Advances in the activity of resveratrol and its derivatives in cardiovascular diseases

Cardiovascular diseases (CVDs), the leading cause of human death worldwide, are diseases that affect the heart and blood vessels and include arrhythmias, coronary atherosclerotic heart disease, hypertension, and so on. Resveratrol (RSV) is a natural nonflavonoid phenolic compound with antioxidant, anti-inflammatory, anticancer, and cardiovascular protection functions. RSV has shown significant protective effects against CVD. However, RSV's clinical application is limited by its tendency to be oxidized and metabolized easily. Therefore, it is necessary to optimize the RSV structure. This review will introduce the activity, synthesis, and structure-activity relationships of RSV derivatives, and the mechanism of the action of RSV in CVDs in recent years.

Novel pyridazinone derivatives bind to KSRP: Synthesis, anti-tumor biological evaluations and modelling insights

Pyridazinone derivatives have been extensively used as anticancer agents. IMB5036 is a structure specific pyridazinone compound with potential antitumor activity via targeting KSRP protein which controls gene expression at multiple levels. In this study, fifteen IMB5036 analogues were synthesized and preliminary structure-activity relationships were explored. Among them, compounds 8 and 10 exhibited remarkably anti-proliferation of various cancer cells and a good cancer cell selectivity (against human fetal hepatocyte L02 cells). More detailed investigation was included that both 8 and 10 inhibited colony formation and migration in concentration-dependent mode against MCF-7 cells. Additionally, 8 and 10 induced apoptosis and cell cycle arrest, decreased mitochondrial membrane potential, damaged DNA, and increased reactive oxygen species. Moreover, 8 displayed a potent antitumor efficacy (TGI = 74.2 %, at a dose of 30 mg/kg) in MCF-7 xenograft model by i.p. injection. Further, we synthesized a biotinylated probe 16 for identifying the detail domain of KSRP. Through pull down assay and molecular docking study, we validated that the KH23 domain functioned as the binding pocket for the compounds. Thus, compound 8 was identified as a novel targeting KSRP pyridazinone-based compound and exhibited excellent antitumor activity both in vitro and in vivo.

Mono- and Difluoromethylation of 3(2H)-Pyridazinones

A method for direct N-monofluoromethylation of pyridazinones with S-monofluoromethyl-S-phenyl-2,3,4,5-tetramethylphenylsulfonium triflate is disclosed. A method for the N- and O-difluoromethylated pyridazinones with TMSCF2Br as the only promising difluorocarbene precursor is also reported. Substrates with various relevant functional groups, including analogues of Lynparza, are tolerated under both methods.

Precision, integrative medicine for pain management in sickle cell disease

Sickle cell disease (SCD) is a prevalent and complex inherited pain disorder that can manifest as acute vaso-occlusive crises (VOC) and/or chronic pain. Despite their known risks, opioids are often prescribed routinely and indiscriminately in managing SCD pain, because it is so often severe and debilitating. Integrative medicine strategies, particularly non-opioid therapies, hold promise in safe and effective management of SCD pain. However, the lack of evidence-based methods for managing SCD pain hinders the widespread implementation of non-opioid therapies. In this review, we acknowledge that implementing personalized pain treatment strategies in SCD, which is a guideline-recommended strategy, is currently fraught with limitations. The full implementation of pharmacological and biobehavioral pain approaches targeting mechanistic pain pathways faces challenges due to limited knowledge and limited financial and personnel support. We recommend personalized medicine, pharmacogenomics, and integrative medicine as aspirational strategies for improving pain care in SCD. As an organizing model that is a comprehensive framework for classifying pain subphenotypes and mechanisms in SCD, and for guiding selection of specific strategies, we present evidence updating pain research pioneer Richard Melzack's neuromatrix theory of pain. We advocate for using the updated neuromatrix model to subphenotype individuals with SCD, to better select personalized multimodal treatment strategies, and to identify research gaps fruitful for exploration. We present a fairly complete list of currently used pharmacologic and non-pharmacologic SCD pain therapies, classified by their mechanism of action and by their hypothesized targets in the updated neuromatrix model.

