Antimicrobial, Anti-Inflammatory and Antioxidant Activities of Polyoxygenated Chalcones

Antibacterial potential of chalcones and its derivatives against Staphylococcus aureus

Chalcones are natural substances found in the metabolism of several botanical families. Their structure consists of 1,3-diphenyl-2-propen-1-one and they are characterized by having in their chains an α, β-unsaturated carbonyl system, two phenol rings and a three-carbon chain that unites them. In plants, Chalcones are mainly involved in the biosynthesis of flavonoids and isoflavonoids through the phenylalanine derivation. This group of substances has been shown to be a viable alternative for the investigation of its antibacterial potential, considering the numerous biological activities reported and the increase of the microbial resistance that concern global health agencies. Staphylococcus aureus is a bacterium that has stood out for its ability to adapt and develop resistance to a wide variety of drugs. This literature review aimed to highlight recent advances in the use of Chalcones and derivatives as antibacterial agents against S. aureus, focusing on research articles available on the Science Direct, Pub Med and Scopus data platforms in the period 2015-2021. It was constructed informative tables that provided an overview of which types of Chalcones are being studied more (Natural or Synthetic); its chemical name and main Synthesis Methodology. From the analysis of the data, it was observed that the compounds based on Chalcones have great potential in medicinal chemistry as antibacterial agents and that the molecular skeletons of these compounds as well as their derivatives can be easily obtained through substitutions in the A and B rings of Chalcones, in order to obtain the desired bioactivity. It was verified that Chalcones and derivatives are promising agents for combating the multidrug resistance of S. aureus to drugs.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-022-03398-7.

Metal Complexation of Bis-Chalcone Derivatives Enhances Their Efficacy against Fusarium Wilt Disease, Caused by Fusarium equiseti, via Induction of Antioxidant Defense Machinery

Sweet pepper (Capsicum annuum L.) is one of the most widely produced vegetable plants in the world. Fusarium wilt of pepper is one of the most dangerous soil-borne fungal diseases worldwide. Herein, we investigated the antifungal activities and the potential application of two chalcone derivatives against the phytopathogenic fungus, Fusarium equiseti, the causal agent of Fusarium wilt disease in vitro and in vivo. The tested compounds included 3-(4-dimethyl amino-phenyl)-1-{6-[3-(4 dimethyl amino-phenyl)-a cryloyl]-pyridin-2-yl}-propanone (DMAPAPP) and its metal complex with ruthenium III (Ru-DMAPAPP). Both compounds had potent fungistatic activity against F. equiseti and considerably decreased disease progression. The tested compounds enhanced the vegetative growth of pepper plants, indicating there was no phytotoxicity on pepper plants in greenhouse conditions. DMAPAPP and Ru-DMAPAPP also activated antioxidant defense mechanisms that are enzymatic, including peroxidase, polyphenole oxidase, and catalase, and non-enzymatic, such as total soluble phenolics and total soluble flavonoids. DMAPAPP and Ru-DMAPAPP also promoted the overexpression of CaCu-SOD and CaAPX genes. However, CaGR and CaMDHAR were downregulated. These results demonstrate how DMAPAPP and Ru-DMAPAPP could be employed as a long-term alternative control approach for Fusarium wilt disease as well as the physiological and biochemical mechanisms that protect plants.

Cyclohexanone-Based Chalcones as Alternatives for Fuel Additives

The use of small molecules, such as chalcones and their derivatives, for more efficient fuels is in increasing demand due to environmental factors. Here, three crystal structures (BH I, II, and III) of cyclohexanone-based chalcones were synthesized and described by single-crystal X-ray diffraction and Hirshfeld surface analysis. The supramolecular modeling analysis on the hyperconjugative interaction energies and QTAIM analysis at the ωB97XD/6-311++G(d,p) level of theory were carried out to analyze the intermolecular interactions in the solid-state. The structure-property relationship, frontier molecular orbital, molecular electrostatic potential, and the experimental calorific value analysis show that the three compounds are a good alternative to be used as an additive for some fuels. Our findings represent a further step forward in the development of cheaper and more efficient fuel additives and pose an opportunity for further investigation on similar analogues.

Insights on a new sulfonamide chalcone with potential antineoplastic application

Chalcones (E)-1,3-diphenyl-2-propene-1-ones, a class of biosynthetic precursor molecules of flavonoids, have a wide variety of biological applications. Besides the natural products, many synthetic derivatives and analogs became an object of continued interest in academia and industry. In this work, a synthesis and an extensive structural study were performed on a sulfonamide chalcone 1-Benzenesulfonyl-3-(4-bromobenzylidene)-2-(2-chlorophenyl)-2,3-dihydro-1H-quinolin-4-one with potential antineoplastic application. In addition, in silico experiments have shown that the sulfonamide chalcone fits well in the ligand-binding site of EGFR with seven μ-alkyl binding energy interactions on the ligand-binding site. Finally, the kinetic stability and the pharmacophoric analysis for EGFR indicated the necessary spatial characteristics for potential activity of sulfonamide chalcone as an antagonist.

