A new coumarin derivative, 4-acetatecoumarin, with antifungal activity and association study against Aspergillus spp

Antibacterial Activity for Synthesized Coumarin Derivatives and a Coumarin Component of Lime Peel (Citrus aurantifolia)

In this study, we investigated the antibacterial activity of the coumarin component isolated from lime peel and coumarin derivatives synthesized using various techniques against eight types of food-poisoning bacteria. The minimum inhibitory concentration (MIC) for the 3b [5,7-dihydroxy-4-trifluoromethylcoumarin] derivative was measured as 1.5 mM in Bacillus cereus, Micrococcus luteus, Listeria monocytogenes, and Staphylococcus aureus subsp. aureus; that for the 3c [7-hydroxy-4-trifluoromethylcoumarin] derivative was 1.7 mM in Enterococcus facium; and that for the 3n [dicoumarol] derivative was 1.2 mM in L. monocytogenes. These results confirmed that coumarin derivatives with CF3 and OH substituents had enhanced antibacterial activity.

Plant-Derived Coumarins: A Narrative Review of Their Structural and Biomedical Diversity

Plant-derived coumarin (PDC) is a naturally occurring heterocyclic backbone that belongs to the benzopyrone family. PDC and its based products are characterized by low toxicity and high distribution in a variety of herbal treatments that have numerous therapeutic potentials. These include anticoagulants, antibacterials, anti-inflammatory agents, anticancer agents, antioxidants, and others. So, it may be appropriate to investigate the qualities and potential bioactivities of PDCs. This article provides an overview of the biomedical potentials, availability, and clinical use possibilities of PDCs, with a focus on their important modes of action, using information on various pharmacological qualities discovered. The data used in this study came from published research between 2015 and 2023. We reviewed a selection of databases, including PubMed, Scopus, Web of Science, and Google Scholar, during that period. In conclusion, because of their abundance in medicinal plants, the clinical biochemistry attributes of PDCs are currently of interest. In a variety of medical specialties, PDCs serve a useful role as therapeutic agents.

Isoborneol as a natural sporulation quenching agent to control Aspergillus flavus

In an effort to seek natural antisporulating agents used in the control of Aspergillus flavus, 54 essential oil compounds were employed to evaluate their antisporulating activity against A. flavus at the concentration of 100 μg/mL. The results indicated that isoborneol could inhibit spore production at 100 μg/mL. The light microscopy and scanning electron microscopy (SEM) observations revealed that A. flavus did not produce any conidia, vesicles, phialides and conidiophores after treatment with isoborneol at 80 μg/mL, confirming the effectiveness of isoborneol. The in vivo bioassay results demonstrated that isoborneol could prevent the peanuts from A. flavus contamination by inhibiting the sporulation when treated with isoborneol at concentrations higher than 100 μg/mL. RT-qPCR results suggested that isoborneol exerts its antisporulating activity by suppressing the fluG expression. These results proved that isoborneol could be used as a natural and safe antisporulating agent for commercial applications to control spore infections of A. flavus.

An Efficient Synthesis of Novel 3-[(Heteroaryl-2-ylimino)-methyl]-4-hydroxy-chromen-2-ones and Analogue of Tetrazole Derivatives and Their Antibacterial Activity

