Coumarin Structure Research Articles

Discovery of Novel Coumarin Pleuromutilin Derivatives as Potent Anti-MRSA Agents.

Treating methicillin-resistant Staphylococcus aureus (MRSA) infection remains one of the most difficult challenges in clinical practice, primarily due to the resistance of MRSA to multiple antibiotics. Therefore, there is an urgent need to develop novel antibiotics with high efficacy and low cross-resistance rates. In this study, a series of novel pleuromutilin derivatives with coumarin structures were synthesized and subsequently assessed for their biological activities. Most of these derivatives showed potent antimicrobial activity against drug-resistant Gram-positive bacterial strains. Compound 14b displayed particularly rapid bactericidal effects, slow resistance development, and low cytotoxicity. Moreover, it decreased bacterial loads in the lung, liver, kidney, spleen, and heart and exhibited better antibacterial efficacy (ED50 = 11.16 mg/kg) than tiamulin (ED50 = 28.93 mg/kg) in a mouse model of systemic MRSA infection. Both in vitro and in vivo analyses suggest that compound 14b is a promising agent for the treatment of MRSA infections.

Coumarin Derivatives: Pioneering New Frontiers in Biological Applications

Abstract: Coumarins are a vital class of compounds recognized for their significant therapeutic potential, both in their natural forms and as synthetic derivatives. Characterized by a benzene ring fused to an α-pyranose ring, coumarins have garnered considerable attention from the scientific community due to their diverse pharmacological activities. This review article highlights the importance of coumarin hybrids, showcasing their enhanced biological properties and reactivity compared to traditional coumarin structures. We explore the pharmacological profiles of various coumarin derivatives, including their anti-cancer, anti-inflammatory, antiviral, antioxidant, antibacterial, and anti-tuberculosis activities, among others. The review examines how the incorporation of different functional groups on the coumarin scaffold can modulate its effectiveness against various diseases, particularly cancer. Furthermore, we discuss promising results from coumarin-based hybrids, such as coumarinpyridine, coumarin-uracil, and coumarin-quinoline derivatives, demonstrating their efficacy against a range of pathogens. This comprehensive overview serves as a valuable resource for researchers interested in the potential of coumarin derivatives in therapeutic applications.

Computational assessment of the radical scavenging activity of cleomiscosin.

Coumarinolignans such as cleomiscosin A (CMA), cleomiscosin B (CMB), and cleomiscosin C (CMC) are secondary metabolites that were isolated from diverse plant species. Cleomiscosins (CMs) have numerous interesting biological activities, including noteworthy cytotoxicity of cancer cell lines along with hepatoprotective and assumed antioxidant activities. In this present study, the antioxidant properties of three cleomiscosins were investigated with a focus on the structure-activity relationship using thermodynamic and kinetic calculations with the M06-2X/6-311++G(d,p) method. The results show that CMs, including CMA, CMB, and CMC, are weak antioxidants in apolar environments, with k overall of 7.52 × 102 to 6.28 × 104 M-1 s-1 for the HOO˙ radical scavenging reaction in the gas phase and 3.47 × 102 to 6.44 × 104 M-1 s-1 in pentyl ethanoate. Remarkably, the difference in the fusion of phenylpropanoid structure with coumarin via two ortho-hydroxyl groups (CMA and CMB) does not cause any noticeable effect on their antioxidant activity, while the presence of a methoxy substitute on the aromatic ring of phenylpropanoid units (CMC) increases the reaction rate to about 61 to 84 times faster than that of CMA. In contrast, the studied CMs exhibit a good antioxidant capacity in polar environments, with a k overall range from 4.03 × 107 to 8.66 × 107 M-1 s-1, 102-103 times faster than that of Trolox, equal to that of ascorbic acid and resveratrol. The angular fusion of the phenylpropanoid and coumarin structures, as well as the methoxy substitution on the aromatic ring of the phenylpropanoid unit of the studied CMs, do not have any considerable effect on their antioxidant activity under the studied conditions.