Exploring Three Avenues: Chemo- and Regioselective Transformations of 1,2,4-Triketone Analogs into Pyrazoles and Pyridazinones

A convenient approach to substituted pyrazoles and pyridazinones based on 1,2,4-triketones is presented. Chemo- and regiocontrol in condensations of t-Bu, Ph-, 2-thienyl-, and CO2Et-substituted 1,2,4-triketone analogs with hydrazines are described. The direction of preferential nucleophilic attack was shown to be switched depending on the substituent nature in triketone as well as the reaction conditions. The acid and temperature effects on the selectivity of condensations were revealed. Regiochemistry of heterocyclic core formation was confirmed by NMR and XRD studies. The facile construction of heterocyclic motifs bearing acetyl and (or) carbethoxy groups suggests them as promising mono- or bifunctional building blocks for subsequent transformations.

Lysyl Oxidases as Targets for Cancer Therapy and Diagnostic Imaging

The understanding of the contribution of the tumour microenvironment to cancer progression and metastasis, in particular the interplay between tumour cells, fibroblasts and the extracellular matrix has grown tremendously over the last years. Lysyl oxidases are increasingly recognised as key players in this context, in addition to their function as drivers of fibrotic diseases. These insights have considerably stimulated drug discovery efforts towards lysyl oxidases as targets over the last decade. This review article summarises the biochemical and structural properties of theses enzymes. Their involvement in tumour progression and metastasis is highlighted from a biochemical point of view, taking into consideration both the extracellular and intracellular action of lysyl oxidases. More recently reported inhibitor compounds are discussed with an emphasis on their discovery, structure-activity relationships and the results of their biological characterisation. Molecular probes developed for imaging of lysyl oxidase activity are reviewed from the perspective of their detection principles, performance and biomedical applications.

Copper-Catalyzed Hydroamination: Enantioselective Addition of Pyrazoles to Cyclopropenes

Chiral N-cyclopropyl pyrazoles and structurally related heterocycles are prepared using an earth-abundant copper catalyst under mild reaction conditions with high regio-, diastereo-, and enantiocontrol. The observed N2:N1 regioselectivity favors the more hindered nitrogen of the pyrazole. Experimental and DFT studies support a unique mechanism that features a five-centered aminocupration.

Anti-inflammatory activity of pyridazinones: A review

The pyridazinone core has emerged as a leading structure for fighting inflammation, with low ulcerogenic effects. Moreover, easy functionalization of various ring positions of the pyridazinone core structure makes it an attractive synthetic and therapeutic target for the design and synthesis of anti-inflammatory agents. The present review surveys the recent advances of pyridazinone derivatives as potential anti-inflammatory agents to provide insights into the rational design of more effective anti-inflammatory pyridazinones.

Moving Toward a Multimodal Analgesic Regimen for Acute Sickle Cell Pain with Non-Opioid Analgesic Adjuncts: A Narrative Review

Purpose of Review

Sickle cell disease (SCD) is an inherited hemoglobinopathy with potential life-threatening complications that affect millions of people worldwide. Severe and disabling acute pain, referred to as a vaso-occlusive crisis (VOC), is a fundamental symptom of the disease and the primary driver for acute care visits and hospitalizations. Despite the publication of guidelines for VOC management over the past decade, management of VOCs remains unsatisfactory for patients and providers.

Recent Findings

Acute SCD pain includes pain secondary to VOCs and other forms of acute pain. Distinguishing VOC from non-VOC pain may be challenging for both patients and clinicians. Further, although opioids have been the gold-standard for VOC pain management for decades, the current highest standard of care for all acute pain is a multimodal approach that is less dependent on opioids, and, instead incorporates analgesics and adjuvants from different mechanistic pathways. In this narrative review, we focus on a multimodal pharmacologic approach for acute SCD pain management and explore the evidence for existing non-opioid pharmacological adjuncts. Moreover, we present an explanatory model of pain, which is not only novel in its application to SCD pain but also captures the multidimensional nature of the SCD pain experience and supports the need for such a multimodal approach. This model also highlights opportunities for new investigative and therapeutic targets - both pharmacological and non-pharmacological.

Summary

Multimodal pain regimens that are less dependent on opioids are urgently needed to improve acute pain outcomes for individuals with SCD. The proposed explanatory model for SCD pain offers novel opportunities to improve acute pain management for SCD patients.

