Chalcone: A Privileged Structure in Medicinal Chemistry

Simple cyclic chalcone dye with multiple optical functions: Piezochromism and lysosomes staining

Both artificially synthesized and naturally occurring cyclic chalcones have been widely studied for their excellent biological activities. However, research on its photophysical properties is still limited. In the present study, we designed and synthesized a small molecule fluorescent dye based on the ICT effect, using dimethylamino as the electron-donating group and carbonyl as the electron withdrawing group, and investigated its photophysical properties in depth. Although YB is a simple small molecule, it exhibits significant piezochromic properties. The fluorescence of YB can change from green to yellow through grinding. After solvent fumigation, the fluorescence reverts to green. Furthermore, YB was used successfully in the lysosomal targeting. This study expands the research on the photophysical properties of cyclic chalcone and give richness to application of cyclic chalcone compounds.

Photocatalytic Cross-Coupling of Aldehydes and Alkenes for Aryl Vinyl Ketones by a Single Catalyst

Herein is the first example of photocatalytic cross-coupling of alkenes with aldehydes by a single catalyst without an external photosensitizer and any additives. Irradiation of the aromatic aldehyde and cobaloxime catalyst results in the formation of an acyl radical, which undergoes radical addition with alkene or indole and subsequently β-H elimination to afford alkenyl ketone. The reaction features cheap and readily available raw materials, a broad substrate scope, and mild conditions, even for late-stage derivatization of bioactive compounds.

Synthesis of α-Trifluoromethylated Ketones from α,β-Unsaturated Ketones via Catecholboron Enolates

Herein, we report a protocol for the synthesis of α-trifluoromethylated ketones through trifluoromethylation of the corresponding catecholboron enolates of α,β-unsaturated ketones. The reaction of the 1,4-hydroborated product of enones with the Togni II reagent affords the α-trifluoromethylated ketones without any catalyst or additive. Moreover, the protocol has been employed on a series of α,β-unsaturated ketones, including chalcones, substrate-bearing heterocycles, and bioactive molecules. Mechanistic studies suggest the involvement of a trifluoromethyl radical during the reaction.

Inhibition of monoamine oxidases and neuroprotective effects: chalcones vs. chromones

Eighteen compounds derived from two sub-series, (HC1-HC9) and (HF1-HF9), were synthesized and evaluated for their inhibitory activities against monoamine oxidase (MAO). HC (chalcone) series showed higher inhibitory activity against MAO-B than against MAO-A, whereas the HF (chromone) series showed reversed inhibitory activity. Compound HC4 most potently inhibited MAO-B with an IC50 value of 0.040 μM, followed by HC3 (IC50 = 0.049 μM), while compound HF4 most potently inhibited MAO-A (IC50 = 0.046 μM), followed by HF2 (IC50 = 0.075 μM). The selectivity index (SI) values of HC4 and HF4 were 50.40 and 0.59, respectively. Structurally, HC4 (4-OC2H5 in B-ring) showed higher MAO-B inhibition than other derivatives, suggesting that the -OC2H5 substitution of the 4-position in the B-ring contributes to the increase of MAO-B inhibition, especially -OC2H5 (HC4) > -OCH3 (HC3) > -F (HC7) > -CH3 (HC2) > -Br (HC8) > -H (HC1) in order. In MAO-A inhibition, the substituent 4-OC2H5 in the B-ring of HF4 contributed to an increase in inhibitory activity, followed by -CH3 (HF2), -F (HF7), -Br (HF8), -OCH3 (HF3), and-H (HF1). In the enzyme kinetics and reversibility study, the Ki value of HC4 for MAO-B was 0.035 ± 0.005 μM, and that of HF4 for MAO-A was 0.035 ± 0.005 μM, and both were reversible competitive inhibitors. We confirmed that HC4 and HF4 significantly ameliorated rotenone-induced neurotoxicity, as evidenced by the reactive oxygen species and superoxide dismutase assays. This study also supports the significant effect of HC4 and HF4 on mitochondrial membrane potential in rotenone-induced toxicity. A lead molecule was used for molecular docking and dynamic simulation studies. These results show that HC4 is a potent selective MAO-B inhibitor and HF4 is a potent MAO-A inhibitor, suggesting that both compounds can be used as treatment agents for neurological disorders.

Increasing structure diversity of farnesylated chalcones by a fungal aromatic prenyltransferase

Farnesylated chalcones were favored by researchers due to their different biological activities. However, only five naturally occurring farnesylated chalcones were described in the literature until now. Here, the farnesylation of six chalcones by the Aspergillus terreus aromatic prenyltransferase AtaPT was reported. Fourteen monofarnesylated chalcones (1F1-1F5, 2F1-2F3, 3F1, 3F2, 4F1, 4F2, 5F1, 6F1, and 6F2) and a difarnesylated product (2F3) were obtained, enriching the diversity of natural farnesylated chalcones significantly. Ten of them are C-farnesylated products, which complement O-farnesylated chalcones by chemical synthesis. Fourteen products have not been reported prior to this study. Nine of the produced compounds (1F2-1F5, 2F1-2F3, 5F1, and 6F1) exhibited inhibitory effect on α-glucosidase with IC50 values ranging from 24.08 ± 1.44 to 190.0 ± 0.28 μM. Among them, compounds 2F3 with IC50 value at 24.08 ± 1.44 μM and 1F4 with IC50 value at 30.09 ± 0.59 μM showed about 20 times stronger than the positive control acarbose with an IC50 at 536.87 ± 24.25 μM in α-glucosidase inhibitory assays.

Isobavachalcone induces hepatotoxicity in zebrafish embryos and HepG2 cells via the System Xc--GSH-GPX4 signaling pathway in ferroptosis response

Isobavachalcone (IBC) is a flavonoid component of the traditional Chinese medicine Psoraleae Fructus, with a range of pharmacological properties. However, IBC causes some hepatotoxicity, and the mechanism of toxicity is unclear. The purpose of this paper was to investigate the possible mechanism of toxicity of IBC on HepG2 cells and zebrafish embryos. The results showed that exposure to IBC increased zebrafish embryo mortality and decreased hatchability. Meanwhile, IBC induced liver injury and increased expression of ALT and AST activity. Further studies showed that IBC caused the increase of ROS and MDA the decrease of CAT, GSH, and GSH-Px; the increase of Fe2+ content; and the changes of ferroptosis related genes (acsl4, gpx4, and xct) and iron storage related genes (tf, fth, and fpn) in zebrafish embryos. Through in vitro verification, it was found that IBC also caused oxidative stress and increased Fe2+ content in HepG2 cells. IBC caused depolarization of mitochondrial membrane potential (MMP) and reduction of mitochondrial ATP, as well as altered expression of ACSl4, SLC7A11, GPX4, and FTH1 proteins. Treatment of HepG2 cells with ferrostatin-1 could reverse the effect of IBC. Targeting the System Xc--GSH-GPX4 pathway of ferroptosis and preventing oxidative stress damage might offer a theoretical foundation for practical therapy and prevention of IBC-induced hepatotoxicity.

The influence of the chlorine atom on the biological activity of 2'-hydroxychalcone in relation to the lipid phase of biological membranes - Anticancer and antimicrobial activity

The study investigates the effect of the presence of a chlorine atom in the 2'-hydroxychalcone molecule on its interaction with model lipid membranes, in order to discern its potential pharmacological activity. Five chlorine derivatives of 2'-hydroxychalcone were synthesized and evaluated against liposomes composed of POPC and enriched with cationic (DOTAP) or anionic (POPG) lipids. The physicochemical properties of the compounds were initially simulated using SwissAdame software, revealing high lipophilicity (ilogP values: 2.79-2.90). The dynamic light scattering analysis of liposomes showed that chloro chalcones induce minor changes in the diameter of liposomes of different surface charges. Fluorescence quenching assays with a TMA-DPH probe demonstrated the strong ability of the compounds to interact with the lipid bilayer, with varying quenching capacities based on chlorine atom position. FTIR studies indicated alterations in carbonyl, phosphate, and choline groups, suggesting a transition area localization rather than deep penetration into the hydrocarbon chains. Additionally, dipole potential reduction was observed in POPC and POPC-POPG membranes, particularly pronounced by derivatives with a chlorine atom in the B ring. Antibacterial and antibiofilm assays revealed enhanced activity of derivatives with a chlorine atom compared to 2'-hydroxychalcone, especially against Gram-positive bacteria. The MIC and MBIC50 values showed increased efficacy in the presence of chlorine with 3'-5'-dichloro-2'-hydroxychalcone demonstrating optimal antimicrobial and antibiofilm activity. Furthermore, antiproliferative assays against breast cancer cell lines indicated higher activity of B-ring chlorine derivatives, particularly against MDA-MB-231 cells. In general, the presence of a chlorine atom in 2'-hydroxychalcone improves its pharmacological potential, with derivatives showing improved antimicrobial, antibiofilm, and antiproliferative activities, especially against aggressive breast cancer cell lines. These findings underscore the importance of molecular structure in modulating biological activity and highlight chalcones with a chlorine as promising candidates for further drug development studies.

