Discovery of Chalcone-Based Hybrid Structures as High Affinity and Site-Specific Inhibitors against SARS-CoV-2: A Comprehensive Structural Analysis Based on Various Host-Based and Viral Targets.

Previous studies indicated that natural-based chalcones have significant inhibitory effects on the coronavirus enzymes 3CLpro and PLpro as well as modulation of some host-based antiviral targets (HBATs). In this study, a comprehensive computational and structural study was performed to investigate the affinity of our compound library consisting of 757 chalcone-based structures (CHA-1 to CHA-757) for inhibiting the 3CLpro and PLpro enzymes and against twelve selected host-based targets. Our results indicated that CHA-12 (VUF 4819) is the most potent and multi-target inhibitor in our chemical library over all viral and host-based targets. Correspondingly, CHA-384 and its congeners containing ureide moieties were found to be potent and selective 3CLpro inhibitors, and benzotriazole moiety in CHA-37 was found to be a main fragment for inhibiting the 3CLpro and PLpro. Surprisingly, our results indicate that the ureide and sulfonamide moieties are integral fragments for the optimum 3CLpro inhibition while occupying the S1 and S3 subsites, which is fully consistent with recent reports on the site-specific 3CLpro inhibitors. Finding the multi-target inhibitor CHA-12, previously reported as an LTD4 antagonist for the treatment of inflammatory pulmonary diseases, prompted us to suggest it as a concomitant agent for relieving respiratory symptoms and suppressing COVID-19 infection.

Chalcone-based Ferrocenyl-Derivatives as an Antimicrobial Drug

The lack of development of new antibiotics is the major concern at the present scenario. One key factor contributing to the rise of antibiotic-resistant bacteria is the widespread movement of people throughout the world. The world has seen the consequences of the migration in the case of COVID-19 very recently. To tackle or cope with the situation, development of new antibiotics is very essential, which can be inhibited multidrug-resistant bacteria. In this framework, chalcone-based ferrocenyl containing compounds showed a diversity of pharmacological properties and its derivatives possess a high degree of structural diversity and it is helpful for the discovery of new therapeutic agents. Thus, there is a need for new antibacterial drug candidates with increased strength, new targets, low cost, superior pharmacokinetic properties and minimum side effects. The present review concluded and focuses on the recent developments in the area of medicinal chemistry to explore the diverse chemical structures of potent antibacterial agents and also describes its structure-activity relationship studies (SAR). This review will help to the researchers in the medical field to find out the future generation potential drug discovery and development. © 2023 Chemical Publishing Co.. All rights reserved.

Synthesis and evaluation of imidazole-bearing chalcones as a potential treatment for pulmonary aspergillosis

Pulmonary aspergillosis (PA) is a category of respiratory illnesses that significantly impacts the lives of immunocompromised individuals. However, new classifications of secondary infections like influenza associated aspergillosis (IAA) and COVID-19 associated pulmonary aspergillosis (CAPA) only exacerbate matters by expanding the demographic beyond the immunocompromised. Meanwhile anti-fungal resistant strains of Aspergillus are causing current treatments to act less effectively. Symptoms can range from mild (difficulty breathing, and expectoration of blood) to severe (multi organ failure, and neurological disease). Millions are affected yearly, and mortality rates range from 20-90% making it imperative to develop novel medicines to curtail this evolving group of diseases. Chalcones and imidazoles are current antifungal pharmacophores used to treat PA. Chalcones are a group of plant-derived flavonoids that have a variety of pharmacological effects, such as, antibacterial, anticancer, antimicrobial, and anti-inflammatory activities. Imidazoles are another class of drug that possess antibacterial, antiprotozoal, and anthelmintic activities. The increase in antifungal resistant Aspergillus and Candida species make it imperative for us to synthesize novel pharmacophores for therapeutic use. Our objective was to synthesize a chalcone and imidazole into a single pharmacophore and to evaluate its effectiveness against three different fungi from the Aspergillus or Candida species. The chalcones were synthesized via the Claisen-Schmidt aldol condensation of 4-(1H-Imizadol-1-yl) benzaldehyde with various substituted acetophenones using aqueous sodium hydroxide in methanol. The anti-fungal activity of the synthesized chalcones were evaluated via a welldiffusion assay against Aspergillus fumigatus, Aspergillus niger, and Candida albicans. The data obtained suggests that chalcone derivatives with electron-withdrawing substituents are moderately effective against Aspergillus and has the potential for further optimization as a treatment for pulmonary aspergillosis. This project was supported by grants from the National Institutes of Health (NIH), National Institute of General Medicine Sciences (NIGMS), IDeA Networks of Biomedical Research Excellence (INBRE), Award number: P20GM103466. The content is solely the responsibility of the authors and do not necessarily represent the official views of the NIH.Copyright © 2023 The American Society for Biochemistry and Molecular Biology, Inc.