Tetrodecadazinone, a novel tetrodecamycin-pyridazinone hybrid with anti-liver fibrosis activity from Streptomyces sp. HU051

Tetrodecadazinone (1), a novel tetrodecamycin-pyridazinone hybrid possessing a new 1,2-dimethyl-1-(2-methylnonyl)decahydronaphthalene skeleton, and 4-hydroxydihydrotetrodecamycin (2) were separated from a culture of Streptomyces sp. HU051, together with a known compound, dihydrotetrodecamycin (3). Diverse spectroscopic approaches were applied to assign the structures of 1-3, and the structure of 1 was further confirmed by single crystal X-ray diffraction analysis. Compound 1 is the first example of a pyridazinone-containing natural product. Biosynthetically, 1 is proposed to be derived from a Michael addition reaction of a PKS-derived tetrodecamycin and a piperazic-acid-derived pyridazinone. Biological evaluation revealed 1 could reduce the expressions of extracellular matrix proteins (fibronectin and collagen I) and α-smooth muscle actin (α-SMA) in transforming growth factor-β (TGF-β1)-activated LX-2 cells. Preliminary mechanism study showed 1 exerted its anti-liver fibrosis effect by regulating TGF-β1/Smad2/3 signaling pathway.

Direct synthesis of indazole derivatives via Rh(III)-catalyzed C-H activation of phthalazinones and allenes

A novel Rh(III)-catalyzed annulation of phthalazinones or pyridazinones with various allenes was developed, leading to the formation of indazole derivatives bearing a quaternary carbon in moderate to good yields. The targeted products were synthesized via sequential C-H activation and olefin insertion, followed by β-hydride elimination and intramolecular cyclization. The synthetic protocol proceeded efficiently with broad functional group tolerance, high atom efficiency and high Z-selectivity. The practicability of this method was proved by synthetic transformation.

Synthesis of Spiro[cycloalkane-pyridazinones] with High Fsp3 Character Part 2*

Abstract:

An extended compound library of spiro[cycloalkane-pyridazinones] with a high Fsp3 character is targeted. There are two possibilities to improve the physicochemical parameters of a drug candidate molecules or building blocks, either to replace the aromatic systems with bioisoster heteroaromatic moieties, e.g. with one or two nitrogen containing ring systems (pyridines, pyridazines, pyrimidines, etc.), or to increase the Fsp3 character of the compounds. Using a new synthetic approach, the Grignard reaction of 2-oxaspiro[4.5]decane-1,3-dione and 2-oxaspiro[4.4]nonane-1,3-dione with p-halophenyl- or p-alkylphenyl-magnesium bromide resulted in the formation of the corresponding 2-oxoethyl-cycloalkanecarboxylic acids, which served as starting materials for the pyridazinones by reaction with hydrazine or phenylhydrazine. The pyridazinones obtained were alkylated with methyliodide or benzylbromide. 16 Novel 4-tolyl- or 4-halophenyl-2,3-diazaspiro[5.5]undec-3-en-1-one and 4-tolyl- or 4-halopyhenyl-7,8-diazaspiro[4.5]dec-8-en-6-one, and their N-methyl, N-benzyl, and N-phenyl derivatives were synthetized. The physicochemical parameters and the Fsp3 character of the novel compounds obtained were studied. A few of them showed excellent logP and clogP values, but the introduction of a further phenyl group seemed to be disadvantageous.

Azolo[d]pyridazinones in medicinal chemistry

Azolo[d]pyridazinone is a privileged structure and versatile pharmacophore whose derivatives are associated with diverse biological activities, in particular antidiabetic, antiasthmatic, anticancer, analgesic, anti-inflammatory, antithrombotic, antidepressant and antimicrobial activities. The importance of this scaffold against some targets like PDE, COX and DPP-4 has been reviewed in detail previously. In the present review, we have summarized comprehensive information on azolo[d]pyridazinone derivatives investigated by many researchers for their diverse pharmacological activities, structure-activity relationship and molecular modeling studies since 2000. The review may lead scientists in the research fields of organic synthesis, medicinal chemistry and pharmacology to the strategic design and development of azolo[d]pyridazinone-based drug candidates in the future.

