Synthesis, biological evaluation and molecular docking studies of some novel indenospiro derivatives as anticancer agents

Design and synthesis of new spirooxindole candidates and their selenium nanoparticles as potential dual Topo I/II inhibitors, DNA intercalators, and apoptotic inducers

A new wave of dual Topo I/II inhibitors was designed and synthesised via the hybridisation of spirooxindoles and pyrimidines. In situ selenium nanoparticles (SeNPs) for some derivatives were synthesised. The targets and the SeNP derivatives were examined for their cytotoxicity towards five cancer cell lines. The inhibitory potencies of the best members against Topo I and Topo II were also assayed besides their DNA intercalation abilities. Compound 7d NPs exhibited the best inhibition against Topo I and Topo II enzymes with IC50 of 0.042 and 1.172 μM, respectively. The ability of compound 7d NPs to arrest the cell cycle and induce apoptosis was investigated. It arrested the cell cycle in the A549 cell at the S phase and prompted apoptosis by 41.02% vs. 23.81% in the control. In silico studies were then performed to study the possible binding interactions between the designed members and the target proteins.

Structure activity relationship (SAR) and anticancer activity of pyrrolidine derivatives: Recent developments and future prospects (A review)

Pyrrolidine molecules are a significant class of synthetic and natural plant metabolites, which show the diversity of pharmacological activities. An extensive variety of synthetic pyrrolidine compounds with numerous derivatization like spirooxindole, thiazole, metal complexes, coumarin, etc have revealed significant anticancer activity. Pyrrolidine molecules are found not only as potential anticancer candidates but also retain the lowest side effects. Depending upon the diverse substitution patterns of the derivatives, these molecules have demonstrated an incredible ability to regulate the various targets to give excellent anti-proliferative activities. Taking these into consideration, efforts have been taken by the scientific fraternity to design and develop a potent anticancer scaffold with negligible side effects. In the present review, we cover the latest advancements in the synthesis of pyrrolidine molecules which have promising anticancer activity toward numerous cancer cell lines. Additionally, it also highlights the effectiveness of derivatives via elucidation of Structural-Activity-Relationship (SAR) which is discussed in detail.

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.

Synthesis of optically active 2-amino-1′-benzyl-2′,5-dioxo-5H-spiro[indeno[1,2-b]pyran-4,3′-indoline]-3-carbonitriles catalyzed by a bifunctional squaramide derived from quinine

The first organocatalytic asymmetric reaction of propylene malononitrile with oxoindole and 1,3-indandione for the synthesis of chiral indeno-spiro compounds has been developed.

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.

Synthesis, characterization, molecular docking and anticancer studies of fluoroaniline derivatives of hydroxybenzoquinone and hydroxynaphthoquinone

Two series of fluoro substituted-anilino derivatives of naturally occurring hydroxybenzoquinone and hydroxynaphthoquinone were synthesized using TFA as catalyst to improve the product yield. Recently, fluorine containing compounds are being used as anticancer drugs. The aim of this study is to find compounds that are active against melanoma cells. This six new fluoro substituted quinone compounds were synthesized and characterized. All of these compounds were then subjected to molecular docking studies against B-raf protein using Discovery Studio 4.0 and the binding affinities were calculated. The energy scores of in silico analysis revealed that all the compounds exhibited better binding affinity towards B-raf protein. Moreover, all the derivatives and the parent compounds, embelin and plumbagin along with standard drug, PLX4032 were investigated for its in vitro cytotoxicity in A375 cell lines (Melanoma) and in vitro ELISA assay in B-raf isolated from melanoma cells. Among them, 5-(3-chloro-4-trifluoromethoxy-phenylamino)-2-hydroxy-3-undecyl-[1,4]benzoquinone exhibited lower cell viability with lowest LC₅₀ of 12.25 μg/mL and thus poses suitability to be a lead molecule for further drug discovery.Communicated by Ramaswamy H. Sarma.

One-pot, catalyst-free synthesis of novel spiro[indole-3,4′-pyrano[2′,3′:4,5]pyrimido [2,1-b][1,3]benzothiazole] derivatives

The present report describes one-pot three-component condensation of isatins, malononitrile, and 2-hydroxy-4 H-pyrimido[2,1- b][1,3]benzothiazol-4-one in water–ethanol mixture at reflux to develop an efficient one-pot protocol for the synthesis of novel spiro[indole-3,4′-pyrano[2′,3′:4,5]pyrimido[2,1- b][1,3]benzothiazole] derivatives. The significant features of this protocol are short reaction times, avoidance of toxic catalysts, and provision of excellent yields, no column chromatographic purification, and use of ethanol-water as an environmentally benign solvent. The molecular structure of 4a has been supported by single-crystal X-ray diffraction.