Anti-SARS-CoV-2 Activity of Ampelozizyphus amazonicus (Saracura-Mirá): Focus on the Modulation of the Spike-ACE2 Interaction by Chemically Characterized Bark Extracts by LC-DAD-APCI-MS/MS.

Traditional medicine shows several treatment protocols for COVID-19 based on natural products, revealing its potential as a possible source of anti-SARS-CoV-2 agents. Ampelozizyphus amazonicus is popularly used in the Brazilian Amazon as a fortifier and tonic, and recently, it has been reported to relieve COVID-19 symptoms. This work aimed to investigate the antiviral potential of A. amazonicus, focusing on the inhibition of spike and ACE2 receptor interaction, a key step in successful infection. Although saponins are the major compounds of this plant and often reported as its active principles, a polyphenol-rich extract was the best inhibitor of the spike and ACE2 interaction. Chemical characterization of A. amazonicus bark extracts by LC-DAD-APCI-MS/MS before and after clean-up steps for polyphenol removal showed that the latter play an essential role in maintaining this activity. The effects of the extracts on viral replication were also assessed, and all samples (aqueous and ethanol extracts) demonstrated in vitro activity, inhibiting viral titers in the supernatant of Calu-3 cells after 24 hpi. By acting both in the SARS-CoV-2 cell entry process and its replication, A. amazonicus bark extracts stand out as a multitarget agent, highlighting the species as a promising candidate in the development of anti-SARS-CoV-2 drugs.

Activity of Some Novel Chalcone Substituted 9-anilinoacridines against Coronavirus (COVID-19): A Computational Approach

Background: In the year earlier part of 2020, many scientists urged to discover novel drugs against for the treatments of COVID-19. Coronavirus Disease 2019 (COVID-19), a life-threatening viral disease, was discovered first in China and quickly spread throughout the world. Objective(s): In the present article, some novel chalcone substituted 9-anilinoacridines (1a-z) were developed by in silico studies for their COVID19 inhibitory activity. Molecular docking studies of the ligands 1a-z were performed against COVID19 (PDB id-5R82) targeting the coronavirus using Schrodinger suite 2019-4. Method(s): The molecular docking studies were performed by the Glide module and the binding energy of ligands was calculated using the PRIME MM-GB/SA module of Schrodinger suite 2019-4. Result(s): From the results, many compounds are significantly active against COVID19 with a Glide score of more than-5.6 when compared to the currently used drug for the treatment of COVID19, Hy-droxychloroquine (-5.47). The docking results of the compounds exhibited similar mode of interactions with COVID19 and the residues, THR25, THR26, LEU27, SER46, MET49, HIE41, GLN189, ARG188, ASP187, VAL186, HIE164, ASN142, and GLY143 play a crucial role in binding with ligands. MM-GBSA binding calculations of the most potent inhibitors are more stably favourable. Conclusion(s): From the results of in-silico studies, it provides strong evidence for the consideration of valuable ligands in chalcone substituted 9-anilinoacridines as potential COVID19 inhibitors and the compounds, 1x,a,r,s with significant Glide scores may produce significant COVID19 activity for further development, which may prove their therapeutic potential.Copyright © 2020 Bentham Science Publishers.

