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Coumarin and its derivatives, presenting in many organisms (plants, fungi, and bacteria), are critical metabolites composed of fused benzene and α-pyrone rings. With unique biological and chemical properties, coumarin derivatives possess great technological potential in the agrochemicals, pharmaceuticals, food, and cosmetic industries. The increasing demand for coumarin derivatives accelerates the research in biological and chemical synthesis to provide stable and scalable sources of coumarins. However, the complex structures and unknown pathways have limited the progress in the biosynthesis of coumarin derivatives. Here, we summarize recent developments and provide a detailed analysis of coumarin derivative biosynthetic pathways in different organisms.

White spot disease (WSD), attributed to the white spot syndrome virus (WSSV), represents a substantial danger to the international shrimp sector, resulting in considerable losses in both production and economic terms. Nevertheless, there are currently no approved therapeutic measures to control the outbreak. This study involved the synthesis of 15 new compounds for the assessment of their anti-WSSV efficacy in Litopenaeus vannamei post-larvae. Among these compounds, N-(4-methyl-2-oxo-2H-chromen-7-yl)acetamide (P13) exhibited a maximum antiviral response of > 90 %, with a median effective concentration (EC50) < 12 mg/L, making P13 the most promising antiviral compound. In the cases where the larvae were simultaneously incubated with WSSV and P13, as well as where the larvae were first infected with WSSV and then treated with P13, the replication of WSSV was significantly inhibited. However, pre-treatment with P13 had minimal impact on WSSV multiplication, suggesting a potential therapeutic effect. Simultaneously, the cumulative mortality rate of WSSV-infected post-larvae decreased in the presence of P13. After the shrimp larvae were infected with WSSV, continuously changing the aquacultural water containing DMSO resulted in a mortality rate of 80 % at 120 hours post-infection (hpi); whereas continuously changing the aquaculture water containing P13 resulted in a mortality rate of 45 %. Given that P13 remains stable in farmed water for up to two days, it is recommended to regularly replace the medication to eliminate the virus threat. In conclusion, P13 demonstrates a positive anti-WSSV activity and holds potential for further development as an antiviral therapy against WSSV infection.

Coronaviruses have emerged as a global health challenge, with the recent outbreak of SARS-CoV-2 affecting more than 600 million individuals worldwide. While vaccination remains a central preventive approach, addressing SARS-CoV-2 involves antiviral drugs, monoclonal antibodies, and corticosteroids. Research indicates that coumarin exhibits potent antiviral properties. Therefore, this study aimed to investigate the antiviral properties of newly synthesized coumarin analogues (NCA) against coronaviruses. The study involved the synthesis of NCAs through esterification, hydrazination, imination, and cyclo-condensation reactions, followed by their characterization using FTIR, NMR, and Mass Spectrometry. Cell viability analysis was conducted using HEK-293 cells, and the viral replication inhibition activity of NCAs against OC43 was assessed using plaque assays. The antiviral activity of NCAs against the Infectious Bronchitis Virus (IBV) was evaluated based on mortality rate, lesion development, and viral RNA load suppression. The study successfully synthesized NCAs and elucidated their structures. The viral plaque assay demonstrated the ability of NCAs to effectively inhibit viral replication. Analysis of viral RNA by qRTPCR confirmed a decrease in OC43 viral load following NCA treatment. Immunofluorescence assays also showed a reduction in SARS-CoV-2 infection in the presence of NCAs. Evaluation of cytotoxicity using HEK-293 cells indicated that NCAs exhibited a favourable safety profile while effectively inhibiting IBV viral replication. These findings highlight the promising antiviral activities of NCAs against coronavirus replication and infection.

Coumarin derivatives were synthesized herein from 3-acetyl coumarin and 4-(pyrimidin-2-yldiazenyl) antipyrine, leading to the azo chalcone intermediate compound. The final spiro-heterocyclic coumarins were produced through the cyclization of the azo-chalcone with thiourea, guanidine hydrochloride, benzene-1,2-diamine, 2-aminophenol, and hydroxylamine hydrochloride, respectively. The obtained target compounds were purified by column chromatography and characterized by FT-IR, 1H NMR, 13C-NMR and elemental analysis. The antibacterial activity of the synthesized compounds was evaluated in vitro against Gram-negative and Gram-positive bacteria. One of the compounds showed significant antibacterial activity. Furthermore, the docking study of this compound with DNA gyrase for E. coli and S. aureus bacterial strains was investigated, which revealed vital interactions and binding.