An overview of spirooxindole as a promising scaffold for novel drug discovery

Introduction: Spirooxindole, a unique and versatile scaffold, has been widely studied in some fields such as pharmaceutical chemistry and synthetic chemistry. Especially in the application of medicine, quite a few compounds featuring spirooxindole motif have displayed excellent and broad pharmacological activities. Many identified candidate molecules have been used in clinical trials, showing promising prospects.Areas covered: This article offers an overview of different applications and developments of spirooxindoles (including the related natural products and their derivatives) in the process of drug innovation, including such as in anticancer, antimicrobial, anti-inflammatory, analgesic, antioxidant, antimalarial, and antiviral activities. Furthermore, the crucial structure-activity relationships, molecular mechanisms, pharmacokinetic properties, and main synthetic methods of spirooxindoles-based derivatives are also reviewed.Expert opinion: Recent progress in the biological activity profiles of spirooxindole derivatives have demonstrated their significant position in present-day drug discovery. Furthermore, we believe that the multidirectional development of novel drugs containing this core scaffold will continue to be the research hotspot in medicinal chemistry in the future.

Sericin Inhibits Devitrification of Amorphous Drugs

The purpose of the present investigation was to analyze devitrification of amorphous drugs such as lornoxicam, meloxicam, and felodipine in the presence of sericin. The binary solid dispersions comprising varying mass ratios of drug and sericin were subject to amorphization by spray drying, solvent evaporation, ball milling, and physical mixing. Further, obtained solid dispersions (SDs) were characterized by HPLC, ATR-FTIR, H¹NMR, molecular docking, accelerated stability study at 40°C and 75 ± 2% RH (XRD and DSC), and in vitro dissolution studies. The HPLC analysis indicated no decomposition of the drugs during the spray drying process. From ATR-FTIR, NMR, and molecular docking study, it was revealed that H-bonding played a vital role in amorphous drug stabilization. An excellent devitrification inhibition was observed in case of lornoxicam (SDLS3) and meloxicam (SDMS3) SDs prepared by spray drying. On the other hand, spray-dried SD of felodipine (SDFS3) showed traces of microcrystals. The percent crystallinity of SDLS3, SDMS3, and SDFS3 was found to be 7.4%, 8.23%, and 18.31% respectively indicating adequate amorphization. The dissolution performance of SDLS, SDMS, and SDFS after 3 months showed > 85% than SDs prepared by other methods. Thus, sericin significantly inhibited crystallization and was responsible for amorphous state stabilization of pharmaceuticals.

Dibenzepinones, dibenzoxepines and benzosuberones based p38α MAP kinase inhibitors: Their pharmacophore modelling, 3D-QSAR and docking studies

In the present study, a series of dibenzepinones, dibenzoxepines, and benzosuberones targeting p38α MAP kinase were subjected to pharmacophore modelling, 3D-QSAR and molecular docking studies. The IC₅₀ values for these 67 compounds ranged between 0.003 and 6.80 μM. A five-point model (DDHHR.8) was generated using these compounds. This model was found to be statistically significant and was found to have high correlation (R² = 0.98), cross-validation coefficient (Q² = 0.95) and F (330) values at six component PLS factor. Tests were performed to ascertain the efficacy of the generated model. These tests included external validation, Tropsha's test for predictive ability, Y-randomisation test and domain of applicability (APD). In order to check the restrictivity of the model, enrichment studies were performed with inactive compounds by using decoy set molecules. To evaluate the effectiveness of the docking protocol, the co-crystallised ligand was extracted from the ligand-binding domain of the protein and was re-docked into the same position. Both the conformers were then superimposed, suggesting satisfactory docking parameters with an RMSD value of less than 1.0 Å (0.853 Å). A 10 ns molecular dynamics simulation confirmed the docking results of the 3UVP-ligand complex and the presumed active conformation. The outcome of the present study provides insight into the molecular features that promote bioactivity and can be exploited for the prediction of novel potent p38α MAP kinase inhibitors before carrying out their synthesis and anticancer evaluation.

In silico design, synthesis, characterization and pharmacological evaluation of captopril conjugates in the treatment of renal fibrosis

Application of glutamic acid and taurine conjugates of captopril for kidney targeting.