Rational Design of Highly Phosphorescent Nanoclusters for Efficient Photocatalytic Oxidation

Analyzing the molecular structure-photophysical property correlations of metal nanoclusters to accomplish function-oriented photocatalysis could be challenging. Here, the selective heteroatom alloying has been exploited to a Au15 nanocluster, making up a structure-correlated nanocluster series, including homogold Au15, bimetallic AgxAu15-x and CuxAu15-x, trimetallic AgxCuyAu15-x-y, and tetrametallic Pt1AgxCuyAu15-x-y. Their structure-dependent photophysical properties were investigated due to the atomically precise structures of these nanoclusters. Cu-alloyed CuxAu15-x showed intense phosphorescence and the highest singlet oxygen production efficiency. Moreover, the generation of 1O2 species from excited nanoclusters enabled CuxAu15-x as a suitable catalyst for efficient photocatalytic oxidation of silyl enol ethers to produce α,β-unsaturated carbonyl compounds. The generality and applicability of the CuxAu15-x catalysts toward different photocatalytic oxidations were assessed. Overall, this study presents an intriguing Au15-based cluster series enabling an atomic-level understanding of structure-photophysical property correlations, which hopefully provides guidance for the fabrication of cluster-based catalysts with customized photocatalytic performance.

Antiparasitic activity of chalcones analogue against Trichomonas vaginalis: biochemical, molecular and in silico aspects

Trichomonas vaginalis is the etiologic agent of trichomoniasis, a worldwide distributed sexually transmitted infection (STI) that affects the genitourinary tract. Even though this disease already has a treatment in the prescription of drugs of the 5-nitroimidazole class, described low treatments adhesion, adverse side effects and cases of resistant isolates demonstrate the need for new formulations. With this in mind, chalcones emerge as a potential alternative to be tested, being compounds widely distributed in nature, easy to chemically synthesize and presenting several biological activities already reported. In this experiment, we evaluated the antiparasitic activity of 10 chalcone at a concentration of 100 μM against ATCC 30236 T. vaginalis isolates, considering negative (live trophozoites), positive (Metronidazole 100 μM) and vehicle (DMSO 0.6%) controls. Compounds 3a, 3c, 3 g and 3i showed promising results, with MICs set at 70 μM, 80 μM, 90 μM and 90 μM, respectively (p < 0,05). Cytotoxicity assays were performed on VERO and HMVII cell lines and revealed low inhibition rates at concentrations bellow 20 μM. To elucidate a possible mechanism of action for these molecules, the DPPH, ABTS and FRAP assays were performed, in which none of the four compounds presented antioxidant activity. Assays to verify ROS and lipid peroxidation in the parasite membrane were performed. None of the tested compounds identified ROS accumulation after incubation with trophozoites. 3 g molecule promoted an increase in MDA production after incubation. Results presented in this paper demonstrate the promising trichomonicidal profile, although further tests are still needed to optimize their performance and better elucidate the mechanisms of action involved.

A novel drug prejudice scaffold-imidazopyridine-conjugate can promote cell death in a colorectal cancer model by binding to β-catenin and suppressing the Wnt signaling pathway

INTRODUCTION

Globally, colorectal cancer (CRC) is the third most common type of cancer, and its treatment frequently includes the utilization of drugs based on antibodies and small molecules. The development of CRC has been linked to various signaling pathways, with the Wnt/β-catenin pathway identified as a key target for intervention.

OBJECTIVES

We have explored the impact of imidazopyridine-tethered chalcone-C (CHL-C) in CRC models.

METHODS

To determine the influence of CHL-C on apoptosis and autophagy, Western blot analysis, annexin V assay, cell cycle analysis, acridine orange staining, and immunocytochemistry were performed. Next, the activation of the Wnt/β-catenin signaling pathway and the anti-cancer effects of CHL-C in vivo were examined in an orthotopic HCT-116 mouse model.

RESULTS

We describe the synthesis and biological assessment of the CHL series as inhibitors of the viability of HCT-116, SW480, HT-29, HCT-15, and SNU-C2A CRC cell lines. Further biological evaluations showed that CHL-C induced apoptosis and autophagy in down-regulated β-catenin, Wnt3a, FZD-1, Axin-1, and p-GSK-3β (Ser9), and up-regulated p-GSK3β (Tyr216) and β-TrCP. In-depth analysis using structure-based bioinformatics showed that CHL-C strongly binds to β-catenin, with a binding affinity comparable to that of ICG-001, a well-known β-catenin inhibitor. Additionally, our in vivo research showed that CHL-C markedly inhibited tumor growth and triggered the activation of both apoptosis and autophagy in tumor tissues.

CONCLUSION

CHL-C is capable of inducing apoptosis and autophagy by influencing the Wnt/β-catenin signaling pathway.

Synthesis and In vitro evaluation of bichalcones as novel anti-toxoplasma agents

Toxoplasmosis is a zoonotic disease caused by Toxoplasma gondii, an apicomplexan parasite that infects approximately a third of the world's human population. This disease can cause serious complications during pregnancy and can be fatal in immunocompromised hosts. The current treatment options for toxoplasmosis face several limitations. Thus, to address the urgent medical need for the discovery of novel anti-toxoplasma potential drug candidates, our research focused on exploring a series of monomeric and dimeric chalcones, polyphenolic molecules belonging to the class of flavonoids. Chalcones 1aa-1bg and axially chiral A-A'-connected bichalcones 2aa-2bg were evaluated in vitro against the proliferation of the parasite in a cell-based assay. A comparison of the efficacy demonstrated that, in several cases, bichalcones exhibited increased bioactivity compared to their corresponding monomeric counterparts. Among these compounds, a bichalcone with a phenyl substituent and a methyl moiety 2ab showed the most potent and selective inhibitory activity in the nanomolar range. Both enantiomers of this bichalcone were synthesized using an axially chiral biphenol building block. The biaryl bond was forged using Suzuki cross-coupling in water under micellar catalysis conditions. Separation of the atropisomers of this biphenol building block was conducted by chiral HPLC on a preparative scale. The biological evaluation of the enantiomers revealed that the (R a)-enantiomer (R a)-2ab is the eutomer. These studies suggest that bichalcones may be important drug candidates for further in vivo evaluations for the discovery of anti-toxoplasma drugs.

(E)-2-Benzylidenecyclanones: Part XIX. Reaction of (E)-2-(4'-X-Benzylidene)-1-tetralones with Cellular Thiols: Comparison of Thiol Reactivities of Open-Chain Chalcones and Their Six- and Seven-Membered Cyclic Analogs

Non-enzyme-catalyzed thiol addition onto the α,β-unsaturated carbonyl system is associated with several biological effects. Kinetics and diastereoselectivity of non-enzyme catalyzed nucleophilic addition of reduced glutathione (GSH) and N-acetylcysteine (NAC) to the six-membered cyclic chalcone analogs 2a and 2b were investigated at different pH values (pH 3.2, 7.4 and 8.0). The selected compounds displayed in vitro cancer cell cytotoxicity (IC50) of different orders of magnitude. The chalcones intrinsically reacted with both thiols under all incubation conditions. The initial rates and compositions of the final mixtures depended both on the substitution and the pH. The stereochemical outcome of the reactions was evaluated using high-pressure liquid chromatography with UV detection (HPLC-UV). The structures of the formed thiol-conjugates and the retro-Michael products (Z)-2a and (Z)-2b were confirmed by high-pressure liquid chromatography-mass spectrometry (HPLC-MS). Frontier molecular orbitals and the Fukui function calculations were carried out to investigate their effects on the six-membered cyclic analogs. Data were compared with those obtained with the open-chain (1) and the seven-membered (3) analogs. The observed reactivities do not directly relate to the difference in in vitro cancer cell cytotoxicity of the compounds.

