Synthesis, cytostatic evaluation and structure activity relationships of novel bis-indolylmethanes and their corresponding tetrahydroindolocarbazoles

A Review on Carbazole and Its Derivatives as Anticancer Agents From 2013 to 2024

Carbazole, a natural alkaloid, has been recognized as an effective anticancer agent for over 40 years. However, only a limited number of carbazole-based compounds have received FDA approval for cancer treatment. Current cancer therapies are often associated with significant side effects, causing physical, emotional, and financial burdens for patients. Additionally, despite advancements, cancer prevention and treatment remain challenging due to suboptimal clinical outcomes. The development of new drugs is crucial for achieving safer and more effective cancer therapies. This review focuses on various carbazole derivatives and hybrid composites, highlighting their interactions with distinct receptors and their mechanisms of anticancer action, along with a general structure-activity relationship (SAR). It also emphasizes carbazole-based compounds employed in chemoprevention, which aim to delay or prevent malignant progression. By covering carbazole derivatives and their anticancer potential from 2013 to the present, along with their current clinical status, this study offers valuable insights and updates for researchers in the field.

Bisindole Compounds-Synthesis and Medicinal Properties

The indole nucleus stands out as a pharmacophore, among other aromatic heterocyclic compounds with remarkable therapeutic properties, such as benzimidazole, pyridine, quinoline, benzothiazole, and others. Moreover, a series of recent studies refer to strategies for the synthesis of bisindole derivatives, with various medicinal properties, such as antimicrobial, antiviral, anticancer, anti-Alzheimer, anti-inflammatory, antioxidant, antidiabetic, etc. Also, a series of natural bisindole compounds are mentioned in the literature for their various biological properties and as a starting point in the synthesis of other related bisindoles. Drawing from these data, we have proposed in this review to provide an overview of the synthesis techniques and medicinal qualities of the bisindolic compounds that have been mentioned in recent literature from 2010 to 2024 as well as their numerous uses in the chemistry of materials, nanomaterials, dyes, polymers, and corrosion inhibitors.

Construction of heterocycle-fused tetrahydrocarbazoles through a formal [3 + 3]-annulation of 2-indolylmethanols with para-quinone methides

A metal-free approach for the synthesis of tetrahydroindolo[2,3-b]carbazoles has been developed through an acid-mediated one-pot [3 + 3]-annulation of 2-indolylmethanols and 3-indolyl-substituted para-quinone methides. This operationally simple protocol allowed us to prepare many unsymmetrical tetrahydroindolo[2,3-b]carbazoles in good to excellent yields with a broad substrate scope. This concept was also elaborated to the synthesis of tetrahydrothieno[2,3-b]carbazoles and tetrahydrothieno[3,2-b]carbazoles.

Synthesis and antibacterial activity of novel arylbis(indol-3-yl)methane derivatives

A series of new compounds-arylbis(indol-3-yl)methylium derivatives-were synthesized and their antimicrobial activity was evaluated. All the compounds turned out to be highly active, with MIC depending on their structure and the length of N-alkyl residues. The parent triarylmethane compounds possess weaker activity.

Towards breast cancer targeting: Synthesis of tetrahydroindolocarbazoles, antibreast cancer evaluation, uPA inhibition, molecular genetic and molecular modelling studies

A series of some new tetrahydroindolocarbazole derivatives has been synthesized. The structure of the synthesized compounds has been confirmed by different spectroscopic techniques such as IR, NMR, elemental analysis and mass spectrometry. The target compounds were evaluated for their antitumor activity against breast cancer cell line MCF-7, their GI% and their LC₅₀ have been determined. Six of the synthesized compounds exhibited GI% values against MCF-7 cell lines exceeding 70% ranging from 71.9 to 85.0% in addition that compound 11 expressed GI% values of 99.9% and considered the most active derivatives among the synthesized ones. Compound 11 showed a remarkable decrease of u PA level to 3.5 ng/ml compared to DOX. Compound 5, 11 and 15 showed significant decrease in expression of MTAP and CDKN2A, in addition to a remarkable decrease in DNA damage comet assay method. Molecular modeling studies were performed to interpretate the behavior of active ligands as uPA inhibitors.

