Novel N-pyrocatechoyl and N-pyrogalloyl hydrazone antioxidants endowed with cytotoxic and antibacterial activity

Over the years, pharmacological agents bearing antioxidant merits arose as beneficial in the prophylaxis and treatment of various health conditions. Hazardous effects of radical species hyperproduction disrupt normal cell functioning, thus increasing the possibility for the development of various oxidative stress-associated disorders, such as cancer. Contributing to the efforts for efficient antioxidant drug discovery, a thorough in vitro and in silico assessment of antioxidant properties of 14 newly synthesized N-pyrocatechoyl and N-pyrogalloyl hydrazones (N-PYRs) was accomplished. All compounds exhibited excellent antioxidant potency against the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical. The extensive in silico analysis revealed multiple favorable features of N-PYRs to inactivate harmful radical species, which supported the obtained in vitro results. Also, in silico experiments provided insights into the preferable antioxidant pathways. Prompted by these findings, the cytotoxicity effects and the influence on the redox status of cancer HCT-116 cells and healthy fibroblasts MRC-5 were evaluated. These investigations exposed four analogs exhibiting both cytotoxicity and selectivity toward cancer cells. Furthermore, the frequently uncovered antimicrobial potency of hydrazone-type hybrids encouraged investigations on G+ and G- bacterial strains, which revealed the antibacterial potency of several N-PYRs. These findings highlighted the N-PYRs as excellent antioxidant agents endowed with cytotoxic and antibacterial features.

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.

Synthesis, in silico and in vitro studies of hydrazide-hydrazone imine derivatives as potential cholinesterase inhibitors

A series of hydrazide-hydrazone imine derivative compounds (3a-k) were synthesized and their structures characterized using FTIR, 1 H, and 13 C (NMR) spectroscopic methods. In addition, molecular structures of compounds 3a, 3d, and 3g were elucidated by X-ray diffraction technique. In vitro inhibition activities of hydrazide-hydrazone imine derivatives against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) were investigated. Compound 3i (IC50  = 2.01 μM) exhibited the best inhibitory activity against AChE, comparable to the control Galantamine (IC50  = 2.60 μM). Against BChE, compound 3h (IC50  = 2.83 μM) showed the best inhibitory property which is higher control Galantamine (IC50  = 3.70 μM). The Ki values of compound 3i (Ki = 0.63 μM) and compound 3h (Ki = 0.94 μM) that have the strongest inhibitory potential were determined against AChE and BChE, respectively. According to the docking result, the most stable conformation of AChE and compound 3i showed that it has a binding affinity of -10.82 kcal/moL. The binding affinity of the most stable conformation formed by BChE and compound 3h is -8.60 kcal/moL. Finally, in silico results and pharmacokinetic parameters of ADME showed that these compounds have good oral bioavailability properties.

The application of hydrazones and hydrazide-hydrazones in the synthesis of bioactive azetidin-2-one derivatives: A mini review

The hydrazones and hydrazide-hydrazones beside possessing crucial bioactivity can serve as useful intermediates in the synthesis of heterocyclic systems like 1,3-benzothiazin-4-one, 1,3-thiazolidin-4-one, azetidin-2-one and 1,3,4-oxadiazole derivatives. The azetidin-2-one derivatives show mainly antibacterial, antitubercular and antifungal activity as well as anti-inflammatory, antioxidant, anticonvulsant and antidepressant activity and activity against Parkinson's disease. This review is focused on the literature reports which consider the synthesis and biological properties of azetidin-2-one derivatives.

Searching for novel antimicrobial agents among hydrazide-hydrazones of 4-iodosalicylic acid

Searching for novel antimicrobial agents is up to day topic for many group of researchers due to the fact that each year the number of bacterial strains resistant to currently used medicines increases. Special attention in the scientific literature among various groups of bioactive organic compounds is focused on the antimicrobial activity of hydrazide-hydrazones. Due to this fact presented study is focused on the design, synthesis and in vitro antimicrobial properties of novel hydrazide-hydrazones of 4-iodosalicylic acid. Target compounds were synthesized by the condensation reaction of the hydrazide of 4-iodosalicylic acid with substituted (hetero)aromatic aldehydes. Chemical structure of obtained molecules was confirmed by spectral methods (¹H NMR and ¹³C NMR). Bioactivity screening results revealed interesting antimicrobial properties of tested compounds against reference Gram-positive bacteria and fungi belonging to Candida spp. Especially, hydrazide-hydrazones 3-5 showed very strong or strong bactericidal effect towards some cocci and bacilli (MIC = 7.81-15.62 µg/mL).

