Synthesis and in vitro bioactivity study of new hydrazide-hydrazones of 5-bromo-2-iodobenzoic acid

Synthesis, Structural Properties and Biological Activities of Novel Hydrazones of 2-, 3-, 4-Iodobenzoic Acid

Nowadays, searching for novel antimicrobial agents is crucial due to the increasing number of resistant bacterial strains. Moreover, cancer therapy is a major challenge for modern medicine. Currently used cytostatics have a large number of side effects and insufficient therapeutic effects. Due to the above-mentioned facts, we undertook research to synthesize novel compounds from the acylhydrazone group aimed at obtaining potential antimicrobial and anticancer agents. As a starting material, we employed hydrazides of 2-, 3- or 4-iodobenzoic acid, which gave three series of acylhydrazones in the condensation reaction with various aldehydes. The chemical structure of all obtained compounds was confirmed by IR, 1H NMR, and 13C NMR. The structure of selected compounds was determined by single-crystal X-ray diffraction analysis. Additionally, all samples were characterized using powder X-ray diffraction. The other issue in this research was to examine the possibility of the solvent-free synthesis of compounds using mechanochemical methods. The biological screening results revealed that some of the newly synthesized compounds indicated a beneficial antimicrobial effect even against MRSA-the methicillin-resistant Staphylococcus aureus ATCC 43300 strain. In many cases, the antibacterial activity of synthesized acylhydrazones was equal to or better than that of commercially available antibacterial agents that were used as reference substances in this research. Significantly, the tested compounds do not show toxicity to normal cell lines either.

Design, Synthesis, and In Vitro and In Vivo Bioactivity Studies of Hydrazide-Hydrazones of 2,4-Dihydroxybenzoic Acid

In this research, twenty-four hydrazide-hydrazones of 2,4-dihydroxybenzoic acid were designed, synthesized, and subjected to in vitro and in vivo bioactivity studies. The chemical structure of the obtained compounds was confirmed by spectral methods. Antimicrobial activity screening was performed against a panel of microorganisms for all synthesized hydrazide-hydrazones. The performed assays revealed the interesting antibacterial activity of a few substances against Gram-positive bacterial strains including MRSA-Staphylococcus aureus ATCC 43300 (compound 18: 2,4-dihydroxy-N-[(2-hydroxy-3,5-diiodophenyl)methylidene]benzohydrazide-Minimal Inhibitory Concentration, MIC = 3.91 µg/mL). In addition, we performed the in vitro screening of antiproliferative activity and also assessed the acute toxicity of six hydrazide-hydrazones. The following human cancer cell lines were used: 769-P, HepG2, H1563, and LN-229, and the viability of the cells was assessed using the MTT method. The HEK-293 cell line was used as a reference line. The toxicity was tested in vivo on Danio rerio embryos using the Fish Embryo Acute Toxicity (FET) test procedure according to OECD No. 236. The inhibitory concentration values obtained in the in vitro test showed that N-[(4-nitrophenyl)methylidene]-2,4-dihydroxybenzhydrazide (21) inhibited cancer cell proliferation the most, with an extremely low IC50 (Inhibitory Concentration) value, estimated at 0.77 µM for LN-229. In addition, each of the compounds tested was selective against cancer cell lines. The compounds with a nitrophenyl substituent were the most promising in terms of inhibition cancer cell proliferation. The toxicity against zebrafish embryos and larvae was also very low or moderate.

New Anthranilic Acid Hydrazones as Fenamate Isosteres: Synthesis, Characterization, Molecular Docking, Dynamics & in Silico ADME, in Vitro Anti-Inflammatory and Anticancer Activity Studies

In this study, twenty new anthranilic acid hydrazones 6-9 (a-e) were synthesized and their structures were characterized by Fourier-transform Infrared (FT-IR), Nuclear Magnetic Resonance (1 H-NMR - 13 C-NMR), and High-resolution Mass Spectroscopy (HR-MS). The inhibitory effects of the compounds against COX-II were evaluated. IC50 values of the compounds were found in the range of >200-0.32 μM and compounds 6e, 8d, 8e, 9b, 9c, and 9e were determined to be the most effective inhibitors. Cytotoxic effects of the most potent compounds were investigated against human hepatoblastoma (Hep-G2) and human healthy embryonic kidney (Hek-293) cell lines. Doxorubicin (IC50 : 8.68±0.16 μM for Hep-G2, 55.29±0.56 μM for Hek-293) was used as standard. 8e is the most active compound, with low IC50 against Hep-G2 (4.80±0.04 μM), high against Hek-293 (159.30±3.12), and high selectivity (33.15). Finally, molecular docking and dynamics studies were performed to understand ligand-protein interactions between the most potent compounds and COX II, Epidermal Growth Factor Receptor (EGFR), and Transforming Growth Factor beta II (TGF-βII). The docking scores were calculated in the range of -10.609--6.705 kcal/mol for COX-II, -8.652--7.743 kcal/mol for EGFR, and -10.708--8.596 kcal/mol for TGF-βII.