New Spiro[cycloalkane-pyridazinone] Derivatives with Favorable Fsp3 Character

The large originator pharmaceutical companies need more and more new compounds for their molecule banks, because high throughput screening (HTS) is still a widely used method to find new hits in the course of the lead discovery. In the design and synthesis of a new compound library, important points are in focus nowadays: Lipinski’s rule of five (RO5); the high Fsp3 character; the use of bioisosteric heterocycles instead of aromatic rings. With said aim in mind, we have synthesized a small compound library of new spiro[cycloalkane-pyridazinones] with 36 members. The compounds with this new scaffold may be useful in various drug discovery projects.

New insights on the arylpiperazinylalkyl pyridazinone ET1 as potent antinociceptive and anti-inflammatory agent

Pyridazine derivatives, such as arylpiperazinylalkyl pyridazinones, display antinociceptive effects to thermal and chemical stimuli. Here, we extended our previous knowledge on the pharmacological profile of 4-amino-6-methyl-2-(3-(4-(4-methylcyclohexa-1,3-dien-1-yl)piperazin-1-yl)propyl)-5-vinylpyridazin-3(2H)-one, here referred as ET1, paving the way for the comprehension of its complete mechanism of action. To this aim, we have evaluated the mouse behavioural responses in several animal models of pain, the effect of ET1 in the murine model of zymosan-induced paw oedema and air-pouch, assessing the cytokines and the cellular phenotype and finally, an in vitro radioligand binding study was performed on a panel of 30 different receptors. In the formalin test, ET1 reduced both neurogenic and inflammatory phase of nociception induced by the aldehyde. Similarly, ET1 strongly reduced paw licking response in the capsaicin test, the abdominal stretching in the writhing test and the carrageenan-induced thermal hyperalgesia. ET1 also evoked a long-lasting reduction of thermal hyperalgesia. Furthermore, ET1 produced a long-lasting anti-inflammatory effect in the zymosan-induced mouse paw oedema and air-pouch through the selective inhibition of inflammatory monocytes recruitment and the modulation of IL-1β, IL-6, TNF-α and MCP-1. Binding experiments confirmed an inhibitory effect on adrenergic α_1A, α_1B and α_2A receptors subtypes and, for the first time, a moderate affinity was observed for the following receptors: histamine H₁, imidazoline I₂, sigma non-opioid intracellular receptor 1 and σ2. These results prompt ET1 as a potent analgesic and anti-inflammatory agent, and support the possibility that it may be suitable for clinical applications in a wide-range of inflammatory-based diseases.

[4 + 2] Annulation Reaction of In Situ Generated Azoalkenes with Azlactones: Access to 4,5-Dihydropyridazin-3(2H)-Ones

An unprecedented [4 + 2] annulation reaction between in situ formed azoalkenes and azlactones has been developed. This reaction provides a facile access to an array of 4,5-dihydropyridazin-3(2H)-one derivatives, which are very promising in medicinal applications as potential biologically active candidates. Notably, these dihydropyridazinones could also be synthesized via a one-pot reaction protocol by using the in situ formed azlactones from N-acyl amino acids and in situ generated azoalkenes from α-halogeno hydrazones. The potential applications of the methodology were also demonstrated by gram-scale experiments and the versatile conversions of the products into other nitrogen-containing compounds.

2-Butyl-6-phenyl-4,5-dihydropyridazin-3(2H)-one: Synthesis, In Silico Studies and In Vitro Cyclooxygenase-2 Inhibitory Activity

Pyridazinone derivatives are a great template for developing cyclooxygenase-2 (COX-2) inhibitors. The 2-butyl-6-phenyl-4,5-dihydropyridazin-3(2H)-one was prepared by reacting 6-phenyl-4,5-dihydropyridazin-3(2H)-one with n-butyl bromide in the presence of potassium carbonate. The structure of the compound was confirmed based on its FTIR, 1H-NMR, 13C-NMR, and Mass data. The molecular docking studies assessed the COX-2 binding capability of the synthesized compound. The in silico physicochemical and pharmacokinetic parameters of this compound concerning selected drugs were also calculated. The COX-2/COX-1 analysis revealed the synthesized compound as a novel potent COX-2 inhibitor, in comparison to indomethacin, with a promising physicochemical and pharmacokinetic profile.

