Recent developments in biological activities of chalcones: a mini review

Chemoproteomics unveils Sofalcone targeting ribosomal proteins to inhibit protein synthesis in Staphylococcus aureus

The escalating threat of antibiotic resistance, particularly in Staphylococcus aureus (including methicillin-resistant strains, MRSA), underscores the urgent need for novel therapeutics. Sofalcone (Sof), a chalcone derivative from Sophora subprostrata with established anti-inflammatory and anti-ulcer properties, exhibits promising yet underexplored antibacterial activity. Here, we demonstrate that Sof potently inhibits S. aureus and MRSA while showing minimal cytotoxicity in human cells. Notably, Sof synergized with amoxicillin, and significantly reduced the pathogenicity of S. aureus through inhibiting biofilm formation addressing key virulence factors. Through chemoproteomic profiling using a clickable Sof-derived probe, ribosomal proteins, specifically the 50S subunit protein rplB, were identified as primary targets. Sof covalently binds to rplB via cysteine residues, as validated by cellular thermal shift assays, microscale thermophoresis, and competition assays. Bio-orthogonal noncanonical amino acid tagging revealed that Sof disrupts bacterial protein synthesis by impairing ribosomal function, a mechanism distinct from conventional antibiotics. In a murine model of S. aureus-induced acute lung injury, Sof greatly reduced bacterial load in lungs, attenuated systemic inflammation, and mitigated histopathological damage. Its dual antibacterial and anti-inflammatory efficacy, coupled with activity against Gram-negative Escherichia coli, highlights broad-spectrum potential. This study unveils a covalent ribosomal-targeting strategy, positioning Sof as a multifaceted candidate against multidrug-resistant infections. Our findings bridge natural product pharmacology and mechanistic antimicrobial discovery, offering a template for combating the global antibiotic resistance crisis.

Diverse pharmacological activities of β-carbolines: Substitution patterns, SARs and mechanisms of action

β-Carbolines, a class of indole-containing heterocyclic alkaloids, are widely distributed in nature and possess diverse bioactivities, making them promising drug candidates against a wide range of diseases. The remarkable medicinal potential of β-carbolines has spurred the pharmaceutical research community to study their derivatives extensively. This review updates the development of β-carboline derivatives in recent years (2015-2024), particularly with a focus on their anticancer, antiparasitic, antimicrobial, antiviral, and neuroprotective properties, based on the modification approaches such as substitution on indole N (ring B), pyridine or its reduced forms (ring C), and dimerization of β-carbolines. Moreover, the mechanisms of action and structure-activity relationships of these β-carboline derivatives are highlighted to offer valuable insights on the design and development of new β-carbolines with better pharmacological activities.

Ultrasound-Assisted Synthesis of Substituted Chalcone-Linked 1,2,3-Triazole Derivatives as Antiproliferative Agents: In Vitro Antitumor Activity and Molecular Docking Studies

The synthesis of (E)-1-(1-benzyl-5-methyl-1H-1,2,3-triazol-4-yl)-3-phenyl-2-propen-1-one derivatives was carried out in two steps, using benzylic chloride derivatives as starting material. The structural determination of intermediates and final products was performed by spectroscopic methods: infrared spectroscopy, nuclear magnetic resonance spectroscopy and mass spectrometry (IR, NMR, and MS). In vitro evaluation of cytotoxic activity on adherent and non-adherent cells showed that triazole chalcones exhibited significant activity against three of the five cell lines studied: non-Hodgkin lymphoma U937, glioblastoma multiform tumor T98G, and gallbladder cancer cells Gb-d1. In contrast, the cytotoxic activity observed for cervical cancer HeLa and gallbladder adenocarcinoma G-415 was considerably lower. Additionally, in the cell lines where activity was observed, some compounds demonstrated an In vitro inhibitory effect superior to that of the control, paclitaxel. Molecular docking studies revealed specific interactions between the synthesized ligands and therapeutic targets in various cell lines. In U937 cells, compounds 4a and 4c exhibited significant inhibition of vascular endothelial growth factor receptor (VEGFR) kinase, correlating with their biological activity. This effect was attributed to favorable interactions with key residues in the binding site. In T98G cells, compounds 4r and 4w showed affinity for transglutaminase 2 (TG2) protein, driven by their ability to form hydrophobic interactions. In Gb-d1 cells, compounds 4l and 4p exhibited favorable interactions with mitogen-activated protein kinase (MEK) protein, similar to those observed with the known inhibitor selumetinib. In HeLa cells, compounds 4h and 4g showed activity against dihydrofolate reductase (DHFR) protein, driven by hydrogen bonding interactions and favorable aromatic ring orientations. On the other hand, compounds 4b and 4t exhibited no activity, likely due to unfavorable interactions related to halogen substitutions in the aromatic rings.

Antimicrobial and anti-biofilm activity of a mucoadhesive hydrogel functionalized with aminochalcone on titanium surfaces and in Galleria mellonella model: In vitro and in vivo study

Peri-implantitis associated with dental implants shares characteristics with destructive periodontal diseases. Both conditions are multifactorial and strongly correlated with the presence of microorganisms surrounding the prostheses or natural dentition. This study aimed to evaluate the antimicrobial activity and toxicity of a mucoadhesive hydrogel functionalized with aminochalcone (HAM-15) against Aggregatibacter actinomycetemcomitans, Fusobacterium periodonticum, Prevotella intermedia, Porphyromonas gingivalis, Tannerella forsythia, and Candida albicans. Various experiments were conducted to determine the minimum inhibitory concentrations (MIC) and minimum bactericidal/fungicidal concentrations (MBC/MFC), as well as the antibiofilm potential and toxicity in human gingival fibroblasts and a G. mellonella animal model. Infection and treatment studies were also performed in G. mellonella. The results demonstrated that both aminochalcone (AM-15) and the aminochalcone-functionalized hydrogel (HAM-15) exhibited antimicrobial activity, with MICs ranging from 7.8 to 31.2 μg/mL for the tested strains. Treatment with HAM-15 at 300 μg/mL reduced the monospecies biofilm of C. albicans and P. gingivalis by 7 log10 and 6 log10, respectively, and the mixed-species biofilm of these microorganisms by 7 log10 and 8 log10, respectively. Regarding toxicity, HAM-15 showed cytotoxic effects on human gingival fibroblasts at high concentrations, but in the G. mellonella model, survival was 70 % at a dose of 1 mg/mL. Additionally, AM-15, when administered after larval infection, protected 90 % of the animals (p < 0.05). These results suggest that AM-15 is a promising candidate for the prevention and treatment of anaerobic infections and yeasts, demonstrating significant antimicrobial efficacy and an acceptable safety profile in experimental models.

N-Heterocyclic functionalized chalcone derivatives as anti-inflammatory agents for atopic dermatitis treatment by inhibiting JAK1/STAT3 signaling pathway

Atopic dermatitis (AD) is difficult to cure as a chronic inflammatory skin disease. In the present study, a series of N-heterocyclic functionalized chalcone derivatives have been prepared to investigate their in vitro and in vivo anti-inflammatory activities. The results indicated that many derivatives could effectively inhibit NO generation with low toxicity. In vivo studies revealed that 4f could improve the skin condition of AD-like mice, reduce inflammatory infiltration, inhibit the expressions of p-JAK1/JAK1 and p-STAT3/STAT3, and mitigate the excessive immune response on MC903-induced AD-like mice. The molecular docking study indicated that 4f had an obvious binding site with the target 4ehz and 6QHD. Therefore, these derivatives may be considered as potent agents for AD treatment by inhibiting JAK1/STAT3 signaling pathway.

