Thieno[3,2-c]pyran-4-one based novel small molecules: Their synthesis, crystal structure analysis and in vitro evaluation as potential anticancer agents

Regioselective Synthesis of 3-Substituted Isocoumarin-1-imines via Palladium-Catalyzed Denitrogenative Transannulation of 1,2,3-Benzotriazin-4(3H)-ones and Terminal Alkynes

A palladium-catalyzed denitrogenative transannulation strategy to access various 3-substituted isocoumarin-1-imine frameworks using 1,2,3-benzotriazin-4(3H)-ones and terminal alkynes is described. The reaction is highly regioselective and tolerates a wide range of functional groups. The reaction is believed to proceed via a five-membered palladacycle intermediate extruding environmentally benign molecular nitrogen as a by-product. The utility of this method was showcased through the one-pot synthesis of biologically relevant 3-substituted isocoumarin scaffolds.

Rh(III)-Catalyzed Synthesis of Amino-isocoumarins with N-Functionalized Cyclic Carbonates via C-H/O-H Annulation

A practical method to access amino-isocoumarins catalyzed by a Rh(III) complex through redox-neutral C-H/O-H annulation has been disclosed. The use of N-functionalized cyclic carbonates is crucial to facilitate the catalytic turnover, and a broad spectrum of amino-isocoumarin derivatives were prepared with satisfactory yields. Amino-isocoumarin estrone conjugated with a selenocyano functionality was identified to be nearly four times as active as the marketed drug abiraterone against T47D cancer cells.

Ultrasound-assisted Synthesis of 6-substituted indolo[2,3-b]quinolines: their Evaluation as Potential Cytotoxic Agents

BACKGROUND

The indolo[2,3-b]quinoline framework is often found in various natural products displaying a range of pharmacological activities. This is an attractive template for the design and discovery of potential drugs especially for the identification of new anticancer agents.

METHODS

The synthesis of 6-substituted indolo[2,3-b]quinolones was undertaken and carried out using a ultrasound assisted method involving two sequential C-N bond forming reactions between 3-(2- bromophenyl)-2-chloroquinoline and amines in a single pot in the presence of Pd(OAc)2 and a ligand (S)-BINAP. All the synthesized compounds were tested in vitro against two cancer cell lines e.g. MCF7 and HepG2 along with non-cancerous HEK293 cell lines.

RESULTS

Two of these compounds showed promising and selective growth inhibition of MCF7 cell lines and one induced significant apoptosis in cancer (MCF7) cells.

CONCLUSION

Compounds based on indolo[2,3-b]quinolone framework may be useful for the identification of new cytotoxic agents thereby potential cure for breast cancer.

2,4-Diarylpyrano[3,2-c]chromen-5(4H)-ones as Antiproliferative Agents

In the present study, a series of 2,4-diarylpyrano[3,2-c]chromen-5(4H)-ones were synthesised and evaluated as antiproliferative agents. The compounds were evaluated against a panel of human cancer cell lines. CH-1 exhibited significant cytoxicity against HCT 116 cell lines with an IC50 value of 1.4 and 4.3 µM against "MiaPaCa-2" cell lines. The compound CH-1 was found to induce apoptosis as evidenced by phase contrast microscopy, Hoechst 33258 staining and mitochondrial membrane potential (MMP) loss. The cell phase distribution studies indicated that the apoptotic population increased from 10.22% in the control sample to 57.19% in a sample treated with 20 µM compound CH-1.

The value of pyrans as anticancer scaffolds in medicinal chemistry

Pyran-based heterocycles are promising for anticancer drug discovery.

