Synthesis of N,N'-bis(5-arylidene-4-oxo-3,5-dihydro-4H-imidazol-2-yl)diamines bearing various linkers and biological evaluation as potential inhibitors of kinases

Clean and Efficient Green Protocol of N,N'-Bis(2-(arylazo)-2-(aroyl)vinyl)ethane-1,2-diamines in Aqueous Medium without Catalyst: Synthesis and Photophysical Characterization

An interesting platform for the construction of novel N,N'-bis(2-(arylazo)-2-(aroyl)vinyl)ethane-1,2-diamines is reported in this work. These bis-arylazo compounds were assembled based on the reaction of ethylenediamine with various 2-arylhydrazono-3-oxopropanals in aqueous conditions under both conventional stirring and microwave conditions at ambient temperature. The factors affecting the optimization conditions were intensively practiced. The structures of the new products were established from their spectroscopic analyses and X-ray single crystals. The photophysical behavior of the bis-arylazo derivatives was examined. The UV-vis spectra showed maximum absorption band in the range of 348-383 nm with molar extinction coefficients ranging from 0.89 × 104 to 4.02 × 104 M-1 cm-1. The highest molar absorptivity coefficient (∼45 × 103 M-1 cm-1) was observed in CHCl3 solvent. The fluorescence properties showed that some compounds were interesting fluorophore materials with high Stokes shifts. The photoluminescence study of some compounds was promising, with maximal emission peaks ranging between 417-436 nm.

Structure-Activity Relationship Study and Design Strategies of Hydantoin, Thiazolidinedione, and Rhodanine-Based Kinase Inhibitors: A Two-Decade Review

Cancer is one of the most prominent causes of the rapidly growing mortality numbers worldwide. Cancer originates from normal cells that have acquired the capability to alter their molecular, biochemical, and cellular traits. The alteration of cell signaling enzymes, such as kinases, can initiate and amplify cancer progression. As a curative method, the targeted therapy utilized small molecules' capability to inhibit kinase's cellular function. This review provides a brief history (1999-2023) of Small Molecule Kinase Inhibitors (SMKIs) discovery with their molecular perspective. Furthermore, this current review also addresses the application and the development of hydantoin, thiazolidinedione, and rhodanine-based derivatives as kinase inhibitors toward several subclasses (EGFR, PI3K, VEGFR, Pim, c-Met, CDK, IGFR, and ERK) accompanied by their structure-activity relationship study and their molecular interactions. The present work summarizes and compiles all the important structural information essential for developing hydantoin, thiazolidinedione, and rhodanine-based kinase inhibitors to improve their potency in the future.

A Green Approach for Organic Transformations Using Microwave Reactor

Microwave-assisted organic transformation (MAOR) is presently gaining wide popularity in the field of organic synthesis. The conventional heating technique is gradually being removed from the laboratory and a novel microwave heating technique established to be used in both academia and industry. As compared to the classical organic methodology, the green technology tools have several advantages like dramatically reduced reaction times, improved yields, site selectivity, and the increased product purities with simplification of work-up procedures. In the current study, we have briefly described the overview of recent developments and applications of microwave irradiation in organic transformation with schematic compiling of the organic reactions, bioactive heterocyclic compounds, and so on. This review also presents a critical analysis of the various advantages of microwave irradiation in organic synthesis/transformation compared to the classical or conventional heating. So, we believe that our current study of the green microwave heating technique will be highly beneficial for the researchers from both academia and industry in their near future.