Carbazole scaffolds in cancer therapy: a review from 2012 to 2018

For over half a century, the carbazole skeleton has been the key structural motif of many biologically active compounds including natural and synthetic products. Carbazoles have taken an important part in all the existing anti-cancer drugs because of their discovery from a large variety of organisms, including bacteria, fungi, plants, and animals. In this article, we specifically explored the literature from 2012 to 2018 on the anti-tumour activities reported to carbazole derivatives and we have critically collected the most significant data. The most described carbazole anti-tumour agents were classified according to their structure, starting from the tricyclic–carbazole motif to fused tetra-, penta-, hexa- and heptacyclic carbazoles. To date, three derivatives are available on the market and approved in cancer therapy.

Porous metal oxides derived from Cu-Al layered double hydroxide as an efficient heterogeneous catalyst for the Friedel-Crafts alkylation of indoles with benzaldehydes under microwave irradiation

Four Cu-Mg-Al mixed metal oxides (MMO) were synthesized through the calcination of layered double hydroxides (LDHs). These catalysts were fully characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), Brunauer-Emmett-Teller surface area (BET), and inductively coupled plasma optical emission spectrometer (ICP-OES). The catalytic efficiency of porous metal oxides derived from LDHs has been tested successfully for the synthesis of bis(indolyl)methanes via the Friedel–Crafts alkylation of indoles with aromatic aldehydes under solvent-free microwave irradiation. The Cu-Al MMO showed the best catalytic activity to produce the expected products up to 98% yield and 100% selectivity for only 20 min under solvent-free microwave irradiation. Moreover, the catalyst can be recovered quickly from the reaction mixture by filtration and reused several times without significant loss of the reactivity.

Tetrahydroindolocarbazoles (THICZs) as new class of urokinase (uPA) inhibitors: Synthesis, anticancer evaluation, DNA-damage determination, and molecular modelling study

Tetrahydroindolocarbazoles (THICZs) with versatile substituents, have been designed, synthesized, structure characterized, then investigated for their in-vitro anticancer screening, urokinase inhibition (uPA) evaluated, DNA-damage determination was further explored. Compounds 5, 8, 10 and 17 displayed the most promising antitumor activities against the breast cancer cell line as compared to the standard drug, doxorubicin with IC₅₀ = 5.24 ± 0.37, 4.00 ± 0.52, 7.20 ± 0.90 and 9.60 ± 1.10 µg/ml (versus 3.30 ± 0.48 µg/ml for doxorubicin). Compounds 5, 8, 10 and 17 represents the most significant uPA inhibitors of our study with IC₅₀ of 3.80, 2.70. 4.75, 10.80 (ng/ml) respectively. The expression levels of CDKN2A gene were decreased in 8, 10 and 17 cell lines as compared to those in positive control samples. Cell lines treated with 5, 8, 10 and 17 clearly observed a high score of damaged DNA cells. A deeper examination revealed that our hetroaromatics showed an extensive hydrogen bonding interactions that is required in the S pocket which is important for activity Arg 217, Gly 219, Gly 216, Lys 143 and Ser 190. So we present THICZs as promising uPA inhibitors expected as significant promise for further development as anti-invasiveness drugs.

Expedient Synthesis of Indolo[2,3-b]quinolines, Chromeno[2,3-b]indoles, and 3-Alkenyl-oxindoles from 3,3'-Diindolylmethanes and Evaluation of Their Antibiotic Activity against Methicillin-Resistant Staphylococcus aureus

Easily accessible 3,3'-diindolylmethanes (DIMs) were utilized to generate a focused library of indolo[2,3-b]quinolines (2), chromeno[2,3-b]indoles (3), and 3-alkenyl-oxindoles (4) under 2,3-Dichloro-5,6-dicyano-1,4-benzoquinone (DDQ)-mediated oxidative conditions. DIMs with ortho-NHTosyl (NHTs) phenyl group afforded indolo[2,3-b]quinolines (2), whereas DIMs with ortho-hydroxy phenyl groups yielded chromeno[2,3-b]indoles (3) and 3-alkenyl-oxindoles (4). The mild conditions and excellent yields of the products make this method a good choice to access a diverse library of bioactive molecules from a common starting material. Two optimized compounds 2a and 2n displayed excellent activity against clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA). Compound 2a showed the minimum inhibitory concentration values in the concentration between 1 and 4 μg/mL, whereas compound 2n revealed the values of 1-2 μg/mL. Furthermore, both the compounds were highly bactericidal and capable to kill the MRSA completely within 360 min. Collectively, the results suggested that both compounds 2a and 2n possess enormous potential to be developed as anti-MRSA agents.