Design, synthesis, molecular docking and biological evaluation of thiophen-2-iminothiazolidine derivatives for use against Trypanosoma cruzi

In this study, we designed and synthesized a series of thiophen-2-iminothiazolidine derivatives from thiophen-2-thioureic with good anti-Trypanosoma cruzi activity. Several of the final compounds displayed remarkable trypanocidal activity. The ability of the new compounds to inhibit the activity of the enzyme cruzain, the major cysteine protease of T. cruzi, was also explored. The compounds 3b, 4b, 8b and 8c were the most active derivatives against amastigote form, with significant IC50 values between 9.7 and 6.03μM. The 8c derivative showed the highest potency against cruzain (IC50=2.4μM). Molecular docking study showed that this compound can interact with subsites S1 and S2 simultaneously, and the negative values for the theoretical energy binding (Eb=-7.39kcal·mol(-1)) indicates interaction (via dipole-dipole) between the hybridized sulfur sp(3) atom at the thiazolidine ring and Gly66. Finally, the results suggest that the thiophen-2-iminothiazolidines synthesized are important lead compounds for the continuing battle against Chagas disease.

Design and microwave assisted synthesis of novel 2-phenyl/2-phenylethynyl-3-aroyl thiophenes as potent antiproliferative agents

In the present study, 2-phenyl/2-phenylethynyl-3-aroyl thiophenes have been designed and evaluated as antiproliferative agents. The significant antiproliferative potential of compounds 12j and 14h were might be attributed to their potential to induce cell cycle arrest at G₂/M phase.

AlCl3-mediated heteroarylation-cyclization strategy: one-pot synthesis of fused quinoxalines containing the central core of Lamellarin D

Pyrano[3,4-b]indole fused quinoxalines were synthesized via an AlCl₃-mediated heteroarylation-cyclization method as potential anticancer agents.

Synthesis of 4-hydroxyindole fused isocoumarin derivatives and their fluorescence “Turn-off” sensing of Cu(ii) and Fe(iii) ions

A simple and efficient protocol has been developed for the synthesis of 4-hydroxyindole fused isocoumarins from easily available starting materials.

One-pot cascade reactions of 1-arylpenta-3,4-dien-2-ones leading to 2-arylphenols and dibenzopyroanones

A one-pot tandem reaction of 1-arylpenta-3,4-dien-2-ones with activated ketones allowed for an efficient synthesis of 2-arylphenols. Moreover, this reaction was found to be also compatible and combinable with Pd-catalyzed C–H activation and carbonylation of the in situ formed 2-arylphenols to provide dibenzopyranones.

Silica sulfuric acid: a reusable solid catalyst for one pot synthesis of densely substituted pyrrole-fused isocoumarins under solvent-free conditions

A convenient and efficient methodology for the synthesis of densely substituted pyrrole-fused isocoumarins, which employs solid-supported silica sulfuric acid (SSA) as catalyst, has been developed. When the mixture of ninhydrin adducts of acetylacetone/ethyl acetoacetate and primary amines was heated on the solid surface of SSA under solvent-free conditions, the pyrrole-fused isocoumarins were formed in good yields. This synthetic method has several advantages such as the employment of solvent-free reaction conditions without the use of any toxic reagents and metal catalysts, the ease of product isolation, the use of a recyclable catalyst, the low cost, the easy availability of the starting materials, and the excellent yields of products.

Construction and functionalization of pyranone ring fused with pyran moiety: design and synthesis of novel pyrano[4,3-b]pyran-5(4H)-ones as potential inhibitors of sirtuins

Novel pyrano[4,3-b]pyran-5(4H)-one based small molecules were designed as potential inhibitors of sirtuins (i.e., yeast sir2, a homolog of human SIRT1). Elegant synthesis of these compounds was performed via a multi-step sequence consisting of MCR, Sandmeyer type iodination, Sonogashira type coupling followed by iodocyclization and then Pd-mediated various C-C bond forming reactions. The overall strategy involved the construction of a pyran ring followed by the fused pyranone moiety and subsequent functionalization at C-8 position of the resultant core pyrano[4,3-b]pyran-5(4H)-one framework. The crystal structure analysis of a representative iodolactonized product (6d) is presented. Some of the synthesized compounds showed promising inhibitory activities when tested against yeast sir2 in vitro. The compound 6g showed dose dependent inhibition (IC50=78.05μM) of yeast sir2 and good interactions with this protein in silico.