Synthesis and Evaluation of Novel Metacetamol Derivatives with Hydrazone Moiety as Anticancer and Antimicrobial Agents.

By exploiting the wide biological potential of the hydrazone scaffold, a series of hydrazone derivatives were synthesized, starting from N-(3-hydroxyphenyl)acetamide (metacetamol). The structures of the compounds were determined using IR, 1 H and 13 C-NMR, and mass spectroscopic methods. The obtained molecules (3 a-j) were evaluated for their anticancer potential against MDA-MB-231 and MCF-7 breast cancer cell lines. According to the CCK-8 assay, all tested compounds showed moderate to potent anticancer activity. Among them, N-(3-(2-(2-(4-nitrobenzylidene)hydrazinyl)-2-oxoethoxy)phenyl)acetamide (3 e) was found to be the most effective derivative with an IC50 value of 9.89 µM against MDA-MB-231 cell lines. This compound was further tested for its potential effects on the apoptotic pathway. Molecular docking studies was also carried out for 3 e in the colchicine binding pocket of tubulin. Additionally, compound 3 e also demonstrated effective antifungal activity, particularly against Candida krusei (MIC=8 µg/ml), indicating that nitro group at the 4th  position of the phenyl ring was the most preferable substituent for both cytotoxic and antimicrobial activity. Our preliminary findings suggest that compound 3 e could be exploited as a leading structure for further anticancer and antifungal drug development.

Synthesis, antimicrobial properties and in silico studies of aryloxyacetic acid derivatives with hydrazone or thiazolidine-4-one scaffold.

In this work, twenty hydrazide-hydrazone and 4-thiazolidinone derivatives were synthesized starting from m-cresol. Antimicrobial evaluation was carried out by microdilution method against Enterococcus faecalis and Staphylococcus aureus as Gram-positive bacteria and Escherichia coli and Pseudomonas aeruginosa as Gram-negative bacteria, and three pathogenic fungi Candida albicans, Candida parapsilosis and Candida krusei. Some compounds possessed considerable antimicrobial properties against the tested microorganisms, particularly against E. coli. 4-Thiazolidinones containing 3-methoxyphenyl and 3,5-dichlorophenyl moieties (4h and 4i) were found to be the most active derivatives with MICs of 2 µg/mL against E. coli. N'-[(3,5-dichlorophenyl)methylidene]-2-(3-methylphenoxy)acetohydrazide (3i) also displayed antifungal activity against Candida krusei that was comparable to fluconazole. Calculated drug-likeness and ADMET parameters of the most active compounds confirmed their potential as antimicrobial drug candidates. Molecular docking investigations were carried out in the thiamine diphosphate-binding site of pyruvate dehydrogenase multienzyme complex E1 component (PDHc-E1) to clarify the potential antibacterial mechanism against E. coli. The results showed the potential and importance of developing new hydrazones and 4-thiazolidinones that would be effective against microbial strains.Communicated by Ramaswamy H. Sarma.

Synthesis, Molecular Docking Studies and ADME Prediction of Some New Albendazole Derivatives as α-Glucosidase Inhibitors.

A series of novel 2-(substituted arylidene)-N-(5-(propylthio)-2,3-dihydro-1H-benzo[d]imidazol-2-yl)hydrazine-1-carboxamide derivatives 3a-i were synthesized via condensation of N-(5-(propylthio)-1H-benzo[d]imidazol-2-yl) hydrazinecarboxamide (2), with the corresponding ketone or aldehydes. The chemical structures of the compounds prepared were confirmed by analytical and spectral data. The compounds were screened for their α-glucosidase inhibitory activity and all of them showed better inhibition than acarbose, except 3h. In particular, compound 3a proved to be the most active compound among all synthetic derivatives having IC50 value 12.88±0.98 µM. Also, molecular docking studies were carried out for the compounds to figure out the binding interactions. Compound 3a has exhibited the highest binding energy (ΔG = -9.4 kcal/mol) and the most hydrogen bond interactions with active sites. Eventually, in silico studies were in good agreement with in vitro studies.