Fluorescent zinc acrylate resins containing coumarin structures with enhanced antifouling performance

The demand for non-toxic antifouling coatings has led to the development of multifunctional antifouling coatings. In this work, a series of coumarin acids with fluorescence were first prepared via the Knoevenagel condensation reaction. Then, multifunctional zinc acrylate resins were produced successfully by employing an acrylic acid monomer, ZnO, and coumarin acids by free radical polymerization and polycondensation processes. The self-polishing and antifouling properties of the resins were investigated by dynamic simulation experiments, E. coli growth inhibition experiments, algae adhesion inhibition experiments, and marine environment antifouling experiments. The results show that the zinc acrylate resins containing the coumarin structures not only have good self-polishing performance but also have better antifouling performances than the zinc acrylate resin containing benzoic acid. This work not only reveals the antifouling mechanism of the multifunctional resins, but also provides a new strategy for the development of environmentally friendly antifouling coatings.

Evaluation of the Anti-diabetic Activity of Purified Compounds of Ferula assafoetida by in vitro and in silico Methods

Objective Postprandial hyperglycemia is considered an early sign of diabetes. Enzyme inhibitors, such as α-amylase and α-glucosidase inhibitors, are currently being studied as potential drugs for preventing postprandial hyperglycemia. Methods In this study, we investigated the effects of four purified 7-hydroxycoumarine derivatives from Ferula assafoetida: umbelliprenin, farnesiferol A, farnesiferol C, and samarcandin. We evaluated cell toxicity using the MTT method and also examined glucose uptake and inhibition of α-amylase and α-glucosidase enzymes in vitro. Additionally, we conducted a molecular docking study to investigate the mechanism of enzyme inhibition. Results The cell toxicity of the terpenoid coumarin derivatives (umbelliprenin, farnesiferol A, farnesiferol C, and samarcandin) on HepG2 cells was found to be approximately 28 to 37 µg/ml. The glucose uptake assay showed that these compounds (at a concentration of 25 µg/ml) were able to increase glucose consumption by HepG2 cells to a level comparable to that of the positive control (metformin at 50 µg/ml). Furthermore, umbelliprenin significantly inhibited the activity of α-amylase and α-glucosidase (by 35.07% and 4.98%, respectively). Molecular docking results indicated that umbelliprenin, with a farnesyl chain, had a more potent inhibitory effect. Conclusion Our findings suggest that umbelliprenin may be a valuable compound for controlling postprandial hyperglycemia and diabetes. However, further in vivo studies and clinical trials are necessary to validate these effects. While this research offers potential for the development of more effective compounds with coumarin structures, further studies are needed to confirm these findings.

Karakterisasi Struktur Kumarin pada Akar Tumbuhan Langsat (Lansium domesticum Corr.)

Lansium plants produce not only terpenoids as the main constituent but also contain phenolics on the basis of phytochemical analysis. Unfortunately, there are still limited information about phenolic structures from this plants. This study was conducted to identify one of phenolic structures from chloroform fraction of Lansium domesticum root. The chloroform fraction was fractionated and purified by chromatographic techniques such as vacuum liquid chromatography (VLC) and column chromatography (CC) to obtain a coumarin. Additionally, the coumarin structure was characterized by 1H-NMR. The isolated coumarin showed a positive result for the phenolic test with FeCl3 5%. The 1H-NMR spectrum of isolated coumarin revealed chemical shifts at δH 7,60 (1H, d, J = 9,5 Hz), 6,92 (1H, s), 6,84 (1H, s), 6,27 (1H, d, J = 9,5 Hz), 6,14 (1H, s), and 3,95 (3H, s). Based on those results and comparison with literature data, it can be concluded that the isolated coumarin is iso-scopoletin (1)

Synthesis, Characterization, Thermal and Dielectric Properties of Amino Acid-Centered Coumarin and Chalcone Hybrid Structures Via Click Reaction

