Ferrocenyl chalcones with O-alkylated vanillins: synthesis, spectral characterization, microbiological evaluation, and single-crystal X-ray analysis

Synthesis, characterization, and biological activity of some 2,4-diketo esters containing dehydrozingerone fragment: DNA and protein binding study

Due to the increased resistance to antibiotics, in recent years there has been a growing interest in the discovery of new antimicrobial agents from different sources. Bacteria that are resistant to most antibiotics are a global public health concern. In order to find a new antimicrobial drug, we synthesized a small series of 2,4-diketo esters and tested them on some gram-positive and gram-negative bacterial strains. Two compounds showed very good antibacterial activity against Staphylococcus aureus and Bacillus subtilis, respectively. Trichophyton mentagrophytes proved to be the most sensitive of the tested species regarding antifungal activity. Also, research was conducted on the biomolecule of bovine serum albumin. Examining these interactions, we concluded that all compounds have the appropriate binding affinity for bovine serum albumin, which is vital. Furthermore, to investigate the potential antitumor activity, interactions with DNA were carried out. Examining the interactions between our compounds and DNA using fluorescence, we concluded that all but one of the compounds interacts with the DNA molecule by intercalation. In addition, a molecular docking study was performed to investigate the binding mode of the tested compounds to DNA and bovine serum albumin. In conclusion, all the results indicate a great potential for the future application of these compounds in clinical practice in the future.

Novel eco-friendly [1,2,4]triazolo[3,4-a]isoquinoline chalcone derivatives efficiency against fungal deterioration of ancient Egyptian mummy cartonnage, Egypt

Fungal deterioration is one of the major factors that significantly contribute to mummy cartonnage damage. Isolation and molecular identification of thirteen fungal species contributing to the deterioration of ancient Egyptian mummy cartonnage located in El-Lahun regions, Fayoum government, Egypt was performed. The most dominant deteriorated fungal species are Aspergillus flavus (25.70%), Aspergillus terreus (16.76%), followed by A. niger (13.97%). A newly synthesized series of tetrahydro-[1,2,4]triazolo[3,4-a]isoquinoline chalcone derivatives were synthesized and evaluated for their antifungal activities in vitro against the isolated deteriorated fungal species (Aspergillus flavus, A. niger, A. terreus, Athelia bombacina, Aureobasidium iranianum, Byssochlamys spectabilis, Cladosporium cladosporioides, C. ramotenellum, Penicillium crustosum, P. polonicum, Talaromyces atroroseus, T. minioluteus and T. purpureogenus). The most efficient chalcone derivatives are new chalcone derivative numbers 9 with minimum inhibitory concentration (MIC) ranging from 1 to 3 mg/mL followed by chalcone derivatives number 5 with MIC ranging from 1 to 4 mg/mL.

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.

Antioxidant and Antimicrobial Potential, BSA and DNA Binding Properties of Some 3-Hydroxy-3-Pyrrolin-2-Ones Bearing Thenoyl Fragment

Background:

It is known that pyrrolidinone derivates belong to a class of biologically active compounds with broad spectrum of biological actions. Nowadays, many scientists are making effort in the discovery of the more effective way to eliminate reactive oxygen species (ROS) which cause oxidative stress or to eliminate the harmful microorganisms from the organism in humans. Therefore, pyrrolidinones seem to be great candidates for the investigations this field.

Methods:

The antimicrobial activity of tested compounds was estimated by the determination of the minimal inhibitory concentration by the broth micro-dilution method against four species of bacteria and five species of fungi. The antioxidant activity was evaluated by free radical scavenging and reducing power.

Results:

Among the tested compounds, P22 showed marked antibacterial activity on Staphylococcus aureus with a MIC value of 0.312 mg/mL. Maximum antifungal activity with MIC value 0.625 mg/mL was shown by P23 and P25 compounds against Trichophyton mentagrophytes. Tested samples showed a relatively strong scavenging activity on DPPH radical (IC50 ranged from 166.75-727.17 µg/mL). The strongest DPPH radical scavenging activity was shown by the P3 compound with an IC50 value of 166.75 µg/mL. Moreover, the tested compounds had effective reducing power. Compounds P3, P10, and P13 showed the highest reducing power than those from the other samples. Results of the interactions between DNA or BSA and P3 indicated that P3 had the affinity to displace EB from the EB-DNA complex through intercalation [Ksv = (1.4 ± 0.1) × 105 M-1], while Ka values obtained via titration of BSA with P23 or P25 [Ka = (6.2 ± 0.2) and (5.0 ± 0.2) × 105 M-1] indicate that the notable quantity of the drug can be transmitted to the cells.