Efficacy evaluation of quercetin and its analogues on the main protease enzyme of the COVID-19 using molecular docking studies

Introduction: COVID-19 is an acute respiratory infectious disease caused by the SARS-CoV-2 virus. There is an urgent need to discover antiviral drugs for better performance against new strains of coronaviruses (CoVs) due to the rapid spread of the disease despite scientific advances in vaccine development. This study aimed to evaluate the efficacy of quercetin and its analogues on the COVID-19 Mpro enzyme. Material & Methods: In this descriptive-analytical study, the three-dimensional structures of quercetin analogues (20 compounds), standard drugs (ritonavir and lopinavir), and the COVID-19 Mpro enzyme were obtained from PubChem and PDB databases for bioinformatics study, respectively. Molecular docking studies of the compounds on theMpro were performed using MOE-2014 software. Afterward, the physicochemical properties and biological activity of the compounds were predicted using Swiss ADME, PASS, and Swiss Target Prediction software. Findings: The findings of the present study showed that the most important bonds involved in drug-receptor binding are hydrogen, hydrophobic, and - interaction bonds. The best docking results were obtained for Baicalein, Genistein, Naringenin, and Quercetin compounds with strong binding energy (-12.83 to -13.54 kcal/mol), compared to ritonavir and lopinavir. These compounds have a greater tendency to bind to the catalytic amino acids His41 and Cys145 and other key amino acids of the active site of the COVID-19 Mpro enzyme. Discussion & Conclusion: Based on the results of bioinformatics studies, quercetin analogues had more effective inhibition than standard chemical drugs due to their suitable placement in the active site of the main protease enzyme of COVID-19 and can be good candidates for in vitro and in vivo studies.

The Interaction of Antiviral Drugs with SARS-Cov-2 3CL Protease

SARS COV2 is one of the most destructive pandemics the world has faced and led to extreme economic losses. For its clinical therapy, SARS-COV-2 3CL Protease (3CLpro) is considered a target because of its crucial role in replication. Inhibition of this 3CLpro can lead to a decrease in viral load and infection. Different studies used various compounds and tested their inhibiting activity. Among them, flavonoids, serine derivatives, Chalcones, and alpha-keto amides were proven to have inhibitory effects. Many in-vitro tests were done to check the binding and inhibition abilities of such compounds. In vivo, some studies are done, but more is needed to prove this discovery. As far as research is concerned, therapeutic drugs against COVID-19 can be made by using such inhibitors. More in vivo studies and animal model experimentation should be done to confirm the findings.Copyright © 2022 Wolters Kluwer Medknow Publications. All rights reserved.

Recruitment of chalcone's potential in drug discovery of anti-SARS-CoV-2 agents.

Chalcone is an interesting scaffold found in the structure of many naturally occurring molecules. Medicinal chemists are commonly interested in designing new chalcone-based structures because of having the α, ß-unsaturated ketone functional group, which allows these compounds to participate in Michael's reaction and create strong covalent bonds at the active sites of the targets. Some studies have identified several natural chalcone-based compounds with the ability to inhibit the severe acute respiratory syndrome coronavirus and Middle East respiratory syndrome coronavirus proteases. A few years after the advent of the coronavirus disease 2019 pandemic and the publication of many findings in this regard, there is some evidence that suggests chalcone scaffolding has great potential for use in the design and development of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) inhibitors. Artificial placement of this scaffold in the structure of optimized anti-SARS-CoV-2 compounds can potentially provide irreversible inhibition of the viral cysteine proteases 3-chymotrypsin-like protease and papain-like protease by creating Michael interaction. Despite having remarkable capabilities, the use of chalcone scaffold in drug design and discovery of SARS-CoV-2 inhibitors seems to have been largely neglected. This review addresses issues that could lead to further consideration of chalcone scaffolding in the structure of SARS-CoV-2 protease inhibitors in the future.

Structural investigations and theoretical insights of a polymethoxy chalcone derivative: Synthesis, crystal structure, 3D energy frameworks and SARS CoV-2 docking studies