Synthesis and Anticancer and Antimicrobial Evaluation of Novel Ether-linked Derivatives of Ornidazole.

OBJECTIVES: Some novel 1-(2-methyl-5-nitro-1H-imidazol-1-yl)-3-(substituted phenoxy)propan-2-ol derivatives (3a-g) were designed and synthesized. MATERIALS AND METHODS: Compounds 3a-g were obtained by refluxing ornidazole (1) with the corresponding phenolic compounds (2a-g) in the presence of anhydrous K2CO3 in acetonitrile. RESULTS: Following the structure elucidation, the in vitro antimicrobial activity and cytotoxic effects of compounds 3a-g on K562 leukemia and NIH/3T3 mouse embryonic fibroblast cells were measured. As a part of this study, the compliance of the compounds with the drug-likeness properties was evaluated. The physico-chemical parameters (log P, TPSA, nrotb, number of hydrogen bond donors and acceptors, logS) were calculated using the software OSIRIS. CONCLUSION: All the synthesized compounds except 3a showed significant activity (MIC=4-16 µg mL-1) against the bacterial strain Bacillus subtilis as compared to the standard drug, whereas antileukemic activities were rather limited. Furthermore, all the compounds were nontoxic and the selectivity index outcome indicated that the antileukemic and antimicrobial effects of the compounds were selective with good estimated oral bioavailability and drug-likeness scores.

Synthesis, molecular docking and evaluation of novel sulfonyl hydrazones as anticancer agents and COX-2 inhibitors.

In trying to develop new anticancer agents, a series of sulfonylhydrazones were synthesized. All synthesized compounds were checked for identity and purity using elemental analysis, TLC and HPLC and were characterized by their melting points, FT-IR and NMR spectral data. All synthesized compounds were evaluated for their cytotoxic activity against prostate cancer (PC3), breast cancer (MCF-7) and L929 mouse fibroblast cell lines. Among them, N'-[(2-chloro-3-methoxyphenyl)methylidene]-4-methylbenzenesulfonohydrazide (3k) showed the most potent anticancer activity against both cancer cells with good selectivity (IC50 = 1.38 µM on PC3 with SI = 432.30 and IC50 = 46.09 µM on MCF-7 with SI = 12.94). Further investigation confirmed that 3k displayed morphological alterations in PC3 and MCF-7 cells and promoted apoptosis through down-regulation of the Bcl-2 and upregulation of Bax expression. Additionally, compound 3k was identified as the most potent COX-2 inhibitor (91% inhibition) beside lower COX-1 inhibition. Molecular docking of the tested compounds represented important binding modes which may be responsible for their anticancer activity via inhibition of the COX-2 enzyme. Overall, the lead compound 3k deserves further development as a potential anticancer agent. Sulfonylhydrazones was synthesized and N'-[(2-chloro-3-methoxyphenyl)methylidene]-4- methylbenzenesulfonohydrazide (3k) was identified as the most potent anticancer agent and COX-2 inhibitor. In addition, this compound docked inside the active site of COX-2 succesfully.

A Novel Anti-Hepatitis C Virus and Antiproliferative Agent Alters Metabolic Networks in HepG2 and Hep3B Cells.

A series of novel diflunisal hydrazide-hydrazones has been reported together with their anti-hepatitis C virus and antiproliferative activities in a number of human hepatoma cell lines. However, the mechanisms underlying the efficacy of these agents remain unclear. It was chosen to investigate the lead diflunisal hydrazide-hydrazone, 2',4'-difluoro-4-hydroxy-N'- [(pyridin-2-yl)methylidene]biphenyl-3-carbohydrazide (compound 3b), in two cultured human hepatoma cell lines-HepG2 and Hep3B-using a metabolomic protocol aimed at uncovering any effects of this agent on cellular metabolism. One sub-therapeutic concentration (2.5 µM) and one close to the IC50 for antimitotic effect (10 µM), after 72 h in cell culture, were chosen for both compound 3b and its inactive parent compound diflusinal as a control. A GCMS-based metabolomic investigation was performed on cell lysates after culture for 24 h. The intracellular levels of a total of 42 metabolites were found to be statistically significantly altered in either HepG2 or Hep3B cells, only eight of which were affected in both cell lines. It was concluded that compound 3b affected the following pathways-purine and pyrimidine catabolism, the glutathione cycle, and energy metabolism through glycolysis and the pentose phosphate pathway. Although the metabolomic findings occurred after 24 h in culture, significant cytotoxicity of compound 3b to both HepG2 and Hep3B cells at 10 µM were reported not to occur until 72 h in culture. These observations show that metabolomics can provide mechanistic insights into the efficacy of novel drug candidates prior to the appearance of their pharmacological effect.

