Spirooxindole-pyrrolidine heterocyclic hybrids promotes apoptosis through activation of caspase-3

Caspase-driven cancer therapies: Navigating the bridge between lab discoveries and clinical applications

Apoptosis is the cell's natural intrinsic regulatory mechanism of normal cells for programmed cell death, which plays an important role in cancer as a classical mechanism of tumor cell death causing minimal inflammation without causing damage to other cells in the vicinity. Induction of apoptosis by activation of caspases is one of the primary targets for cancer treatment. Over the years, a diverse range of natural, synthetic, and semisynthetic compounds and their derivatives have been investigated for their caspase-mediated apoptosis-induced anticancer activities. The review aims to compile the preclinical evidence and highlight the critical mechanistic pathways related to caspase-induced cell apoptosis in cancer treatment. The focus is placed on the key components of the mechanisms, including their chemical nature, and specific attention is given to phytochemicals derived from natural sources and synthetic and semisynthetic compounds. 180+ compounds from the past two decades with potential as anticancer agents are discussed in this review article. By summarizing the current knowledge and advancements in this field, this review provides a comprehensive overview of potential therapeutic strategies targeting apoptosis in cancer cells. The findings presented herein contribute to the ongoing efforts to combat cancer and stimulate further research into the development of effective and targeted anticancer therapies.

C3-Spirooxindoles: Divergent chemical synthesis and bioactivities (2018-2023)

This scientific review documents the recent progress of C3-spirooxindoles chemistry (synthesis and reaction mechanism) and their bioactivities, focusing on the promising results as well as highlighting the biological mechanism via the reported molecular docking findings of the most bioactive derivatives. C3-Spirooxindoles are attractive bioactive agents and have been found in a variety of natural compounds, including alkaloids. They are widely investigated in the field of medicinal chemistry and play a key role in medication development, such as antivirals, anticancer agents, antimicrobials, etc. Regarding organic synthesis, several traditional and advanced strategies have been reported, particularly those that started with isatin derivatives.

1,3-Dipolar cycloaddition reactions of isatin-derived azomethine ylides for the synthesis of spirooxindole and indole-derived scaffolds: recent developments

The unique therapeutic and biological characteristics of spirooxindole have led to the presentation of numerous reactions for the synthesis of spirooxindoles through 1,3-Dipolar cycloaddition of highly reactive isatin-derived azomethine ylides with activated olefins as the main tool for the formation of spirocyclic oxindoles during the last 4 years. Therefore, there is a need to highlight the recent developments in this area, along with the representative synthetic methods and relevant reaction mechanisms from 2018 to 2021. The representative synthetic methodologies were listed in four sections based on the procedure to form the azomethine ylide species including isatins and amino acids, isatin-derived α-(trifluoromethyl)imine, isatins and benzylamines, and from isatin-derived cyclic imine 1,3-dipoles.

Involvement of Both Extrinsic and Intrinsic Apoptotic Pathways in Tridecylpyrrolidine-Diol Derivative-Induced Apoptosis In Vitro

Despite the decreasing trend in mortality from colorectal cancer, this disease still remains the third most common cause of death from cancer. In the present study, we investigated the antiproliferative and pro-apoptotic effects of (2S,3S,4R)-2-tridecylpyrrolidine-3,4-diol hydrochloride on colon cancer cells (Caco-2 and HCT116). The antiproliferative effect and IC₅₀ values were determined by the MTT and BrdU assays. Flow cytometry, qRT-PCR and Western blot were used to study the cellular and molecular mechanisms involved in the induction of apoptotic pathways. Colon cancer cell migration was monitored by the scratch assay. Concentration-dependent cytotoxic and antiproliferative effects on both cell lines, with IC₅₀ values of 3.2 ± 0.1 μmol/L (MTT) vs. 6.46 ± 2.84 μmol/L (BrdU) for HCT116 and 2.17 ± 1.5 μmol/L (MTT) vs. 1.59 ± 0.72 μmol/L (BrdU), for Caco-2 were observed. The results showed that tridecylpyrrolidine-induced apoptosis was associated with the externalization of phosphatidylserine, reduced mitochondrial membrane potential (MMP) accompanied by the activation of casp-3/7, the cleavage of PARP and casp-8, the overexpression of TNF-α and FasL and the dysregulation of Bcl-2 family proteins. Inhibition of the migration of treated cells across the wound area was detected. Taken together, our data show that the anticancer effects of tridecylpyrrolidine analogues in colon cancer cells are mediated by antiproliferative activity, the induction of both extrinsic and intrinsic apoptotic pathways and the inhibition of cell migration.

Asymmetric Double Oxidative [3 + 2] Cycloaddition for the Synthesis of CF3-Containing Spiro[pyrrolidin-3,2'-oxindole]

An asymmetric double oxidative [3 + 2] cycloaddition is reported. Oxidation of 3-((2,2,2-trifluoroethyl)amino)indolin-2-ones and β-aryl-substituted aldehydes simultaneously and subsequent asymmetric cycloaddition in the presence of the chiral amino catalyst generated highly functionalized chiral CF₃-containing spiro[pyrrolidin-3,2'-oxindole] with four contiguous stereocenters stereoselectively, which is characterized by directly constructing two C-C bonds from four C(sp³)-H bonds. This new method features mild conditions, broad substrate scope, and excellent functional group compatibility.