Conclusion:

Achieved results indicate that our compounds are potential candidates for use as medicaments.

Recent developments of metal-based compounds against fungal pathogens

This review provides insight into the rapidly expanding field of metal-based antifungal agents. In recent decades, the antibacterial resistance crisis has caused reflection on many aspects of public health where weaknesses in our medicinal arsenal may potentially be present - including in the treatment of fungal infections, particularly in the immunocompromised and those with underlying health conditions where mortality rates can exceed 50%. Combination of organic moieties with known antifungal properties and metal ions can lead to increased bioavailability, uptake and efficacy. Development of such organometallic drugs may alleviate pressure on existing antifungal medications. Prodigious antimicrobial moieties such as azoles, Schiff bases, thiosemicarbazones and others reported herein lend themselves easily to the coordination of a host of metal ions, which can vastly improve the biocidal activity of the parent ligand, thereby extending the library of antifungal drugs available to medical professionals for treatment of an increasing incidence of fungal infections. Overall, this review shows the impressive but somewhat unexploited potential of metal-based compounds to treat fungal infections.

Comparative analyses of new donor-π-acceptor ferrocenyl-chalcones containing fluoro and methoxy-fluoro acceptor units as synthesized dyes for organic solar cell material

Two organometallic compounds known as (E)-1-ferrocenyl-(3-fluorophenyl)prop-2-en-1-one (Fc1) and (E)-1-ferrocenyl-(3-fluoro-4-methoxyphenyl)prop-2-en-1-one (Fc2) are designed and synthesized for application in dye-sensitized solar cell (DSSC) based on a donor-π-acceptor (D-π-A) architecture. By strategically introducing a methoxy group into the acceptor side of the compound, Fc2 which has adopted a D-π-A-AD structure are compared with the basic D-π-A structure of Fc1. Both compounds were characterized by utilizing the IR, NMR and UV-Vis methods. Target compounds were further investigated by X-ray analysis and studied computationally using Density Functional Theory (DFT) and Time-Dependent DFT (TD-DFT) approaches to explore their potential performances in DSSCs. An additional methoxy group has been proven in enhancing intramolecular charge transfer (ICT) by improving the planarity of Fc2 backbone. This good electronic communication leads to higher HOMO energy level, larger dipole moment and better short-circuit current density (J_sc) values. Eventually, the presence of methoxy group in Fc2 has improved the conversion efficiency as in comparison to Fc1 under the same conditions.

Sonochemical Synthesis of 2'-Hydroxy-Chalcone Derivatives with Potential Anti-Oomycete Activity

This work reports on the synthesis of eight new 2′-hydroxy-chalcones with potential anti-phytopathogenic applications in agroindustry, AMONG others, via Claisen–Schmidt condensation and ultrasound assisted reaction. Assays showed three chalcones with allyl moieties strongly inhibited growth of phytopathogenic oomycete Phytophthora infestans; moreover, compound 8a had a half maximal effective concentration (EC₅₀) value (32.5 µg/mL) similar to that of metalaxyl (28.6 µg/mL). A software-aided quantitative structure–activity relationship (QSAR) analysis of the whole series suggests that the structural features of these new chalcones—namely, the fluoride, hydroxyl, and amine groups over the carbon 3′ of the chalcone skeleton—increase anti-oomycete activity.

Chalcone derivatives and their antibacterial activities: Current development

The increase in antibiotic resistance due to various factors has encouraged the look for novel compounds which are active against multidrug-resistant pathogens. In this framework, chalcone-based 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. The growing resistance to antibiotics worldwide has endangered their efficacy. This has led to a surging interest in the discovery of new antibacterial agents. Thus, there is an urgent 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 relationships studies. The various synthetic structures leading to this class of neutral protective compound is common and additional structural optimization is promising for potential drug discovery and development.

