Structure-based design and biological profile of (E)-N-(4-Nitrobenzylidene)-2-naphthohydrazide, a novel small molecule inhibitor of IκB kinase-β

The Magic Methyl and Its Tricks in Drug Discovery and Development

One of the key scientific aspects of small-molecule drug discovery and development is the analysis of the relationship between its chemical structure and biological activity. Understanding the effects that lead to significant changes in biological activity is of paramount importance for the rational design and optimization of bioactive molecules. The "methylation effect", or the "magic methyl" effect, is a factor that stands out due to the number of examples that demonstrate profound changes in either pharmacodynamic or pharmacokinetic properties. In many cases, this has been carried out rationally, but in others it has been the product of serendipitous observations. This paper summarizes recent examples that provide an overview of the current state of the art and contribute to a better understanding of the methylation effect in bioactive small-molecule drug candidates.

Acylhydrazones and Their Biological Activity: A Review

Due to the structure of acylhydrazones both by the pharmacophore -CO-NH-N= group and by the different substituents present in the molecules of compounds of this class, various pharmacological activities were reported, including antitumor, antimicrobial, antiviral, antiparasitic, anti-inflammatory, immunomodulatory, antiedematous, antiglaucomatous, antidiabetic, antioxidant, and actions on the central nervous system and on the cardiovascular system. This fragment is found in the structure of several drugs used in the therapy of some diseases that are at the top of public health problems, like microbial infections and cardiovascular diseases. Moreover, the acylhydrazone moiety is present in the structure of some compounds with possible applications in the treatment of other different pathologies, such as schizophrenia, Parkinson's disease, Alzheimer's disease, and Huntington's disease. Considering these aspects, we consider that a study of the literature data regarding the structural and biological properties of these compounds is useful.

Novel Regioisomeric Analogues of Naphthyl-N-Acylhydrazone Derivatives and Their Anti-Inflammatory Effects

BACKGROUND

When homeostasis is disturbed it can result in a pathological event named inflammation. The main drugs used in the treatment consist of non-steroidal and steroidal anti-inflammatory drugs. However, the side effects remain an obstacle during the treatments. In this study, we aimed to evaluate three new regioisomers analogues of naphthyl-N-acylhydrazone derivatives.

METHODS

Acute models of inflammation in vivo (formalin-induced licking and carrageenan-induced inflammation) as well as in vitro were used to evaluate the effects of LASSBio-2039, LASSBio-2040, and LASSBio-2041.

RESULTS

All three substances (at 1, 10 or 30 µmol/kg) presented significant effects in the in vivo model reducing leukocyte migration, nitric oxide (NO) and interleukin-1β production. It was observed that only LASSBio-2039 significantly reduced cell migration in vitro. None of the LASSBios affected inducible nitric oxide synthase activity nor presented nitric oxide (NO) scavenger effect. No toxic effect was observed, either in vivo or in vitro. The new regioisomers analogues of naphthyl-N-acylhydrazone derivatives presented significant anti-inflammatory activity, suggesting LASSBio-2039 has a direct effect in leukocytes migratory capacity.

CONCLUSIONS

Taken together, the data indicate that these substances present promising effects for the development of a prototype for new drugs.

Pronounced Magnetic Bistability in Highly Cooperative Mononuclear [Fe(Lnpdtz)2(NCX)2] Complexes

Molecular materials that exhibit stimuli-responsive bistability are promising candidates for the development of molecular switches and sensors. We herein report on the coexistence of a wide thermal hysteretic spin crossover (SCO) effect and a thermally inducible metastable high-spin state at low temperatures achieved with the two new complexes [Fe^II(L^npdtz)₂(NCX)₂] (X = S; Se), with L^npdtz being (2-naphthyl-5-pyridyl-1,2,4-thiadiazole) and X = S (1) and Se (2). Pronounced π-π-stacking of the aromatic side residues of the ligands enables strong intermolecular interactions, leading to abrupt SCO properties and broad magnetic hysteresis of 10 K for X = S and 58 K for X = Se. In this paper, we also present the pressure-induced spin-state switching around 0.8 GPa. A pronounced thermally induced excited spin state trapping (TIESST effect) is observed for the highly cooperative SCO compounds, which was experimentally followed by low-temperature single crystal structure analysis (20 K) and temperature-dependent Mössbauer spectroscopy.