Synthesis of Diflunisal Thiazolidinones as Anticancer Agents.

A series of diflunisal 4-thiazolidinones were synthesized. Some selected compounds were determined at one dose towards the full panel of 60 human cancer cell lines by National Cancer Institute. 2',4'-Difluoro-4-hydroxy-N-[4-oxo-2-(thiophen-2-yl)-1,3-thiazolidin-3-yl]biphenyl- 3-carboxamide (4a) demonstrated the most marked effect on K-562 cancer cell line with 58.59 % growth inhibition at 10 µM. Compound 4a was evaluated in vitro using the MTT colorimetric method against human leukemia cell line K-562 and mouse embryonic fibroblasts cell line NIH- 3T3 at different doses for cell viability and growth inhibition. Compound 4a exhibited anticancer activity with IC50 value of 5.2 µM against K-562 cells and did not display cytotoxicity towards NIH-3T3 cells compared with diflunisal. In addition, this compound could be an interesting prototype as an antiproliferative agent.

Synthesis of novel diflunisal hydrazide-hydrazones as anti-hepatitis C virus agents and hepatocellular carcinoma inhibitors.

Hepatitis C virus (HCV) infection is a main cause of chronic liver disease, leading to liver cirrhosis and hepatocellular carcinoma (HCC). The objective of our research was to develop effective agents against viral replication. We have previously identified the hydrazide-hydrazone scaffold as a promising hepatitis C virus (HCV) and hepatocelluler inhibitor. Herein we describe the design a number of 2',4'-difluoro-4-hydroxy-N'-(arylmethylidene) biphenyl-3-carbohydrazide (3a-t) as anti-HCV and anticancer agents. Results from evaluation of anti-HCV activity indicated that most of the synthesized hydrazone derivatives inhibited viral replication in the Huh7/Rep-Feo1b and Huh 7.5-FGR-JCI-Rluc2A reporter systems. Antiproliferative activities of increasing concentrations of 2',4'-difluoro-4-hydroxy-N'-(2-pyridyl methylidene)biphenyl-3-carbohydrazide 3b and diflunisal (2.5-40 µM) were assessed in liver cancer cell lines (Huh7, HepG2, Hep3B, Mahlavu, FOCUS and SNU-475) with sulforhodamine B assay for 72 h. Compound 3b with 2-pyridinyl group in the hydrazone part exhibited promising cytotoxic activity against all cell lines with IC50 values of 10, 10.34 16.21 4.74, 9.29 and 8.33 µM for Huh7, HepG2, Hep3B, Mahlavu, FOCUS and SNU-475 cells, respectively, and produced dramatic cell cycle arrest at SubG1/G0 phase as an indicator of apoptotic cell death induction.

Recent advances in bioactive pyrazoles.

Pyrazole is a five membered and two-nitrogen containing heterocyclic ring. These structures have been investigated in the development of novel compounds with hypoglycemic, analgesic, anti-inflammatory, antimicrobial, anticonvulsant, antidepressant, antimycobacterial, antioxidant, antiviral, insecticidal and antitumor activities. Therefore, these compounds have been synthesized as target structures by many researchers and were evaluated for their biological activities. We hope that the bioactivity of pyrazole derivatives will be beneficial for the rational design of new generation of small molecule drugs. In this review, we report the structures of 1H-pyrazoles with their corresponding biological activities for 21st (in 2000-2014 years) century.