Transition Metal-Catalyzed Transformations of Chalcones

Chalcones are a class of naturally occurring flavonoid compounds associated to a variety of biological and pharmacological properties. Several reviews have been published describing the synthesis and biological properties of a vast array of analogues. However, overviews on the reactivity of chalcones has only been explored in a few accounts. To fill this gap, a systematic survey on the most recent developments in the transition metal-catalyzed transformation of chalcones was performed. The chemistry of copper, palladium, zinc, iron, manganese, nickel, ruthenium, cobalt, rhodium, iridium, silver, indium, gold, titanium, platinum, among others, as versatile catalysts will be highlighted, covering the literature from year 2000 to 2023, in more than 380 publications.

Design, synthesis, and biological evaluation of chalcone acetamide derivatives against triple negative breast cancer

Chalcones are chemical scaffolds found in natural products, particularly in plants, and are considered for structural diversity in medicinal chemistry for drug development. Herein, we designed and synthesised novel acetamide derivatives of chalcone, characterizing them using 1H NMR, 13C NMR, HRMS, and IR spectroscopic methods. These derivatives were then screened against human cancer cells for cytotoxicity using the SRB assay. Among the tested derivatives, 7g, with a pyrrolidine group, exhibited better cell growth inhibition activity against triple-negative breast cancer (TNBC) cells. Further assays, including SRB, colony formation, and fluorescent dye-based microscopic analysis, confirmed that 7g significantly inhibited MDA-MB-231 cell proliferation. Furthermore, 7g promoted apoptosis by upregulating cellular reactive oxygen species (ROS) levels and disrupting mitochondrial membrane potential (MMP). Elevated expression of pro-apoptotic proteins (Bax and caspase-3) and a higher Bax/Bcl-2 ratio with downregulation of anti-apoptotic (Bcl-2) protein levels were observed in TNBC cells. The above results suggest that 7g can promote cellular death through apoptotic mechanisms in TNBC cells.

Therapeutic potential and action mechanisms of licochalcone B: a mini review

Licochalcone B (LicB), a chalcone derived from Glycyrrhiza uralensis and Glycyrrhiza glabra, has received considerable attention due to its diverse pharmacological properties. Accumulated data indicates that LicB has pharmacological effects that include anti-cancer, hepatoprotective, anti-inflammatory, and neuroprotective properties. The action mechanism of LicB has been linked to several molecular targets, such as phosphoinositide 3-kinase/Akt/mammalian target of rapamycin, p53, nuclear factor-κB, and p38, and the involvements of caspases, apoptosis, mitogen-activated protein kinase-associated inflammatory pathways, and anti-inflammatory nuclear factor erythroid 2-related factor 2 signaling pathways highlight the multifaceted therapeutic potential of LicB. This review systematically updates recent findings regarding the pharmacological effects of LicB, and the mechanistic pathways involved, and highlights the potential use of LicB as a promising lead compound for drug discovery.

Design, synthesis and biological evaluation of novel pyrazole-based compounds as potential chemotherapeutic agents

Aim: Design and synthesis of pyrazole-based chemotherapeutic agents. Materials & methods: A series of novel diphenyl pyrazole-chalcone derivatives were synthesized and assessed for their cytotoxic activities against 14 cancer cell lines and their antimicrobial activities against MRSA and Escherichia coli along with their safety using HSF normal cell line. Results & conclusion: Majority of the compounds showed moderate-to-significant anticancer activity with selective high percentage inhibition (>80%) against HNO-97 while being nontoxic toward normal cells. Compounds 6b and 6d were the most potent congeners with IC50 of 10 and 10.56 μM respectively. The synthesized compounds exhibited moderate to potent antimicrobial activities. Interestingly, compound 6d exhibited a minimum inhibitory concentration of 15.7 μg/ml against MRSA; and a minimum inhibitory concentration of 7.8 μg/ml versus E. coli.

Isocoumarins incorporating chalcone moieties act as isoform selective tumor-associated carbonic anhydrase inhibitors

Aim: A series of isocoumarin-chalcone hybrids were prepared and assays for the inhibition of four isoforms of human carbonic anhydrase (hCA; EC 4.2.1.1), hCA I, II, IX and XII. Materials & methods: Isocoumarin-chalcone hybrids were synthesized by condensing acetyl-isocoumarin with aromatic aldehydes. They did not significantly inhibit off-target cytosolic isoforms hCA I and II (KI >100 μM) but acted as low micromolar or submicromolar inhibitors for the tumor-associated isoforms hCA IX and XII. Results & conclusion: Our work provides insights into a new and scarcely investigated chemotype which provides interesting tumor-associated CA inhibitors, considering that some such derivatives like sulfonamide SLC-0111 are in advanced clinical trials for the management of metastatic advanced solid tumors.

Supporting the assignment of NMR spectra with variable-temperature experiments

Nuclear magnetic resonance (NMR) spectroscopy is one of the most powerful tools in analytical chemistry. An important step in the analysis of NMR data is the assignment of resonance frequencies to the corresponding atoms in the molecule being investigated. The traditional approach considers the spectrum's characteristic parameters: chemical shift values, internuclear couplings, and peak intensities. In this paper, we show how to support the process of assigning a series of spectra of similar organic compounds by using temperature coefficients, that is, the rates of change in chemical shift values associated with given changes in temperature.

Identification of potential biogenic chalcones against antibiotic resistant efflux pump (AcrB) via computational study

The cases of bacterial multidrug resistance are increasing every year and becoming a serious concern for human health. Multidrug efflux pumps are key players in the formation of antibiotic resistance, which transfer out a broad spectrum of drugs from the cell and convey resistance to the host. Efflux pumps have significantly reduced the efficacy of the previously available antibiotic armory, thereby increasing the frequency of therapeutic failures. In gram-negative bacteria, the AcrAB-TolC efflux pump is the principal transporter of the substrate and plays a major role in the formation of antibiotic resistance. In the current work, advanced computer-aided drug discovery approaches were utilized to find hit molecules from the library of biogenic chalcones against the bacterial AcrB efflux pump. The results of the performed computational studies via molecular docking, drug-likeness prediction, pharmacokinetic profiling, pharmacophore mapping, density functional theory, and molecular dynamics simulation study provided ZINC000004695648, ZINC000014762506, ZINC000014762510, ZINC000095099506, and ZINC000085510993 as stable hit molecules against the AcrB efflux pumps. Identified hits could successfully act against AcrB efflux pumps after optimization as lead molecules.Communicated by Ramaswamy H. Sarma.

Synthesis, fungal biotransformation, and evaluation of the antimicrobial potential of chalcones with a chlorine atom

Chalcones are intermediate products in the biosynthesis of flavonoids, which possess a wide range of biological properties, including antimicrobial and anticancer activities. The introduction of a chlorine atom and the glucosyl moiety into their structure may increase their bioavailability, bioactivity, and pharmacological use. The combined chemical and biotechnological methods can be applied to obtain such compounds. Therefore, 2-chloro-2'-hydroxychalcone and 3-chloro-2'-hydroxychalcone were synthesized and biotransformed in cultures of two strains of filamentous fungi, i.e. Isaria fumosorosea KCH J2 and Beauveria bassiana KCH J1.5 to obtain their novel glycosylated derivatives. Pharmacokinetics, drug-likeness, and biological activity of them were predicted using cheminformatics tools. 2-Chloro-2'-hydroxychalcone, 3-chloro-2'-hydroxychalcone, their main glycosylation products, and 2'-hydrochychalcone were screened for antimicrobial activity against several microbial strains. The growth of Escherichia coli 10,536 was completely inhibited by chalcones with a chlorine atom and 3-chlorodihydrochalcone 2'-O-β-D-(4″-O-methyl)-glucopyranoside. The strain Pseudomonas aeruginosa DSM 939 was the most resistant to the action of the tested compounds. However, chalcone aglycones and glycosides with a chlorine atom almost completely inhibited the growth of bacteria Staphylococcus aureus DSM 799 and yeast Candida albicans DSM 1386. The tested compounds had different effects on lactic acid bacteria depending on the tested species. In general, chlorinated chalcones were more effective in the inhibition of the tested microbial strains than their unchlorinated counterparts and aglycones were a little more effective than their glycosides.