Microwave-Assisted Synthesis of Near-Infrared Chalcone Dyes: a Systematic Approach

(E)-3-[4-(Dimethylamino)phenyl]-1-(2-hydroxyphenyl)prop-2-en-1-one is an organic dye with potential application in dye-sensitized solar cells. In order to fully investigate and characterize this molecule, many synthetic approaches were applied, including base and acid-catalyzed synthetic methodologies. NaOH, KOH, Ba(OH)2·8H2O, K2CO3, Et3N, SOCl2, HCl, HOAc, and Ac2O were utilized in different solvents and reaction conditions; however, all attempts failed to access the desired product in an efficient and productive way. A good success was achieved employing excess of piperidine, as base in refluxing ethanol. The reaction completed in 3 days; however, the product was obtained in 85% purity. In order to minimize the formation of side products, and taking in consideration a greener approach, such as shortening the extended reaction time and reducing excess production of organic wastes, the reaction was performed under controlled microwave reaction conditions. With greater success, the desired product was obtained in excellent isolated yield and high purity, in a shorter reaction time. This novel approach was then explored to investigate its scope and limitations to access other chalcone dyes.

Microplate Reader-TLC-HPLC-UPLC-MS: A Rapid Screening Strategy for Isoliquiritigenin-Transforming Bacteria

This article primarily develops a new technology for the rapid large-scale screening of isoliquiritigenin-transforming strains based on the MTHM (microplate reader-TLC-HPLC-UPLC-MS) method. ISO is a chalcone compound with potential pharmacological activity, and its rich substitution sites on the benzene ring provide a solid foundation for structural modification and drug development. This study screened approximately 1500 strains and employed a microplate reader, thin-layer chromatography, high-performance liquid chromatography, and mass spectrometry to verify the transformation products, identifying 15 strains with significant transformation capabilities. This study demonstrates that the optimized MTHM method is efficient and reliable, capable of rapidly detecting subtle structural changes in flavonoids before and after microbial transformation. During the transformation process, bioactive flavonoid compounds, such as amentoflavone and 5'-methoxyflavonoid, were discovered. Additionally, the experiments revealed that Czapek medium, modified Martin medium, and LB medium exhibited high efficiency in screening transforming strains. This research provides new technical approaches for ISO structural optimization and drug development while highlighting the important application potential of microbial transformation in natural product development. Future studies could further explore the metabolic potential of these strains, optimize transformation conditions, and promote the application of ISO in the medical field.

Tubulin/HDAC dual-target inhibitors: Insights from design strategies, SARs, and therapeutic potential

Microtubules, one of the cytoskeletons in eukaryotic cells, maintain the proper operation of several cellular functions. Additionally, they are regulated by the acetylation of HDAC6 and SIRT2 which affects microtubule dynamics. Given the fact that tubulin and HDAC inhibitors play a synergistic effect in the treatment of many cancers, the development of tubulin/HDAC dual-target inhibitors is conducive to addressing multiple limitations including drug resistance, dose toxicity, and unpredictable pharmacokinetic properties. At present, tubulin/HDAC dual-target inhibitors have been obtained in three main ways: uncleavable linked pharmacophores, cleavable linked pharmacophores, and modification of single-target drugs. Their therapeutic efficacy has been verified in vivo and in vitro assays. In this article, we reviewed the research progress of tubulin/HDAC dual inhibitors from design strategies, SARs, and biological activities, which may provide help for the discovery of novel tubulin/HDAC dual inhibitors.

Chalcone-based imidazo[2,1-b]thiazole derivatives: synthesis, crystal structure, potent anticancer activity, and computational studies

In this work, two novel chalcone-based imidazothiazole derivatives ITC-1 and ITC-2 were synthesized and characterized by 1H NMR, 13C NMR and high-resolution mass spectrometry with electrospray ionization, and chemical structure of ITC-1 was confirmed by single-crystal X-ray diffraction. Also, the anticancer activity of ITC-1 and ITC-2 was evaluated. First, antiproliferative activity tests were performed against cancer cells namely, human-derived breast adenocarcinoma (MCF-7), lung carcinoma (A-549), and colorectal adenocarcinoma (HT-29) cell lines, and mouse fibroblast healthy cell line (3T3-L1) by XTT assay. Afterward, mitochondrial membrane disruption (MMP), caspase activity, and apoptosis tests were performed on MCF-7 cells to elucidate the anticancer mechanism of action of the test compounds by flow cytometry analysis. XTT results revealed that both compounds exhibited a very high degree of antiproliferative effects on each tested cancer cell line with very low IC50 values while showing much lower antiproliferation on 3T3-L1 normal cells with much higher IC50 values. Besides, ITC-2 was determined to have a striking cytotoxic power competing with the chemotherapeutic drug carboplatin. Flow cytometry results demonstrated the mitochondrial-mediated apoptotic effects of both compounds through membrane disruption and multi-caspase activation in MCF-7 cells. Finally, molecular docking studies were performed to determine the structural understanding of the test compounds by their interactions on caspase-3 and DNA dodecamer enzymes, respectively. The interactions between the compound and the crystal structure were determined according to parameters such as free binding energies (ΔGBind), Glide score values, and determination of the active binding site. The obtained data suggest that ITC-1 and ITC-2 may be considered remarkable anticancer drug candidates. In addition to molecular docking via in silico approaches, the pharmacokinetic properties of compounds ITC-1 and ITC-2 were calculated using the Schrödinger 2021-2 Qikprop wizard.Communicated by Ramaswamy H. Sarma.

Comprehensive Insight into Green Synthesis Approaches, Structural Activity Relationship, and Therapeutic Potential of Pyrazolic Chalcone Derivative

Pyrazolic chalcone exhibits diverse therapeutic activities, including anti-inflammatory, antioxidant, antimicrobial, antitumor, and anti-diabetic properties. Structural activity relationship (SAR) studies play a crucial role in understanding the molecular aspects governing their biological effects, guiding the rational design of derivatives with enhanced efficacy and reduced side effects. This review provides an overview of pyrazolic chalcone derivatives, emphasizing their synthesis through both conventional and green methods. In comparison, conventional synthesis methods have been widely employed in the past for the production of pyrazolic chalcones, often relying on traditional chemical processes that may involve the use of hazardous reagents and generate significant waste. On the other hand, green synthesis methods, in harmony with the growing emphasis on sustainable practices in drug discovery, offer a more environmentally friendly alternative. Green synthesis typically involves the use of eco-friendly reagents, solvents, and energy-efficient processes, resulting in reduced environmental impact and improved resource efficiency. Overall, pyrazolic chalcone derivatives represent a promising class of compounds with significant potential for therapeutic applications.

Three Dihydroquinolin-4-one Derivatives as Potential Biodiesel Additives: From the Molecular Structure to Machine Learning Approach

Biodiesel offers an alternative to fossil fuels, primarily because it is derived from renewable sources, with the potential to mitigate issues such as pollutant and greenhouse gas emissions, resource scarcity, and the market instability of petroleum derivatives. However, lower durability and stability pose challenges. To address this, researchers worldwide are exploring technologies that employ specific molecules to slow down biodiesel's oxidation process, thereby preserving its key physicochemical properties. This study investigates heterocyclic dihydroquinolinone derivatives as potential additives to enhance the oxidative stability of diesel-biodiesel blends. Comprehensive structural and computational analyses were carried out by density functional theory to investigate the reactivity aspects of these compounds as potential additive candidates. The supramolecular arrangements were predominantly stabilized by weak molecular interactions, such as C-H···O and C-H···π, which are associated with antioxidant and antibacterial properties. We demonstrate that these groups can act as electron-donating or electron-withdrawing substituents. We explored frontier molecular orbitals, which provide insights into chemical reactivity, acidity, basicity, and the best oxidizing and reducing agents. Finally, the molecular chemical potential maps indicate the nucleophilic and electrophilic regions and the Fukui indices show the sites of nucleophilic, electrophilic, and radical attacks. This comprehensive study paves the way to understanding how dihydroquinolinone-based compounds serve as alternatives for fuel additives.