Solvent and substitution effects on the UV/Vis spectroscopic and fluorescence behaviour of seven synthesized 3-substituted 4-hydroxycoumarin derivatives were tested. The tested compounds were dissolved in ethyl acetate, acetonitrile, and dimethyl sulfoxide. Absorption and emission spectra were recorded in the range of 200–800 nm. All tested 4-hydroxycoumarin derivatives showed good absorption in a wide range of 200–550 nm, depending on the properties of the substituents on the benzene ring of the cinnamoyl moiety and the type of solvent. In comparison to the unsubstituted analogue, compounds with an electron-donating group exhibited bathochromically shifted UV/Vis absorption and emission spectra. The highest fluorescence quantum yield was observed for compounds with dimethylamino and acetamido groups as substituents at the benzene ring. Considering that both substitution and solvent affect the absorption and emission spectra of the tested compounds, it can be concluded that judiciously selecting these parameters can improve their absorption and fluorescence properties, making them suitable for various analytical uses.

Introduction: Echinococcus granulosus is the causative agent of hydatid cysts, which are distributed worldwide. Nowadays, much research is being done to inactivate hydatid cyst protoscoleces. This study was conducted with the aim to compare the scolicidal effect of two chemical compounds 12 and 2 on hydatid cyst protoscoleces in vitro. Material & Methods: The scolicidal activity of two amini-hydrox-phenylcoumarin and amini-bromo-phenylcoumarin at concentrations of 1.2, 1.5, 1.10 and 1.100 after 15, 30 and 60 minutes of incubation was tested separately and each of the experiments was repeated three times. The viability of protoscoleces was checked with 0.1% eosin dye under a light microscope. Subsequently data were analyzed using GraphPad version 5 software and two-way repeated measures ANOVA and values (P > 0.05) was considered a significant level. Findings: The results of this study showed that the chemical compound amini-bromophenylcoumarin at a concentration of 1.10 destroyed 100% of protoscoleces after 60 minutes of exposure compared to the control group, but amini-hydroxophenyl-coumarin, at a concentration of 1.100 could destroy 98% of protoscolecia after 60 minutes of exposure. Discussion & Conclusion: The results of the present study showed that amini-bromophenylcoumarin had stronger protoscolicidal effects than amini-hydroxophenyl-coumarin. However, further studies and in vivo studies are needed to evaluate the efficacy of these chemical compounds.

Tumour associated carbonic anhydrases (CAs) IX and XII have been recognised as potential targets for the treatment of hypoxic tumours. Therefore, considering the high pharmacological potential of the chromene scaffold as selective ligand of the IX and XII isoforms, two libraries of compounds, namely 2H-chromene and 7H-furo-chromene derivatives, with diverse substitution patterns were designed and synthesised. The structure of the newly synthesised compounds was characterised and their inhibitory potency and selectivity towards human CA off target isoforms I, II and cancer-associated CA isoforms IX and XII were evaluated. Most of the compounds inhibit CA isoforms IX and XII with no activity against the I and II isozymes. Thus, while the potency was influenced by the substitution pattern along the chromene scaffold, the selectivity was conserved along the series, confirming the high potential of both 2H-chromene and 7H-furo-chromene scaffolds for the design of isozyme selective inhibitors.

Introduction/Objective. Coumarin therapy represents one of the best models for applying pharmacogenetics. The contribution of factors influencing coumarin therapy can vary significantly between ethnic groups, which justifies conducting population-specific studies. The aim of this study was to analyze the influence of the most important genetic factors (VKORC1 and CYP2C9 genes) that affect coumarin therapy in patients from Serbia. Methods. A retrospective study involving 207 patients on acenocoumarol therapy was conducted. Genetic analyses were performed by direct sequencing. Influence on acenocoumarol dose of variants (VKORC1, CYP2C9*2, CYP2C9*3) causing hypersensitivity and VKORC1 variants causing resistance to acenocoumarol were analyzed. Multiple regression analysis was used to design a mathematical model for predicting individual drug dosage based on clinical-demographic and genetic data. Results. The study confirmed significant influence of the analyzed genetic factors on acenocoumarol maintenance dose. We designed mathematical model for predicting individual acenocoumarol dose and its unadjusted R2 was 61.8. In the testing cohort, our model gave R2 value of 42.6 and showed better prediction in comparison with model given by other authors. In the analyzed patients, nine different variants in the VKORC1 coding region were found. Among carriers of these variants 78% were completely resistant, and it was not possible to achieve therapeutic effect even with high doses of acenocoumarol. Conclusions. Population-specific model for prediction individual dose of acenocoumarol, may show advantages over protocols that are used in a generalized manner. Also, VKORC1 variants which cause coumarin resistance should be considered when planning therapy.