Bu çalışma, kalkon ve kumarin grupları içeren amino asit konjugatlarının dielektrik özellikleri ve termal kararlılıklarının karşılaştırmalı bir analizini içermektedir. Bu konjugatların elektriksel davranışını incelemek amacıyla dielektrik sabiti, dielektrik kaybı ve AC iletkenliği araştırılırken, termal kararlılıklarını incelemek için termogravimetrik analiz (TGA) kullanılmıştır. Konjugatlar, kalkon veya kumarin yapılarının amino asit omurgalarına klik kimyası ile dahil edilmesiyle sentezlenmiştir. Dielektrik sabiti ölçümleri, kumarin bazlı amino asit konjugatlarının, kumarin sisteminin genişletilmiş π-konjugasyonu ve polarize edilebilirliği nedeniyle kalkon bazlı konjugatlara kıyasla daha yüksek değerler sergilediğini ortaya koymuştur. Dielektrik kayıp analizi, her iki konjugat türünün de yük transfer süreçleri ve moleküler hareketlerle ilişkili kayıplar sergilediğini göstermiştir. TGA ile termal stabilite değerlendirmesi, kalkon içeren konjugatın daha yüksek bozunma sıcaklıkları ile iyi termal stabilite sergilediğini ortaya koymuştur. Yüksek sıcaklıklarda gözlenen ağırlık kaybı, organik bileşenlerin termal bozunmasını göstermiştir. Bu etkili sonuçlar, dielektrik sabiti, dielektrik kaybı ve AC iletkenliği dahil olmak üzere dielektrik özelliklerin yanı sıra kalkon veya kumarin içeren amino asit konjugatlarının termal kararlılığı hakkında değerli bilgiler sağlamaktadır. Bulgular, elektronik cihazlar ve fonksiyonel malzemelerdeki potansiyel uygulamalar için önemli olan elektriksel davranışlarının ve termal özelliklerinin anlaşılmasına katkıda bulunmaktadır..

Annulated Heterocyclic[g]Coumarin Composites: Synthetic Approaches and Bioactive Profiling.

Coumarins, widely abundant natural heterocyclic compounds, are extensively employed in creating various biologically and pharmacologically potent substances. The hybridization of heterocycles presents a key opportunity to craft innovative multicyclic compounds with enhanced biological activity. Fusing different heterocyclic rings with the coumarin structure presents an intriguing method for crafting fresh hybrid compounds possessing remarkable biological effects. In the pursuit of creating heterocyclic-fused coumarins, a wide range of annulated heterocyclic[g]coumarin composites has been introduced, displaying impressive biological potency. The influence of the linear attachment of heterocyclic rings to the coumarin structure on the biological performance of the resulting compounds has been investigated. This review centers on the synthetic methodologies, structural activity relationship investigation, and biological potentials of annulated heterocyclic[g]coumarin composites. We conducted searches across several databases, including Web of Science, Google Scholar, PubMed, and Scopus. After sieving, we ultimately identified and included 71 pertinent studies published between 2000 and the middle of 2023. This will provide valuable perspectives for medicinal chemists in the prospective design and synthesis of lead compounds with significant therapeutic effects, centered around heterocycle-fused coumarin frameworks.

Design, Synthesis and Anticholinesterase Activity of Coumarin‐1,3,5‐triazine Derivatives

AbstractA series of coumarin‐1,3,5‐triazine derivatives were designed, synthesized and evaluated as acetylcholinesterase inhibitors. The structures of those compounds were characterized by IR, NMR, HRMS, HPLC, and X‐ray. The structures of those coumarin‐1,3,5‐triazine derivatives are the mixtures of two geometric isomers. The 1H‐NMR of compound 3 g without coumarin structure and its hydrochloride and single crystal structure of compound 3 g were studied to prove the coumarin‐1,3,5‐triazine derivatives are the mixtures of two geometric isomers. The acetylcholinesterase and butyrylcholinesterase inhibitory activities of the synthesized compounds were determinated by Ellman's method. The results showed that all the compounds could inhibit acetylcholinesterase selectively. Among them, compound 3 b was found to have the strongest inhibitory effect on acetylcholinesterase with an IC50 value of 0.018 μM, which was closest to the IC50 of the positive control donepezil (IC50=0.016 μM). Enzyme kinetic studies indicate that this compound inhibited acetylcholinesterase with a mixed mode. Molecular docking, molecular dynamics simulation study and binding free energy calculation experiments demonstrated that compound 3 b could stably interact with key amino acids in the catalytically active site and the peripheral anion site of acetylcholinesterase. According to the results, compound 3 b demonstrates promising potential as acetylcholinesterase inhibitors for the treatment of Alzheimer's disease.