Novel polycyclic "turn-on" and "turn-off" pyrazoline and pyrazole fluorescent sensors for selective real-world monitoring of Fe3+/Fe2+ in aqueous environments

Seven novel polycyclic pyrazoline and pyrazole sensors were synthesised and screened for useful photophysical properties with pyrazoline 2 and pyrazole 7, displaying an Fe3+ "turn-off" response in aqueous environments with Fe3+ limits of detection (LoD) of 2.12 μM and 3.41 μM, respectively. Both 2 and 7 sensors functioned in aqueous environments with real-world examples of Fe3+ detection in tap water and mineral water samples. 2 and 7 are suitable for the detection of Fe3+ at concentrations below the maximum iron limits for drinking water set by the Environmental Protection Agency (EPA) and European Union (EU).

Chalcones induce apoptosis, autophagy and reduce spreading in osteosarcoma 3D models

Osteosarcoma is the most common primary bone malignancy with a challenging prognosis marked by a high rate of metastasis. The limited success of current treatments may be partially attributed to an incomplete understanding of osteosarcoma pathophysiology and to the absence of reliable in vitro models to select the best molecules for in vivo studies. Among the natural compounds relevant for osteosarcoma treatment, Licochalcone A (Lic-A) and chalcone derivatives are particularly interesting. Here, Lic-A and selected derivatives have been evaluated for their anticancer effect on multicellular tumor spheroids from MG63 and 143B osteosarcoma cell lines. A metabolic activity assay revealed Lic-A, 1i, and 1k derivatives as the most promising candidates. To delve into their mechanism of action, caspase activity assay was conducted in 2D and 3D in vitro models. Notably, apoptosis and autophagic induction was generally observed for Lic-A and 1k. The invasion assay demonstrated that Lic-A and 1k possess the ability to mitigate the spread of osteosarcoma cells within a matrix. The effectiveness of chalcone as a natural scaffold for generating potential antiproliferative agents against osteosarcoma has been demonstrated. In particular, chalcones exert their antiproliferative activity by inducing apoptosis and autophagy, and in addition they are capable of reducing cell invasion. These findings suggest Lic-A and 1k as promising antitumor agents against osteosarcoma cells.

Design, synthesis and potent anti-pancreatic cancer activity of new pyrazole derivatives bearing chalcone, thiazole and thiadiazole moieties: gene expression, DNA fragmentation, cell cycle arrest and SAR

Less than 5% of pancreatic cancer patients survive for more than five years after diagnosis. Therefore, there is an urgent need for novel therapeutic drugs to treat pancreatic cancer. Herein, we report the synthesis and full characterization of fifteen novel pyrazole derivatives bearing chalcone (4-10), thiazole (16-19) and thiadiazole (23-26) moieties. All the newly synthesized pyrazole derivatives were tested in vitro as anti-cancer agents against pancreatic cancer (PaCa-2), breast cancer (MCF-7), prostate cancer (PC3), and normal cell lines (BJ1). Three pyrazolyl-chalcone derivatives (4, 5, and 7) and a pyrazolyl-thiadiazole derivative (25) showed potent anti-cancer activity against the PaCa-2 cell line with IC50 values of 13.0, 31.5, 24.9, and 5.5 μg mL-1, respectively, compared with doxorubicin (IC50 = 28.3 μg mL-1). Compound 25 showed potent anti-cancer activity against the PC3 cell line with an IC50 value of 11.8 μg mL-1. In contrast, compounds 4, 5 and 7 are safer against the normal human-cell line (BJ1) with IC50 values of 74.2, 76.6 and 81.1 μg mL-1, respectively, compared with compound 25, which has an IC50 value of 23.7 μg mL-1. The mechanism of action of compounds 4, 5 and 7 against pancreatic cancer cells was studied by investigating gene expression, DNA fragmentation, comet assay and flow cytometry experiments using doxorubicin as a reference drug. Moreover, the structure-activity relationship between the structures of these compounds and their biological properties was discussed.

Synthesis and Biochemical Evaluation of Ethanoanthracenes and Related Compounds: Antiproliferative and Pro-Apoptotic Effects in Chronic Lymphocytic Leukemia (CLL)

Chronic lymphocytic leukemia (CLL) is a malignancy of mature B cells, and it is the most frequent form of leukemia diagnosed in Western countries. It is characterized by the proliferation and accumulation of neoplastic B lymphocytes in the blood, lymph nodes, bone marrow and spleen. We report the synthesis and antiproliferative effects of a series of novel ethanoanthracene compounds in CLL cell lines. Structural modifications were achieved via the Diels-Alder reaction of 9-(2-nitrovinyl)anthracene and 3-(anthracen-9-yl)-1-arylprop-2-en-1-ones (anthracene chalcones) with dienophiles, including maleic anhydride and N-substituted maleimides, to afford a series of 9-(E)-(2-nitrovinyl)-9,10-dihydro-9,10-[3,4]epipyrroloanthracene-12,14-diones, 9-(E)-3-oxo-3-phenylprop-1-en-1-yl)-9,10-dihydro-9,10-[3,4]epipyrroloanthracene-12,14-diones and related compounds. Single-crystal X-ray analysis confirmed the structures of the novel ethanoanthracenes 23f, 23h, 24a, 24g, 25f and 27. The products were evaluated in HG-3 and PGA-1 CLL cell lines (representative of poor and good patient prognosis, respectively). The most potent compounds were identified as 20a, 20f, 23a and 25n with IC50 values in the ranges of 0.17-2.69 µM (HG-3) and 0.35-1.97 µM (PGA-1). The pro-apoptotic effects of the potent compounds 20a, 20f, 23a and 25n were demonstrated in CLL cell lines HG-3 (82-95%) and PGA-1 (87-97%) at 10 µM, with low toxicity (12-16%) observed in healthy-donor peripheral blood mononuclear cells (PBMCs) at concentrations representative of the compounds IC50 values for both the HG-3 and PGA-1 CLL cell lines. The antiproliferative effect of the selected compounds, 20a, 20f, 23a and 25n, was mediated through ROS flux with a marked increase in cell viability upon pretreatment with the antioxidant NAC. 25n also demonstrated sub-micromolar activity in the NCI 60 cancer cell line panel, with a mean GI50 value of 0.245 µM. This ethanoanthracene series of compounds offers potential for the further development of lead structures as novel chemotherapeutics to target CLL.

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.

The metabolomics analysis of cecal contents elucidates significant metabolites involved in the therapeutic effects of total flavonoids derived from Sonchus arvensis L. in male C57BL/6 mice with ulcerative colitis

Ulcerative colitis (UC), an inflammatory disease affecting the colon and rectal mucosa, is characterized by chronic and heterogeneous behavior of unknown origin. The primary cause of UC is chronic inflammation, which is closely linked to the development of colorectal cancer. Sonchus arvensis L. (SAL), a plant consumed worldwide for its nutritional and medicinal properties, holds significance in this context. In this study, we employed the total flavone in SAL as a treatment for male C57BL/6 mice with UC. The cecal contents metabolic profile of C57BL/6 mice in different groups, including UC (group ML; n = 5), UC treated with aspirin (group AN; n = 5), UC treated with the total flavone in SAL (group FE; n = 5), and healthy male C57BL/6 mice (group CL; n = 5), was examined using UHPLC-Triple-TOF-MS. Through the identification of variations in key metabolites associated with UC and the exploration of their underlying biological mechanisms, our understanding of the pathological processes underlying this condition has been enhanced. This study identified a total of seventy-three metabolites that have a significant impact on UC. Notably, the composition of total flavone in SAL, a medication used for UC treatment, differs from that of aspirin due to the presence of four distinct metabolites (13,14-Dihydro-15-keto-PGE2, Prostaglandin I2 (PGI2), (20R,22R)-20,22-dihydroxycholesterol, and PS (18:1(9Z)/0:0)). These metabolites possess unique characteristics that set them apart. Moreover, the study identified a total of eleven pathways that were significantly enriched in mice with UC, including Aminoacyl-tRNA biosynthesis, Valine, leucine and isoleucine biosynthesis, Linoleic acid metabolism, PPAR signaling pathway, mTOR signaling pathway, Valine, leucine and isoleucine degradation, Lysine degradation, VEGF signaling pathway, Melanogenesis, Endocrine and other factor-regulated calcium reabsorption, and Cocaine addiction. These findings contribute to a better understanding of the metabolic variations in UC following total flavonoids of SAL therapy and provide valuable insights for the treatment of UC.Keywords: Ulcerative colitis; Total flavonoids of Sonchus arvensis L.; Key metabolites; Metabonomics; Cecal contents of male C57BL/6 mice.