Density Functional Theory and Molecular Docking Investigations of the Chemical and Antibacterial Activities for 1-(4-Hydroxyphenyl)-3-phenylprop-2-en-1-one

The present investigation informs a descriptive study of 1-(4-Hydroxyphenyl) -3-phenylprop-2-en-1-one compound, by using density functional theory at B3LYP method with 6-311G** basis set. The oxygen atoms and π-system revealed a high chemical reactivity for the title compound as electron donor spots and active sites for an electrophilic attack. Quantum chemical parameters such as hardness (η), softness (S), electronegativity (χ), and electrophilicity (ω) were yielded as descriptors for the molecule’s chemical behavior. The optimized molecular structure was obtained, and the experimental data were matched with geometrical analysis values describing the molecule’s stable structure. The computed FT-IR and Raman vibrational frequencies were in good agreement with those observed experimentally. In a molecular docking study, the inhibitory potential of the studied molecule was evaluated against the penicillin-binding proteins of Staphylococcus aureus bacteria. The carbonyl group in the molecule was shown to play a significant role in antibacterial activity, four bonds were formed by the carbonyl group with the key protein of the bacteria (three favorable hydrogen bonds plus one van der Waals bond) out of six interactions. The strong antibacterial activity was also indicated by the calculated high binding energy (−7.40 kcal/mol).

C3 amino-substituted chalcone derivative with selective adenosine rA1 receptor affinity in the micromolar range

ABSTRACT

To identify novel adenosine receptor (AR) ligands based on the chalcone scaffold, herein the synthesis, characterization and in vitro and in silico evaluation of 33 chalcones (15-36 and 37-41) and structurally related compounds (42-47) are reported. These compounds were characterized by radioligand binding and GTP shift assays to determine the degree and type of binding affinity, respectively, against rat (r) A1 and A2A ARs. The chalcone derivatives 24, 29, 37 and 38 possessed selective A1 affinity below 10 µM, and thus, are the most active compounds of the present series; compound 38 was the most potent selective A1 AR antagonist (K i (r) = 1.6 µM). The structure-affinity relationships (SAR) revealed that the NH2-group at position C3 of ring A of the chalcone scaffold played a key role in affinity, and also, the Br-atom at position C3' on benzylidene ring B. Upon in vitro and in silico evaluation, the novel C3 amino-substituted chalcone derivative 38-that contains an α,ß-unsaturated carbonyl system and easily allows structural modification-may possibly be a synthon in future drug discovery.

GRAPHIC ABSTRACT

C3 amino-substituted chalcone derivative (38) with C3' Br substitution on benzylidene ring B possesses selective adenosine rA1 receptor affinity in micromolar range.

Biological Properties and Absolute Configuration of Flavanones From Calceolaria thyrsiflora Graham

Flavanones (-)-(2S)-5,4'-dihydroxy-7-methoxyflavanone (1) and (-)-(2S)-5,3',4'-trihydroxy-7-methoxyflavanone (2) were isolated from the extracts of Calceolaria thyrsiflora Graham, an endemic perennial small shrub growing in the central zone of Chile. The absolute configuration of these compounds was resolved by optical rotation experiments and in silico calculations. Three analogs (3, 4, and 5) were synthesized to do structure-activity relationships with the biological assays studied. Biological tests revealed that only flavanone 2 exhibited a moderate inhibitory activity against the methicillin-resistant strain S. aureus MRSA 97-77 (MIC value of 50 µg/ml). In addition, flavanone 2 showed a potent, selective, and competitive inhibition of 5-hLOX, which supports the traditional use of this plant as an anti-inflammatory in diseases of the respiratory tract. Also, 2 exhibited cytotoxic and selective effects against B16-F10 (8.07 ± 1.61 µM) but 4.6- and 17-fold lesser activity than etoposide and taxol.

Novel Insights into the Mode of Action of Vasorelaxant Synthetic Polyoxygenated Chalcones

Polyphenols consumption has been associated with a lower risk of cardiovascular diseases (CVDs) notably through nitric oxide (NO)- and estrogen receptor α (ERα)-dependent pathways. Among polyphenolic compounds, chalcones have been suggested to prevent endothelial dysfunction and hypertension. However, the involvement of both the NO and the ERα pathways for the beneficial vascular effects of chalcones has never been demonstrated. In this study, we aimed to identify chalcones with high vasorelaxation potential and to characterize the signaling pathways in relation to ERα signaling and NO involvement. The evaluation of vasorelaxation potential was performed by myography on wild-type (WT) and ERα knock-out (ERα-KO) mice aorta in the presence or in absence of the eNOS inhibitor Nω-nitro-L-arginine methyl ester (L-NAME). Among the set of chalcones that were synthesized, four (3, 8, 13 and 15) exhibited a strong vasorelaxant effect (more than 80% vasorelaxation) while five compounds (6, 10, 11, 16, 17) have shown a 60% relief of the pre-contraction and four compounds (12, 14, 18, 20) led to a lower vasorelaxation. We were able to demonstrate that the vasorelaxant effect of two highly active chalcones was either ERα-dependent and NO-independent or ERα-independent and NO-dependent. Thus some structure-activity relationships (SAR) were discussed for an optimized vasorelaxant effect.