Attenuation of Quorum Sensing Mediated Virulence Factors and Biofilm Formation in Pseudomonas Aeruginosa PAO1 by Substituted Chalcones and Flavonols

Flavonoids epitomize structural scaffolds in many biologically active synthetic and natural compounds. They showcase a diverse spectrum of biological activities including anticancer, antidiabetic, antituberculosis, antimalarial, and antibiofilm activities. The antibiofilm activity of a series of new chalcones and flavonols against clinically significant Pseudomonas aeruginosa PAO1 strain was studied. Antivirulence activities were screened by analysing the effect of compounds on the production of virulence factors like pyocyanin, LasA protease, cell surface hydrophobicity, and rhamnolipid. The best ligands towards the quorum sensing proteins LasR, RhlR, and PqsR were recognised using a molecular docking study. The gene expression in P. aeruginosa after treatment with test compounds was evaluated on quorum sensing genes including rhlA, lasB, and pqsE. The antibiofilm potential of chalcones and flavonols was confirmed by the efficient reduction in the production of virulence factors and downregulation of gene expression.

Discovery of Loureirin analogues with colorectal cancer suppressive activity via regulating cell cycle and Fas death receptor

Chalcones and dihydrochalcones (DHCs) are important bioactive natural products (BNPs) isolated from traditional Chinese medicine. In this study, 13 chalcones were designed with the inspiration of Loureirin, a DHC extracted from Resina Draconis, and synthesized by classical Claisen-Schmidt reactions. Afterwards the reduction reactions were carried out to obtain the corresponding DHCs. Cytotoxicity assay indicated chalcones and DHCs possessed selective cytotoxicity against colorectal cancer (CRC) cells. The preliminary structure-activity relationships (SAR) of these compounds suggested the α, β-unsaturated ketone of the chalcones were crucial for the anticancer activity. Interestingly, compounds 3d and 4c exhibited selective anticancer activity against CRC cell line HCT116 with IC50s of 8.4 and 17.9 μM but not normal cell. Moreover, 4c could also inhibit the migration and invasion of CRC cells. Mechanism investigations showed 4c could induce cell cycle G2/M arrest by regulating cell cycle-associated proteins and could also up-regulate Fas cell surface death receptor. The virtual docking further pointed out that compounds 3d and 4c could nicely bind to the Fas/FADD death domain complex (ID: 3EZQ). Furthermore, silencing of Fas significantly enhanced the proliferation of CRC cells and attenuated the cytotoxicity induced by 4c. These results suggested 4c exerted its anticancer activity possibly regulating cell cycle and Fas death receptor. In summary, this study investigated the anticancer activity and mechanism of Loureirin analogues in CRC, suggesting these compounds may warrant further investigation as promising anticancer drug candidates for the treatment of CRC.

Significance of Chalcone Scaffolds in Medicinal Chemistry

Chalcone is a simple naturally occurring α,β-unsaturated ketone with biological importance, which can also be easily synthesized in laboratories by reaction between two aromatic scaffolds. In plants, chalcones occur as polyphenolic compounds of different frameworks which are bioactive molecules that have been in traditional medicinal practice for many years. Chalcone-based lead molecules have been developed, possessing varied potentials such as antimicrobial, antiviral, anti-inflammatory, anticancer, anti-oxidant, antidiabetic, antihyperurecemic, and anti-ulcer effects. Chalcones contribute considerable fragments to give important heterocyclic molecules with therapeutic utilities targeting various diseases. These characteristic features have made chalcone a topic of interest among researchers and have attracted investigations into this widely applicable structure. This review highlights the extensive exploration carried out on the synthesis, biotransformations, chemical reactions, hybridization, and pharmacological potentials of chalcones, and aims to provide an extensive, thorough, and critical review of their importance, with emphasis on their properties, chemistry, and biomedical applications to boost future investigations into this potential scaffold in medicinal chemistry.

A survey of isatin hybrids and their biological properties

The emergence of diverse infections worldwide, which is a serious global threat to human existence, necessitates the urgent development of novel therapeutic candidates that can combat these diseases with efficacy. Molecular hybridization has been established as an efficient technique in designing bioactive molecules capable of fighting infections. Isatin, a core nucleus of an array of compounds with diverse biological properties can be modified at different positions leading to the creation of novel drug targets, is an active area of medicinal chemistry. This review containing published articles from 2005 to 2022 highlights isatin hybrids which have been synthesized and reported in the literature alongside a discussion on their biological properties. The enriched structure-activity relationship studies discussed provides insights for the rational design of novel isatin hybrids with tailored biological properties as effective therapeutic candidates inspired by nature.

Morpholinodiazenyl chalcone blocks influenza A virus capsid uncoating by perturbing the clathrin-mediated vesicular trafficking pathway

Influenza A virus (IAV) is a highly contagious respiratory pathogen that significantly threatens global health by causing seasonal epidemics and occasional, unpredictable pandemics. To identify new compounds with therapeutic potential against IAV, we designed and synthesized a series of 4'-morpholinodiazenyl chalcones using the molecular hybridization method, performed a high-content screen against IAV, and found that (E)-1-{4-[(E)-morpholinodiazenyl]phenyl}-3-(3,4,5-trimethoxyphenyl)prop-2-en-1-one (MC-22) completely neutralized IAV infection. While MC-22 allowed IAV to successfully internalize into the cell and fuse at the acidic late endosomes, it prevented viral capsid uncoating and genome release. Since IAV majorly utilizes clathrin-mediated endocytosis (CME) for cellular entry, we examined whether MC-22 had any effect on CME, using nonviral cargoes that enter cells via clathrin-dependent or -independent pathways. Although MC-22 showed no effect on the uptake of choleratoxin B, a cargo that enters cells majorly via the clathrin-independent pathway, it significantly attenuated the clathrin-dependent internalization of both epidermal growth factor and transferrin. Cell biological analyses revealed a marked increase in the size of early endosomes upon MC-22 treatment, indicating an endosomal trafficking/maturation defect. This study reports the identification of MC-22 as a novel CME-targeting, highly potent IAV entry inhibitor, which is expected to neutralize a broad spectrum of viruses that enter the host cells via CME.

Michael Acceptors as Anti-Cancer Compounds: Coincidence or Causality?

Michael acceptors represent a class of compounds with potential anti-cancer properties. They act by binding to nucleophilic sites in biological molecules, thereby disrupting cancer cell function and inducing cell death. This mode of action, as well as their ability to be modified and targeted, makes them a promising avenue for advancing cancer therapy. We are investigating the molecular mechanisms underlying Michael acceptors and their interactions with cancer cells, in particular their ability to interfere with cellular processes and induce apoptosis. The anti-cancer properties of Michael acceptors are not accidental but are due to their chemical structure and reactivity. The electrophilic nature of these compounds allows them to selectively target nucleophilic residues on disease-associated proteins, resulting in significant therapeutic benefits and minimal toxicity in various diseases. This opens up new perspectives for the development of more effective and precise cancer drugs. Nevertheless, further studies are essential to fully understand the impact of our discoveries and translate them into clinical practice.

Direct synthesis, characterization, in vitro and in silico studies of simple chalcones as potential antimicrobial and antileishmanial agents

Chalcone represents a vital biosynthetic scaffold owing to its numerous therapeutic effects. The present study was intended to synthesize 17 chalcone derivatives (3a-q) by direct coupling of substituted acetophenones and benzaldehyde. The target chalcones were characterized by spectroscopic analyses followed by their in vitro antimicrobial, and antileishmanial investigations with reference to standard drugs. The majority of the chalcones displayed good to excellent biological activities. Chalcone 3q (1000 µg ml-1) exhibited the most potent antibacterial effect with its zone of inhibition values of 30, 33 and 34 mm versus Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa respectively. The results also confirmed chalcone 3q to be the most potent versus Leishmania major with the lowest IC50 value of 0.59 ± 0.12 µg ml-1. Chalcone 3i (500 µg ml-1) was noticed to be the most potent antifungal agent with its zone of inhibition being 29 mm against Candida albicans. Computational studies of chalcones 3i and 3q supported the preliminary in vivo results. The existence of the amino moiety and bromine atom on ring-A and methoxy moieties on ring-B caused better biological effects of the chalcones. In brief, the investigations reveal that chalcones (3i and 3q) can be employed as building blocks to discover novel antimicrobial agents.