This study presents a novel method for the photocatalytic synthesis of 4-aryl-6-(3-coumarinyl) pyrimidin-2 (1H)-ones (a coumarin derivative) using strawberry dye-sensitized TiO2 (SD-TiO2) under visible light. The synthesis of 4-aryl-6-(3-coumarinyl) pyrimidin-2 (1H)-ones was achieved through a three-component, one-pot condensation reaction involving 3-acetyl coumarin, aldehydes, and urea, utilizing SD-TiO2 as a reusable and innovative photocatalyst at room temperature. The resulting SD-TiO2 photocatalyst was thoroughly characterized using FT-IR, XPS, XRD, SEM, and BET. The efficacy of SD-TiO2 was evaluated by comparing it to pristine TiO2 in terms of photocatalytic activity, and the optimal conditions for the synthesis process were determined. Notably, the SD-TiO2 photocatalyst exhibited a maximum yield of the compound, reaching up to 96% in just 30 min with a catalyst concentration of 1 mg/mL. This yield surpasses traditional thermal procedures employing reflux conditions, where 1 mg/mL of SD-TiO2 is sufficient to complete the reaction. The resulting 4-aryl-6-(3-coumarinyl) pyrimidin-2 (1H)-ones were further characterized using 1H-NMR and 13C-NMR. Moreover, the stability of the SD-TiO2 photocatalyst was confirmed through recyclability experiments and spectroscopic characterization, demonstrating its practicality for up to three consecutive reaction cycles.

In this study, potent coumarin derivatives containing oxime ester 1 ∼ 28 as α-glucosidase inhibitors were developed through a stepwise structure optimization, and the structure activity relationship was uncovered. Among them, compound 20 exhibited outstanding α-glucosidase inhibitory activity with IC50 of 2.54 ± 0.04 μM compared to 640.57 ± 1.13 μM of Acarbose. Kinetic study ascertained that compound 20 was a reversible and uncompetitive α-glucosidase inhibitor. 3D fluorescence results showed that the interaction of compound 20 with α-glucosidase caused the changes of microenvironments and polypeptide backbone structure of α-glucosidase. CD spectra results revealed that compound 20 decreased the α-helix content and increased the β-sheet content. Molecular docking analysis indicated that compound 20 well located into the active site and mainly bind with Phe157, His239, His279, Tyr71, and Arg312 to reduce the catalytic activity of α-glucosidase.

In the present work, we synthesized seven complexes. All complexes were identified by ESI-HRMS, 1H-NMR, 19F-NMR and 13C-NMR spectroscopies. The synthesized complexes were tested for their anticancer activities in vitro against three different human cell lines, including breast MDAMB231, cervical Hela, liver HepG2. IC50 values of complexes 1-7 were 34.98–667.35 µM. Complex 5 revealed higher sensitivity towards MDAMB231 cells with IC50 values 34.98 μM in comparison to 5-FU as positive control. Moreover, complex 5 caused a decrease of mitochondrial membrane potential and effectively induced ROS production against MDAMB231 cells. Western blot analysis showed that complex 5 could up-regulate the expression of Bax protein and down-regulate the expression of Bcl-2, activate Caspase-3, slightly down-regulate the expression of HO-1. The docking studies showed that complex 5 could be interacted with Bcl-2 protein through hydrophobic interactions, hydrogen bonds and salt bridges to enhance the binding affinity. All the analyzed coumarins obeyed the Lipinski’s rule of five for orally administered drugs. Based on the aforementioned results, it suggests that the complex induced apoptosis cell via mitochondria pathways. Collectively, complex 5 could be considered as a promising hit for new anti-breast cancer agents. Carbonyl cobalt CORMs, as potential anticancer therapeutic agents, provided a new idea for the development of metal anticancer drugs.