Phthalazinone-Assisted C-H Amidation Using Dioxazolones Under Rh(III) Catalysis

The preparation of phthalazinone derivatives is pivotal for their utilization as pharmaceutical agents and other entities. Herein, we report the phthalazinone-assisted carbon-nitrogen bond forming reaction using dioxazolones as robust amidation sources under Rh(III) catalysis. The broad functional group tolerance and complete site-selectivity are observed. Notably, a series of transformations of synthesized compounds into biologically relevant N-heterocycles demonstrates the applicability of the developed methodology.

Discovery of Novel Pyridazine-Based Cyclooxygenase-2 Inhibitors with a Promising Gastric Safety Profile

Cyclooxygenase-2 (COX-2) is implicated in the development of chronic inflammatory diseases. Recently, pyridazine derivatives have emerged as a novel prototype to develop COX-2 inhibitors. Accordingly, some pyridazine-based COX-2 inhibitors are reported herein. The reaction of aldehyde 3 and different hydrazines yielded the corresponding hydrazones. The hydrazones were further derivatized to the title compounds, which were assessed for COX-1 and COX-2 inhibitory action, gastric ulcerogenic effects, and lipid peroxidation properties. Molecular docking studies and determination of the physicochemical parameters were also carried out. The allocated structures of the reported compounds were coherent with their spectroscopic data. The compounds 9a (IC₅₀ = 15.50 nM, 114.77%), 9b (IC₅₀ = 17.50 nM, 101.65%), 12 (IC₅₀ = 17.10 nM, 104.03%), 16b (IC₅₀ = 16.90 nM, 105.26%), and 17 (IC₅₀ = 17.70 nM, 100.5%) displayed better COX-2 inhibition than celecoxib (IC₅₀ = 17.79 nM, 100%). These outcomes were harmonious with the molecular docking studies of 9a, 9b, 12, 16b, and 17. These compounds also displayed comparable onset and the duration of action concerning celecoxib and indomethacin in the in vivo studies. No ulcerogenic effects were observed for 9a and 12, whereas 9b, 16b, and 17 showed an insignificant ulcerogenic effect compared to celecoxib. The compounds 9a, 9b, 12, 16b, and 17 displayed a better lipid peroxidation profile than celecoxib and indomethacin. The compounds 9a (%ABS = 84.09), 9b (%ABS = 84.09), 12 (%ABS = 66.87), 16b (%ABS = 75.02), and 17 (%ABS = 81.42) also displayed appreciable calculated absorption compared to celecoxib (%ABS = 82.09). The compounds 9a, 9b, 11, 16b, and 17 have been recognized and postulated as non-ulcerogenic COX-2 inhibitors with promising physicochemical parameters and gastric safety profile. These compounds may be useful candidates to combat diseases caused by higher levels of COX-2.

Ru(II)-Catalyzed C-H Hydroxyalkylation and Mitsunobu Cyclization of N-Aryl Phthalazinones

Ruthenium(II)-catalyzed C(sp²)-H functionalization of N-aryl phthalazinones with a range of aldehydes and activated ketone is described. Initial formation of hydroxyalkylated phthalazinones and subsequent Mitsunobu cyclization provided facile access to biologically relevant indazolophthalazinones. The utility of this method is highlighted by synthetic transformations into a series of potentially bioactive scaffolds.

In Vitro Antimicrobial Activities of 6-Substituted-3(2H)- pyridazinone-2-acetyl-2- (substituted/nonsubstitutedbenzal/ acetophenone) Hydrazone Derivatives

Aim: In vitro antibacterial activity of 6-substituted-3(2H)-pyridazinone-2-acetyl-2-(substituted/nonsubstitutedbenzal/ acetophenone) hydrazone derivatives were tested in common species causing hospital-acquired infections. Material and Method: Antimicrobial activities of the compounds were performed by determining minimum inhibitory concentration (MIC) value against four Gram-positive, five Gram-negative and four Candida species fungi. Modified serial microdilution method was carried out. Reference strains of American Type Culture Collection (ATCC) were used. Results: In general, eleven compounds exhibited considerable activity. Comparatively, compound 3 exhibited strong activity against Enterobacter hormaechei and 5, 11 were the most active against Acinetobacter baumannii at 31.25 μg/mL. Compounds 1,2,3,4,8 and 10 were found to be as active as positive control ampicillin trihidrate against Stenotrophomonas maltophilia. On the other hand, compounds 1,2,3,4,7,8,9,10 and 11 showed strong antifungal activitiy as much as fluconazole against Candida tropicalis. Compound 1 was mostly active against Candida albicans, Candida glabrata, Candida parapsilosis and Candida tropicalis. It was also revealed that the antifungal activity of compounds 1, 6, 7, 8 and 9 were higher than the others. Compound 1 and 8 exhibited the best activity against Candida glabrata and Candida parapsilosis respectively. Conclusions: All tested compounds showed better activity against Gram-negative bacteria and yeast than Gram-positive bacteria. These compounds may be considered as alternative antimicrobial agents in the treatment of multiple drug resistant Gram-negative, Gram-positive bacteria and fungal pathogens. Especially, we suggested that Compound 1 and 8 might be a promising candidate of new antifungal agents