Evidence that a Novel Chalcone Derivative, Compound 27, Acts on the Epithelium Via the PI3K/AKT/Nrf2-Keap1 Signaling Pathway, to Mitigate LPS-Induced Acute Lung Injury in Mice

Acute lung injury (ALI) is a highly heterogeneous clinical syndrome and an important cause of mortality in critically ill patients, with limited treatment options currently available. Chalcone, an essential secondary metabolite found in edible or medicinal plants, exhibits good antioxidant activity and simple structure for easy synthesis. In our study, we synthesized a novel chalcone derivative, compound 27 (C27). We hypothesized that C27 could be a potential treatment for acute respiratory distress syndrome (ARDS). Therefore, the protective effects of C27 on lung epithelial cells during ALI and the underlying molecular mechanisms were investigated. In vivo, Intratracheal instillation of LPS (10 mg/kg) was used to induce acute lung injury in mice. In vitro, the bronchial epithelial cell line (Beas-2b) was treated with 30 μM tert-butyl hydroperoxide (t-BHP) to simulate oxidative stress. Our findings demonstrate that pretreatment with C27 reduces LPS-induced oxidative destruction and cellular apoptosis in lung tissues of mice. Furthermore, it significantly attenuates t-BHP-induced cellular reactive oxygen species (ROS) generation, mitochondrial damage, and apoptosis in vitro. Mechanistically, the signaling pathway involving Nrf2-Keap1 and the downstream antioxidative proteins were activated by C27 in vivo. Additionally, PI3K inhibitor LY294002 and Nrf2 inhibitor ML385 abolished the effect of C27 in vitro, indicating that the protective effect of C27 is mediated via the PI3K/AKT/Nrf2-Keap1 pathway. Our study provides evidence that C27 protects against LPS-induced ALI by mitigating oxidative stress via activation of the PI3K/AKT/Nrf2-Keap1 signaling pathway. Therefore, we hypothesize that C27 represents a viable alternative for ALI therapy.

Testing of Anti-EMT, Anti-Inflammatory and Antibacterial Activities of 2',4'-Dimethoxychalcone

Chalcone (1,3-diaryl-2-propen-1-one) is an α, β-unsaturated ketone that serves as an active constituent or precursor of numerous natural substances, exhibiting a broad spectrum of pharmacological effects. In this study, the classical Claisen-Schmidt condensation method was used to synthesize the chalcone derivative 2',4'-dimethoxychalcone (DTC) and evaluate its pharmacological activity. By upregulating the expression of the epithelial cell marker E-cadherin and downregulating the expression of the mesenchymal cell marker vimentin, DTC was found to inhibit transforming growth factor-β1 (TGF-β1)-induced epithelial-mesenchymal transition (EMT) process in A549 cells, maintaining the cells' epithelial-like morphology and reducing the ability of the cells to migrate. Additionally, DTC demonstrated the ability to decrease the expression levels of nitric oxide (NO), tumor necrosis factor (TNF-α), interleukin-6 (IL-6), and interleukin-1β (IL-1β) in RAW264.7 cells, suggesting a possible anti-inflammatory effect. Furthermore, DTC was found to exhibit bacteriostatic activity against Staphylococcus aureus (S. aureus), Proteus vulgaris (P. vulgaris), methicillin-resistant Staphylococcus aureus (MRSA), and Candida albicans (C. albicans), indicating that this chemical may possess broad-spectrum antibacterial activity.

Lactone Enolates of Isochroman-3-ones and 2-Coumaranones: Quantification of Their Nucleophilicity in DMSO and Conjugate Additions to Chalcones

Owing to stereoelectronic effects, lactones often deviate in reactivity from their open-chain ester analogues as demonstrated by the CH acidity (in DMSO) of 3-isochromanone (pKa = 18.8) and 2-coumaranone (pKa = 13.5), which is higher than that of ethyl phenylacetate (pKa = 22.6). We have now characterized the reactivity of the lactone enolates derived from 3-isochromanone and 2-coumaranone by following the kinetics of their Michael reactions with p-quinone methides and arylidenemalonates (reference electrophiles) in DMSO at 20 °C. Evaluation of the experimentally determined second-order rate constants k2 by the Mayr-Patz equation, lg k2 = sN(N + E), furnished the nucleophilicity parameters N (and sN) of the lactone enolates. By localizing their position on the Mayr nucleophilicity scale, the scope of their electrophilic reaction partners becomes predictable, and we demonstrate a novel catalytic methodology for a series of carbon-carbon bond-forming reactions of lactone enolates with chalcones under phase transfer conditions in toluene.

Structure-Activity Relationship Study of (E)-3-(6-Fluoro-1H-indol-3-Yl)-2-methyl-1-(3,4,5-trimethoxyphenyl)prop-2-en-1-one (FC116) Against Metastatic Colorectal Cancers Resistant to Oxaliplatin

Advanced metastatic colorectal cancer (mCRC) and the development of drug resistance to chemotherapy pose significant challenges in clinical settings. In previous studies, we have demonstrated the potent cytotoxic activity of (E)-3-(6-fluoro-1H-indol-3-yl)-2-methyl-1-(3,4,5-trimethoxyphenyl)prop-2-en-1-one (FC116) and related 30 derivatives against mCRC by targeting microtubules. In this study, we aimed to evaluate the efficacy of the 31 compounds and explore the structure-activity relationship (SAR) against oxaliplatin-resistant mCRC. We found that most of the derivatives showed high sensitivity toward the oxaliplatin-resistant HCT-116/L cells. Particularly, FC116 exhibited a better GI50 value against the resistant mCRC cell line, HCT-116/L, compared to standard therapies. We also observed a safer therapeutic window for FC116 and a synergistic effect when it was used in combination with oxaliplatin. Mechanistically, FC116 induced the G2/M phase arrest by downregulating cyclin B1 expression through its interaction with microtubules in resistant colorectal cancer cells. Furthermore, in vivo experiments demonstrated that FC116 significantly suppressed tumor growth, achieving a 78% reduction at a dose of 3 mg/kg, which was superior to the 40% reduction achieved by oxaliplatin treatment. Overall, our findings suggest that the indole-chalcone compound FC116 represents a promising lead for chemotherapy in oxaliplatin-resistant mCRC.

Chalcones-Features, Identification Techniques, Attributes, and Application in Agriculture

This review article is a comprehensive and current overview on chalcones, covering their sources, identification methods, and properties with a particular focus on their applications in the agricultural sector. The widespread use of synthetic pesticides has not only led to increased resistance among weeds and pests, resulting in economic losses, but it has also raised significant health concerns due to the overuse of these chemicals. In line with the European Green Deal 2030 and its Farm to Fork strategy, there is a targeted 50% reduction in the use of chemical pesticides by 2030, emphasizing a shift towards natural alternatives that are more environmentally sustainable and help in the restoration of natural resources. Chalcones and their derivatives, with their herbicidal, fungicidal, bactericidal, and antiviral properties, appear to be ideal candidates. These naturally occurring compounds have been recognized for their beneficial health effects for many years and have applications across multiple areas. This review not only complements the previous literature on the agricultural use of chalcones but also provides updates and introduces methods of detection such as chromatography and MALDI technique.

Unveiling the ion sensing capabailities of 'click' derived chalcone-tailored 1,2,3-triazolic isomers for Pb(ii) and Cu(ii) ions: DFT analysis

In this study, two novel chalcone-derived 1,2,3-triazole-appended positional isomers (probe 6 and probe 9) were synthesized via the 'CuAAC' (Cu(i) - catalysed alkyne azide cycloaddition) methodology for the purpose of metal ion detection. The synthesized probes underwent characterization utilizing standard spectroscopic methodologies including FTIR, NMR (1H and 13C), and mass spectrometry. Subsequently, the sensing capabilities of these probes were explored using UV-Vis and fluorescence spectroscopy, wherein their selective recognition potential was established for Pb(ii) and Cu(ii), both of which can pose serious health hazards when prevalent in the environment above permissible limits. Both the probes exhibited fairly low limits of detection (LoD), determined as 5.69 μM and 6.55 μM in the case of probe 6 for Pb(ii) and Cu(ii) respectively; whereas the probe 9 exhibited an LoD of 5.06 μM and 7.52 μM for Pb(ii) and Cu(ii), respectively. The job's plot for the probe demonstrates the formation of a 1 : 1 complex between the metal and ligand. Furthermore, the interaction of the free probes with the metal ions in the metal-ligand complex was elucidated through 1H NMR analysis and validated theoretically using Density Functional Theory (DFT) simulations with the B3LYP/6-311G++(d,p) and B3LYP/LANL2DZ basis sets for geometry optimization of the probes and their corresponding metal complexes. These findings offer a reliable approach to Cu(ii) and Pb(ii) ion detection and can be further used for the potential applications in environmental monitoring and analytical chemistry.