Background: Ferulago angulata (Schltdl.) Boiss. is a herbaceous perennial plant distributed in Iran, Turkey and Iraq. The aromatic aerial parts of this plant are commonly used as antiseptic, sedative, wound healing, analgesic and food additive. Methods: Column chromatography on silica gel (normal phase and RP-18) and Sephadex LH-20, along with recrystallization method were applied to isolation of the phytochemicals extracted from F. angulata fruits. The structures of the isolated compounds were characterized by 1H-NMR and 13C-NMR spectral analysis. Chemical composition of the fruits essential oil obtained by hydrodistillation (HD) and steam distillation (SD) methods were also analyzed using GC-MS technique. Results: Six coumarin derivatives; suberosin (1), isoimperatorin (2), imperatorin (3), bergapten (4), tamarin (5) and suberenol (6), a monoterpene glycoside; verbenone-5-O-β-D-glucopyranoside (7), together with five flavonol-3-O-glycosides; isorhamnetin-3-O-rutinoside (narcissin) (8), kaempferol-3-O-rutinoside (nicotiflorin) (9), quercetin-3-O-rutinoside (rutin) (10), isorhamnetin-3-O-β-D-glucuronide (11), isorhamnetin-3-O-β-D-glucopyranoside (12) were isolated from F. angulata fruits. Essential oil extraction using HD and SD methods afforded colorless oils in 4.1 and 1.8% (v/w) yields, respectively. A total of 28 compounds were identified in essential oils, of which (Z)-β-ocimene (HD; 48.97%, SD; 50.02%), α-pinene (HD; 21.32%, SD; 23.06%) and allo-ocimene (HD; 6.98%, SD; 5.61%) were the main compounds. Conclusion: This study introduces F. angulata fruits as a new source of coumarin derivatives and flavonoid glycosides. The presence of these compounds with known biological properties provides more medicinal potentials for the fruits of F. angulata. The present study also reports hydrodistillation, as an efficient method for extraction of essential oil from these aromatic fruits.

Graphical AbstractA novel series of 3-phenyl-coumarin derivatives containing pyridinium salts was prepared, indicating significant inhibitory activity against AChE and BuChE as well as precious neuroprotective and anti-Aβ aggregation effects.

The fluorescence coumarin derivatives were synthesised by an efficient one-pot, three-component reaction in 80–90% yields. The optical properties of these coumarin derivatives (4a-4d), such as the influence of different solvent to the fluorescence intensity and absorption intensity, and the influence of different substituent groups and the concentration of the solution are investigated. The results show that the fluorescence intensity of the compounds are the largest in the DMF（N,N-dimethyllformamide). Specifically speaking, the absorption spectrum is at approximately 308 nm, the fluorescence spectrum is at nearly 435 nm in the DMF, the Stocks shift approaches127 nm. In our case the fluorescence intensity decreases with the increase of the concentration of the solution, which is called concentration quenching. Additionally, the affection of solvent was also confirmed by TD-DFT (Time-dependent density functional theory)calculations.

Three coumarin-based boron complexes (L1, L2 and L3) were designed and successfully incorporated into polymeric matrixes for evaluation as temperature probes. The photophysical properties of the complexes were carried out in different solvents and in the solid state. In solution, compound L1 exhibited the highest fluorescence quantum yield, 33%, with a positive solvatochromism also being observed on the absorption and emission when the polarity of the solvent increased. Additionally in the presence of anions, L1 showed a colour change from yellow to pink, followed by a quenching in the emission intensity, which is due to deprotonation with the formation of a quinone base. Absorption and fluorescence spectra of L1 were calculated at different temperatures by the DFT/B3LYP method. The decrease in fluorescence of compound L1 with an increase in temperature seems to be due to the presence of pronounced torsional vibrations of the donor and acceptor fragments relative to the single bond with C(carbonyl)-C (styrene fragment). L1, L2 and L3, through their incorporation into the polymeric matrixes, became highly emissive by aggregation. These dye@doped polymers were evaluated as temperature sensors, showing an excellent fluorescent response and reversibility after 15 cycles of heating and cooling.