An oligonucleotide probe incorporating the chromophore of green fluorescent protein is useful for the detection of HER-2 mRNA breast cancer marker

Diagnosis and treatment of breast cancer can be greatly enhanced and personalized based on the quantitative detection of mRNA markers. Here, we targeted the development of a fluorescent oligonucleotide probe to detect specifically the HER-2 mRNA breast cancer marker. We have selected the chromophore of the Green Fluorescent Protein (GFP), 4-hydroxybenzylidene imidazolinone (HBI), as a fluorophore covalently bound to an oligonucleotide probe and potentially capable of intercalating within a probe-mRNA duplex. We first synthesized the two-ring scaffold of the HBI chromophore 5 and coupled it to 2'-deoxyuridine at C5-position via a 7-atom-spacer, to give 4. Indeed, in the highly viscous glycerol used to mimic the reduced conformational flexibility of the intercalated HBI, chromophore 4 displayed a quantum yield of 0.29 and brightness of 20600 M^-1cm^-1, while no fluorescent signal was observed in methanol. Next, we synthesized a 20-mer oligonucleotide probe incorporating 4 at position 6 (5'-CCCGTUTCAACAGGAGTTTC-3'), ON^HBI, targeting nucleotides 1233-1253 of HER-2 mRNA. A 16-fold enhancement of ON^HBI emission intensity upon hybridization with the complementary RNA vs that of the oligonucleotide probe alone indicated the presence of target oligonucleotide and proved the intercalation of the chromophore (quantum yield 0.52; brightness 23500 M^-1cm^-1). Even more, an 11-fold enhancement of ON^HBI emission (quantum yield 0.50; brightness 23200 M^-1cm^-1) was observed when the probe was mixed with total RNA extract from a human cell line that has high levels of HER2 mRNA expression. Thus, we propose ON^HBI as a promising probe potentially useful for the sensitive and specific detection of HER2 mRNA breast cancer marker.

Unravelling the potency of 4,5-diamino-4H-1,2,4 triazole-3-thiol derivatives for kinase inhibition using a rational approach

This report describes the design of potent kinase inhibitors by simply fine tuning the surroundings of triazole core with diversified derivatization.

Glycogen synthase kinase-3 and its inhibitors: Potential target for various therapeutic conditions

Glycogen Synthase Kinase-3 (GSK-3) is a serine/threonine kinase which is ubiquitously expressed and is regarded as a regulator for various cellular events and signalling pathways. It exists in two isoforms, GSK-3α and GSK-3β and can phosphorylate a wide range of substrates. Aberrancy in the GSK-3 activity can lead to various diseases like Alzheimer's, diabetes, cancer, neurodegeneration etc., rendering it an attractive target to develop potent and specific inhibitors. The present review focuses on the recent developments in the area of GSK-3 inhibitors and also enlightens its therapeutic applicability in various disease conditions.

Synthetic Development of New 3-(4-Arylmethylamino)butyl-5-arylidene-rhodanines under Microwave Irradiation and Their Effects on Tumor Cell Lines and against Protein Kinases

A new route to 3-(4-arylmethylamino)butyl-5-arylidene-2-thioxo-1,3-thiazolidine-4-one 9 was developed in six steps from commercial 1,4-diaminobutane 1 as starting material. The key step of this multi-step synthesis involved a solution phase “one-pot two-steps” approach assisted by microwave dielectric from N-(arylmethyl)butane-1,4-diamine hydrochloride 6a–f (as source of the first point diversity) and commercial bis-(carboxymethyl)-trithiocarbonate reagent 7 for construction of the rhodanine platform. This platform was immediately functionalized by Knoevenagel condensation under microwave irradiation with a series of aromatic aldehydes 3 as second point of diversity. These new compounds were prepared in moderate to good yields and the fourteen synthetic products 9a–n have been obtained with a Z-geometry about their exocyclic double bond. These new 5-arylidene rhodanines derivatives 9a–n were tested for their kinase inhibitory potencies against four protein kinases: Human cyclin-dependent kinase 5-p25, HsCDK5-p25; porcine Glycogen Synthase Kinase-3, GSK-3α/β; porcine Casein Kinase 1, SsCK1 and human HsHaspin. They have also been evaluated for their in vitro inhibition of cell proliferation (HuH7 D12, Caco 2, MDA-MB 231, HCT 116, PC3, NCI-H727, HaCat and fibroblasts). Among of all these compounds, 9j presented selective micromolar inhibition activity on SsCK1 and 9i exhibited antitumor activities in the HuH7 D12, MDA-MBD231 cell lines.