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Chalcones are bioactive molecules of natural and synthetic sources, whose physicochemical properties, reactivity, and biological activities are well-known among the scientific community. However, there are many molecules strictly related to chalcones with significantly less recognition like bis -chalcones. Several studies indicated that bis -chalcones have advantages over chalcones in specific bioactivities like anti-inflammatory activity. This review article describes the chemical structure and chemical properties of bis -chalcones, as well as the methods reported in the literature for the synthesis of these compounds highlighting the most recent developments. Finally, the anti-inflammatory activity of bis -chalcones is described, emphasizing the active structures found in literature and their mechanisms of action. [Display omitted] • Bis -chalcones are a subclass of chalcones that earned considerable interest. • Chemical synthesis of bis -chalcones based on established knowledge on chalcones. • Improvement of classic synthetic methodologies with new reaction conditions. • Very few bis- chalcones are associated with anti-inflammatory activity. • More studies on anti-inflammatory bis -chalcones are required to establish a SAR. [ABSTRACT FROM AUTHOR]

Abstract: A family of diphenylmethane derivatives has been synthesized and their luminescence properties characterized. While in solution the compounds are weakly emissive, showing no aggregation-induced emission enhancement, the crystals of three dialkyl 5,5′-methylenebis(2-hydroxybenzoate) samples exhibit intense emission. This emission enhancement upon crystallization is ascribed to particular molecular packing, which stiffens the structure of the compounds via hydrogen bonds, preventing consecutive π–π interactions. [Copyright &y& Elsevier]

Abstract: A new synthesis of a tetrahedral tecton, tetrakis(4-methoxyphenyl)methane, is reported. This compound exhibits a strong fluorescence around 340nm at room temperature, both in solution and in the solid state. Upon crystallization, another luminescence band can be observed around 500nm, attributed to phosphorescence. A study of the single-crystal structure of the compound provided a rationalization of this crystallization induced phosphorescence. The crystal of tetrakis(4-methoxyphenyl)methane belongs to the tetragonal space group P 21 c, and the structural analysis revealed a close packing of the molecules, with no void space and no solvent molecules in the crystal. The molecules are held together in a columnar array via multiple C–H⋯π hydrogen bonds. The hydrogen bonds between the molecules impede the torsional vibrations of the aromatic rings, preventing thermal relaxation from the triplet state, and hence promoting phosphorescence at room temperature. [Copyright &y& Elsevier]

New polyhydroxylated flavon-3-ols and 3-hydroxy-2-styrylchromones were prepared and assessed as reactive oxygen species (ROS) and reactive nitrogen species (RNS) scavengers. The synthetic strategy involved the preparation of 2′-hydroxychalcones and 2′-hydroxycinnamylidenoacetophenones from base-catalyzed aldol reaction of appropriate 2′-hydroxyacetophenones and benzaldehydes/cinnamaldehydes, followed by an Algar-Flynn-Oyamada (AFO) reaction to give the polyalkoxy(flavon-3-ols and 3-hydroxy-2-styrylchromones). The last step of this synthetic route consisted in the cleavage of the protecting groups affording the expected polyhydroxylated derivatives. The present work consisted in the study of the in vitro scavenging activities of the synthetized compounds against the most physiologically relevant ROS [superoxide radical (O 2 - ), hydrogen peroxide (H 2 O 2 ), hypochlorous acid (HOCl), singlet oxygen ( 1 O 2 ) and peroxyl radical (ROO )] and RNS [nitric oxide ( NO) and peroxynitrite anion (ONOO − )]. Generally, all the tested new polyhydroxylated flavon-3-ols and 3-hydroxy-2-styrylchromones exhibited scavenging effects dependent on the concentration, and with IC 50 values found within the micromolar range. This work allowed the establishment of new structure-activity relationships and brought the knowledge about the selective choice of a structure depending on the targeted reactive species. [ABSTRACT FROM AUTHOR]

The Henry-type Barbier addition of bromonitromethane to 3-formylchromone, immediately followed by acetylation and concomitant elimination to afford nitroalkenes in excellent yield and total ( E )-selectivity is described. Cycloaddition of N -methylhydrazones with the obtained nitroalkenes gave the corresponding pyrazoles. Among the prepared pyrazoles, derivative 6j , which contains a catechol moiety, showed simultaneously a potent 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity and an α-glucosidase inhibitory activities. [ABSTRACT FROM AUTHOR]

A two-step procedure transformation starting from the reaction of ortho -phenylenediamines on 2-acetylbutyrolactone 1 yielded ( Z )-3-(1-aminoethylidene)butyrolactones 2 , which were treated with either N , N -dimethylformamide dimethyl acetal, triphosgene, or carbon disulfide under different reaction conditions to produce a new series of benzimidazole–, benzimidazolone–, or benzimidazole-2-thione–butyrolactone dyads 3 – 5 , respectively. The structures of compounds 2 – 5 were established by NMR and mass spectrometry. The isolation of important reaction intermediates as single-crystals allowed the determination of the ( Z )-configuration in the resulting conjugate heterocyclic systems 3 – 5 by X-ray diffraction studies. [ABSTRACT FROM AUTHOR]

Neutrophils are considered the central cells of acute inflammation. Flavonoids have been suggested as therapeutic agents to avoid damages induced by inflammatory processes. It is well known the reactivity of flavonoids with hypochlorous acid produced by neutrophils, to form stable mono and dichlorinated products. In this study, we synthesized novel chlorinated flavonoids and investigated their effect in neutrophils' oxidative burst and in its lifespan, in comparison with the parent non-chlorinated flavonoids. The obtained results demonstrate that chlorinated flavonoids were more efficient than their parent compounds in modulating neutrophils' oxidative burst in phorbol myristate acetate-activated neutrophils. Some of the tested flavonoids drive neutrophil apoptosis in a caspase 3-dependent fashion. The present data showed that 8-chloro-3′,4′,5,7-tetrahydroxyflavone ( 4a ) constitute an alternative anti-inflammatory therapy, due to the proven ability to suppress mechanisms engaged at the onset and progression of inflammation. [ABSTRACT FROM AUTHOR]