Azomethine Ylides-Versatile Synthons for Pyrrolidinyl-Heterocyclic Compounds

Azomethine ylides are nitrogen-based three-atom components commonly used in [3+2]-cycloaddition reactions with various unsaturated 2π-electron components. These reactions are highly regio- and stereoselective and have attracted the attention of organic chemists with respect to the construction of diverse heterocycles potentially bearing four new contiguous stereogenic centers. This review article complies the most important [3+2]-cycloaddition reactions of azomethine ylides with various olefinic, unsaturated 2π-electron components (acyclic, alicyclic, heterocyclic, and exocyclic ones) reported over the past two decades.

Spirooxindole: A Versatile Biologically Active Heterocyclic Scaffold

Spirooxindoles occupy an important place in heterocyclic chemistry. Many natural spirooxindole-containing compounds have been identified as bio-promising agents. Synthetic analogs have also been synthesized utilizing different pathways. The present article summarizes the recent development of both natural and synthetic spirooxindole-containing compounds prepared from isatin or its derivatives reported in the last five years. The spirooxindoles are categorized based on their mentioned biological properties.

Tandem construction of biological relevant aliphatic 5-membered N-heterocycles

Nature often uses cascade reactions in a highly stereocontrolled manner for assembly structurally diverse nitrogen-containing heterocyclic scaffolds, i.e. secondary metabolites, important for medicinal chemistry and pharmacy. Five-membered nitrogen-containing heterocycles as standalone rings, as well as spiro and polycyclic systems are pharmacophores of drugs approved in various therapies, i.a. antibacterial or antiviral, antifungal, anticancer, antidiabetic, as they target many key enzymes. Furthermore, a large number of pyrrolidine derivatives are currently considered as drug candidates. Cascade transformations, also known as domino or tandem reactions, offer straightforward methods to build N-heterocyclic libraries of the great structural variety desired for drawing SAR conclusions. The tandem transformations are often atom economic and time-saving because they are performed as the one-pot, so no need for purification after each 'virtual' step and the limited necessity of protective groups are characteristic for these processes. Thus, the same results as in classical multistep synthesis can be achieved at markedly lower costs and shorter time, which is in line with modern green chemistry rules. Great advantage of cascade reactions is often reflected in their high regio- and stereoselectivities, enabling the preparing of the heterocyclic compound better fitted to the expected target in cells. This review reveals the biological relevance of N-heterocyclic scaffolds based on saturated 5-membered rings since we showed a number of examples of approved drugs together with the recent biologically attractive leading structures of drug candidates. Next, novel cascade synthetic procedures, taking into account the structure of the reactants and reaction mechanisms, enabling to obtain biological-relevant heterocyclic frameworks with good yields and relatively high stereoselectivity, were reviewed and compared. The review covers the advances of designing biological active N-heterocycles mainly from 2018 to 2021, whereas the synthetic part is focused on the last 7 years.

Design, synthesis, in vitro and in vivo anti-respiratory syncytial virus (RSV) activity of novel oxizine fused benzimidazole derivatives

Respiratory syncytial virus (RSV) causes serious lower respiratory tract infections. Currently, the only clinical anti-RSV drug is ribavirin, but ribavirin has serious toxic side effect and can only be used by critically ill patients. A series of benzimidazole derivatives were synthesized starting from 1,4:3,6-dianhydro-d-fructose and a variety of o-phenylenediamines. Evaluation of their antiviral activity showed that compound a27 had the highest antiviral activity with a half maximal effective concentration (EC₅₀) of 9.49 μM. Investigation of the antiviral mechanism of compound a27 indicated that it can inhibit the replication of RSV by inhibiting apoptosis and autophagy pathways. Retinoic acid-inducible gene (RIG)-I, TNF receptor associated factor (TRAF)-3, TANK binding kinase (TBK)-1, interferon regulatory factor (IRF)-3, nuclear factor Kappa-B (NF-κB), interferon (IFN)-β, Toll-like receptor (TLR)-3, interleukin (IL)-6 were suppressed at the cellular level. Mouse lung tissue was subjected to hematoxylin and eosin (HE) staining and immunohistochemistry, which showed that RSV antigen and M gene expression could be reduced by compound a27. Decreased expression of RIG-I, IRF-3, IFN-β, TLR-3, IL-6, interleukin (IL)-8, interleukin (IL)-10, inducible nitric oxide synthase (iNOS) and tumor necrosis factor (TNF)-α was also found in vivo.

Engaging Isatins in Multicomponent Reactions (MCRs) - Easy Access to Structural Diversity

Multicomponent reactions (MCRs) are a valuable tool in diversity-oriented synthesis. Its application to privileged structures is gaining relevance in the fields of organic and medicinal chemistry. Isatin, due to its unique reactivity, can undergo different MCRs, affording multiple interesting scaffolds, namely oxindole-derivatives (including spirooxindoles, bis-oxindoles and 3,3-disubstituted oxindoles) and even, under certain conditions, ring-opening reactions occur that leads to other heterocyclic compounds. Over the past few years, new methodologies have been described for the application of this important and easily available starting material in MCRs. In this review, we explore these novelties, displaying them according to the structure of the final products obtained.