A new compound of thiophenylated pyridazinone IMB5043 showing potent antitumor efficacy through ATM-Chk2 pathway

Through cell-based screening models, we have identified a new compound IMB5043, a thiophenylated pyridazinone, which exerted cytotoxicity against cancer cells. In the present study, we evaluated its antitumor efficacy and the possible mechanism. By MTT assay, IMB5043 inhibited the proliferation of various human cancer cells lines, especially hepatocarcinoma SMMC-7721 cells. IMB5043 blocked cell cycle with G2/M arrest, induced cell apoptosis, and inhibited the migration and invasion of SMMC-7721 cells. As verified by comet assay and γ-H2AX foci formation, IMB5043 caused DNA damage and activated ATM, Chk2 and p53 through phosphorylation. As shown by Gene microarray analysis, the differentially expressed genes in SMMC-7721 cells treated with IMB5043 were highly related to cell death and apoptosis. IMB5043 suppressed the growth of hepatocarcinoma SMMC-7721 xenograft in athymic mice. By histopathological examination, no lesions were found in bone marrow and various organs of the treated mice. Our findings reveal that IMB5043 as an active compound consisting of both pyridazinone and thiophene moieties exerts antitumor efficacy through activation of ATM-Chk2 pathway. IMB5043 may serve as a promising leading compound for the development of antitumor drugs.

Synthesis and biological evaluation of pyridazinone derivatives as potential anti-inflammatory agents

Cyclic nucleotide phosphodiesterase type 4 (PDE4), that controls intracellular level of cyclic nucleotide cAMP, has aroused scientific attention as a suitable target for anti-inflammatory therapy in respiratory diseases. Here we describe the development of two families of pyridazinone derivatives as potential PDE4 inhibitors and their evaluation as anti-inflammatory agents. Among these derivatives, 4,5-dihydropyridazinone representatives possess promising activity, selectivity towards PDE4 isoenzymes and are able to reduce IL-8 production by human primary polymorphonuclear cells.

An isothiourea-catalyzed asymmetric formal [4 + 2] cycloaddition of in situ generated azoalkenes with C1 ammonium enolates

An efficient isothiourea-catalyzed stereoselective formal [4 + 2] cycloaddition of α-chloro cyclic hydrazones with carboxylic acids has been developed.

Synthesis, molecular docking and biological evaluation of some newer 2-substituted-4-(benzo[d][1,3]dioxol-5-yl)-6-phenylpyridazin-3(2H)-ones as potential anti-inflammatory and analgesic agents

A new series of 2-substituted-4-(benzo[d][1,3]dioxol-5-yl)-6-phenylpyridazin-3(2H)-one derivatives has been synthesized and studied. The in vivo anti-inflammatory and analgesic activities of the synthesized compounds were evaluated using carrageen rat paw edema model and acetic acid induced writhing model, respectively. Side effect profile of the newly synthesized pyridazinones was assessed by gastric ulcerogenic and anti-platelet activity. The compounds were further evaluated for their inhibitory activity against cyclooxygenase enzyme (COX-1/COX-2) by in vitro colorimetric COX (ovine) inhibitor screening assay method. The p-flourophenylpiperazine substituted analogue 14 exhibited most potent anti-inflammatory and analgesic activities with lower ulcer index and extremely good selectivity towards COX-2 versus COX-1 enzyme with a selectivity index of 10. Molecular docking studies showed appreciable binding of new pyridazinone analogues with the amino acids present at the active site of hCOX-2 enzyme.