In this study, a series of coumarin derivatives, either alone or as hybrids with cinnamic acid, were synthesized and evaluated for their cytotoxicity against a panel of cancer cells using the MTT assay. Then, the most active compounds were inspected for their mechanism of cytotoxicity by cell-cycle analysis, RT-PCR, DNA fragmentation, and Western blotting techniques. Cytotoxic results showed that compound (4) had a significant cytotoxic effect against HL60 cells (IC50 = 8.09 µM), while compound (8b) had a noticeable activity against HepG2 cells (IC50 = 13.14 µM). Compounds (4) and (8b) mediated their cytotoxicity via PI3K/AKT pathway inhibition. These results were assured by molecular docking studies. These results support further exploratory research focusing on the therapeutic activity of coumarin derivatives as cytotoxic agents.

MAO-B leads to an increase in the levels of hydrogen peroxide and oxidative free radicals, which contribute to the aetiology of the AD. Thus, both iron ion chelators and MAO-B inhibitors can be used to treat AD. Taking the coumarin derivatives and hydroxypyridinones as the lead compounds, a series of dual-target hybrids were designed and synthesised by Click Chemistry. The compounds were biologically evaluated for their iron ion chelating and MAO-B inhibitory activity. Most of the compounds displayed excellent iron ion chelating activity and moderate to good anti-MAO-B activity. Compounds 27b and 27j exhibited the most potent MAO-B inhibitory activity, with IC50 values of 0.68 and 0.86 μM, respectively. In summary, these dual-target compounds have the potential anti-AD activity.

Pancreatic carcinoma still represents one of the most lethal malignant diseases in the world although some progress has been made in treating the disease in the past decades. Current multi-agent treatment options have improved the overall survival of patients, however, more effective treatment strategies are still needed. In this paper we have characterized the anticancer potential of coumarin-palladium(II) complex against pancreatic carcinoma cells. Cells viability, colony formation and migratory potential of pancreatic carcinoma cells were assessed in vitro, followed by evaluation of apoptosis induction and in vivo testing on zebrafish. Presented results showed remarkable reduction in pancreatic carcinoma cells growth both in vitro and in vivo, being effective at micromolar concentrations (0.5 μM). Treatments induced apoptosis, increased BAX/BCL-2 ratio and suppressed the expression of SOX9 and SOX18, genes shown to be significantly up-regulated in pancreatic ductal adenocarcinoma. Importantly, treatments of the zebrafish-pancreatic adenocarcinoma xenografts resulted in significant reduction in tumor mass, without provoking any adverse toxic effects including hepatotoxicity. Presented results indicate the great potential of the tested compound and the perspective of its further development towards pancreatic cancer therapy.

Derivatives of coumarin, containing oxidant-sensitive boronate group, were recently developed for fluorescent detection of inflammatory oxidants. Here, we report the synthesis and the characterization of 3-(2-benzothiazolyl)-7-coumarin boronic acid pinacol ester (BC-BE) as a fluorescent probe for the detection of peroxynitrite (ONOO–), with high stability and a fast response time. The BC-BE probe hydrolyzes in phosphate buffer to 3-(2-benzothiazolyl)-7-coumarin boronic acid (BC-BA) which is stable in the solution even after a prolonged incubation time (24 h). BC-BA is slowly oxidized by H2O2 to form the phenolic product, 3-benzothiazol-2-yl-7-hydroxy-chromen-2-one (BC-OH). On the other hand, the BC-BA probe reacts rapidly with ONOO−. The ability of the BC-BA probe to detect ONOO– was measured using both authentic ONOO– and the system co-generating steady-state fluxes of O2•– and •NO. BC-BA is oxidized by ONOO– to BC-OH. However, in this reaction 3-benzothiazol-2-yl-chromen-2-one (BC-H) is formed in the minor pathway, as a peroxynitrite-specific product. BC-OH is also formed in the reaction of BC-BA with HOCl, and subsequent reaction of BC-OH with HOCl leads to the formation of a chlorinated phenolic product, which could be used as a specific product for HOCl. We conclude that BC-BA shows potential as an improved fluorescent probe for the detection of peroxynitrite and hypochlorite in biological settings. Complementation of the fluorescence measurements by HPLC-based identification of oxidant-specific products will help to identify the oxidants detected.