Chalcone derivatives with various functional groups have shown potent pharmacological and non-linear optical properties. A multi‑methoxy substituted (E)-1-(3,4-dimethoxyphenyl)-3-(3,4,5-trimethoxyphenyl) prop‑2-en-1-one, chalcone derivative has been synthesized and spectroscopically characterized by 1H and 13C NMR, LC-MS and FT-IR techniques. A pale yellow colored rectangular shaped single crystals of the compound were obtained by slow evaporation method and the three dimensional structure was confirmed using X-ray diffraction studies. The compound crystallized in the monoclinic crystal system with P21/a space group. The crystal and molecular structure is stabilized by CH···O inter and intra molecular hydrogen bond interactions apart from the prominent CH···π and π···π stacking interactions. These interactions were studied using Hirshfeld surface analysis to understand the nature and strength of interactions;the 2D fingerprint plot quantifies each individual intermolecular contact and revealed that the H…H (49.2%) interactions have the major contribution to the molecular surface. The analysis of 3D molecular energy frameworks revealed that the dispersion energy (-208.16 kJ mol−1) dominates all other energies and their visualization identifies the packing order of the molecules in the crystalline environment. The lattice energy of the compound is found to be -398.1 kJ mol−1. The electronic properties of the compound were quantified using theoretical quantum chemical computations with DFT-B3LYP/6–311+G (d, p) level basis set. The electronic energy band gap of the chalcone molecule is found to be 3.6961 eV. The NBO and Mulliken atomic charges were computed and the molecular electrostatic potential map was plotted to identify the chemical reactive sites on the molecular surface. The second-order nonlinear optical properties of the molecule based on the first static hyperpolarizability (β) have been investigated. Further, the molecular docking studies of the chalcone derivative against corona virus 2 (SARS-CoV-2) protein have been carried out to shed light on the possible significant molecular interactions.

FLAVONOIDS AS POTENTIAL DRUG AGAINST POST-COVID-19 MUCORMYCOSIS: AN IN-SILICO STUDY

Covid-19 associated mucormycosis rose sharply during India’s 2nd wave of coronavirus infections. The administration of immunosuppressive drugs led to increased susceptibility of patients to oppurtunistic diseases like mucormycosis. One of the causative species of mucormycosis is Rhizopus microsporus. For this study, we choose two chalcones and examined their ability to act as potential anti-mucormycosis agents by inhibiting the R. microsporus endo β-1,4-Mannanase protein. We studied their possibility to inhibit the SARSCoV-2 main protease and RNA dependent RNA polymerase. The chalcones were docked against the proteins of interest using Autodock 4.0 followed by Molecular dynamics simulation. Our study revealed that 2’, 4’-dihydroxychalcone had the best docking with the endo β-1,4-Mannanase protein with steady root mean square deviation values and showed favourable docking with the SARS-CoV-2 proteins while passing all the drug likeliness filters. Thus 2’, 4’-dihydroxychalcone can be put through further verification to test its efficacy against the causative agents of mucormycosis and the Covid-19 pandemic.

Exploration of chalcones as 3-chymotrypsin-like protease (3CLpro) inhibitors of SARS-CoV-2 using computational approaches.

The main protease 3CLpro is one of the potential targets against coronavirus. Inhibiting this enzyme leads to the interruption of viral replication. Chalcone and its derivatives were reported to possess the ability to bind to 3CLpro protease in the binding pocket. This study explored an in-house database of 269 chalcones as 3CLpro inhibitors using in silico screening models, including molecular docking, molecular dynamics simulation, binding free energy calculation, and ADME prediction. C264 and C235 stand out as the two most potential structures. The top hit compound C264 was with the Jamda score of -2.8329 and the MM/GBSA binding energy mean value of -28.23 ± 3.53 kcal/mol, which was lower than the reference ligand. Despite the lower mean binding energy (-22.07 ± 3.39 kcal/mol), in-depth analysis of binding interaction suggested C235 could be another potential candidate. Further, in vitro and in vivo experiments are required to confirm the inhibitory ability. Supplementary Information: The online version contains supplementary material available at 10.1007/s11224-022-02000-3.

Chalcone-amide, a privileged backbone for the design and development of selective SARS-CoV/SARS-CoV-2 papain-like protease inhibitors.

The newly emerged coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that caused the COVID-19 pandemic, is the closest relative of SARS-CoV with high genetic similarity. The papain-like protease (PLpro) is an important SARS-CoV/SARS-CoV-2 nonstructural protein that plays a critical role in some infection processes such as the generation of the functional replication complex, maturation of crude polyproteins, and regulation of the host antiviral immune responses. Therefore, the research to discover SARS-CoV-2 PLpro inhibitors could be a sensible strategy to obtain therapeutic agents for the treatment of COVID-19. Aiming to find SARS-CoV/SARS-CoV-2 PLpro inhibitors, various high throughput screenings (HTS) have been performed over the past two decades. Interestingly, the result of these efforts is the identification of hit/lead compounds whose structures have one important feature in common, namely having a chalcone-amide (N-benzylbenzamide) backbone. Structure-activity relationship (SAR) studies have shown that placing an (R)-configurated methyl group on the middle carbon adjacent to the amide group creates a unique backbone called (R)-methyl chalcone-amide, which dramatically increases PLpro inhibitory potency. Although this scaffold has not yet been introduced by medicinal chemists as a specific skeleton for the design of PLpro inhibitors, structural considerations show that the most reported PLpro inhibitors have this skeleton. This review suggests the (R)-methyl chalcone-amide scaffold as a key backbone for the design and development of selective SARS-CoV-2 PLpro inhibitors. Understanding the SAR and binding mode of these inhibitors in the active site of SARS-CoV-2 PLpro can aid the future development of anti-COVID-19 agents.

