Synthesis, in vitro antiproliferative activities, and Chk1 inhibitory properties of pyrrolo[3,4-a]carbazole-1,3-diones, pyrrolo[3,4-c]carbazole-1,3-diones, and 2-aminopyridazino[3,4-a]pyrrolo[3,4-c]carbazole-1,3,4,7-tetraone

BF3-OEt2 Catalyzed C3-Alkylation of Indole: Synthesis of Indolylsuccinimidesand Their Cytotoxicity Studies

A simple and efficient BF₃-OEt₂ promoted C3-alkylation of indole has been developed to obtain3-indolylsuccinimidesfrom commercially available indoles and maleimides, with excellent yields under mild reaction conditions. Furthermore, anti-proliferative activity of these conjugates was evaluated against HT-29 (Colorectal), Hepg2 (Liver) and A549 (Lung) human cancer cell lines. One of the compounds, 3w, having N,N-Dimethylatedindolylsuccinimide is a potent congener amongst the series with IC₅₀ value 0.02 µM and 0.8 µM against HT-29 and Hepg2 cell lines, respectively, and compound 3i was most active amongst the series with IC₅₀ value 1.5 µM against A549 cells. Molecular docking study and mechanism of reaction have briefly beendiscussed. This method is better than previous reports in view of yield and substrate scope including electron deficient indoles.

Carbazole Derivatives as Kinase-Targeting Inhibitors for Cancer Treatment

Protein Kinases (PKs) are a heterogeneous family of enzymes that modulate several biological pathways, including cell division, cytoskeletal rearrangement, differentiation and apoptosis. In particular, due to their crucial role during human tumorigenesis and cancer progression, PKs are ideal targets for the design and development of effective and low toxic chemotherapeutics and represent the second group of drug targets after G-protein-coupled receptors. Nowadays, several compounds have been claimed to be PKs inhibitors, and some of them, such as imatinib, erlotinib and gefitinib, have already been approved for clinical use, whereas more than 30 others are in various phases of clinical trials. Among them, some natural or synthetic carbazole-based molecules represent promising PKs inhibitors due to their capability to interfere with PK activity by different mechanisms of action including the ability to act as DNA intercalating agents, interfere with the activity of enzymes involved in DNA duplication, such as topoisomerases and telomerases, and inhibit other proteins such as cyclindependent kinases or antagonize estrogen receptors. Thus, carbazoles can be considered a promising this class of compounds to be adopted in targeted therapy of different types of cancer.

Selective Synthesis and Photoluminescence Study of Pyrazolopyridopyridazine Diones and N-Aminopyrazolopyrrolopyridine Diones

The newly designed luminol structures of pyrazolopyridopyridazine diones and N-aminopyrazolopyrrolopyridine diones were synthesized from versatile 1,3-diaryfuropyrazolopyridine-6,8-diones, 1,3-diarylpyrazolopyrrolopyridine-6,8-diones, or 1,3-diaryl-7-methylpyrazolopyrrolopyridine-6,8-diones with hydrazine monohydrate. Photoluminescent and solvatofluorism properties containing UV–Vis absorption, emission spectra, and quantum yield (Φ_f) study of pyrazolopyridopyridazine diones and N-aminopyrazolopyrrolopyridine diones were also studied. Generally, most of pyrazolopyrrolopyridine-6,8-diones 6 exhibited the significant fluorescence intensity and the substituent effect when compared with N-aminopyrazolopyrrolopyridine diones, particularly for 6c and 6j with a m-chloro group. Additionally, the fluorescence intensity of 6j was significantly promoted due to the suitable conjugation conformation. Based on the quantum yield (Φ_f) study, the value of compound 6j (0.140) with planar structural skeletal was similar to that of standard luminol (1, 0.175).

Tandem Synthesis of Polycyclic Isoindoles

We report an easy multicomponent synthesis of polycyclic isoindoles from cyclic 1,3-dicarbonyls, aldehydes, isocyanides, and maleimides. The key step consists of the one-pot Diels-Alder trapping of a reactive 2-aminofuran intermediate, formed by a sequence of a Knoevenagel condensation and a [4+1] cycloaddition. Moreover, a further microwave-promoted dehydrogenative N-C bond forming reaction allows the straightforward synthesis of a natural product like isoindolocarbazole, validating the utility of our methodology to obtain isoindoles as useful intermediates for the synthesis of complex polycyclic molecules.