Anticancer potential of spirocompounds in medicinal chemistry: A pentennial expedition

Spirocompounds constitute an important class of organic frameworks enveloping numerous pharmacological activities, among them, the promising anticancer potential of spirocompounds have enthused medicinal chemists to explore new spiro derivatives with significantly improved pharmacodynamic and pharmacokinetic profile along with their mechanism of action. The current review intends to provide a sketch of the anticancer activity of various spirocompounds like spirooxindole, spiroisoxazole, spiroindole etc, from the past five years unfolding various aspects of pharmacological activities and their structure-activity relationships (SARs). This literature analysis may provide future direction for the efficient design of novel spiromolecules with enhanced safety and efficacy.

Enantioselective organocatalytic formal [3+2]-cycloaddition of isatin-derived ketimines with benzylidenemalononitriles and benzylidineindanones

Electron-deficient alkenes undergo organocatalysed formal [3+2]-cycloaddition with isatin-derived imines, generating complex spirocyclic products with high yield and stereoselectivity.

The application of isatin-based multicomponent-reactions in the quest for new bioactive and druglike molecules

Oxindole derivatives are known for their great interest in the field of Medicinal Chemistry, as they display vast biological activities. Recent efforts concerning the preparation of oxindole derivatives using isatin-based multicomponent reactions (MCRs) constitute a great advance in generating druglike libraries fast and with wide scaffold diversity. In this review, we address those recent developments, exploring the synthetic pathways and biological activities described for these compounds, namely antitumor, antibacterial, antifungal, antiparasitic, antiviral, antioxidant, anti-inflammatory and central nervous system (CNS) pathologies. To add new depth to this work, we used a well-established web-based free tool (SwissADME) to evaluate the most promising scaffolds in what concerns their druglike properties, namely by evaluating their compliance with some of the most valuable rules applied by medicinal chemists in both academia and industrial settings (Lipinski, Ghose, Veber, Egan, Muegge). The aim of this review is to endorse isatin-based MCRs as a valuable synthetic approach to attain new hit compounds bearing the oxindole privileged structure, while critically exploring these scaffolds' druglike properties.

Al-thamili D, Almansour AI, Arumugam N, Dege N. [Bmim]Br Accelerated One-Pot Three-Component Cascade Protocol for the Construction of Spirooxindole-Pyrrolidine Heterocyclic Hybrids

Our synthetic approach for the assembly of structurally complex spirooxindole heterocyclic hybrids was based on an ionic liquid, [bmim]Br mediated one-pot three-component cascade reaction strategy involving 1,3-dipolar cycloaddition reaction of N-1-(2-pyridinylmethyl)-3,5-bis[(E)-arylmethylidene]tetrahydro-4(1H)-pyridinones and azomethine ylide generated in situ from isatin and L-phenyl alanine, affording a series of spirooxindole-pyrrolidine heterocyclic hybrids in good-to-excellent yields. In addition to serving as the reaction medium, [bmim]Br also functioned as a catalyst in this cycloaddition reaction and hence accelerated the reaction rate affording the cycloadducts in short reaction time.

Access to highly enantioselective and diastereoselective spirooxindole dihydrofuran fused pyrazolones

Access to highly enantioselective and diastereoselective spirooxindole dihydrofuran fused pyrazolones from MBH-carbonates and pyrazole 4,5-diones.

Design, Synthesis and In Vitro Mechanistic Investigation of Novel Hexacyclic Cage-Like Hybrid Heterocycles

Novel hexacyclic cage-like hybrid heterocycles have been synthesized in excellent yields employing a relatively less explored non-stabilized azomethine ylides derived from acenaphthenequinone and tyrosine with functionalized dipolarophiles using [3 + 2] cycloaddition strategy. The synthesized hexacyclic cage-like hybrid heterocycles were characterized by spectroscopic analysis. Following the physical characterization, these cage-like hybrid heterocycles were tested for their biological activity by means of different cancer (A549 and Jurkat cells) and non-cancer (BRL-3A and PCS-130) in vitro cell culture systems. The results of the study under tested concentrations (up to 100 μM) indicated that these compounds are not affecting any viability to the cell growth of non-cancer cells, while providing significant anticancer activity against both of the cancer cells. Further analysis of in-depth mechanistic study for the cell death indicated that these compounds are exhibiting late apoptosis or early necrosis pathway to the cells where it is operated by the induction of caspases.

A regio- and stereocontrolled approach to the synthesis of 4-CF3-substituted spiro[chromeno[3,4-c]pyrrolidine-oxindoles]viareversible [3+2] cycloaddition of azomethine ylides generated from isatins and sarcosine to 3-nitro-2-(trifluoromethyl)-2H-chromenes

The first example of regio- and stereocontrolled synthesis of 4-CF₃-spiro[chromeno[3,4-c]pyrrolidine-oxindoles] with anticancer activity.