Computational description of quantum chemical calculations and pharmacological studies of the synthesized chalcone derivative: A promising NLO material

The intended chalcone, (E)-1-(4-aminophenyl)-3-(4-ethoxyphenyl)-prop-2-en-1-one (4A3EP), was synthesized in an alkaline medium by the Claisen–Schmidt condensation reaction of 4-aminoacetophenone with 4-ethoxybenzaldehyde. Spectroscopic analytical techniques such as UV–visible, FT-IR, FT-RAMAN, 1H NMR, and 13C NMR investigations were used to analyze the molecular structure of the title molecule. The optimized molecular structure of the chalcone in gas phase vibrational frequencies and associated vibrational assignments were theoretically studied and compared with experimental results using the B3LYP/6–311++G techniques. All the experimental results were found to be in line with the theoretical values. The non linear optical activity of the title compound was proved from the hyperpolarizability calculations. In addition, EHOMO (−5.9038 eV), ELUMO (−2.2833 eV), energy gap (3.6205 eV) and electrophilicity index (4.628) were calculated to explore the reactivity, stability and bio activity of the title compound. The molecular electrostatic potential map was generated in order to spot the electrophilic and nucleophilic sites in the title compound. Natural bond orbital analysis was investigated in order to forecast the stability and charge transfer tendency of a title molecule. FUKUI FUNCTIONS were also calculated using DFT. Its anti-inflammatory, anti-diabetic, and anti-oxidant activities were also investigated. A molecular docking model was used to study the ligand-protein binding interactions of a synthetic chalcone derivative with the main protease of SARS-CoV-2 (the PDB code is 6yb7).

Towards Covid-19 TMPRSS2 enzyme inhibitors and antimicrobial agents: Synthesis, antimicrobial potency, molecular docking, and drug-likeness prediction of thiadiazole-triazole hybrids.

1,3,4-Thiadiazole analogues 3 and 4 were synthesised via the reaction of 1-(5-methyl-1-(5-(methylthio)-1,3,4-thiadiazol-2-yl)-1H-1,2,3-triazol-4-yl)ethan-1one 2 with vanillin or thiophene-2-carboxaldhyde, respectively through chalcone reaction. Compounds 3 and 4 were submitted to react with thiosemicarbazide affording 5-(4­hydroxy-3-methoxyphenyl)-3-(5-methyl-1-(5-(methylthio)-1,3,4-thiadiazol-2-yl)-1H-1,2,3-triazol-4-yl)-4,5-dihydro-1H-pyrazole-1-carbothioamide (5) give 3-(5-methyl-1-(5-(methylthio)-1,3,4-thiadiazol-2-yl)-1H-1,2,3-triazol-4-yl)-5-(thiophen-2-yl)-4,5 dihydro-1H-pyrazole-1-carbothioamide (6), respectively. The letters were reacted with N-(4-chlorophenyl)-2-oxopropanehydrazonoyl chloride to give compounds 7 and 8. The chemical compositions of the novel compounds were affirmed by spectral and microanalytical data. Meanwhile, all the newly synthesized compounds have been screened for their ability to prevent the proliferation of different pathogens named Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis, Staphylococcus aureus, and Candida albicans in vitro. Additionally, the potency of the newly synthesized compounds to be anti-COVID-19 candidates was studied through a molecular docking study. The newly prepared molecules 2-8 were studied in silico against transmembrane serine protease 2 (TMPRSS2) to identify their potential therapeutic activity against Coronavirus. Moreover, the drug-likeness of the compounds was tested theoretically by ADMET studies. Compound 8 exhibited a better binding affinity (-9.1 kcal/mol) against the target enzyme TMPRSS2. Additionally, it respects Lipinski's rule of five and has acceptable ADMET properties, indicating that compound 8 could be interesting for the treatment of Covid-19.

