Design, synthesis and biological evaluation of novel indolin-2-ones as potent anticancer compounds

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.

Lead/Drug Discovery from Natural Resources

Natural products and their derivatives have been shown to be effective drug candidates against various diseases for many years. Over a long period of time, nature has produced an abundant and prosperous source pool for novel therapeutic agents with distinctive structures. Major natural-product-based drugs approved for clinical use include anti-infectives and anticancer agents. This paper will review some natural-product-related potent anticancer, anti-HIV, antibacterial and antimalarial drugs or lead compounds mainly discovered from 2016 to 2022. Structurally typical marine bioactive products are also included. Molecular modeling, machine learning, bioinformatics and other computer-assisted techniques that are very important in narrowing down bioactive core structural scaffolds and helping to design new structures to fight against key disease-associated molecular targets based on available natural products are considered and briefly reviewed.

Pharmacophore-linked pyrazolo[3,4-d]pyrimidines as EGFR-TK inhibitors: Synthesis, anticancer evaluation, pharmacokinetics, and in silico mechanistic studies

Targeting the epidermal growth factor receptors (EGFRs) with small inhibitor molecules has been validated as a potential therapeutic strategy in cancer therapy. Pyrazolo[3,4-d]pyrimidine is a versatile scaffold that has been exploited for developing potential anticancer agents. On the basis of fragment-based drug discovery, considering the essential pharmacophoric features of potent EGFR tyrosine kinase (TK) inhibitors, herein, we report the design and synthesis of new hybrid molecules of the pyrazolo[3,4-d]pyrimidine scaffold linked with diverse pharmacophoric fragments with reported anticancer potential. These fragments include hydrazone, indoline-2-one, phthalimide, thiourea, oxadiazole, pyrazole, and dihydropyrazole. The synthesized molecules were evaluated for their anticancer activity against the human breast cancer cell line, MCF-7. The obtained results revealed comparable antitumor activity with that of the reference drugs doxorubicin and toceranib. Docking studies were performed along with EGFR-TK and ADMET profiling studies. The results of the docking studies showed the ability of the designed compounds to interact with key residues of the EGFR-TK through a number of covalent and noncovalent interactions. The obtained activity of compound 25 (IC50  = 2.89 µM) suggested that it may serve as a lead for further optimization and drug development.

The development of 3-substituted indolin-2-one derivatives as kinase inhibitors for cancer therapy

Kinases are pivotal regulators in tumorigenesis and metastasis by modulating the expression of oncogenes and the transcription of antioncogenes directly or indirectly. Correspondingly, multifarious 3-substituted indolin-2-one derivatives as selective kinase inhibitors for cancer therapy exhibited a low nanomolar activity with prominent efficacy, superior response rate and admirable tolerability. Particularly, certain 3-substituted indolin-2-one derivatives have met the requirements for clinical trials or the pharmaceutical market. Herein, we focus on the traits of 3-substituted indolin-2-one derivatives as kinase inhibitors for cancer therapy, overview recent progress of 3-substituted indolin-2-one derivatives as kinase inhibitors for cancer therapy, analyze the selectivity for tyrosine kinases inhibitors and serine/threonine kinases inhibitors from the molecular aspects based on the molecular docking studies, summarize the structure-activity relationships (SARs) as selective kinase inhibitors and provide our perspectives for the development of 3-substituted indolin-2-one derivatives as kinase inhibitors for cancer therapy.

WITHDRAWN: Discovery of indoline derivatives as anticancer agents via inhibition of tubulin polymerization

Human esophageal squamous cell carcinoma (ESCC) is one of the most lethal cancers in human digestive system. It is necessary to discover novel antitumor agents for the treatment of esophageal cancers because of its poor prognosis. Indoline has been reported as an efficient anticancer fragment to design novel anticancer agents. In this work, indoline derivatives were designed, synthesized and explored their anticancer activity. Compound 9d, which exhibited potent antiproliferative activity with IC50 values of 1.84 μM (MGC-803 cells), 6.82 μM (A549 cells), 1.61 μM (Kyse30 cells), 1.49 μM (Kyse450 cells), 2.08 μM (Kyse510 cells) and 2.24 μM (EC-109 cells), respectively. The most active compound 9d was identified as a tubulin inhibitor targeting colchicine binding site with an IC50 value of 3.4 µM. Compound 9d could strongly suppress the tubulin polymerization in Kyse450 cells. The results of molecular docking also suggested compound 9d could tightly bind into the colchicine binding site of β-tubulin. Besides, compound 9d inhibited the growth of KYSE450 cells in time and dose-dependent manners. All the results suggest that the indoline derivatives might be a class of novel tubulin inhibitors with potential anticancer activity and is worthy of further study.