Perspectives of ferrocenyl chalcones: synthetic scaffolds toward biomedical and materials science applications

Ferrocene and its derivatives constitute versatile and interesting scaffolds for the global chemical enterprise due to its multiple applications that range from biomedical to materials science. Ferrocenyl derivatives are the leading compounds in our research for the syntheses and characterization as well as their potential biological applications. Among them, our recent focus has been in ferrocenyl chalcones as a framework for further derivatization. The proposed modifications consist on the incorporation of heterocyclic moieties into the ferrocenyl chalcone core. This can be afforded either by introducing a heterocyclic aromatic moiety as a substituent or functionalizing the α-β unsaturated system. Another modification explored is the formation of ammonium or pyridinium salts to increase water solubility. Studied ferrocenyl chalcones exhibit remarkable stability, physical, and electrochemical properties. These factors have led the approaches for them to be precursors of biologically active compounds (cancer, bacteria, malaria, and neurobiological diseases). Moreover, other potential applications include molecular materials, redox-sensors, and polymers. Our goal in this mini review is to highlight the chemistry of ferrocene derivatives with particular prominence to those ferrocenyl chalcones studied in our laboratory and their applications. Moreover, we are providing a background on ferrocene, chalcones, and ferrocenyl chalcones, emphasizing the methodologies with preeminent yields.

Synthesis and DFT Calculations of Novel Vanillin-Chalcones and Their 3-Aryl-5-(4-(2-(dimethylamino)-ethoxy)-3-methoxyphenyl)-4,5-dihydro-1H-pyrazole-1-carbaldehyde Derivatives as Antifungal Agents

Novel (E)-1-(aryl)-3-(4-(2-(dimethylamino)ethoxy)-3-methoxyphenyl) prop-2-en-1-ones 4 were synthesized by a Claisen-Schmidt reaction of 4-(2-(dimethylamino)ethoxy)-3-methoxy-benzaldehyde (2) with several acetophenone derivatives 3. Subsequently, cyclocondensation reactions of chalcones 4 with hydrazine hydrate afforded the new racemic 3-aryl-5-(4-(2-(dimethylamino)ethoxy)-3-methoxyphenyl)-4,5-dihydro-1H-pyrazole-1-carbaldehydes 5 when the reaction was carried out in formic acid. The antifungal activity of both series of compounds against eight fungal species was determined. In general, chalcone derivatives 4 showed better activities than pyrazolines 5 against all tested fungi. None of the compounds 4a–g and 5a–g showed activity against the three Aspergillus spp. In contrast, most of the compounds 4 showed moderate to high activities against three dermatophytes (MICs 31.25–62.5 µg/mL), being 4a followed by 4c the most active structures. Interestingly, 4a and 4c possess fungicidal rather than fungistatic activities, with MFC values between 31.25 and 62.5 μg/mL. The comparison of the percentages of inhibition of C. neoformans by the most active compounds 4, allowed us to know the role played by the different substituents of the chalcones’ A-ring. Also the most anti-cryptococcal compounds 4a–c and 4g, were tested in a second panel of five clinical C. neoformans strains in order to have an overview of their inhibition capacity not only of standardized but also of clinical C. neoformans strains. DFT calculations showed that the electrophilicity is the main electronic property to explain the differences in antifungal activities for the synthesized chalcones and pyrazolines compounds. Furthermore, a quantitative reactivity analysis showed that electron-withdrawing substituted chalcones presented the higher electrophilic character and hence, the greater antifungal activities among compounds of series 4.

Cytotoxic and Antimicrobial Activity of Dehydrozingerone based Cyclopropyl Derivatives

A small series of 1-acetyl-2-(4-alkoxy-3-methoxyphenyl)cyclopropanes was prepared, starting from dehydrozingerone (4-(4-hydroxy-3-methoxyphenyl)-3-buten-2-one) and its O-alkyl derivatives. Their microbiological activities toward some strains of bacteria and fungi were tested, as well as their in vitro cytotoxic activity against some cancer cell lines (HeLa, LS174 and A549). All synthesized compounds showed significant antimicrobial activity and expressed cytotoxic activity against tested carcinoma cell lines, but they showed no significant influence on normal cell line (MRC5). Butyl derivative is the most active on HeLa cells (IC₅₀ = 8.63 μm), while benzyl one is active against LS174 and A549 cell lines (IC₅₀ = 10.17 and 12.15 μm, respectively).

Ferrocenyl based pyrazoline derivatives with vanillic core: synthesis and investigation of their biological properties

Synthesis of four novel series of ferrocenyl based pyrazoline derivatives with vanillic core are described and microbiological, BSA and DNA binding studies conducted.