Therapeutic Effects of Anti-Inflammatory N-Acylhydrazones in the Resolution of Experimental Colitis

Inflammatory bowel diseases are caused by inflammation of the gastrointestinal tract, which may or may not have a specific cause or pathogen. They affect millions of people around the world and there are still few effective treatments. The aim of this work is to investigate the anti-inflammatory effect of the IKK-β inhibitor LASSBio-1524 and its three analogs, LASSBio-1760, LASSBio-1763, and LASSBio-1764, on mediator production and expression of inflammatory enzymes using experimental animal models of intestinal inflammatory diseases. Colitis was performed using two different models, which mimic Crohn disease (induced by dinitrobenzene acid) and ulcerative colitis (induced by sodium dextran sulfate) in mice. In both models, a therapeutic protocol with a daily dose of 1, 3, or 30 μmol/kg was performed. LASSBio-1524 and its three analogs reduced the secretion of tumor necrosis factor-α, IL-1β, IL-6, IL-12, and IFN-γ and increased secretion of IL-10, protecting gastrointestinal homeostasis. All compounds reduced macro- and microscopic colonic damage caused by experimental colitis and p38 mitogen-activated protein kinase expression in the colon, as well as leukocytosis and anemia resulting from the disease. Our data may suggest LASSBio-1524 and its analogs (LASSBio-1760, LASSBio-1763, and LASSBio-1764) as promising candidates for new prototypes designed to treat inflammatory bowel diseases. SIGNIFICANCE STATEMENT: Three new N-acylhydrazones were synthetized as analogs of LASSBio-1524. All new substances were evaluated in dextran sulfate- and dinitrobenzene acid-induced colitis, with LASSBio-1760, LASSBio-1762, and LASSBio-1763 presenting a significant effect in both models of colitis without toxic effects. The new substances could be considered as a new prototype for the development of new anti-inflammatory treatments of colitis.

New 2-amino-pyridinyl-N-acylhydrazones: Synthesis and identification of their mechanism of anti-inflammatory action

AIMS

The main aim of this paper was the synthesis and the evaluation of the anti-inflammatory activity of LASSBio-1828 (an amino-pyridinyl-N-acylhydrazone) and its respective hydrochloride, based on a p38α MAPK inhibitor (LASSBio-1824) previously synthesized by our group.

MAIN METHODS

The compounds were tested regarding their cell viability effect and on acute models of inflammation such as formalin-induced licking test, cell migration and inflammatory mediators quantification.

KEY FINDINGS

Treatment with the compounds inhibited p38α, reduced inflammatory pain, cell migration and inflammatory mediators that participate on the MAPK pathway such as TNF-α and IL-1β.

SIGNIFICANCE

Taken together, these results suggest that the synthesis of the corresponding hydrochloride of LASSBio-1828 enhanced its potency as a p38 inhibitor, and also that this compound could be considered a good anti-inflammatory drug candidate after further studies.

Synthesis and pharmacological evaluation of novel isoquinoline N-sulphonylhydrazones designed as ROCK inhibitors

In this study, we synthesized a new congener series of N-sulphonylhydrazones designed as candidate ROCK inhibitors using the molecular hybridization of the clinically approved drug fasudil (1) and the IKK-β inhibitor LASSBio-1524 (2). Among the synthesized compounds, the N-methylated derivative 11 (LASSBio-2065) showed the best inhibitory profile for both ROCK isoforms, with IC50 values of 3.1 and 3.8 µM for ROCK1 and ROCK2, respectively. Moreover, these compounds were also active in the scratch assay performed in human breast cancer MDA-MB 231 cells and did not display toxicity in MTT and LDH assays. Molecular modelling studies provided insights into the possible binding modes of these N-sulphonylhydrazones, which present a new molecular architecture capable of being optimized and developed as therapeutically useful ROCK inhibitors.

Discovery of naphthyl-N-acylhydrazone p38α MAPK inhibitors with in vivo anti-inflammatory and anti-TNF-α activity

Protein kinases constitute attractive therapeutic targets for development of new prototypes to treat different chronic diseases. Several available drugs, like tinibs, are tyrosine kinase inhibitors; meanwhile, inhibitors of serine/threonine kinases, such as mitogen-activated protein kinase (MAPK), are still trying to overcome some problems in one of the steps of clinical development to become drugs. So, here we reported the synthesis, the in vitro kinase inhibitory profile, docking studies, and the evaluation of anti-inflammatory profile of new naphthyl-N-acylhydrazone derivatives using animal models. Although all tested compounds (3a-d) have been characterized as p38α MAPK inhibitors and have showed in vivo anti-inflammatory action, LASSBio-1824 (3b) presented the best performance as p38α MAPK inhibitor, with IC₅₀  = 4.45 μm, and also demonstrated to be the most promising anti-inflammatory prototype, with good in vivo anti-TNF-α profile after oral administration.

