In recent years, indole-indazolyl hydrazide-hydrazone derivatives with strong cell growth inhibition and apoptosis induction characteristics are being strongly screened for their cancer chemo-preventive potential. In the present study, N-methyl and N,N-dimethyl bis(indolyl)hydrazide-hydrazone analog derivatives were designed, synthesized and allowed to evaluate for their anti-proliferative and apoptosis induction potential against cervical (HeLa), breast (MCF-7 and MDA-MB-231) and lung (A549) cancer cell lines relative to normal HEK293 cells. The MTT assay in conjunction with mitochondrial potential assays and the trypan blue dye exclusion were employed to ascertain the effects of the derivatives on the cancer cells. Further, mechanistic studies were conducted on compound 14a to understand the biochemical mechanisms and functional interactions with various signaling pathways triggered in HeLa and MCF-7 cells. Compound 14a induced apoptosis via caspase independent pathway through the participation of mitogen-activated protein kinases (MAPK) such as extracellular signal related kinase (ERK) and p38 as well as p53 pathways. It originates the activation of pro-apoptotic proteins such as Bak and Mcl-1s and also strongly induced the generation of reactive oxygen species. In downstream signaling pathway, activated p53 protein interacted with MAPK pathways, including SAPK/c-Jun N-terminal protein kinase (JNK), p38 and ERK kinases resulting in apoptotic cell death. The involvement of MAPK cascades such as p38, ERK and p38 on compound 14a induced apoptotic cell death was evidenced by the fact that the inclusion of specific inhibitors of p38, ERK1/2 and JNK MAPK (SB2035809, PD98059 and SP600125) prevented the compound 14a towards induced apoptosis. The results clearly showed that MAP kinase cascades were crucial for apoptotic response in compound 14a induced cellular killing and were dependent on p53 activity. Based on the results, compound 14a was identified as a promising candidate for cancer therapeutics and these findings furnish a basis for further in vivo experiments on anti-proliferative activity.