Selective and tunable synthesis of 3-arylsuccinimides and 3-arylmaleimides from arenediazonium tetrafluoroborates and maleimides

A highly efficient and tunable synthetic strategy for 3-arylsuccinimides or 3-arylmaleimides has been developed from arenediazonium tetrafluoroborates and maleimides with satisfactory yields in the presence of TiCl₃ or CuCl.

Synthesis and biological evaluation of novel carbazolyl glyoxamides as anticancer and antibacterial agents

A new library of 24 carbazolyl glyoxamides14a–xwere designed and synthesized from glyoxalic acids and arylamines in the presence of HATU as a coupling reagent under MW irradiation.

Diastereoselective synthesis of functionalised carbazoles via a sequential Diels–Alder/ene reaction strategy

A one-pot, three-component, synthesis of saturated carbazoles and related pyridazino[3,4-b]indoles is described, involving an intermolecular Diels–Alder/intermolecular ene reaction sequence with relative stereocontrol of up to four stereocentres.

TFAA/H3PO4 mediated unprecedented N-acylation of carbazoles leading to small molecules possessing anti-proliferative activities against cancer cells

For the first time TFAA/H3PO4 has facilitated the direct and metal-free N-acylation of carbazoles leading to a number of N-acylated derivatives. Several of these compounds were found to be promising when tested for their anti-proliferative properties against oral cancer cell lines.

Gold(I) or silver catalyzed synthesis of α-indolylacrylates

Methyl 2-acetamidoacrylate reacted with various 2-substituted indoles in the presence of catalytic amounts of AgSbF6 or AuPPh3NTf2 to provide the corresponding methyl 2-(2-substituted-1H-indol-3-yl)acrylates.

Synthesis and cytotoxic activity of the heptaphylline and 7-methoxyheptaphylline series

Nineteen carbazole alkaloids modified from heptaphylline (I) and 7-methoxyheptaphylline (II) isolated from Clausena harmandiana were synthesized. Among these derivatives, Ih and IIi showed cytotoxicity against the NCI-H187 cell line with IC(50) values of 0.02 and 0.66 μM, respectively, which are about 138 and 4 fold stronger than the ellipticine standard. In addition, oxime Ih displayed cytotoxicity against KB cells with an IC(50) value of 0.17 μM which is about 10 times stronger than the ellipticine. This compound demonstrated weak cytotoxicity against Vero cells (IC(50) = 66.01 μM). The results show convincingly that Ih may be a promising lead for the development of cytotoxic agents.

Synthesis and antiproliferative activity of oxazinocarbazole and N,N-bis(carbazolylmethyl)amine derivatives

The synthesis, structure elucidation and antitumoral activity of novel heterocyclic compounds containing a carbazole nucleus are reported. Oxazinocarbazoles were synthesized by application of the Mannich reaction to the corresponding hydroxylated derivatives leading to 41 new molecules. Their cytotoxic activity was evaluated against various human tumor cell lines including three leukemic cell lines: CEM and Jurkat (type T), Raji (type B); breast cancer cell line (MCF-7); colorectal cancer cell line (Caco-2). A primary screening at 100 microM allowed the selection of the 10 most active compounds, which showed an antiproliferative activity on all the cell lines. A dose-effect study between 12.5 and 100 microM sorted two compounds with a significant activity: 5t and 7e against leukemic cell lines CEM, Jurkat and Raji with IC50 values around 12 microM.

Marine pyrrolocarbazoles and analogues: synthesis and kinase inhibition

Granulatimide and isogranulatimide are alkaloids obtained from marine sources which have been shown to inhibit cell-cycle G2-checkpoint, targeting more particularly checkpoint 1 kinase (Chk1). At a structural level, they possess a characteristic pyrrolocarbazole framework also shared by the well-known rebeccamycin and staurosporine microbial metabolites which have been described to inhibit topoisomerase I and diverse kinases, respectively. This review reports precisely on the synthesis and kinase inhibitory activities of pyrrolocarbazole-based analogues of granulatimide.

Synthesis, checkpoint kinase 1 inhibitory properties and in vitro antiproliferative activities of new pyrrolocarbazoles

In the course of structure-activity relationship studies on granulatimide analogues, new pyrrolo[3,4-c]carbazoles have been synthesized in which the imidazole heterocycle was replaced by a five-membered ring lactam system or a dimethylcyclopentanedione. Moreover, the synthesis of an original structure in which a sugar moiety is attached to the indole nitrogen and to a six-membered D ring via an oxygen is reported. The inhibitory activities of the newly synthesized compounds toward checkpoint kinase 1 and their in vitro antiproliferative activities toward three tumor cell lines: murine leukemia L1210, and human colon carcinoma HT29 and HCT116 are described.