Discovery of indoline derivatives as anticancer agents via inhibition of tubulin polymerization

Human esophageal squamous cell carcinoma (ESCC) is one of the most lethal cancers in human digestive system. It is necessary to discover novel antitumor agents for the treatment of esophageal cancers because of its poor prognosis. Indoline has been reported as an efficient anticancer fragment to design novel anticancer agents. In this work, indoline derivatives were designed, synthesized and explored their anticancer activity. Compound 9d, which exhibited potent antiproliferative activity with IC50 values of 1.84 μM (MGC-803 cells), 6.82 μM (A549 cells), 1.61 μM (Kyse30 cells), 1.49 μM (Kyse450 cells), 2.08 μM (Kyse510 cells) and 2.24 μM (EC-109 cells), respectively. The most active compound 9d was identified as a tubulin inhibitor targeting colchicine binding site with an IC50 value of 3.4 µM. Compound 9d could strongly suppress the tubulin polymerization in Kyse450 cells. The results of molecular docking also suggested compound 9d could tightly bind into the colchicine binding site of tubulin. Besides, compound 9d inhibited the growth of KYSE450 cells in a time and dose-dependent manner. All the results suggest that the indoline derivatives may be a class of novel tubulin inhibitors with potential anticancer activity, and which is worthy of further study.

Synthesis and biological evaluation of suffrutines A, B and their N-fused analogues

The synthesis, structure confirmation, stability and isomerization features of suffrutines A, B and their N-fused analogues were reported. Biological tests showed that the introduction of nitrogen atom might be beneficial to the anticancer activity.

Indirubin derivatives are potent and selective anti-Trypanosoma cruzi agents

Current treatment for combatting Chagas disease, a life-threatening illness caused by the kinetoplastid protozoan parasite Trypanosoma cruzi is inadequate, and thus the discovery of new antiparasitic compounds is of prime importance. Previous studies identified the indirubins, a class of ATP kinase inhibitors, as potent growth inhibitors of the related kinetoplastid Leishmania. Herein, we evaluated the inhibitory activity of a series of 69 indirubin analogues screened against T. cruzi trypomastigotes and intracellular amastigotes. Seven indirubins were identified as potent T. cruzi inhibitors (low μΜ, nM range). Cell death analysis of specific compounds [3'oxime-6-bromoindirubin(6-BIO) analogues 10, 11 and 17, bearing a bulky extension on the oxime moiety and one 7 substituted analogue 32], as evaluated by electron microscopy and flow cytometry, showed a different mode of action between compound 32 compared to the three 6-BIO oxime- substituted indirubins, suggesting that indirubins may kill the parasite by different mechanisms dependent on their substitution. Moreover, the efficacy of four compounds that show the most potent anti-parasitic effect in both trypomastigotes and intracellular amastigotes (10, 11, 17, 32), was evaluated in a mouse model of T. cruzi infection. Compound 11 (3ʹpiperazine-6-BIO) displayed the best in vivo efficacy (1/6 mortality, 94.5% blood parasitaemia reduction, 12 dpi) at a dose five times reduced over the reference drug benznidazole (20 mg/kg vs100 mg/kg). We propose 3ʹpiperazine-6-BIO as a potential lead for the development of new treatments of Chagas disease.

(E)-3-(Aryl(arylamino)Methylene)Indolin-2-One Derivatives: An Efficient Synthetic Approach and Evaluation of their Cancer Inhibitory Activity

A series of (E)-3-(aryl(arylamino)methylene)indolin-2-one derivatives were synthesised using an efficient synthetic approach. The method involved reaction of 3-bromo-3-(bromo(aryl)methyl)indolin-2-one with substituted anilines through nucleophilic substitution and a simultaneous elimination using NaHCO3 in DMF. The anticancer activity of the products against four cell lines, HCT-116, A549, SKOV3 and MDA-MB-231, was also evaluated, and several compounds showed moderate inhibitory activity.

MCR-click synthesis, molecular docking and cytotoxicity evaluation of a new series of indole–triazole–coumarin hybrid peptidomimetics

The design and synthesis of a new series of indole–triazole-coumarin hybrids as potential CDK2 inhibitors is described.