Assessment of activity of chalcone compounds as inhibitors of 3-chymotrypsin like protease (3CLPro) of SARS-CoV-2: in silico study.

The COVID-19 is still pandemic due to emerging of various variant of concern of SARS-CoV2. Hence, it is devastating the world, causing significant economic as well as social chaos. This needs great effort to search and develop effective alternatives along with vaccination. Therefore, to continue drug discovery endeavors, we used chalcone derivatives to find an effective drug candidate against SARS-CoV2. Chalcone is a common simple scaffold that exists in many diets as well as in traditional medicine. Natural as well as synthetic chalcones have shown numerous interesting biological activities and are also effective in fighting various diseases. Hence, various computational methods were applied to find out potential inhibitors of 3CLPro using a library of 3000 compounds of chalcones. Firstly, the screening by structure-based pharmacophore model yielded 84 hits that were subjected to molecular docking. The top 10 docked compounds were characterized for stability by using 100 ns molecular dynamic (MD) simulation approach. Further, the binding free energy calculation by MMPBSA showed that four compounds bind to 3CLPro enzyme with high affinity, i.e., - 87.962 (kJ/mol), - 66.125 (kJ/mol), - 59.589 (kJ/mol), and - 66.728 (kJ/mol), respectively. Since chalcone is a common simple scaffold that is present in many diets as well as in traditional medicine, we suggest that screened compounds may emerge as promising drug candidates for SARS-CoV-2. These compounds may be investigated in vitro to evaluate the efficacy against SARS-CoV-2. Supplementary Information: The online version contains supplementary material available at 10.1007/s11224-022-01887-2.

SPECTROSCOPIC PROFILING AND MOLECULAR DOCKING OF NOVEL CHALCONE DERIVATIVE (2E)-1-(3,4-DIMETHOXYPHENYL)-3-(4-N-PROPYLOXYPHENYL)-2-PROPEN-1-ONE-A PROSPECTIVE RESPIRATORY DRUG

The present study explores the wide potential applications of an organic pharmacophore (2E)-1-(3,4-dimethoxyphenyl)-3-(4-n-propyloxyphenyl)-2propen-1-one (DMPP) using experimental and theoretical analysis for the design of prospective respiratory drugs using docking simulations for virtual screening with different strategies. The theoretical analysis was done using Gaussian 09Wsoftware. Optimized geometry, vibrational frequencies were deduced from B3LYP/6-311++G(d,p) basis set. To understand the structure and functional groups of DMPP, UV-Vis, FT-Raman, FT-IR and NMR, ESI-HR mass spectral analysis spectral studies was compared in solid phase and gas phase and found to be in good accord with each other. Fukui functions, Electron Localization Function (ELF) and Localized Orbital Locator (LOL) were studied to diagnose the most active reactive sites of DMPP. Natural Bond Orbital (NBO) and AIM (Atoms Inside Molecule) analysis revealed the inner stability of the compound under investigation. The in vitro and virtual screening of DMPP discloses worthy cytotoxic behavior against normal (VERO) cell lines and anticancer activity with A549-Human Lung cancer cell line, and also proclaims good response against COVID-19 virus. In comparison with the standard clinical trials, the obtained results unveil that the crystalline organic compound is a new material with promising results via molecular docking studies. Thus the diverse methods used in the present study proves the effectiveness of DMPP to be suitable for a respiratory drug where extended in vitro and in vivo research has to be extended towards clinical trials.

Current Discovery Progress of Some Emerging Anti-infective Chalcones: Highlights from 2016 to 2017.

The anti-infective potentials of the natural products are very well known for centuries and are a part of traditional healing. The foremost therapeutic classes include flavones, isoflavones, flavonols, flavanones, flavanols, proanthocyanidins, anthocyanidins, chalcones, and aurones. The chalcone or 1,3-diphenyl-2E-propene-1-one represents the class of natural products which are comprised of benzylideneacetophenone function; i.e. two aromatic moieties linked together by an α, ß-unsaturated carbonyl bridge comprising three-carbons. At present, chalcone is one of the privileged scaffolds that can be synthesized in the laboratory to derive different pharmacologically active compounds. This article is the continued form of the previously published work on anti-infective perspectives of chalcones (highlighted till 2015). The current work emphasizes on the discovery process of the chalcone in the period of 2016 to 2017 on malaria, trypanosomiasis, leishmaniasis, filaria, tuberculosis, netamodes, Human Immunodeficiency Virus (HIV), Tobacco Mosaic Virus (TMV), Severe Acute Respiratory Syndrome (SARS), and miscellaneous conditions. This review comprehensively focuses on the latest progress related with the anti-infective chalcones. The content includes the crucial structural features of chalcone scaffold including structure-activity relationship(s) along with their plausible mechanism of action(s) from the duration Jan 2016 to Dec 2017. This literature will be of prime interest to medicinal chemists in getting ideas and concepts for better rational development of potential anti-infective inhibitors.