A new series of solid state fluorescent disperse dyes based on hybrid structure of pyrrolinone ester (PES)/coumarin moiety was prepared and fully characterized using spectroscopic analysis such as 1HNMR, MS and IR spectra. The coumarin derivative (7- amino-4- methyl coumarin) was initially prepared from amino phenol via multi steps condensation reactions and its diazonium salt coupled with the pyrrolinone ester to form the hydrazone dyes. 1HNMR data of the prepared dyes exhibited a pure hydrazone form as a mixture of E, Z isomers. These dyes showing a significant emission in solid state as well as on the dyed fabric. The dyeing application on polyester fabrics was investigated which showing that these dyes show high affinity to polyester fabric, and minor change in the dye affinity by changing pH even under alkaline conditions was observed.

Dipeptidyl peptidase III (DPP III), a zinc-dependent exopeptidase, is a member of the metalloproteinase family M49 with distribution detected in almost all forms of life. Although the physiological role of human DPP III (hDPP III) is not yet fully elucidated, its involvement in pathophysiological processes such as mammalian pain modulation, blood pressure regulation, and cancer processes, underscores the need to find new hDPP III inhibitors. In this research, five series of structurally different coumarin derivatives were studied to provide a relationship between their inhibitory profile toward hDPP III combining an in vitro assay with an in silico molecular modeling study. The experimental results showed that 26 of the 40 tested compounds exhibited hDPP III inhibitory activity at a concentration of 10 µM. Compound 12 (3-benzoyl-7-hydroxy-2H-chromen-2-one) proved to be the most potent inhibitor with IC50 value of 1.10 μM. QSAR modeling indicates that the presence of larger substituents with double and triple bonds and aromatic hydroxyl groups on coumarin derivatives increases their inhibitory activity. Docking predicts that 12 binds to the region of inter-domain cleft of hDPP III while binding mode analysis obtained by MD simulations revealed the importance of 7-OH group on the coumarin core as well as enzyme residues Ile315, Ser317, Glu329, Phe381, Pro387, and Ile390 for the mechanism of the binding pattern and compound 12 stabilization. The present investigation, for the first time, provides an insight into the inhibitory effect of coumarin derivatives on this human metalloproteinase.

According to WHO report, globally about 10 million active tuberculosis cases, resulting in about 1.6 million deaths, further aggravated by drug-resistant tuberculosis and/or comorbidities with HIV and diabetes are present. Incomplete therapeutic regimen, meager dosing, and the capability of the latent and/or active state tubercular bacilli to abide and do survive against contemporary first-line and second line antitubercular drugs escalate the prevalence of drug-resistant tuberculosis. As a better understanding of tuberculosis, microanatomy has discovered an extended range of new promising antitubercular targets and diagnostic biomarkers. However, there are still no new approved antitubercular drugs of routine therapy for several decades, except for bedaquiline, delamanid, and pretomanid approved tentatively. Despite this, innovative methods are also urgently needed to find potential new antitubercular drug candidates, which potentially decimate both latent state and active state mycobacterium tuberculosis. To explore and identify the most potential antitubercular drug candidate among various reported compounds, we focused to highlight the promising lead derivatives of isoniazid, coumarin, griselimycin, and the antimicrobial peptides. The aim of the present review is to fascinate significant lead compounds in the development of potential clinical drug candidates that might be more precise and effective against drug-resistant tuberculosis, the world research looking for a long time.

Many natural coumarins and their chemically synthesized analogs and derivatives exert diverse properties, such as anticancer, antioxidant, anti-inflammatory, or anticoagulant, with the latter being of the utmost importance. The widely used warfarin, acenocoumarol, and phenprocoumon exert anticoagulant properties by inhibiting the vitamin K epoxide reductase complex. In this interdisciplinary review, we present biochemical principles of the coagulation processes and possible methods for their tuning based on the use of coumarins. We also summarize chemical methods of synthesis of coumarins and discuss structures and properties of those that have been used for a long time, as well as newly synthesized compounds. Brief information on the clinical use of coumarins and other anticoagulant drugs is given, including the severe effects of overdosing and methods for reversing their action.