Synthesis of a series of the substituted [(pyridinyl and pyrimidin-2-ylimino)-ethyl]-4-hydroxy-chromen-2-ones and their tetrazole derivates is presented in this study. By catalytic condensation of 4-hydroxy-3-acetylcoumarine 2 and 2-aminopyridines 3(a-d), 3-[(pyridin-2-ylimino)-ethyl]-4-hydroxy-chromen-2-ones 4(a-d) are synthesized in high yield. During the condensation reaction of 2 and 4-amino-2,6-dihydroxypyrimidine 3e, 3-[1-(2,6-Dihydroxy-pyrimidin-4-ylimino)-ethyl]-4-hydroxy-chromen-2-one 4e as condensation products is synthesized. In following series, by cyclization reactions of compounds 4 (a-e) with sodium azide, analogue 3-substituted pyridin-2-yl and pyrimidin-2-yl-5-methyl-2,5-dihydro-1H-tetrazol-5-yl]-4-hydroxy-chromen-2-one 5(a-e) are synthesized the products. Structural characterization of the synthesized products is done on the basis of spectrometric data. Antibacterial activity of the compounds 4(a-e) and 5(a-e) against S. aureus, E. coli and Klebsiella was examined by measuring the inhibition zones around the disks marked with the corresponding products solution. The impact of substitutions in antimicrobial is also explored. Compounds with polar groups have shown significant antibacterial activity against these microorganisms.

One-Pot Synthesis of 4-Carboalkoxy-Substituted Benzo[h]coumarins from α- and β-Naphthols and Their Excited-State Properties

One-pot synthesis has been developed for 4-carboethoxybenzo[h]coumarins starting from α-/β-naphthols. Accordingly, diverse 4-carboethoxybenzocoumarins can be synthesized in moderate-to-excellent (31-75%) isolated yields. The synthesis involves initial oxidation of naphthols to the intermediary 1,2-naphthoquinones with 2-iodoxybenzoic acid followed by a cascade of reactions, namely, Wittig olefination, Michael addition, β-elimination, and cyclization. Furthermore, we have comprehensively investigated the excited-state properties of differently substituted 4-carboalkoxybenzo[h]coumarins. It is shown that they exhibit low to high fluorescence quantum yields (1-36%) and excited-state lifetimes (ca. 1-7 ns) depending on the substitution pattern and solvent employed.

Coumarins: antifungal effectiveness and future therapeutic scope

The antifungals that are in current clinical practice have a high occurrence of a side effect and multidrug resistance (MDR). Researchers across the globe are trying to develop a suitable antifungal that has minimum side effect as well as no MDR issues. Due to serious undesired effects connected with individual antifungals, it is now necessary to introduce novel and effective drugs having numerous potentials to regulate complex therapeutic targets of several fungal infections simultaneously. Thus, by taking a lead from this subject, synthesis of potent antifungals from coumarin moiety could contribute to the development of promising antifungal. Its resemblance and structural diversity make it possible to produce an auspicious antifungal candidate. Due to the natural origin of coumarin, its presence in diversity, and their broad spectrum of pharmacological activities, it secures an important place for the researcher to investigate and develop it as a promising antifungal in future. This manuscript discusses the bioavailability of coumarin (natural secondary metabolic molecule) that has privileged scaffold for many mycologists to develop it as a broad-spectrum antifungal against several opportunistic mycoses. As a result, several different kinds of coumarin derivatives were synthesized and their antifungal properties were evaluated. This review compiles various coumarin derivatives broadly investigated for antifungal activities to understand its current status and future therapeutic scope in antifungal therapy.

Recent advances in allelopathy for weed control: from knowledge to applications

Allelopathy is the biological phenomenon of chemical interactions between living organisms in the ecosystem, and must be taken into account in addressing pest and weed problems in future sustainable agriculture. Allelopathy is a multidisciplinary science, but in some cases, aspects of its chemistry are overlooked, despite the need for a deep knowledge of the chemical structural characteristics of allelochemicals to facilitate the design of new herbicides. This review is focused on the most important advances in allelopathy, paying particular attention to the design and development of phenolic compounds, terpenoids and alkaloids as herbicides. The isolation of allelochemicals is mainly addressed, but other aspects such as the analysis and activities of derivatives or analogs are also covered. Furthermore, the use of allelopathy in the fight against parasitic plants is included. The past 12 years have been a prolific period for publications on allelopathy. This critical review discusses future research areas in this field and the state of the art is analyzed from the chemist's perspective. © 2019 Society of Chemical Industry.