Synthesis, Antimicrobial Activities, and Molecular Modeling Studies of Agents for the Sortase A Enzyme

Sortase A (SrtA) is an attractive target for developing new anti-infective drugs that aim to interfere with essential virulence mechanisms, such as adhesion to host cells and biofilm formation. Herein, twenty hydroxy, nitro, bromo, fluoro, and methoxy substituted chalcone compounds were synthesized, antimicrobial activities and molecular modeling strategies against the SrtA enzyme were investigated. The most active compounds were found to be T2, T4, and T19 against Streptococcus mutans (S. mutans) with MIC values of 1.93, 3.8, 3.94 μg/mL, and docking scores of -6.46, -6.63, -6.73 kcal/mol, respectively. Also, these three active compounds showed better activity than the chlorohexidine (CHX) (MIC value: 4.88 μg/mL, docking score: -6.29 kcal/mol) in both in vitro and in silico. Structural stability and binding free energy analysis of S.mutans SrtA with active compounds were measured by molecular dynamic (MD) simulations throughout 100 nanoseconds (ns) time. It was observed that the stability of the critical interactions between these compounds and the target enzyme was preserved. To prove further, in vivo biological evaluation studies could be conducted for the most promising precursor compounds T2, T4, and T19, and it might open new avenues to the discovery of more potent SrtA inhibitors.

Enhanced intramolecular charge transfer and near-infrared fluorescence in 4-dimethylamino-chalcone analogues through extended conjugation: synthesis, photophysical properties, and theoretical modelling

The distinctive characteristics of near-infrared fluorescent organic molecules render them indispensable across diverse applications, from energy harvesting to bioimaging and sensing technologies. In this work, we continue our investigation on the chalcone derivative, 4-dimethylamino-2'-hydroxychalcone (nDHC, n = 1; where n is the number of olefinic bonds), by expanding the number of central double bonds (n = 2 (2DHC) and n = 3 (3DHC)). Additionally, we also synthesized the structurally related chalcones lacking the OH group (DC, 2DC, 3DC) in order to obtain a comprehensive understanding of their effects on the intramolecular charge transfer (ICT). The results show remarkable bathochromic shifts in absorption and fluorescence peaks in solution as n increases. These shifts, 20 nm and 35 nm for absorption and 100 nm and 200 nm for fluorescence in 2DHC and 3DHC, respectively, signify enhanced ICT and a significant increase in the excited state's dipole moment. The presence of OH groups notably amplifies these shifts due to additional electron donation, influencing solute-solvent interactions in solution. Femtosecond fluorescence upconversion and transient absoprtion techniques unraveled distinct dynamics in these derivatives, exhibiting the dominance of vibrational cooling, solvation, and intramolecular motions, particularly in the larger conjugated systems 3DHC and 3DC. The observed changes in the femtosecond transinet absorption spectra suggest the existence of new active states in extended conjugation systems, indicating diverse intramolecular conformational states contributing to their relaxation dynamics. The results of this study provide invaluable insights into excited-state spectroscopy, offering a roadmap for tailoring chalcone derivatives for specific applications.

The Synthesis of 2'-Hydroxychalcones under Ball Mill Conditions and Their Biological Activities

Chalcones are polyphenols that belong to the flavonoids family, known for their broad pharmacological properties. They have thus attracted the attention of chemists for their obtention and potential activities. In our study, a library of compounds from 2'-hydroxychalcone's family was first synthesized. A one-step mechanochemical synthesis via Claisen-Schmidt condensation reaction under ball mill conditions was studied, first in a model reaction between a 5'-fluoro-2'-hydroxyacetophenone and 3,4-dimethoxybenzaldehyde. The reaction was optimized in terms of catalysts, ratio of reagents, reaction time, and influence of additives. Among all assays, we retained the best one, which gave the highest yield of 96% when operating in the presence of 1 + 1 eq. of substituted benzaldehyde and 2 eq. of KOH under two grinding cycles of 30 min. Thus, this protocol was adopted for the synthesis of the selected library of 2'-hydroxychalcones derivatives. The biological activities of 17 compounds were then assessed against Plasmodium falciparum, Leishmania donovani parasite development, as well as IGR-39 melanoma cell lines by inhibiting their viability and proliferation. Compounds 6 and 11 are the most potent against L. donovani, exhibiting IC50 values of 2.33 µM and 2.82 µM, respectively, better than the reference drug Miltefosine (3.66 µM). Compound 15 presented the most interesting antimalarial activity against the 3D7 strain, with IC50 = 3.21 µM. Finally, chalcone 12 gave the best result against IGR-39 melanoma cell lines, with an IC50 value of 12 µM better than the reference drug Dacarbazine (IC50 = 25 µM).

Electrochemical Multicomponent Synthesis of Alkyl Alkenesulfonates using Styrenes, SO2 and Alcohols

A novel electrochemical approach to access alkyl alkenesulfonates via a multicomponent reaction was developed. The metal-free method features easy-to-use SO2 stock solution forming monoalkylsulfites from alcohols with an auxiliary base in-situ. These intermediates serve a dual role as starting materials and as supporting electrolyte enabling conductivity. Anodic oxidation of the substrate styrene, radical addition of these monoalkylsulfites and consecutive second oxidation and deprotonation preserve the double bond and form alkyl β-styrenesulfonates in a highly regio- and stereoselective fashion. The feasibility of this electrosynthetic method is demonstrated in 44 examples with yields up to 81 %, employing various styrenes and related substrates as well as a diverse set of alcohols. A gram-scale experiment underlines the applicability of this process, which uses inexpensive and readily available electrode materials.

Synthesis, molecular docking, ADMET, and evaluation of the anxiolytic effect in adult zebrafish of synthetic chalcone (E)-3-(4-(dimethylamino)phenyl)-1-(2-hydroxyphenyl)prop-2-en-1-one: An in vivo and in silico approach

BACKGROUND

Anxiety disorders represent the complex interaction between biological, psychological, temperamental, and environmental factors; drugs available to treat anxiety such as benzodiazepines (BZDs) are associated with several unwanted side effects. Although there are useful treatments, there is still a need for more effective anxiolytics with better safety profiles than BZDs. Chalcones or 1,3-diphenyl-2-proper-1-ones can be an alternative since this class of compounds has shown therapeutic potential mainly due to interactions with GABAA receptors and serotonergic system.

OBJECTIVES

This study evaluated the anxiolytic potential of chalcone (E)-3-(4-(dimethylamino)phenyl)-1-(2-hydroxyphenyl)prop-2-en-1-one (C2OHPDA) in adult zebrafish (Danio rerio) (ZFa).

METHODS

Each animal (n = 6/group) was treated intraperitoneally (i.p.; 20 μL) with the chalcone (4, 20, and 40 mg/kg) and with the vehicle (DMSO 3%; 20 μL), being submitted to the tests of locomotor activity and 96-h acute toxicity. The light/dark test was also performed, and the serotonergic mechanism (5-HT) was evaluated through the antagonists of the 5-HTR1 , 5-HTR2A/2C , and 5-HTR3A/3B receptors. It was investigated the prediction of the chalcone's position and preferential orientation concerning its receptor, as well as the pharmacokinetic parameters (ADMET) involved in the process after administration.

RESULTS

As a result, C2OHPDA was not toxic and reduced the locomotor activity of ZFa. Furthermore, chalcone demonstrated an anxiolytic effect on the central nervous system (CNS), mediated by the serotonergic system, with action on 5-HT2A and 5-HTR3A/3B receptors. The interaction of C2OHPDA with 5-HT2A R and 5-HT3A receptors was confirmed by molecular docking study, the affinity energy observed was -8.7 and -9.1 kcal/mol, respectively.