Design, Synthesis, and Anticancer Evaluation of Novel Tetracaine Hydrazide-Hydrazones

Tetracaine is an ester derivative used as a local anesthetic molecule. In this study, a series of novel Tetracaine derivatives bearing hydrazide-hydrazone moiety were designed, synthesized, and evaluated for anticancer activity. The structures of these compounds were characterized by spectral (¹H NMR,¹³C NMR, FT-IR, and HRMS analyses) methods. All synthesized compounds were screened for anticancer activity against two different human cancer cell lines (Colo-205 and HepG2). Among the synthesized molecules, compounds 2f and 2m showed the most potent anticancer activity against the Colo-205 cell line (IC₅₀ = 50.0 and 20.5 μM, respectively). Compounds 2k, 2p, and 2s demonstrated the best anticancer activity against the HepG2 cell line (IC₅₀ = 30.5, 35.9, and 20.8 μM, respectively). mRNA transcription levels of Bax and caspase-3 genes were determined by real-time polymerase chain reaction (qRT-PCR) analysis of both Colo-205 and HepG2 cell lines. Doxorubicin was used as a positive sensitivity reference standard. qRT-PCR analysis showed that there was a time-dependent rise in the expression levels of Bax and Caspase 3 on apoptosis. Inhibition of apoptotic proteins PI3K, Akt, PTEN, pPTEN, FoXO1, FoXO3a, TXNIP, and p27 was investigated in Colo-205 and HepG2 cells treated with compounds 2f, 2m, 2k, 2p, and 2s by using Western blotting.

Cyclooxygenase-2 (COX-2) as a Target of Anticancer Agents: A Review of Novel Synthesized Scaffolds Having Anticancer and COX-2 Inhibitory Potentialities

Cancer is a serious threat to human beings and is the second-largest cause of death all over the globe. Chemotherapy is one of the most common treatments for cancer; however, drug resistance and severe adverse effects are major problems associated with anticancer therapy. New compounds with multi-target inhibitory properties are targeted to surmount these challenges. Cyclooxygenase-2 (COX-2) is overexpressed in cancers of the pancreas, breast, colorectal, stomach, and lung carcinoma. Therefore, COX-2 is considered a significant target for the synthesis of new anticancer agents. This review discusses the biological activity of recently prepared dual anticancer and COX-2 inhibitory agents. The most important intermolecular interactions with the COX-2 enzyme have also been presented. Analysis of these agents in the active area of the COX-2 enzyme could guide the introduction of new lead compounds with extreme selectivity and minor side effects.

The N-Substituted-4-Methylbenzenesulphonyl Hydrazone Inhibits Angiogenesis in Zebrafish Tg(fli1: EGFP) Model

One of the most important therapies of malignant neoplasms, which are the second cause of death worldwide, is focused on the inhibition of pathological angiogenesis within the tumor. Therefore, the searching for the efficacious and relatively inexpensive small-molecule inhibitors of this process is essential. In this research, the anti-angiogenic potential of N-substituted-4-methylbenzenesulphonyl hydrazone, possessing antiproliferative activity against cancer cells, was tested. For this purpose, an intersegmental vessel (ISV) angiogenesis assay was performed using 6 hpf (hours post fertilization), 12 hpf and 24 hpf embryos of zebrafish transgenic strain, Tg(fli1: EGFP). They were incubated with different concentrations of tested molecule and after 24 h the development of intersegmental vessels of the trunk was analysed. In turn, the acute toxicity study in the zebrafish model was mainly conducted on strain AB, using the OECD-approved and recommended fish embryo acute toxicity test (FET) procedure. The results showed the moderate toxicity of N-[(3-chloro-4-methoxyphenyl)methylidene]-4-methylbenzenesulphonohydrazide in above-mentioned model with the LC₅₀ value calculated at 23.04 mg/L. Moreover, newly synthesized molecule demonstrated the anti-angiogenic potential proved in Tg(fli1: EGFP) zebrafish model, which may be promising for the therapy of neoplastic tumors as well as other diseases related to pathological angiogenesis, such as age-related macular degeneration and diabetic retinopathy.