Theoretical studies of electronic and optical characteristics in donor-π-Acceptor (D-π-A) dyes: DFT and TD-DFT methods

Abstract This research focused on enhancing D-π-A organic dyes derived from coumarin and its derivatives, collectively referred to as D-CM-A dyes. The study aimed to improve these dyes by introducing various donors and acceptors to the coumarin structure. Six new coumarin dyes were evaluated, primarily for their potential application in dye-sensitized solar cells (DSSCs) to enhance energy efficiency. The analysis involved calculating the geometry, electronic properties, and optoelectronic characteristics of the dye molecules using DFT and TD-DFT methods with the B3LYP functional and the 6-311G basis set in both gas and solvent phases. The primary focus was to understand how modifications to the π-conjugated D-π-A organic dyes influenced their optoelectronic properties, including key factors such as maximum absorption wavelength (λmax), highest occupied molecular orbital energy (EHOMO), lowest unoccupied molecular orbital energy (ELUMO), and energy gap (Egap). Additionally, the study explored the photovoltaic properties of these dyes. The findings highlighted D4-CM-A4 as a promising candidate with the narrowest energy gap, while D1-CM-A1 and D2-CM-A2 showed superior light-harvesting efficiencies (LHE) compared to other derivatives. In conclusion, this study suggests that D1-CM-A1 and D2-CM-A2 are favourable choices for enhancing the performance of DSSCs due to their promising optoelectronic properties.

Highly sensitive fluorescent triarylimidazole derivatives for sensing of 2,4,6-trinitrophenol in aqueous solution and its application for actual environment detection

Two highly sensitive fluorescent triarylimidazole derivatives were synthesized by modifying imidazole with coumarin and large conjugate rigid plane structure. XM-F and XM-L emitted bright yellow-green fluorescent light. Their intense conjugation system generated strong π-π electrostatic interactions with TNP, accompanied by the formation of hydrogen bonds to achieve rapid detection of TNP within 25 s. The detection limits were as low as 0.049 μM and 0.071 μM, respectively. Probes had been successfully applied to rapid detection of TNP in real water samples and manufactured into portable fluorescent test strips. In view of excellent performance of XM-F, it was used to achieve real-time, portable, on-site quantitative detection of TNP by a colorimeter and a smartphone platform. In addition, XM-F also successfully processed into probe-coated TLC plates for efficient detection of fingerprints contaminated with TNP.

Anti-Alzheimer potential of coumarin derivatives: A review

Alzheimer’s is a type of neurodegenerative diseases (NDs) found in old age people which main causes the dementia and various brain disorders. FDA approved drugs used commonly in treatment of moderate to severe Alzheimer's disease are Donepezil, Rivastigmine, Galantamine and Memantine. However, these approved drugs provide only palliative support not complete cure. So, urgency of new molecules has been becoming so important to cure this complex Disease. Coumarin or 2-H-Chromen-2-one is an oxygenated heterocyclic compound, which is isolated from plants named Dipteryx odorata Willd, (Fabaceae). Synthetic coumarin derivatives has been well presence in literature due to existence of their potential pharmacological activities in literature. This review covers the anti-Alzheimer activities of chemically synthesized coumarin derivatives from 2016-2023. Coumarin derivatives profound found exhibits potential anti-Alzheimer activities in literature. Coumarin derivatives showed their anti-Alzheimer potential through various pharmacological pathways such as monoamine oxidase (MAO) inhibitor, acetylcholinesterase (AChE) & Butyl cholinesterase (BuChE) inhibitory activity, Aβ amyloid inhibition, Beta secretase 1 (BACE1 inhibitors). Multi-target directed ligands (MTDLs) approach also extensively reported to design and synthesis of novel coumarin scaffold as potential multifunctional Anti-Alzheimer activities in last one decade. We also covered literature of some coumarin hybrids derivatives as potential Anti-Alzheimer activities. Some common synthetic methods of coumarin structure also covered in this review article. This review supported that coumarin derivatives found excellent anti-Alzheimer activities and it can be play major role to solve the problem of complex AD disease.