Anticoronavirus and Immunomodulatory Phenolic Compounds: Opportunities and Pharmacotherapeutic Perspectives.

In 2019, COVID-19 emerged as a severe respiratory disease that is caused by the novel coronavirus, Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2). The disease has been associated with high mortality rate, especially in patients with comorbidities such as diabetes, cardiovascular and kidney diseases. This could be attributed to dysregulated immune responses and severe systemic inflammation in COVID-19 patients. The use of effective antiviral drugs against SARS-CoV-2 and modulation of the immune responses could be a potential therapeutic strategy for COVID-19. Studies have shown that natural phenolic compounds have several pharmacological properties, including anticoronavirus and immunomodulatory activities. Therefore, this review discusses the dual action of these natural products from the perspective of applicability at COVID-19.

In vitro inhibition and molecular docking of a new ciprofloxacin-chalcone against SARS-CoV-2 main protease.

BACKGROUND/AIM: SARS-CoV-2 is one of the coronavirus families that emerged at the end of 2019. It infected the respiratory system and caused a pandemic worldwide. Fluoroquinolones (FQs) have been safely used as antibacterial agents for decades. The antiviral activity of FQs was observed. Moreover, substitution on the C-7 position of ciprofloxacin enhanced its antiviral activity. Therefore, this study aims to investigate the antiviral activity of 7-(4-(N-substituted-carbamoyl-methyl)piperazin-1yl)-chalcone in comparison with ciprofloxacin against SARS-CoV-2 main protease (Mpro ). MATERIALS AND METHODS: Vero cells were infected with SARS-CoV-2. After treatment with ciprofloxacin and the chalcone at the concentrations of 1.6, 16, 160 nmol/L for 48 h, SARS-CoV-2 viral load was detected using real-time qPCR, SARS-CoV-2 infectivity was determined using plaque assay, and the main protease enzyme activity was detected using in vitro 3CL-protease inhibition assay. The activity of the chalcone was justified through molecular docking within SARS-CoV-2 Mpro , in comparison with ciprofloxacin. RESULTS: The new chalcone significantly inhibited viral load replication where the EC50 was 3.93 nmol/L, the plaque formation ability of the virus was inhibited to 86.8% ± 2.47. The chalcone exhibited a significant inhibitory effect against SARS-CoV-2 Mpro in vitro in a dose-dependent manner. The docking study into SARS-CoV-2 Mpro active site justified the importance of adding a substitution to the parent drug. Additionally, the assessment of the drug-likeness properties indicated that the chalcone might have acceptable ADMET properties. CONCLUSION: The new chalcone might be useful and has new insights for the inhibition of SARS-CoV-2 Mpro .

Synthesis, characterization, and computational study of a new heteroaryl chalcone.

This work presents the synthesis of the chalcone (E)-3-(2,6-difluorophenyl)-1-(furan-2-yl)-prop-2-en-1-one molecule through the equimolar reaction between 1-(furan-2-yl)-ethenone and 2,6-difluorobenzaldehyde. The crystallographic characterization and the extensive theoretical study regarding electronic properties were obtained. The supramolecular arrangement was described by X-ray diffraction and Hirshfeld surfaces. Optimized geometrical structure was obtained by density functional theory, and the electronic study for differences between the solid and gas phases was carried out with M062-X at 6-311++G(2d,2p) basis set. Natural bond orbital, frontier molecular orbitals (HOMO-LUMO), and molecular electrostatic potential map were determined to elucidate the information related to the charge transfer in the molecule. The theoretical and experimental vibrational spectra were plotted, which included the IR intensities, the calculated and experimental vibrational frequencies, and the assigned vibrational modes for the main groups of DTP.