• A series of new scalffod coumarin- pyrazole dyads was synthesized. • The structures of the new hybrid compounds were performed by spectroscopic means. • All the compounds were screened in vitro for their potential anticholinesterase agents and antioxidant activity. • Molecular docking simulations reveal the structural insights of novel Coumarin-pyrazole by the interactions on the anticholinesterase enzymes. • Theoretical calculations and Drug-Likeness analysis were done. A new set of hybrid derivatives bearing pyrazole and coumarin scaffold 3a-f was synthesized and confirmed by different spectroscopic techniques (1H NMR, 13C NMR, FT-IR) and mass spectrometry. This study aimed to evaluate the inhibitory activity of new derivatives against both acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) using Galanthamine as standard drugs. In vitro studies showed that compounds 3e and 3f were the most effective showing high potential AChE inhibitory activities with respective IC50 values of 4.41±0.53 and 5.04±0.96 µg/ml. Compounds 3a and 3b were found to be the best butyrylcholinesterase inhibitor with an IC50 value comparable to that of the standard drugs. All the newly synthesized derivatives 3a–f are evaluated for their antioxidant activity and showed good activity. Molecular docking study was also carried to get insights into binding interactions of synthesized compounds to act as AChE and BChE inhibitors. The docking study of compound 3e with AChE enzyme showed that PAS are occupied by the ligand. In silico predictions of toxicity analysis indicated that these compounds should have good oral bioavailability. A novel series of hybrid structures composed of two known scaffolds, including coumarin and pyrazole 3a-f were efficiently synthesized. The in vitro antiacetylcholinesterase activity showed that the 3e and 3f are the most actives compounds. The butyrylcholinesterase inhibitory activity showed an excellent activity for 3a and 3b. The docking study revealed the best mode of binding in the active site of the cholinesterase. All the synthesized compounds were predicted are not likely to exhibit toxicity. The new substances could be considered as promising cholinesterase inhibitors. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract: The optical properties of coumarin and iminocoumarin were investigated in different solvents by UV/vis absorption and fluorescence spectroscopy at room temperature (298K). These compounds were characterized by UV–vis, FT-IR, mass spectroscopy and NMR. A bathochromic shift is observed in absorption and fluorescence spectra of our molecules with increasing solvent polarity. Solvatochromic correlations were used to obtain the ground-state and excited-state dipole moments. The excited-state dipole moments for all the molecules were found to be larger than the corresponding ground-state dipole moments. [Copyright &y& Elsevier]

Abstract: An efficient two step synthetic methodology of new 5(4)-aryl-4(5)-[3(5)-(2-hydroxyphenyl)-1H-pyrazol-5(3)-yl]-1H-1,2,3-triazole dyads was established. The reaction of (E)-2-styryl-4H-chromen-4-ones, used as building blocks, with sodium azide, gave 4(5)-aryl-5(4)-(chromon-2-yl)-1H-1,2,3-triazoles bearing either electron-donating or electron-withdrawing substituents in their styryl moiety which upon reaction with hydrazine hydrate afforded the expected pyrazoles in moderate to very good yields. [Copyright &y& Elsevier]

Abstract: New flavonoid–porphyrin conjugates were synthesized using the cross-coupling Buchwald–Hartwig amination for the coupling of flavonoid and porphyrin moieties. A unique di-substituted flavone–porphyrin conjugate was also synthesized under similar reaction conditions for the first time. All the conjugates were fully characterized by NMR spectroscopy. The photophysical properties namely fluorescence and singlet oxygen production were evaluated considering their use for photodynamic therapy applications. [Copyright &y& Elsevier]

Abstract: We report the synthesis of novel 2H,8H-pyrano[2,3-f]chromene-2,8-dione based scaffolds by the reaction of 8-formyl-7-hydroxy-4-methylcoumarin with various active methylene compounds. A mechanism of a tandem Knoevenagel condensation and cyclisation reaction is proposed. The structure of all compounds was established on the basis of 1H and 13C NMR data, high resolution mass spectrometry and elemental analysis. [Copyright &y& Elsevier]

A series of 6H,7H-7-(4-Hydroxy-3-coumarinyl)[1]benzopyrano[4,3-b][1]benzopyran-6-ones 4a-g and 3-(2-hydroxybenzoyl)-2H-chromen-2-ones 5a-g derivatives were synthesized by reaction of 4-hydroxycoumarin with 2-hydroxyarylaldehydes 2a-f or 2-hydroxynaphtaldehyde 2g using different solvents and acid/base catalysts. The approach relies on a regioselective cascade reaction involving one/two molar equiv of the 4-hydroxy coumarin iteratively acting as active methylene substrate in a Knoevenagel condensation and in a Michael addition. The structures of all compounds were established by IR, mass spectrometry, 1H-NMR and 13C-NMR. Antioxidant activity of the synthesized compounds were determined using the DPPH scavenging assay, best results being obtained with 5b (IC 50 = 236 µg/mL). Computational studies showed that the compounds bind in the ATP-binding site of p38 MAPK, in a same manner than known polyaromatic potent inhibitors. The synthesized compounds might be considered further for cancer therapy. Image, graphical abstract [ABSTRACT FROM AUTHOR]