Hydrazone analogues with promising antibacterial profiles: Synthesis, morphology, in vitro and in silico approaches

Emergence of resistance to antibacterial drugs remains an important global threat that necessitates an urgent need for the discovery of alternative drugs. This study was undertaken to synthesize some novel nitroaryl/heteroaryl hydrazone derivatives as potential antibacterial agents. After synthesizing by a simple reaction between quinoline/quinazoline hydrazine and nitroaryl/heteroaryl aldehydes, all the compounds were screened for their antibacterial activities, cytotoxicity, and in silico investigations. The compound, 2-(4-nitrobenzylidene)-1-(quinazolin-4-yl)hydrazine (1b) displayed significant antimicrobial activity against several susceptible and resistant bacteria without any cytotoxicity. Moreover, scanning electron microscopy (SEM) revealed the complete destruction of Staphylococcus aureus and Escherichia coli following exposure to this compound after 2 hours exposure. The in silico studies confirmed the better binding energy of these compounds in comparison with the reference drugs in complex with topoisomerase IV and bacterial ribosomal receptor. Compound 1b can be considered as a promising lead compound for the development of broad-spectrum antibacterial medications after further studies.

Novel 2,4,6-Trimethylbenzenesulfonyl Hydrazones with Antibacterial Activity: Synthesis and In Vitro Study

This research describes the synthesis and in vitro antimicrobial activity study of a series of 2,4,6-trimethylbenzenesulfonyl hydrazones. Twenty-five hydrazones (2-26) were synthesized on the basis of condensation reaction. The in vitro bioactivity study confirmed the potential application of obtained derivatives as antimicrobial agents. Among the tested compounds, the highest activity was discovered for derivative 24, which possessed minimal inhibitory concentration (MIC) ranging from 7.81 to 15.62 µg/mL against Gram-positive reference bacterial strains. Synthesized benzenesulfonyl hydrazones can be applied as potential ligands for the synthesis of bioactive metal complexes.

Iodinated 1,2-diacylhydrazines, benzohydrazide-hydrazones and their analogues as dual antimicrobial and cytotoxic agents

Hydrazide-hydrazones have been described as a scaffold with antimicrobial and cytotoxic activities as well as iodinated compounds. A resistance rate of bacterial and fungal pathogens has increased considerably. That is why we synthesized and screened twenty-two iodinated hydrazide-hydrazones 1 and 2, ten 1,2-diacylhydrazines 3 and their three reduced analogues 4 for their antibacterial, antifungal, and cytotoxic properties. Hydrazide-hydrazones were prepared by condensation of 4-substituted benzohydrazides with 2-/4-hydroxy-3,5-diiodobenzaldehydes, diacylhydrazines from identical benzohydrazides and 3,5-diiodosalicylic acid via its chloride. These compounds were investigated in vitro against eight bacterial and eight fungal strains. The derivatives were found potent antibacterial agents against Gram-positive cocci including methicillin-resistant Staphylococcus aureus with the lowest values of minimum inhibitory concentrations (MIC) of 7.81 µM. Four compounds inhibited also human pathogenic fungi (MIC of ≥1.95 µM). The derivatives had different degrees of cytotoxicity for HepG2 and HK-2 cell lines (IC₅₀ values from 11.72 and 26.80 µM, respectively). Importantly, normal human cells exhibited lower sensitivity. The apoptotic effect was also investigated. In general, the presence of 3,5-diiodosalicylidene scaffold (compounds 1) is translated into enhanced both antimicrobial and cytotoxic properties whereas its 4-hydroxy isomers 2 share a low biological activity. N'-Benzoyl-2-hydroxy-3,5-diiodobenzohydrazides 3 have a non-homogeneous activity profile. Focusing on 4-substituted benzohydrazide part, the presence of an electron-withdrawing group (F, Cl, CF₃, NO₂) was found to be beneficial.

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.