Bioprospecting, Synergistic Antifungal and Toxicological Aspects of the Hydroxychalcones and Their Association with Azole Derivates against Candida spp. for Treating Vulvovaginal Candidiasis

Vulvovaginal candidiasis (VVC) remains a prevalent fungal disease, characterized by challenges, such as increased fungal resistance, side effects of current treatments, and the rising prevalence of non-albicans Candida spp. naturally more resistant. This study aimed to propose a novel therapeutic approach by investigating the antifungal properties and toxicity of 2-hydroxychalcone (2-HC) and 3'-hydroxychalcone (3'-HC), both alone and in combination with fluconazole (FCZ) and clotrimazole (CTZ). A lipid carrier (LC) was also developed to deliver these molecules. The study evaluated in vitro anti-Candida activity against five Candida species and assessed cytotoxicity in the C33-A cell line. The safety and therapeutic efficacy of in vivo were tested using an alternative animal model, Galleria mellonella. The results showed antifungal activity of 2-HC and 3'-HC, ranging from 7.8 to 31.2 as fungistatic and 15.6 to 125.0 mg/L as fungicide effect, with cell viability above 80% from a concentration of 9.3 mg/L (2-HC). Synergistic and partially synergistic interactions of these chalcones with FCZ and CTZ demonstrated significant improvement in antifungal activity, with MIC values ranging from 0.06 to 62.5 mg/L. Some combinations reduced cytotoxicity, achieving 100% cell viability in many interactions. Additionally, two LCs with suitable properties for intravaginal application were developed. These formulations demonstrated promising therapeutic efficacy and low toxicity in Galleria mellonella assays. These results suggest the potential of this approach in developing new therapies for VVC.

Synthesis, optical properties, and application of novel chalcone skeleton as pH fluorescent probe: Based AIE + ESIPT strategy

A series of "turn off" pH fluorescence probes with chalcone skeleton for basic system have been developed. The molecules emitted bright yellow fluorescence under acidic condition, resulting AIE coupled ESIPT characteristic and ICT process. What's more, the compounds exhibited excellent sensitivity and selectivity for detecting pH as a facile "On-Off" fluorescence probe, and the fluorescence of them were quenched with the ESIPT process interrupted under alkaline condition. Theoretical calculation for the related compounds also performed to verify the electron effect on photophysical properties and confirm the rational speculation on the mechanism.

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.

Thiazolidinone-linked-1,2,3-triazoles with (R)-Carvone as new potential anticancer agents

Aim: This study explores the cytotoxic and apoptotic effects of novel thiazolidinone-1,2,3-triazole hybrids on HT-1080, A-549, and MDA-MB-231 cancer cell lines.Methods & results: The synthesized compounds underwent comprehensive characterization (NMR and HRMS) to confirm their structures and purity. Subsequent anticancer activity screening across diverse cancer cell lines revealed promising antitumor potential notably, compounds 6f and 6g. Mechanistic investigations unveiled that compound 6f triggers apoptosis through the caspase-3/7 pathway. In terms of in silico studies, the compound 6f was identified as a potent inhibitor of caspase-3 and caspase-7.Conclusion: The present study underscores the therapeutic potential of thiazolidinone-1,2,3-triazole hybrids against certain cancer cells. These findings highlight a promising avenue for the development of cancer treatment strategies utilizing these (R)-Carvone-based derivatives.

Methoxychalcones as potential anticancer agents for colon cancer: Is membrane perturbing potency relevant?

Chalcones are naturally produced by many plants, and constitute precursors for the synthesis of flavons and flavanons. They were shown to possess antibacterial, antifungal, anti-cancer, and anti- inflammatory properties. The goal of the study was to assess the suitability of three synthetic methoxychalcones as potential anticancer agents. In a panel of colon cancer cell lines they were demonstrated to be cytotoxic, proapoptotic, causing cell cycle arrest, and increasing intracellular level of reactive oxygen species. Anticancer activity of the compounds was not diminished in the presence of stool extract containing microbial enzymes that could change the structure of chalcones. Moreover, methoxychalcones interacted strongly with model phosphatidylcholine membranes as detected by differential scanning calorimetry. Metohoxychalcones particularly affected the properties of lipid domains in giant unilamellar liposomes formed from raft-mimicking lipid composition. This may be of importance since many molecular targets for therapy of metastatic colon cancer are raft-associated receptors (e.g., receptor tyrosine kinases). The importance of membrane perturbing potency of methoxychalcones for their biological activity was additionally corroborated by the results obtained by molecular modelling.

Exploring ethynyl-based chalcones as green semiconductor materials for optical limiting interests

The fabrication of molecular electronics from non-toxic functional materials which eventually would potentially able to degrade or being breaking down into safe by-products have attracted much interests in recent years. Hence, in this study, the introduction of mixed highly functional substructures of chalcone (-CO-CH=CH-) and ethynylated (C≡C) as building blocks has shown ideal performance as solution-processed thin film candidatures. Two types of derivatives, (MM-3a) and (MM-3b) repectively, showed a substantial Stokes shifts at 75 nm and 116 nm, in which such emission exhibits an intramolecular charge transfer (ICT) state and fluoresce characteristics. The density functional theory (DFT) simulation shows that MM-3a and MM-3b exhibit low energy gaps of 3.70 eV and 2.81 eV, respectively. TD-DFT computations for molecular electrostatic potential (MEP) and frontier molecular orbitals (FMO) were also used to emphasise the structure-property relationship. A solution-processed thin film with a single layer of ITO/PEDOT:PSS/MM-3a-MM-3b/Au exhibited electroluminescence behaviour with orange and purple emissions when supplied with direct current (DC) voltages. To promote the safer application of the derivatives formed, ethynylated chalcone materials underwent toxicity studies toward Acanthamoeba sp. to determine their suitability as non-toxic molecules prior to the determination as safer materials in optical limiting interests. From the preliminary test, no IC50 value was obtained for both compounds via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay analysis and molecular docking analysis between MM-3a and MM-3b, with profilin protein exhibited weak bond interactions and attaining huge interaction distances.

Metal-free synthesis of γ-ketosulfones through Brønsted acid-promoted conjugate addition of sulfinamides

A straightforward and general metal-free method has been developed to add sufinamide-derived sulfone units on Michael acceptors under mild conditions. This reaction enables the preparation of a large variety of original γ-ketosulfones, of which only a few synthetic methods have been reported. The mild reaction conditions used tolerate a wide diversity of functional groups and empower the implementation of a late-stage functionalisation strategy.

Merging Photocatalytic Doubly-Decarboxylative Csp 2 -Csp 2 Cross-Coupling for Stereo-Selective (E)-α,β-Unsaturated Ketones Synthesis

A photocatalytic domain of doubly decarboxylative Csp 2 -Csp 2 cross coupling reaction is disclosed. Merging iridium and palladium photocatalysis manifested carbon-carbon bonds in a tandem dual-radical pathway. Present catalytic platform efficiently cross-coupled α, β-unsaturated acids and α-keto acids to afford a variety of α, β-unsaturated ketones with excellent (E)-selectivity and functional group tolerance. Mechanistically, photocatalyst implicated through reductive quenching cycle whereas cross coupling proceeded over one electron oxidative pallado-cycle.

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.

