Pyrazoline Containing Compounds as Therapeutic Targets for Neurodegenerative Disorders

Electrocatalytic dehydrogenative and defluorinative coupling between aldehyde-derived N,N-dialkylhydrazones and fluoromalonates: synthesis of 2-pyrazolines

An electrocatalytic synthesis of 2-pyrazolines via dehydrogenative and defluorinative cross-coupling reactions between (hetero)arylaldehyde-derived N,N-dialkylhydrazones and fluoromalonates is disclosed. Salient features of this work include (i) readily available starting materials, (ii) practical reaction conditions, and (ii) a formal oxidative (4 + 1)-cycloaddition via triple C-H bond functionalization. Cyclic voltammetry analyses support the electrocatalytic formation of an α-fluoromalonyl radical.

Pyridinium Ylide-Mediated Diastereoselective Synthesis of Spirocyclopropanyl-pyrazolones via Cascade Michael/Substitution Reaction

We have devised a highly diastereoselective formal [2 + 1] annulation reaction of arylidene/alkylidine-pyrazolones with in situ-generated supported as well as standard pyridinium ylides to construct spirocyclopropanyl-pyrazolones. The cascade approach exhibits a wide range of functional group tolerance, gram-scale capability, and substrate versatility. A diverse range of spirocyclic cyclopropanes was synthesized extensively with both mediators, and the supported pyridine was reused in subsequent cycles. Density functional theory calculations confirmed the formation of spirocyclopropane as the lower energy pathway.

Fluorescent properties in solid-state and solution of novel tricyclic derivatives of chloro/bromophenylchromanones and 2-methylpyrazoline

In this work, we reported the synthesis and spectroscopic characterization of seven novel tricyclic compounds resulting from the reaction of 3-benzylidenechromanone with Cl or Br substituent in different positions and without halogen with methylhydrazine. The structural characterization of compounds was done through different techniques i.e., FTIR,1HNMR,a single and powder X-Ray diffraction. Moreover, fluorescence quantum yield and lifetime assessed their fluorescent properties in the solid state and various solvents. Derivatives with Cl or Br substituent in positions 2 and 4 are isostructural. 4-Cl, 4-Br and 3-Cl compounds exhibit fluorescence with moderate efficiency (quantum yield 0.11-0.26) in solid state due to specific arrangements, so-called π-stack brick stone with head-to-tail self-assembly. Other crystalline compounds (2-Cl, 2-Br and 3-Br) that exhibit negligible fluorescence quantum yield have crossed V-type arrangement. In the solution, the nonhalogenated compound shows the best fluorescence efficiency. In turn, the presence of halogen atoms results in fluorescence decreasing. TD-DFT study revealed that unsubstituted compound higher emissive in solution has a different electron density distribution at HOMO and LUMO levels than less emissive substituted compounds (A3 and A3).

Identification of Potentially Repurposable Drugs for Lewy Body Dementia Using a Network-Based Approach

The conventional method of one drug being used for one target has not yielded therapeutic solutions for Lewy body dementia (LBD), which is a leading progressive neurological disorder characterized by significant loss of neurons. The age-related disease is marked by memory loss, hallucinations, sleep disorder, mental health deterioration, palsy, and cognitive impairment, all of which have no known effective cure. The present study deploys a network medicine pipeline to repurpose drugs having considerable effect on the genes and proteins related to the diseases of interest. We utilized the novel SAveRUNNER algorithm to quantify the proximity of all drugs obtained from DrugBank with the disease associated gene dataset obtained from Phenopedia and targets in the human interactome. We found that most of the 154 FDA-approved drugs predicted by SAveRUNNER were used to treat nervous system disorders, but some off-label drugs like quinapril and selegiline were interestingly used to treat hypertension and Parkinson's disease (PD), respectively. Additionally, we performed gene set enrichment analysis using Connectivity Map (CMap) and pathway enrichment analysis using EnrichR to validate the efficacy of the drug candidates obtained from the pipeline approach. The investigation enabled us to identify the significant role of the synaptic vesicle pathway in our disease and accordingly finalize 8 suitable antidepressant drugs from the 154 drugs initially predicted by SAveRUNNER. These potential anti-LBD drugs are either selective or non-selective inhibitors of serotonin, dopamine, and norepinephrine transporters. The validated selective serotonin and norepinephrine inhibitors like milnacipran, protriptyline, and venlafaxine are predicted to manage LBD along with the affecting symptomatic issues.