CONCLUSION

Thus, this study adds new evidence and highlights that chalcone can potentially be used to develop compounds with anxiolytic properties.

Design and synthesis of novel chloropyridazine hybrids as promising anticancer agents acting by apoptosis induction and PARP-1 inhibition through a molecular hybridization strategy

Guided by the molecular hybridization principle, a novel series of 4-chloropyridazinoxyphenyl conjugates (3a-h, 4a-e, and 5) was designed and synthesized as proposed apoptotic inducers and PARP-1 inhibitors. The growth inhibition % of the designed hybrids was investigated in eleven cancer cell lines, where the anticancer activities were found to be in the following order: 4-chloropyridazinoxyphenyl-aromatic ketones hybrids (3a-h) > 4-chloropyridazinoxyphenyl-benzyloxyphenylethan-1-one hybrids (4a-e) > 4-chloropyridazinoxyphenyl-thiazolidine-2,4-dione hybrid (5). Further, the most sensitive three cancer cell lines (HNO97, FaDu, and MDA-MB-468) were selected to measure the IC50 values of the new hybrids. Moreover, the frontier three members (3c, 3e, and 4b) were selected for the measurements of apoptotic protein markers (p53, BAX, caspase 3, caspase 6, BCL-2, and CK 18). Besides, the impact of compounds 3a-e and 4b on the activity of PARP-1 was investigated, where 3c, 3d, and 3e demonstrated comparable efficiencies to olaparib. Furthermore, γ-H2Ax, a well-established marker for double-strand DNA breaks, was examined and the occurrence of DNA damage was observed. In addition, a significant inhibition of cell proliferation and a remarkable 15 to 50-fold reduction in the number of colonies compared to the control group were recorded. Finally, the PARP-1 inhibitory potential of the novel hybrids was compared to the co-crystal of the target receptor (PDB ID: 6NTU) using molecular docking.

The effect of novel nitrogen-based chalcone analogs on colorectal cancer cells: Insight into the molecular pathways

In colorectal cancer (CRC), aberrations in KRAS are associated with aggressive tumorigenesis and an overall low survival rate because of chemoresistance and adverse effects. Ergo, complementary, and integrative medicines are being considered for CRC treatment. Among which is the use of natural chalcones that are known to exhibit anti-tumor activities in KRAS mutant CRC subtypes treatment regimens. Consequently, we examine the effect of two novel compounds (DK13 and DK14) having chalcones with nitrogen mustard moiety on CRC cell lines (HCT-116 and LoVo) with KRAS mutation. These compounds were synthesized in our lab and previously reported to exhibit potent activity against breast cancer cells. Our data revealed that DK13 and DK14 treatment suppress cell growth, disturb the progression of cell cycle, and trigger apoptosis in CRC cell lines. Besides, treatment with both compounds impedes cell invasion and colony formation in both cell lines as compared to 5-FU; this is accompanied by up and down regulations of E-cadherin and Vimentin, respectively. At the molecular level, both compounds deregulate the expression and phosphorylation of β-catenin, Akt and mTOR, which are the main likely molecular mechanisms underlying these biological occurrences. Our findings present DK13 and DK14 as novel chemotherapies against CRC, through β-catenin/Akt/mTOR signaling pathways.

Design, Synthesis, and In Vivo Evaluation of a New Series of Indole-Chalcone Hybrids as Analgesic and Anti-Inflammatory Agents

Indole-chalcone hybrids have burst into prominence as potent weapons in the battle against pain and inflammation due to their unique features, allowing these ligands to form pivotal interactions with biological targets. In this context, the base-catalyzed Claisen-Schmidt condensation of 3',4'-(methylenedioxy)acetophenone with heteroaromatic aldehydes carrying an indole scaffold yielded new chalcones (1-7). The central and peripheral antinociceptive activities of all chalcones (compounds 1-7) at the dose of 10 mg/kg (i.p.) were evaluated by hot plate (supraspinal response), tail immersion (spinal response), and acetic acid-induced writhing tests in mice. The anti-inflammatory activities of compounds 1-7 were also investigated by means of a carrageenan-induced mouse paw edema model. The results revealed that compounds 1-7 extended the latency of response to thermal stimulus significantly in a hot-plate test similar to dipyrone (300 mg/kg; i.p.), the positive control drug. However, only compounds 2-7 were found to be significantly effective in the tail-immersion test. Compounds 1-7 also significantly showed analgesic effect by reducing the number of writhes and anti-inflammatory activity by inhibiting edema formation at different time intervals and levels. 1-(1,3-Benzodioxol-5-yl)-3-(1-methyl-1H-indol-2-yl)prop-2-en-1-one (4) drew attention by providing the highest efficacy results in both acute analgesia and inflammation models. Based on the in silico data acquired from the QikProp module, compound 4 was predicted to possess favorable oral bioavailability and drug-like properties. Taken together, it can be concluded that chalcones (1-7), especially compound 4, are outstanding candidates for further research to investigate their potential use in the management of pain and inflammation.

A decade of advances in the study of buckwheat for organic farming and agroecology (2013-2023)

During the last decade, research has shown the environment and human health benefits of growing buckwheat (Fagopyrum spp.). This comprehensive review aims to summarize the major advancements made in the study of buckwheat from 2013 to 2023, focusing on its agronomic characteristics, nutritional value, and potential applications in sustainable agriculture. The review examines the diverse applications of buckwheat in organic and agroecological farming systems, and discusses the ability of buckwheat to control weeds through allelopathy, competition, and other sustainable farming methods, such as crop rotation, intercropping and green manure, while improving soil health and biodiversity. The review also explores the nutritional value of buckwheat. It delves into the composition of buckwheat grains, emphasizing their high protein content, and the presence of essential amino acids and valuable micronutrients, which is linked to health benefits such as lowering cholesterol levels, controlling diabetes and acting against different types of cancer, among others. Finally, the review concludes by highlighting the gaps in current knowledge, and proposing future research directions to further optimize buckwheat production in organic or agroecological farming systems. It emphasizes the need for interdisciplinary collaboration, and the integration of traditional knowledge with modern scientific approaches to unlock the full potential of buckwheat as a sustainable crop.

Design, synthesis and in silico insights of novel 1,2,3-triazole benzenesulfonamide derivatives as potential carbonic anhydrase IX and XII inhibitors with promising anticancer activity

Novel 1,2,3-triazole benzenesulfonamide derivatives were designed as inhibitors for the tumor- related hCA IX and XII isoforms. Most of the synthesized compounds showed good inhibitory activity against hCA IX and hCA XII isoforms. Compounds 4d, 5h and 6b, exhibited remarkable activity as hCA IX inhibitors, with Ki values in the range of 0.03 to 0.06 µM, more potent than AAZ. Additionally, compounds 5b and 6d, efficiently inhibited hCA XII isoform, with Ki value of 0.02 µM, respectively, similar to AAZ. Further investigation for those potent derivatives against MCF-7, Hep-3B and WI-38 cell lines was achieved. Compounds 4d and 6d exerted dual cytotoxic activity against MCF-7 and Hep-3B cell lines, with IC50 values of 3.35 & 2.12 µM against MCF-7 cell line and 1.72 & 1.56 µM against Hep-3B cell line, with high SI values ranged from 8.92 to 17.38 on both of the cell lines. Besides, they showed a high safety profile against normal human cell line, WI-38. Moreover, compound 5h had better cytotoxic effect on MCF-7 than the reference, DOX, with IC50 value of 4.02 µM. While, compounds 5b and 6b showed higher activity against Hep-3B if compared to the reference drug, 5-FU. From ADME study, compounds 4d, 5b, 6b and 6d obeyed Lipinski's rule of five, and they might be orally active derivatives, while, compound 5h exerted less oral bioavailability than the reference standard acetazolamide. Molecular docking and MDS studies predicted the binding mode and the stability of the target compounds inside hCA IX and hCA XII active sites, especially for compounds 5b and 6b.