In silico screening of chalcone derivatives as promising EGFR-TK inhibitors for the clinical treatment of cancer

Epidermal growth factor receptor (EGFR) promotes tumorigenic characteristics and activates cancer-associated signaling pathways such as Wnt/-catenin, transforming growth factor (TGF-β), and phosphoinositide-3-kinase (PI3K). Several inhibitors have been reported to suppress the activity of EGFR and are being used in cancer treatment. However, patients in the malignant stage of cancer show resistance to those inhibitors, opening a wide space for research to discover novel inhibitors. Therefore, we carried out machine learning and virtual screening to discover novel inhibitors with high affinity against EGFR-TK. Initially, a library of 2640 chalcones were screened out using a machine-learning model developed based on the random forest algorithm, exhibiting high sensitivity and a Receiver Operating Characteristic curve (ROC area) of 0.99. Furthermore, out of the initial 2640 screened compounds, 412 compounds exhibiting potential activity are subjected to evaluation for drug-likeness properties through different filters: Blood-brain barrier penetration, Lipinski's rule, CMC-50 like rule, Veber rule, and Ghose filter, alongside Cell Line Cytotoxicity Prediction. A total of 30 compounds that successfully pass through all these filters are selected for molecular docking. Of these, 6 compounds display substantial binding affinity and closer interaction with the conserved catalytic residues of the target EGFR-TK compared to the reference molecule (erlotinib). Furthermore, molecular dynamics simulation studies were conducted on four compounds (CID-375861, CID-375862, CID-23636403, and CID-259166) to confirm the stability of the docked complexes over a 100 ns simulation trajectory. Additionally, the binding free energy calculations by MMPBSA reveal that these four chalcone compounds exhibit strong affinity towards the EGFR-TK enzyme, with binding free energies of - 65.421 kJ/mol, - 94.266 kJ/mol, - 80.044 kJ/mol, and - 79.734 kJ/mol, respectively. The findings from this investigation highlight a set of promising chalcone compounds that have the potential to be developed into effective drugs for the treatment of various cancers. Further research and development on these compounds could pave the way for novel therapeutic interventions.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-023-03858-8.

Recent Advancement in Bioactive Chalcone Hybrids as Potential Antimicrobial Agents in Medicinal Chemistry

Chalcones are flavonoid-related aromatic ketones and enones generated from plants. The chalcones have a wide range of biological activities, such as anti-tumor, calming, and antimicrobial activities. In the present review, we have focused on the recently published original research articles on chalcones as a unique antibacterial framework in medicinal chemistry. Chalcones are structurally diverse moieties and can be split into simple and hybrid chalcones, with both having core pharmacophore 1,3-diaryl-2-propen-1-one. Chalcones are isolated from natural sources and also synthesized by using various methods. Their structure-activity relationship, mechanisms, and list of patents are also summarized in this paper. This review article outlines the currently published antimicrobial chalcone hybrids and suggests that chalcone derivatives may be potential antimicrobial agents in the future.

New Chalcone Derivatives Containing 2,4-Dichlorobenzenesulfonamide Moiety with Anticancer and Antioxidant Properties

Chalcones and their derivatives, both natural and synthetic, exhibit diverse biological activities. In this study, we focused on designing and synthesizing (E)-2,4-dichloro-N-(4-cinnamoylphenyl)-5-methylbenzenesulfonamides 4-8 with the following two pharmacophore groups: 2,4-dichlorobenzenesulfonamide and chalcone. The obtained compounds displayed notable anticancer effects on various human cancer cells, such as cervical HeLa, acute promyelocytic leukemia HL-60, and gastric adenocarcinoma AGS, when assessed with the MTT test. The activity of all compounds against cancer cells was significant, and the obtained IC50 values were in the range of 0.89-9.63 µg/mL. Among all the tested compounds, derivative 5 showed the highest activity on the AGS cell line. Therefore, it was tested for cell cycle inhibition, induction of mitochondrial membrane depolarization, and activation of caspase-8 and -9. These results showed that this compound strongly arrested the cell cycle in the subG0 phase, depolarized the mitochondrial membrane, and activated caspase-8 and -9. Similar to the anticancer effects, all the obtained compounds 4-8 were also assessed for their antioxidant activity. The highest antiradical effect was demonstrated for derivative 5, which was able to inhibit DPPH and ABTS radicals. All examined compounds showed dose-dependent activity against neutrophil elastase. Notably, derivatives 7 and 8 demonstrated inhibitory properties similar to oleanolic acid, with IC50 values of 25.61 ± 0.58 and 25.73 ± 0.39 µg/mL, respectively. To determine the antibacterial activity of derivatives 4-8, the minimum bacteriostatic concentration (MIC) values were estimated (>500 µg/mL for all the tested bacterial strains). The findings demonstrate the substantial potential of sulfonamide-based chalcone 5 as a promising drug in anticancer therapy.

Selective recognition of Fe2+ in aqueous solution by chalcones

Recognition of metal ions in aqueous media has direct impact for designing new supramolecular hosts for targeting biochemical pathways. In the present work we have studied the binding behavior of three simple chalcones with variation in number of phenolic OH groups. These chalcones showed very good binding capabilities towards metal ions in CH3OH-H2O (1:1, v/v) solvent system. The receptors R1 has interacted with all metal ions, which are used in the present study through 2:1 mode of complexation whereas R2 have showed equilibrium between the complexes of 2:1 and 1:1 with few exceptions. The highest association constants (K21) of R1 and R2 for Fe2+ is observed as 1.1 × 109 (4) M-1 and 2.3 × 108 (7) M-1 respectively by fluorescence titration method. But R3, which is lack of any phenolic OH group, binds all the metal ions through the formation of 1:1 mode of complex formation by exploiting the only one donor site as carbonyl 'O' atom resulting lower association constant for all the metal ions. So intermolecular hydrogen bonding as well as π- π stacking interaction forced the receptors R1 and R2 to arrange in a pseudo cleft orientation for the recognition of metal ions in 2:1 mode of complex formation. The binding behaviour of the receptors with few alkali metal ions (Na+, K+ and Cs+) and alkaline-earth metal ions (Mg2+, Ca2+ and Ba2+) are also studied and observed weak binding nature in compared with the transition metal ions.

Trypanocidal potential of synthetic p-aminochalcones: In silico and in vitro evaluation

Chagas disease (CD) is a neglected tropical disease of worldwide health concern, caused by the flagellate protozoan Trypanosoma cruzi (T. cruzi), endemic in Latin America and present in North America and Europe. The WHO recommended drug for CD, benznidazole has low safety profile and several limitations. Therefore, an entity with better therapeutic potential to treat CD is required. Chalcones are an important class of compounds, which have shown antichagasic potential. Thus, the objective of this study was to evaluate the activity of synthetic p-aminochalcones against T. cruzi. Chalcones 1 and 2 were synthesized by Claisen-Schmidt condensation and characterized by both spectroscopic and theoretical methods. Initially, they were submitted to molecular docking simulations using cruzain and trypanothione reductase (TR) enzymes. It was expected to observe the possible interactions of chalcones with the catalytic site and other important regions of these main pharmacological targets of T. cruzi. Their cytotoxicity within host cells were assessed by MTT reduction assay using LLC-MK2 cells, with CC50 = 85.6 ± 9.2 µM and 1115 ± 381.7 µM for chalcones 1 and 2, respectively. These molecules were also tested against epimastigote and trypomastigote life forms of T. cruzi, causing reduction in the number of viable parasites. For the evaluation of the effect on intracellular amastigotes, infected LLC-MK2 cells were incubated with the chalcones for 24 h, causing reduction in the percentage of infected cells and the number of amastigotes/100 cells. Finally, flow cytometry assays were performed for analyzing cell death mechanisms (7-AAD/AxPE labelling), cytoplasmic ROS accumulation (DCFH-DA assay) and mitochondrial transmembrane potential disruption (Rho123 assay). Both chalcones (1 and 2) caused membrane damage, ROS accumulation and mitochondrial depolarization. In conclusion, the synthetic p-aminochalcones presented trypanocidal effect, causing membrane damage and oxidative stress. Their mechanism of action may be related to cruzain and TR inhibition.