Discovery of Novel Orally Active Tetrahydro-Naphthyl-N-Acylhydrazones with In Vivo Anti-TNF-α Effect and Remarkable Anti-Inflammatory Properties

LASSBio-1524 was designed as inhibitor of the IKK-β (kappa β kinase inhibitor) enzyme, which participates in the activation of the nuclear factor κB (NF-κB) canonical pathway, and its three N-acylhydrazone new analogues, LASSBio-1760, LASSBio-1763 and LASSBio-1764 are now being tested on their anti-inflammatory potential. The activity of these compounds was evaluated with the subcutaneous air pouch induced by carrageenan and by subsequent measurement of tumor necrosis factor-α (TNF-α), nitric oxide (NO) and reactive oxygen species (ROS). In the acute inflammation model, the oral pretreatment with doses from 0.3 to 30 mg/kg of N-acylhydrazone derivatives was able to significantly reduce leukocyte migration to the cavity. Pretreatment with LASSBio-1524 and its analogues also decreased NO, TNF-α and ROS biosynthesis an events closely involved with NF-kB pathway. The tetrahydronaphthyl-N-acylhydrazone derivative LASSBio-1764 was the most promising compound from this series, surpassing even LASSBio-1524. Additionally, none of the compounds demonstrated myelotoxicity or cytotoxicity. Cell viability was assayed and these compounds demonstrated to be safe at different concentrations. Western blot analysis demonstrated that LASSBio-1524 and LASSBio-1760 inhibited NF-κB expression in RAW 264.7 cell lineage. Our data indicate that the tested compounds have anti-inflammatory activity, which may be related to inhibition of leukocyte migration, reducing the production of NO, TNF-α and ROS. LASSBio-1524 and LASSBio-1760, in addition to these features, also reduced p65 nuclear expression assessed by western blot in RAW 264.7 murine cells.

Synthesis and Herbicidal Activity of New Hydrazide and Hydrazonoyl Derivatives

Three new hydrazide and five new hydrazonoyl derivatives were synthesized. The chemical structures of these compounds were confirmed by ¹H-NMR, IR spectroscopy and elemental analysis. The prepared compounds were tested for their activity to inhibit photosynthetic electron transport in spinach chloroplasts and growth of the green algae Chlorella vulgaris. IC₅₀ values of these compounds varied in wide range, from a strong to no inhibitory effect. EPR spectroscopy showed that the active compounds interfered with intermediates Z^•/D^•, which are localized on the donor side of photosystem II. Fluorescence spectroscopy suggested that the mechanism of inhibitory action of the prepared compounds possibly involves interactions with aromatic amino acids present in photosynthetic proteins.

Binding mode analysis of zerumbone to key signal proteins in the tumor necrosis factor pathway

Breast cancer is the second most common cancer among women worldwide. Several signaling pathways have been implicated as causative and progression agents. The tumor necrosis factor (TNF) α protein plays a dual role in promoting and inhibiting cancer depending largely on the pathway initiated by the binding of the protein to its receptor. Zerumbone, an active constituent of Zingiber zerumbet, Smith, is known to act on the tumor necrosis factor pathway upregulating tumour necrosis factor related apoptosis inducing ligand (TRAIL) death receptors and inducing apoptosis in cancer cells. Zerumbone is a sesquiterpene that is able to penetrate into the hydrophobic pockets of proteins to exert its inhibiting activity with several proteins. We found a good binding with the tumor necrosis factor, kinase κB (IKKβ) and the Nuclear factor κB (NF-κB) component proteins along the TNF pathway. Our results suggest that zerumbone can exert its apoptotic activities by inhibiting the cytoplasmic proteins. It inhibits the IKKβ kinase that activates the NF-κB and also binds to the NF-κB complex in the TNF pathway. Blocking both proteins can lead to inhibition of cell proliferating proteins to be downregulated and possibly ultimate induction of apoptosis.

The diverse and complex roles of NF-κB subunits in cancer

It is only recently that the full importance of nuclear factor-κB (NF-κB) signalling to cancer development has been understood. Although much attention has focused on the upstream pathways leading to NF-κB activation, it is now becoming clear that the inhibitor of NF-κB kinases (IKKs), which regulate NF-κB activation, have many independent functions in tissue homeostasis and normal immune function that could compromise the clinical utility of IKK inhibitors. Therefore, if the NF-κB pathway is to be properly exploited as a target for both anticancer and anti-inflammatory drugs, it is appropriate to reconsider the complex roles of the individual NF-κB subunits.