Recent Trends in the Synthesis and Bioactivity of Coumarin, Coumarin-Chalcone, and Coumarin-Triazole Molecular Hybrids

Molecular hybridization represents a new approach in drug discovery in which specific chromophores are strategically combined to create novel drugs with enhanced therapeutic effects. This innovative strategy leverages the strengths of individual chromophores to address complex biological challenges, synergize beneficial properties, optimize pharmacokinetics, and overcome limitations associated with single-agent therapies. Coumarins are documented to possess several bioactivities and have therefore been targeted for combination with other active moieties to create molecular hybrids. This review summarizes recent (2013-2023) trends in the synthesis of coumarins, as well as coumarin-chalcone and coumarin-triazole molecular hybrids. To cover the wide aspects of this area, we have included differently substituted coumarins, chalcones, 1,2,3- and 1,2,4-triazoles in this review and considered the point of fusion/attachment with coumarin to show the diversity of these hybrids. The reported syntheses mainly relied on well-established chemistry without the need for strict reaction conditions and usually produced high yields. Additionally, we discussed the bioactivities of the reported compounds, including antioxidative, antimicrobial, anticancer, antidiabetic, and anti-cholinesterase activities and commented on their IC50 where possible. Promising bioactivity results have been obtained so far. It is noted that mechanistic studies are infrequently found in the published work, which was also mentioned in this review to give the reader a better understanding. This review aims to provide valuable information to enable further developments in this field.

Photoinduced, Metal-Free Hydroacylation of Aromatic Alkynes for Synthesis of α,β-Unsaturated Ketones via C(sp3)-H Functionalization

Despite the notable advancements made over the past decade in achieving carbon-carbon bonds by transition-metal-catalyzed cross-coupling processes, metal-free cross-coupling reactions for hydroacylation of aromatic alkynes via C(sp3)-H functionalization are still rare and highly desired. Here we report a metal-free reliable approach for the synthesis of α,β-unsaturated ketones (chalcones) via C(sp3)-H functionalization using MeCN:H2O as green solvent, Eosin Y as organic photocatalyst, and ambient air as oxidant. More significantly, this strategy can effectively transform a variety of methyl arenes and aromatic alkynes into the desired product. With high atom efficiency, use of green solvents, metal-free nature, environmental friendliness, and visible light as a renewable energy source, this method is compatible with biologically active molecules.

Chalcone-Based Synthesis of Tetrahydropyridazines via Cloke-Wilson-Type Rearrangement-Involved Tandem Reaction between Cyclopropyl Ketones and Hydrazines

A facile and efficient approach for the synthesis of multisubstituted tetrahydropyridazines starting from cyclopropyl ketones and hydrazines has been developed. The transformation is chalcone-based and takes place via a Cloke-Wilson-type rearrangement-involved tandem reaction catalyzed by TfOH in HFIP.

Palladium-Catalyzed Reductive Heck Hydroarylation of Unactivated Alkenes Using Hydrosilane at Room Temperature

The reductive Heck hydroarylation of unactivated alkenes has emerged as an essential reaction for regioselective hydroarylation. Herein, we report a palladium-catalyzed reductive Heck hydroarylation of unactivated alkenes under mild conditions with enhanced functional group tolerance using hydrosilane as the reducing reagent. Under the optimal conditions, the alkylarene yields increased, resulting in minimal undesired products. Mechanistic studies using deuterated reagents indicated the involvement of two competing catalytic cycles.

Natural Products Inhibition of Cytochrome P450 2B6 Activity and Methadone Metabolism

Methadone is cleared predominately by hepatic cytochrome P450 (CYP) 2B6-catalyzed metabolism to inactive metabolites. CYP2B6 also catalyzes the metabolism of several other drugs. Methadone and CYP2B6 are susceptible to pharmacokinetic drug-drug interactions. Use of natural products such as herbals and other botanicals is substantial and growing, and concomitant use of prescription medicines and non-prescription herbals is common and may result in interactions, often precipitated by CYP inhibition. Little is known about herbal product effects on CYP2B6 activity, and CYP2B6-catalyzed methadone metabolism. We screened a family of natural product compounds used in traditional medicines, herbal teas, and synthetic analogs of compounds found in plants, including kavalactones, flavokavains, chalcones and gambogic acid, for inhibition of expressed CYP2B6 activity and specifically inhibition of CYP2B6-mediated methadone metabolism. An initial screen evaluated inhibition of CYP2B6-catalyzed 7-ethoxy-4-(trifluoromethyl) coumarin O-deethylation. Hits were further evaluated for inhibition of racemic methadone metabolism, including mechanism of inhibition and kinetic constants. In order of decreasing potency, the most effective inhibitors of methadone metabolism were dihydromethysticin (competitive, K i 0.074 µM), gambogic acid (noncompetitive, K i 6 µM), and 2,2'-dihydroxychalcone (noncompetitive, K i 16 µM). Molecular modeling of CYP2B6-methadone and inhibitor binding showed substrate and inhibitor binding position and orientation and their interactions with CYP2B6 residues. These results show that CYP2B6 and CYP2B6-catalyzed methadone metabolism are inhibited by certain natural products, at concentrations which may be clinically relevant. SIGNIFICANCE STATEMENT: This investigation identified several natural product constituents which inhibit in vitro human recombinant CYP2B6 and CYP2B6-catalyzed N-demethylation of the opioid methadone. The most potent inhibitors (K i) were dihydromethysticin (0.074 µM), gambogic acid (6 µM) and 2,2'-dihydroxychalcone (16 µM). Molecular modeling of ligand interactions with CYP2B6 found that dihydromethysticin and 2,2'-dihydroxychalcone bound at the active site, while gambogic acid interacted with an allosteric site on the CYP2B6 surface. Natural product constituents may inhibit CYP2B6 and methadone metabolism at clinically relevant concentrations.

Synthesis and biological evaluation of 2'-hydroxychalcone derivatives as AMPK activators

A series of 2'-hydroxychalcone derivatives with various substituents on B-ring were synthesized and evaluated for AMP-activated protein kinase (AMPK) activation activity in podocyte cells. The results displayed that hydroxy, methoxy and methylenedioxy groups on B-ring could enhance the activitiy better than O-saturated alkyl, O-unsaturated alkyl or other alkoxy groups. Compounds 27 and 29 possess the highest fold change of 2.48 and 2.73, respectively, which were higher than those of reference compound (8) (1.28) and metformin (1.88). Compounds 27 and 29 were then subjected to a concentration-response study to obtain the EC50 values of 2.0 and 4.8 µM, respectively and MTT assays also showed that cell viability was not influenced by the exposure of podocytes to compounds 27 and 29 at concentrations up to 50 μM. In addition, compound 27 was proved to activate AMPK via calcium/calmodulin-dependent protein kinase kinase β (CaMKKβ)-dependent pathway without affecting intracellular calcium levels. The computational study showed that the potent compounds exhibited stronger ligand-binding strength to CaMKKβ, particularly compounds 27 (-8.4 kcal/mol) and 29 (-8.0 kcal/mol), compared to compound 8 (-7.5 kcal/mol). Fragment molecular orbital (FMO) calculation demonstrated that compound 27 was superior to compound 29 due to the presence of methyl group, which amplified the binding by hydrophobic interactions. Therefore, compound 27 would represent a promising AMPK activator for further investigation of the treatment of diabetes and diabetic nephropathy.

Chalcone derivatives' interaction with human serum albumin and cyclooxygenase-2

Chalcone derivatives are an extremely valuable class of compounds, primarily due to the keto-ethylenic group, CO-CH[double bond, length as m-dash]CH-, they contain. Moreover, the presence of a reactive α,β-unsaturated carbonyl group confers upon them a broad range of pharmacological properties. Recent developments in heterocyclic chemistry have led to the synthesis of chalcone derivatives, which have been biologically investigated for their activity against certain diseases. In this study, we investigated the binding of new chalcone derivatives with COX-2 (cyclooxygenase-2) and HSA (Human Serum Albumin) using spectroscopic and molecular modeling studies. COX-2 is commonly found in cancer and plays a role in the production of prostaglandin E (2), which can help tumors grow by binding to receptors. HSA is the most abundant protein in blood plasma, and it transports various compounds, including hormones and fatty acids. The conformation of chalcone derivatives in the HSA complex system was established through fluorescence steady and excited state spectroscopy techniques and FTIR analyses. To gain a more comprehensive understanding, molecular docking, and dynamics were conducted on the target protein (COX-2) and transport protein (HSA). In addition, we conducted density-functional theory (DFT) and single-point DFT to understand intermolecular interaction in protein active sites.