Synthesis and in Silico Studies of Some New 1,2,3-Triazolyltetrazole Bearing Indazole Derivatives as Potent Antimicrobial Agents

1,2,3-Triazole and tetrazole derivatives bearing pyrrolidines are found to exhibit notable biological activity and have become useful scaffolds in medicinal chemistry for application in lead discovery and optimization. Novel indazole bearing 1,2,3-triazolyltetrazoles were designed as potential antimicrobial candidates. The structure of duel heterocyclics was validated by a spectroscopic technique of infrared (IR), nuclear magnetic resonance (1 H and 13 C NMR), and mass spectral data. Compounds 4b, 4c, 4d, and 4h were found to have a stronger antibacterial effect against Gram-positive (S. aureus, B. subtilis, M. Luteus) and Gram-negative (E. coli, P. aeruginosa) microorganisms with MICs ranging from 5±0.03-18±0.02 μM, respectively. Moreover, scaffolds 4a, 4h showed potent antifungal activity against A. flavus, M. gypsuem strains with MIC values of 10±0.02, 11±0.01 μM, which are similar activity that of the standard Itraconazole (MIC=8±0.02, 10±0.01 μM). The binding mode for compound 4 inside the catalytic pocket of S. aureus complexed with nicotinamide adenine dinucleotide phosphate and trimethoprim and produced a network of hydrophobic and hydrophilic interactions (3FRE). From in silico results, 4b demonstrated highly stable hydrogen binding amino acids Leu62(X) [N18…O, 2.47 Å], Arg44(X) [N17…N, 3.11 Å], Thr96(X) [N10…OG1, 3.05 Å], Gly94(X) [F7…N, 2.82 Å], and Gly43(X) [F7…N, 2.90 Å], which are plays a crucial role in ensuring efficient binding of the ligand in a crystal structure of antibacterial receptor. Furthermore, the physicochemical and ADME filtration molecular properties, estimation of toxicity, and bioactivity scores of these novel scaffolds were evaluated by using SwissADME and ADMETlab2.0 online protocols. Thus, the significant antimicrobial activity of indazole linked to duel heterocyclic compounds can be used for development of new antimicrobial agents with further modifications.

Phenolic chalcones as agents against Trichomonas vaginalis

Trichomonas vaginalis, a flagellated and anaerobic protozoan, is a causative agent of trichomoniasis. This disease is among the world's most common non-viral sexually transmitted infection. A single class drug, nitroimidazoles, is currently available for the trichomoniasis treatment. However, resistant isolates have been identified from unsuccessfully treated patients. Thus, there is a great challenge for a discovery of innovative anti-T. vaginalis agents. As part of our ongoing search for antiprotozoal chalcones, we designed and synthesized a series of 21 phenolic chalcones, which were evaluated against T. vaginalis trophozoites. Structure-activity relationship indicated hydroxyl group plays a role key in antiprotozoal activity. 4'-Hydroxychalcone (4HC) was the most active compound (IC50 = 27.5 µM) and selected for detailed bioassays. In vitro and in vivo evaluations demonstrated 4HC was not toxic against human erythrocytes and Galleria mellonella larvae. Trophozoites of T. vaginalis were treated with 4HC and did not present significant reactive oxygen species (ROS) accumulation. However, compound 4HC was able to increase ROS accumulation in neutrophils coincubated with T. vaginalis. qRT-PCR Experiments indicated that 4HC did not affect the expression of pyruvate:ferredoxin oxidoreductase (PFOR) and β-tubulin genes. In silico simulations, using purine nucleoside phosphorylase of T. vaginalis (TvPNP), corroborated 4HC as a promising ligand. Compound 4HC was able to establish interactions with residues D21, G20, M180, R28, R87 and T90 through hydrophobic interactions, π-donor hydrogen bond and hydrogen bonds. Altogether, these results open new avenues for phenolic chalcones to combat trichomoniasis, a parasitic neglected infection.

N-methylpiperazinyl and piperdinylalkyl-O-chalcone derivatives as potential polyfunctional agents against Alzheimer's disease: Design, synthesis and biological evaluation

The series of N-methylpiperazinyl and piperdinylalkyl-O-chalcone derivatives as potential polyfuctional agents against Alzheimer's disease that have been designed, synthesized and then evaluated biologically using in vitro assays for the inhibition of acetylcholinesterase (AChE) activity, AGEs, and free radical formation. The majority of synthesized compounds inhibited AChE & AGEs with additional free radical scavenging activities at nanomolar concentrations. Among these, compound 5k was found to have potent AChE inhibitory activity (IC50  = 11.6 nM), superior than the reference compound donepezil (15.68 nM) along with the good anti-AGEs and free radical formation effect. Its potency was justified by docking studies that revealed its dual binding characteristic with both catalytic active site and peripheral anionic site of AChE, simultaneously. Furthermore, the in vivo evaluation of 5k against streptozotocin (STZ)-induced dementia in rats also showed improvement of memory functions (Morris water maze test) in animals. Also, 5k inhibited STZ-inudced brain AChE activity and oxidative stress which further strengthen the observed in vitro effects. The stability of the ligand-protein complex was then analyzed using a simulation-based interaction protocol. The results revealed that these N-methylpiperazinyl and piperdinylalkyl-O-chalcone derivatives could be considered for potential polyfunctional anti-Alzheimer's molecules.

2-Acetyl-5,8-dihydro-6-(4-methyl-3-pentenyl)-1,4-naphthohydroquinone-Derived Chalcones as Potential Anticancer Agents

Based on previous results with benzoindazolequinone (BIZQ) and 3-methylnaphtho [2,3-d]isoxazole-4,9-quinone (NIQ) derivatives, a novel series of chalcone-1,4-naphthoquinone/benzohydroquinone (CNQ and CBHQ) compounds were synthesized from 2-acetyl-5,8-dihydro-6-(4-methyl-3-pentenyl)-1,4-naphthohydroquinone. Their structures were elucidated via spectroscopy. These hybrids were assessed in vivo for their antiproliferative activity on MCF-7 breast adenocarcinoma and HT-29 colorectal carcinoma cells, revealing cytotoxicity with IC50 values between 6.0 and 110.5 µM. CBHQ hybrids 5e and 5f displayed enhanced cytotoxicity against both cell lines, whereas CNQ hybrids 6a-c and 6e exhibited higher cytotoxic activity against MCF-7 cells. Docking studies showed strong binding energies (ΔGbin) of CNQs to kinase proteins involved in carcinogenic pathways. Furthermore, our in silico analysis of drug absorption, distribution, metabolism, and excretion (ADME) properties suggests their potential as candidates for cancer pre-clinical assays.

Synthesis, Docking Studies and Evaluation of Chalcones as Anti-Helicobacter pylori and antitumoral Agents

Helicobacter pylori colonizes the gastric epithelium of 50 % of world population and it is the main etiological agent of human chronic gastritis, peptic ulcer, and gastric cancer. In this study, we synthesized and characterized a series of 14 chalcones and evaluated their anti-H. pylori, NO inhibition (in vitro and in silico), and AGS cells cytotoxic effects. Compounds 3b and 3h showed MIC of 8 μg/mL. We observed structure-activity relationships, mainly related to the influence of methoxy substituent at C-2 (3b) and the nitro group at C-4 (3h) in chalcone scaffold. The fourteen chalcones inhibited the NO production in LPS-stimulated macrophages and showed potential for interaction on the active site of the iNOS enzyme. Finally, 3b and 3h showed the highest selectivity to the AGS cell lines. Thus, ours results suggest 3b and 3h as potential candidates for design of new and effective agents against H. pylori and related diseases.