The title compounds, C27H20O6, (I) [systematic name: methyl 7-oxo-14-phenyl-1H,7H,14H-pyrano[3,2-c:5,4-c′]dichromene-14a(6bH)-carboxylate], C24H22O5, (II) [systematic name: methyl 1-oxo-6-phenyl-2,3,4,12b-tetrahydro-1H,6H-chromeno[3,4-c]chromene-6a(7H)-carboxylate], and C25H23N3O4, (III) [systematic name: 6-(4-ethylphenyl)-2,4-dimethyl-1,3-dioxo-2,3,4,12b-tetrahydro-1H,6H-chromeno[4′,3′:4,5]pyrano[2,3-d]pyrimidine-6a(7H)-carbonitrile], are pyranochromene derivatives. The central pyran rings (B) of compounds (I) and (III) adopt half-chair conformations, whereas that of compound (II) adopts a sofa conformation. The pyran rings (A) of the chromene ring systems of compounds (II) and (III) adopt half-chair conformations, while that of compound (I) adopts a sofa conformation. The mean plane of the central pyran rings (B) make dihedral angles of 70.02 (6), 61.52 (6) and 69.12 (7)°, respectively, with the mean planes of the chromene moieties (C+A) of compounds (I), (II) and (III). The bicyclic coumarin ring system (C+A+B+E) in compound (I) is almost planar (r.m.s. deviation = 0.042 Å). The carbonitrile side chain in compound (III) is very nearly linear, with the C—C[triple-bond]N angle being 176.6 (2)°. The cyclohexene ring (E), fused with the central pyran ring (B) in compound (II) adopts a sofa conformation. In the molecular structures of compounds (II) and (III), there are C—H...O short contacts, which generate S(7) ring motifs. In the crystal structures of the title compounds, molecules are linked by C—H...O hydrogen bonds, which generate molecular sheets parallel to the ab plane, with R43(28) loops in (I), inversion dimers with R22(10) loops in (II) and chains along [010] with R22(12) ring motifs in (III). In the crystal structures of (I) and (III), there are also C—H...π interactions present, leading to the formation of a three-dimensional framework in (II) and to sheets parallel to (101) in (III).

Coumarin derivatives have gathered major attention largely due to their versatile utility in a wide range of applications. In this framework, we report a comparative computational investigation on the optoelectronic properties of 3-phenylcoumarin and 3-heteroarylcoumarin derivatives established as enzyme inhibitors. Specifically, we concentrate on the variation in the optoelectronic characteristics for the hydroxyl group substitutions within the coumarin moiety. In order to realize our aims, all-electron density functional theory and time dependent density functional theory calculations were performed with a localized Gaussian basis-set matched with a hybrid exchange−correlation functionals. Molecular properties such as highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energies, vertical ionization (IEV) and electron affinity energies, absorption spectra, quasi-particle gap, and exciton binding energy values are examined. Furthermore, the influence of solvent on the optical properties of the molecules is considered. We found a good agreement between the experimental (8.72 eV) and calculated (8.71 eV) IEV energy values for coumarin. The computed exciton binding energy of the investigated molecules indicated their potential optoelectronics application.

Parvovirus B19 (B19V) is a human pathogenic virus, responsible for an ample range of clinical manifestations. Infections are usually mild, self-limiting, and controlled by the development of a specific immune response, but in many cases clinical situations can be more complex and require therapy. Presently available treatments are only supportive, symptomatic, or unspecific, such as administration of intravenous immunoglobulins, and often of limited efficacy. The development of antiviral strategies against B19V should be considered of highest relevance for increasing the available options for more specific and effective therapeutic treatments. This field of research has been explored in recent years, registering some achievements as well as interesting future perspectives. In addition to immunoglobulins, some compounds have been shown to possess inhibitory activity against B19V. Hydroxyurea is an antiproliferative drug used in the treatment of sickle-cell disease that also possesses inhibitory activity against B19V. The nucleotide analogues Cidofovir and its lipid conjugate Brincidofovir are broad-range antivirals mostly active against dsDNA viruses, which showed an antiviral activity also against B19V. Newly synthesized coumarin derivatives offer possibilities for the development of molecules with antiviral activity. Identification of some flavonoid molecules, with direct inhibitory activity against the viral non-structural (NS) protein, indicates a possible line of development for direct antiviral agents. Continuing research in the field, leading to better knowledge of the viral lifecycle and a precise understanding of virus−cell interactions, will offer novel opportunities for developing more efficient, targeted antiviral agents, which can be translated into available therapeutic options.