Effect of the mixture composition of BmimBF4/PC on the solvation structure of C153 in as seen from molecular dynamics study

In this work we report the results of the molecular dynamics (MD) simulation of the effect of the mixture composition of 1-butyl-3-methylimidazolium terafluoroborate (BmimBF4) and propylene carbonate (PC) on the solvation structure of coumarin 153.For this purpose, the local structure around C153 was characterized using distance and angle descriptors of the C-H…A configuration. They are based on the calculation of the nearest neighbor radial distributions between the C or H atoms of one component of the solution (C153, PC, Bmim+) and the electronegative A atoms (F, O) of the other ones. We also considered the combined distribution functions that include the radial and the orientation between the ring of either the cation or the solvent and that of C153.Our results show that in neat ionic liquid, the BF4− anion and in particular its F atoms, is, as expected, located close to the hydrogen atoms of the C153, while the cation, in particular its ring hydrogen atoms, are located close to the F and O atoms of the C153 and its ring has an almost the above/below parallel orientation with respect to the C153 lactone ring. In neat PC, its O atoms are located in the direct environment of the H atoms of C153 and concomitantly, its ring has the above/below parallel orientation with respect to the C153 rings. By comparing the distance and angle descriptors values of the C-H…A configuration, with a threshold hydrogen bond distance 0.30 nm and an angle of 151°, we were able to rank the C-H…A interactions as weak hydrogen bonds. Furthermore, in the excited state, noticeable changes in charge values on the H, F and O atoms of C153, occurs and as a consequence, the radial distribution of the anion, cation and the solvent around these atoms of C153 is more affected.At the mixture composition around 0.20 mol fraction of BmimBF4, the behavior of the distance angle descriptors of the solvation of C153, indicates a cross over between the situation where solvation is dominated by the ions to that dominated by the solvent molecules. In the excited state of C153, the distance descriptor values are slightly decreasing with respect to those in the ground state while the angle descriptor values remain almost the same.

In-vitro anti-diabetic, anti-Alzheimer, anti-tyrosinase, antioxidant activities of selected coumarin and dihydroisocoumarin derivatives

Benzo-α-pyrone structured coumarin derivatives are secondary metabolites first obtained from Coumarouna odorata in 1822. Coumarin and its structural isomer dihydroisocoumarin derivatives are found in many different sources in nature. Several different bioactivities of these compounds have been reported. In this study, preliminary activity screening and comparison of four purchased coumarin derivatives (esculetin, esculin monohydrate, umbelliferon, scoparone) and four previously isolated 3-phenyl-3,4-dihydroisocoumarin derivatives (thunberginol C, scorzocreticoside I, scorzocreticoside II, scorzopygmaecoside) from a medicinal plant were carried out by in-vitro methods. α-Glucosidase, acetylcholinesterase, butyrylcholinesterase, tyrosinase inhibitor activities and antioxidant potentials of the compounds were evaluated. Consequently, thunberginol C (free – not glycosylated form of 3,4-dihydroisocoumarin structure) showed better potential in all enzyme inhibitory activities compared to coumarin structure. Particularly, α-glucosidase inhibitory activity of this compound with a very low IC50 value (94.76±2.98 µM) compared to standard acarbose (1036.2±2.70 µM) should be noted. Glycosylation and/or methoxy substitution of 3,4-dihydroisocoumarin structure resulted a significant decrease in all tested enzyme inhibitory activities. The structures of esculin MH, umbelliferone, scoparone, scorzocreticoside I, and scorzopygmaeceoside might be considered in further synthetic studies as selective acetylcholinesterase inhibitors. Thunberginol C has a promising potential in tyrosinase inhibitory activity. Esculetin and thunberginol C showed the best results with high potentials in antioxidant activity via 2,2-diphenyl-1-picryl-hydrazyl-hydrate free radical scavenging, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid cation radical decolorization, and cupric ion reducing antioxidant capacity assays compared to the standards.