Photophysical and biological aspects of α, β-unsaturated ketones: Experimental and in silico approach

In this work, four fluorinated α, β-unsaturated ketones named as 3-(3-bromophenyl)-1-(3-(trifluoromethyl)phenyl)prop-2-en-1-one (1), 3-(4-methoxyphenyl)-1-(3-(trifluoromethyl)phenyl) prop-2-en-1-one (2), 3-(3-bromo-5-chloro-2-hydroxyphenyl)-1-(3-(trifluoromethyl)phenyl) prop-2-en-1-one (3) and 3-(2-hydroxy-5-methylphenyl)-1-(3-(trifluoromethyl)phenyl)prop-2-en-1-one (4) were synthesized by Claisen-Schmidt reaction. The synthesized molecules were then characterized through ultraviolet-visible spectroscopy (UV-Vis), Fourier transform infrared (FTIR), 1 H-NMR, 13 C-NMR, and mass spectrometry. The antioxidant potential, Urease inhibition, and interaction of compounds 1-4 with Salmon sperm DNA were experimentally explored and supported by molecular docking studies. The synthesized compounds strongly interact with SS-DNA through intercalative mode. It was noticed that compound 1 served as potent Urease inhibitor while compound 4 as better antioxidant among synthesized compounds. Moreover, frontier molecular orbitals, nonlinear optical (NLO) properties, natural bond orbitals, molecular electrostatic potential, natural population analysis, and photophysical properties of synthesized compounds were accomplished through density functional theory and time-dependent density functional theory. The band gap of all the compounds have been worked out using Taucs method. In addition to that, a precise comparative account of UV and IR data obtained from theoretical and experimental findings showed good agreement between theoretical and experimental data. The findings of our studies reflected that compounds 1-4 possess better NLO properties than Urea standard and the band gap data also reflected their prospective use towards optoelectronic materials. The better NLO behavior of compounds was attributed to the noncentrosymmetric structure of synthesized compounds.

Synthesis of Novel Heterocyclic Ferrocenyl Chalcones and Their Biological Evaluation

Breast cancer is currently the most commonly diagnosed cancer, with 287,850 new cases estimated for 2022 as reported by the American Cancer Society. Therefore, finding an effective treatment for this disease is imperative. Chalcones are α,β-unsaturated systems found in nature. These compounds have shown a wide array of biological activities, making them popular synthetic targets. Chalcones consist of two aromatic substituents connected by an enone bridge; this arrangement allows for a large number of derivatives. Given the biological relevance of these compounds, novel ferrocene-heterocycle-containing chalcones were synthesized and characterized based on a hybrid drug design approach. These heterocycles included thiophene, pyrimidine, thiazolyl, and indole groups. Fourteen novel heterocyclic ferrocenyl chalcones were synthesized and characterized. Herein, we also report their cytotoxicity against triple-negative breast cancer cell lines MDA-MB-231 and 4T1 and the noncancer lung cell line MRC-5. System 3 ferrocenyl chalcones displayed superior anticancer properties compared to their system 1 analogues. System 3 chalcones bearing five-membered heterocyclic substituents (thiophene, pyrazole, pyrrole, and pyrimidine) were the most active toward the MDA-MB-231 cancer cell line with IC50 values from 6.59 to 12.51 μM. Cytotoxicity of the evaluated compounds in the 4T1 cell line exhibited IC50 values from 13.23 to 213.7 μM. System 3 pyrazole chalcone had consistent toxicity toward both cell lines (IC50 ∼ 13 μM) as well as promising selectivity relative to the noncancer MRC-5 control. Antioxidant activity was also evaluated, where, contrary to anticancer capabilities, system 1 ferrocenyl chalcones were superior to their system 3 analogues. Antioxidant activity comparable to that of ascorbic acid was observed for thiophene-bearing ferrocenyl chalcone with EC50 = 31 μM.

Evaluation of Anti-Inflammatory and Anti-Tubercular Activity of 4-Methyl-7-Substituted Coumarin Hybrids and Their Structure Activity Relationships

Four sets of previously synthesized 4-methyl-7-substituted coumarin derivatives were screened for their in vitro anti-inflammatory and anti-tubercular activities. The anti-inflammatory potential of 3a-t, 5a-o, 6a-n, and 7a-f synthesized compounds was evaluated by an anti-denaturation assay using diclofenac sodium as the reference standard. Evaluation of the anti-tuberculous activity of the mentioned compounds was performed by the Resazurin test method against four different TB strains using rifampicin and isoniazid as reference drugs. Based on the anti-inflammatory results, compounds 3o, 5f, 6c, and 7d proved to be the most active compounds in their respective series. Additionally, compounds 3k-n, 5b-d, 6d-f, 6k, 7a, and 7f were found to be the most potent anti-tuberculous agents. In fact, most of the screened compounds exhibited promising activity profiles compared to the respective standard drugs. The structure-activity connections revealed a few intriguing aspects, indicating that the presence of electron-donating and nitrogen-rich fragments boost the anti-inflammatory effects of the examined compounds. However, the presence of electron-withdrawing substituents was required to boost the anti-tubercular activity of the evaluated compounds.

Synthesis and antibacterial activity of 2-benzylidene-3-oxobutanamide derivatives against resistant pathogens

Antibiotic resistance evolves naturally through random mutation. Resistance to antimicrobials is an urgent public health crisis that requires coordinated global action. The ESKAPE bacteria (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) are primarily responsible for the rise in resistant pathogens. There is an immediate requirement to identify a novel molecular scaffold with potent anti-microbial properties. We developed an efficient one-step synthesis of 2-benzylidene-3-oxobutanamide and its derivatives, which allowed the introduction of an α,β-unsaturated ketone moiety in the quest to identify a new molecular scaffold. Seven compounds exhibited very good antibacterial activity in vitro against WHO priority drug-resistant bacteria such as methicillin resistant Staphyloccus aureus (MRSA) and Acinetobacter baumannii-Multi drug resistant (MDR-AB). In cultured human embryonic kidney cells and hemolysis assays, the potent compounds displayed minimal toxicity. These findings suggest that these small molecules with excellent diversity have the potential to combat antibacterial resistance.

Recent Development of Novel Aminoethyl-Substituted Chalcones as Potential Drug Candidates for the Treatment of Alzheimer's Disease

No drug on the market, as a single entity, participates in different pathways involved in the pathology of Alzheimer's disease. The current study is aimed at the exploration of multifunctional chalcone derivatives which can act on multiple targets involved in Alzheimer's disease. A series of novel aminoethyl-substituted chalcones have been developed using in silico approaches (scaffold morphing, molecular docking, and ADME) and reported synthetic methods. The synthesized analogs were characterized and evaluated biologically using different in vitro assays against AChE, AGEs, and radical formation. Among all compounds, compound PS-10 was found to have potent AChE inhibitory activity (IC50 = 15.3 nM), even more than the standard drug (IC50 = 15.68 nM). Further, the in vivo evaluation of PS-10 against STZ-induced dementia in rats showed memory improvement (Morris Water Maze test) in rats. Also, PS-10 inhibited STZ-induced brain AChE activity and oxidative stress, further strengthening the observed in vitro effects. Further, the molecular dynamic simulation studies displayed the stability of the PS-10 and AChE complex. The novel aminoethyl-substituted chalcones might be considered potential multifunctional anti-Alzheimer's molecules.

Hydroxy Chalcones and Analogs with Chemopreventive Properties

The aim of this review is to highlight the chemopreventive properties of hydroxy-substituted natural and synthetic chalcones along with a number of their analogs. These products display various biological activities, and have many applications against various diseases. Antioxidant and anti-inflammatory properties of chalcones bearing hydroxy substituents are underlined. The influence of hydroxy substituents located on ring A, B, or both are systematized according to the exhibited biological properties.