Highly efficient, catalyst-free, one-pot sequential four-component synthesis of novel spiroindolinone-pyrazole scaffolds as anti-Alzheimer agents: in silico study and biological screening

Alzheimer's disease is a neurodegenerative disorder that impacts memory, thinking, and behavior, and currently, there is no effective cure available for its treatment. This study explored a one-pot strategy for synthesizing spiroindolinone-pyrazole derivatives through a sequential four-component condensation reaction. These derivatives were further investigated for their potential as anti-Alzheimer's disease agents. The developed synthetic procedure provides remarkable advantages, including a clean reaction profile, abundant starting materials, operational simplicity, and easy purification without traditional methods with good to excellent yields (84-96%). Next, the biological potencies of the newly synthesized spiroindolinone-pyrazole derivatives against AChE and BChE as Alzheimer's disease-related targets were determined. Also, the kinetic study and cytotoxicity of the most potent derivative were investigated. Furthermore, molecular docking and molecular dynamics evaluations were performed employing in silico tools to investigate the interaction, orientation, and conformation of the potent analog over the active site of the enzyme.

Pyrazoline Derivatives as Promising MAO-A Targeting Antidepressants: An Update

Depression is one of the key conditions addressed by the Mental Health Gap Action Programme (mhGAP) of WHO that can lead to self-harm and suicide. Depression is associated with low levels of neurotransmitters, which eventually play a key role in the progression and development of mental illness. The nitrogen-containing heterocyclic compounds exhibit the most prominent pharmacological profile as antidepressants. Pyrazoline, a dihydro derivative of pyrazole, is a well-known five-membered heterocyclic moiety that exhibits a broad spectrum of biological activities. Many researchers have reported pyrazoline scaffold-containing molecules as potential antidepressant agents with selectivity for monoamine oxidase enzyme (MAO) isoforms. Several studies indicated a better affinity of pyrazoline-based moiety as (monoamine oxidase inhibitors) MAOIs. In this review, we have focused on the recent advancements (2019-2023) in the development of pyrazoline-containing derivatives exhibiting promising inhibition of MAO-A enzyme to treat depression. This review provides structural insights on pyrazoline-based molecules along with their SAR analysis, in silico exploration of binding interactions between pyrazoline derivatives and MAO-A enzyme, and clinical trial status of various drug molecules against depression. The in-silico exploration of potent pyrazoline derivatives at the active site of the MAOA enzyme will provide further insights into the development of new potential MAO-A inhibitors for the treatment of depression.

[3+2]-Cycloaddition of Nitrile Imines to Parabanic Acid Derivatives-An Approach to Novel Spiroimidazolidinediones

Approximately 1,3-Dipolar cycloaddition of imidazolidine derivatives containing exocyclic double bonds is a convenient method of creating spiro-conjugated molecules with promising anticancer activity. In this work, the derivatives of parabanic acid (2-thioxoimidazolidine-4,5-diones and 5-aryliminoimidazolidine-2,4-diones) were first investigated as dipolarophiles in the reactions with nitrile imines. The generation of nitrile imines was carried out either by the addition of tertiary amine to hydrazonoyl chlorides «drop by drop» or using the recently proposed diffusion mixing technique, which led to ~5-15% increases in target compound yields. It was found that the addition of nitrile imines to C=S or C=N exocyclic double bonds led to 1,2,4-thiazolines or triazolines and occurred regioselectively in accordance with the ratio of FMO coefficients of reactants. The yield of the resulting spiro-compound depended on the presence of alkyl substituents in the nitrile imine structure and was significantly decreased in reactions with imines with strong electron donor or electron-withdrawing groups. Some of the obtained compounds showed reasonable in vitro cytotoxicity. IC50 values were calculated for HCT116 (colon cancer) cells using the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) test.

Hydrazine Hydrate in Asymmetric Synthesis: A Bifunctional Squaramide Catalytic Approach toward Fused Pyrazolines

A unified strategy has been developed to utilize hydrazine hydrate in asymmetric organic synthesis by overcoming the rapid background reaction with dienone. The H-bond donor ability of the cinchona-alkaloid-derived squaramide catalyst unlocks this previously deemed infeasibility. The dissymmetric hydrazine addition to symmetrical dienones tolerates various substitutions, resulting in the formation of optically pure fused pyrazoline derivatives under mild reaction conditions. Furthermore, the scalability of this methodology and a successful demonstration of postsynthetic transformations have been accomplished.