The novel adamantane derivatives as potential mediators of inflammation and neural plasticity in diabetes mice with cognitive impairment

Diabetes is a chronic disease leading to memory difficulties and deterioration of learning abilities. The previous studies showed that modulation of inflammatory pathways in the diabetic brain may reduce dysfunction or cell death in brain areas which are important for control of cognitive function. In the present study, we investigated the neuroprotective actions of newly synthesized adamantane derivatives on diabetes-induced cognitive impairment in mice. Our study relied on the fact that both vildagliptin and saxagliptin belong to DPP4 inhibitors and, contain adamantanyl group. Efficacy of tested compounds at reversing diabetes-induced different types of memory impairment was evaluated with the use of selected behavioural tests. The following neuroinflammatory indicators were also analyzed: neuroinflammatory indicators and the expression of genes involved in the inflammatory response of brain (Cav1, Bdnf). Our study demonstrated that new adamantane derivatives, similarly to DPP4 inhibitors, can restrict diabetes-induced cognitive deficits. We demonstrated that the overexpression of GLP-1-glucagon-like peptide as well as Bdnf, Cav1 genes translate into central blockade of pro-inflammatory synthesis of cytokines and significantly improvement on memory performance in diabetes mice. Newly synthesized adamantane derivatives might have important roles in prevention and treatment of cognitive impairment by inflammatory events in patients with diabetes or related diseases.

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.

Updated Information on Antimicrobial Activity of Hydrazide-Hydrazones

Hydrazide-hydrazones possess a wide spectrum of bioactivity, including antibacterial, antitubercular, antifungal, anticancer, anti-inflammatory, anticonvulsant, antidepressant, antiviral, and antiprotozoal properties. This review is focused on the latest scientific reports regarding antibacterial, antimycobacterial, and antifungal activities of hydrazide-hydrazones published between 2017 and 2021. The molecules and their chemical structures presented in this article are the most active derivatives, with discussed activities having a hydrazide-hydrazone moiety as the main scaffold or as a side chain. Presented information constitute a concise summary, which may be used as a practical guide for further design of new molecules with antimicrobial activity.

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.

Facile construction of a family of supramolecular gels with good levofloxacin hydrochloride loading capacity

A family of low molecular weight gelators with different alkyl chain lengths was constructed, having excellent gelation ability and antibiotic loading capacity. A low molecular weight hydrogelator was obtained by adjusting the length of alkyl chain.

Synthesis and anticancer properties of novel hydrazone derivatives incorporating pyridine and isatin moieties

Nine novel hydrazone derivatives (4a-i) incorporating pyridine and isatin moieties were synthesized through one-pot, four-component heterocyclic condensation reactions. The structures of all new compounds (2a-e, 3a, 3c-e, and 4a-e) were identified by ¹ H nuclear magnetic resonance (NMR), ¹³ C NMR, and Fourier-transform infrared spectroscopic techniques and elemental analysis. Cell viability assays for the tested hydrazone derivatives were performed and the log IC₅₀ values of the compounds were calculated after a 24-h treatment. All hydrazide derivatives tested showed a promising antitumor activity against A-2780 cells as compared with the standard drug docetaxel with a log IC₅₀ value of 0.2200 μM (p < .05). Seven of the examined compounds (4b-e, 4g-i) showed high cytotoxic activity against A-2780 cells as compared with the standard drug docetaxel. Whereas the log IC₅₀ of docetaxel was 0.2200 μM for A-2780 cells at 24 h, the IC₅₀ values of these compounds were -0.4987, -0.4044, -0.8138, -0.3868, -0.6954, -0.4751, and 0.1809 μM, respectively. Three of the compounds, 4b, 4d, and 4i, showed high cytotoxic activity against MCF-7 cells as compared with docetaxel (p < .05). Whereas the log IC₅₀ of docetaxel was 0.2400 μM for MCF-7 cells at 24 h, the log IC₅₀ values of compounds 4b, 4d, and 4i were -0.1293, -0.1700, and 0.2459 μM, respectively.

Crystal structure of (E)-4-bromo-N′-(3-chloro-2-hydroxybenzylidene)benzohydrazide, C14H10BrClN2O2

C14H10BrClN2O2, orthorhombic, Pca21 (no. 29), a = 32.4137(12) Å, b = 4.6683(2) Å, c = 8.8873(3) Å, V = 1344.80(9) Å3, Z = 4, R gt (F) = 0.0239, wR ref (F 2) = 0.0611, T = 150(2) K.