(E)-2-Benzylidenecyclanones: Part XVIII Study the Possible Link between Glutathione Reactivity and Cancer Cell Cytotoxic Effects of Some Cyclic Chalcone Analogs A Comparison of the Reactivity of the Open-Chain and the Seven-Membered Homologs

Non-enzymatic thiol addition into the α,β-unsaturated carbonyl system is associated with several biological effects. In vivo, the reactions can form small-molecule thiol (e.g., glutathione) or protein thiol adducts. The reaction of two synthetic (4'-methyl- and 4'-methoxy substituted) cyclic chalcone analogs with reduced glutathione (GSH) and N-acetylcysteine (NAC) was studied by (high-pressure liquid chromatography-ultraviolet spectroscopy) HPLC-UV method. The selected compounds displayed in vitro cancer cell cytotoxicity (IC₅₀) of different orders of magnitude. The structure of the formed adducts was confirmed by (high-pressure liquid chromatography-mass spectrometry) HPLC-MS. The incubations were performed under three different pH conditions (pH 3.2/3.7, 6.3/6.8, and 8.0/7.4). The chalcones intrinsically reacted with both thiols under all incubation conditions. The initial rates and compositions of the final mixtures depended on the substitution and the pH. The frontier molecular orbitals and the Fukui function were carried out to investigate the effects on open-chain and seven-membered cyclic analogs. Furthermore, machine learning protocols were used to provide more insights into physicochemical properties and to support the different thiol-reactivity. HPLC analysis indicated diastereoselectivity of the reactions. The observed reactivities do not directly relate to the different in vitro cancer cell cytotoxicity of the compounds.

Chalcone-Derived Lactones: Synthesis, Whole-Cell Biotransformation, and Evaluation of Their Antibacterial and Antifungal Activity

Four compounds with lactone moiety were synthesized from chalcone 1 in three- or four-step synthesis. γ-Bromo-δ-lactone 5 was the only product of bromolactonization of acid 4 whereas bromolactonization of ester 3, apart from lactone 5 also afforded its isomer 6 and two diastereoisomeric δ-hydroxy-γ-lactones 7 and 8. Lactone 8 was also obtained in 88% yield as a product of simultaneous dehalogenation and translactonization of γ-bromo-δ-lactone 5 by Penicillum frequentans AM 359. Chalcone-derived lactones 5-8 were subjected to the tests on antimicrobial activity and the results compared with activity of starting chalcone 1. Obtained lactones 5-8 in most cases limited the growth of tested bacterial and fungal strains. The highest activity was found for δ-hydroxy-γ-lactone 8 which completely inhibited the growth of Staphylococcus aureus, Fusarium graminearum, Aspergillus niger, and Alternaria sp. The introduction of lactone moiety into chalcone scaffold significantly improved antimicrobial activity of the compound: γ-bromo-δ-lactone 6 and δ-hydroxy-γ-lactone 8 were significantly stronger growth inhibitors of S. aureus and F. graminearum. In the case of the latter, a clear positive effect of the lactone function on the antifungal activity was also observed for γ-bromo-δ-lactone 5.

Study on molecular mechanisms of destabilizing Aβ(1-42) protofibrils by licochalcone A and licochalcone B using molecular dynamics simulations

Amyloid-beta (Aβ) protofibrils are closely related to Alzheimer's disease. Their behaviors with or without the presence of Aβ fibrillization inhibitors have been intensively studied by molecular dynamics simulations. In this work, the molecular mechanisms of licochalcone A and licochalcone B on destabilizing Aβ(1-42) protofibrils are explored. It is found that both two licochalcones can disorder the configuration of the Aβ(1-42) protofibril. The stable interactions between the Aβ(1-42) protofibril and licochalcone A or licochalcone B are able to be formed. A reduction of the β-sheet structure contents and an increment of the random coil structures of Aβ(1-42) protofibril are observed in the presence of either licochalcone A or licochalcone B. The hydrogen bonds inside the Aβ(1-42) protofibril could be partially collapsed to varying degrees by two licochalcones. Furthermore, the van der Waals interactions between Aβ(1-42) protofibril and licochalcone A make an important contribution to the binding free energy, while the contribution of the electrostatic interactions between Aβ(1-42) protofibril and licochalcone B is more prominent in the binding affinity. Our work may help in the development of new drug candidates for disrupting the Aβ protofibril.

Chalcone: A potential scaffold for NLRP3 inflammasome inhibitors

Overactivated NLRP3 inflammasome has been shown to associate with an increasing number of disease conditions. Activation of the NLRP3 inflammasome results in caspase-1-catalyzed formation of active pro-inflammatory cytokines (IL-1β and IL-18) resulting in pyroptosis. The multi-protein composition of the NLRP3 inflammasome and its sensitivity to several damage-associated molecular patterns (DAMPs) and pathogen-associated molecular patterns (PAMPs) make this extensively studied inflammasome an attractive target to treat chronic conditions. However, none of the known NLRP3 inhibitors has been approved for clinical use. Sulfonylurea and covalent inhibitors with electrophilic warhead (Michael acceptor) are among the prominent classes of compounds explored for their NLRP3 inhibitory effects. Chalcone, a small molecule with α, β unsaturated carbonyl group (Michael acceptor), has also been studied as a promising scaffold for the development of NLRP3 inhibitors. Low molecular weight, easy to manipulate lipophilicity and cost-effectiveness have attracted many to use chalcone scaffold for drug development. In this review, we highlight chalcone derivatives with NLRP3 inflammasome inhibitory activities. Recent developments and potential new directions summarized here will, hopefully, serve as valuable perspectives for investigators including medicinal chemists and drug discovery researchers to utilize chalcone as a scaffold for developing novel NLRP3 inflammasome inhibitors.

Synthesis, in vitro cytotoxicity evaluation and mechanism of 5' monosubstituted chalcone derivatives as antitumor agents

A series of 5' monosubstituted chalcone derivatives were synthesized to explore their antitumor activity and mechanism of action in vitro. The structures of 5' monosubstituted chalcone derivatives synthesized by reactions such as Suzuki coupling were confirmed by 1H NMR, 13C NMR and MS, and the target compounds were not reported in the literature. The antitumor activity of the aimed compounds was tested by MTT colorimetric method in vitro. Compound 5c has an IC50 value of 1.97 μM for K562 and a value of 2.23 μM for HepG2. Further investigation of the mechanism of action of compound 5c was found to have effects on K562 cell morphology, proliferation, apoptosis, cell cycle, and wound healing of HepG2 cells. The results showed that compound 5c has research value in antitumor activity and mechanism of action in vitro.

Chalcones and Gastrointestinal Cancers: Experimental Evidence

Colorectal (CRC) and gastric cancers (GC) are the most common digestive tract cancers with a high incidence rate worldwide. The current treatment including surgery, chemotherapy or radiotherapy has several limitations such as drug toxicity, cancer recurrence or drug resistance and thus it is a great challenge to discover an effective and safe therapy for CRC and GC. In the last decade, numerous phytochemicals and their synthetic analogs have attracted attention due to their anticancer effect and low organ toxicity. Chalcones, plant-derived polyphenols, received marked attention due to their biological activities as well as for relatively easy structural manipulation and synthesis of new chalcone derivatives. In this study, we discuss the mechanisms by which chalcones in both in vitro and in vivo conditions suppress cancer cell proliferation or cancer formation.

An ongoing journey of chalcone analogues as single and multi-target ligands in the field of Alzheimer's disease: A review with structural aspects

Alzheimer's disease (AD) is a chronic and irreversible neurodegenerative disorder with progressive dementia and cognitive impairment. AD poses severe health challenge in elderly people and become one of the leading causes of death worldwide. It possesses complex pathophysiology with several hypotheses (cholinergic hypothesis, amyloid hypothesis, tau hypothesis, oxidative stress, mitochondrial dysfunction etc.). Several attempts have been made for the management of multifactorial AD. Acetylcholinesterase is the only target has been widely explored in the management of AD to the date. The current review set forth the chalcone based natural, semi-synthetic and synthetic compounds in the search of potential anti-Alzheimer's agents. The main highlights of current review emphasizes on chalcone target different enzymes and pathways like Acetylcholinesterase, β-secretase (BACE1), tau proteins, MAO, free radicals, Advanced glycation end Products (AGEs) etc. and their structure activity relationships contributing in the inhibition of above mentioned various targets of AD.