Coumarin derivatives (CDs) possess diverse pharmacological properties, but their antidiabetic potential is not fully explored. In this perspective, we selected 108 plant-derived CDs and investigated their antidiabetic potency, taking a panel of putative targets: AKT1, ACACB, CDK4, α-amylase, GLUT1, and PTP1B in a computer-aided drug design (CADD) platform. In addition, predicted toxicity, pharmacokinetics, bioavailability, and drug ability profiles of CDs. Further, molecular dynamics (MD) simulations were employed to observe the dynamic behaviour of the two potential CDs (sanandajin or SANA, sinkianone or SINK) and standards (glimepiride or G and resveratrol or RESV) with AKT1 at 100 nanoseconds. Overall, findings reveal that SANA and SINK exhibited stronger binding affinities with AKT1 than standards with lesser toxicity and favorable drug-ability profiles to use as bioactive therapeutic agents for the management of diabetics. The systematic CADD analyses are able to locate potential CDs and encourage further experimental studies for mainstream applications.

Multicomponent reactions between phenols, β-diesters and benzaldehydes for the synthesis of 4-aryl-3,4-dihydrocoumarin derivatives were carried out under mild conditions (room temperature) and presented moderate yields (38-88%) and reasonable reaction times (2-4 days), using niobium pentachloride as a catalyst.

The title compound, C11H6Br2O4, is a new coumarin derivative obtained from the reaction of 3-acetyl-4-hydroxy-2H-chromen-2-one with bromine in acetic acid. The hydroxyl group in involved in an intramolecular O—H...O hydrogen bond. In the crystal, π–π interactions between the rings of the bicycle [intercentroid distances = 3.498 (2) and 3.539 (2) Å] pack molecules into stacks along the b axis, and weak intermolecular C—H...O hydrogen bonds further link these stacks into layers parallel to the ab plane.

A series of new coumarin derivatives 4 containing a 4-arylbut-3-en-2-one moiety were synthesized by condensation of 3-acetylcoumarin 1 with aryl aldehydes 2 in chloroform in the presence of piperidine. The interactions of 3-formyl-4-chlorocoumarin (3) with nitrogen-containg nucleophiles leading to the corresponding substituted chromen-[4,3-c]pyrazol-4-ones 5 are described. The structures of the obtained compounds were established on the basis of 1D NMR, 2D NMR and IR and further the compounds were evaluated for possible antioxidant activities. The coumarinic chalcone 4a has been found to be the most active (IC50 = 2.07 μM) in this study.

Two groups of coumarin derivatives, 4-methyl-2-oxo-2H-chromen-7-yl 4-alkoxybenzoates (coumarin esters), In, and 4-methyl-2-oxo-2H-chromen-7-yl 4-(2-(4-alkoxyphenyl)diazenyl) benzoates (coumarin azoesters), IIn, were synthesized and investigated for their mesophase behavior and stability. Each group constitutes five series that differ from each other by length of the mesogenic part. Within each homologous series, the length of the terminal alkoxy group varies between 6, 8, 10, 12 and 16 carbons. Mesophase behavior was investigated by differential scanning calorimetry (DSC) and identified by polarized light microscopy (PLM). Density functional theory (DFT) calculations for coumarin derivatives were discussed. The results revealed that the incorporation of azo group incorporated in the mesogenic core decreases the energy differences, increases the dipole moments and stabilities of coumarin azoesters series more than coumarin esters.

The parallel solution-phase synthesis of a new combinatorial library of 3-[4-(R1-coumarin-3-yl)-1,3-thiazol-2-ylcarbamoyl]propanoic acid amides 9 has been developed. The synthesis involves two steps: 1) the synthesis of core building blocks – 3- [4-(coumarin-3-yl)-1,3-thiazol-2-ylcarbamoyl]propanoic acids, 6 – by the reaction of 3-(É-bromacetyl)coumarins 1 with 3-amino(thioxo)methylcarbamoylpropanoic acid (5); 2) the synthesis of the corresponding 3-[4-(coumarin-3-yl)-1,3-thiazol-2-yl- carbamoyl]propanoic acids amides 9 using 1,1’-carbonyldimidazole as a coupling reagent. The advantages of the method compared to existing ones are discussed.