Searching for relationships between the structure of selected simple coumarins, their antioxidant capacity and anticancer properties

The antioxidant capacity of 23 simple coumarins was studied by using different total antioxidant capacity assays, namely ABTS, CUPRAC, and FRAP. Simultaneously, the anticancer activity of the investigated derivatives was evaluated by MTT test on lung (A549), cervical (HeLa), prostate (PC3), and liver (HepG2) cancer cell lines. Furthermore, fifty percent inhibitory concentration (IC50) values were calculated, while for the derivatives with the strongest anticancer properties their impact on the viability of normal immortalized prostate cells (PNT2), compared to their cancer counterparts (prostate cancer cells PC3), was determined. The correlation between antioxidant capacity, anticancer potential and the structure of the studied compounds has been observed and discussed. Interestingly, it has been proved that selected derivatives (with two neighboring hydroxyl substituents attached to the aromatic ring) exhibit the strongest antioxidant capacity and anticancer properties. These findings increase our comprehension of the relationship between structure and radical scavenging activity of simple coumarins.

Sesquiterpene Coumarin Ethers with Selective Cytotoxic Activities from the Roots of Ferula huber-morathii Peşmen (Apiaceae) and Unequivocal Determination of the Absolute Stereochemistry of Samarcandin.

Ancient physicians frequently used the resin of Ferula species to treat cancer. Today, some folkloric recipes used for cancer treatment also contain the resin of Ferula species. The dichloromethane extract of the roots of Ferula huber-morathii exhibited cytotoxic activities against COLO 205 (colon), K-562 (lymphoblast), and MCF-7 (breast) cancer cell lines (IC50 = 52 µg/mL, 72 µg/mL, and 20 µg/mL, respectively). Fifteen sesquiterpene coumarin ethers with cytotoxic activity were isolated from the dichloromethane extract of the roots of F. huber-morathii using bioactivity-directed isolation studies. Extensive spectroscopic analyses and chemical transformations have elucidated the structures of these sesquiterpene coumarin ethers as conferone (1), conferol (2), feselol (3), badrakemone (4), mogoltadone (5), farnesiferol A (6), farnesiferol A acetate (7), gummosin (8), ferukrin (9), ferukrin acetate (10), deacetylkellerin (11), kellerin (12), samarcandone (13), samarcandin (14), and samarcandin acetate (15). The absolute configuration of samarcandin (14) was unequivocally determined by the X-ray crystallographic analysis of the semi-synthetic (R)-MTPA ester of samarcandin (24). Conferol (2) and mogoltadone (5) were found to be the most potent cytotoxic compounds against all three cancer cell lines; furthermore, these compounds exhibit low cytotoxic activity against the non-cancerous human umbilical vein epithelial cells (HUVEC) cell line. Investigation of the biological activity mechanisms of mogoltadone (5) revealed that while suppressing the levels of Bcl-XL and procaspase-3 in the COLO 205 cancer cell line, it did not have a significant effect on the Bcl-XL, caspase-3, and β-catenin protein levels of the HUVEC cell line, which may explain the cytotoxic selectivity of mogoltadone (5) on cancer cell lines.

Improving the performance of biobased polyurethane dispersion by the incorporation of photo-crosslinkable coumarin

High biobased carbon content polyurethane dispersions (PUD) are a more sustainable alternative to conventional oil-derived waterborne dispersions in coatings. However, there are still many performance limitations from restricted availability of effective renewable monomers and oligomers. This work demonstrates the improvement of the properties of high biobased content PUD and derived coating by introducing a photo-reversibly crosslinkable coumarin as chain extender within the structure. The effect of partial substitution of 1,3-propanediol biobased by a di-hydroxy photo-reactive cyclic coumarin on the particle size and the stability was analyzed by dynamic light scattering (DLS) and multiple light scattering (MLS). The lateral and more rigid structure of coumarin involved a moderated increment in particle size without significant effect on the dispersion stability for at least 45 days. Associated improvement in hardness and toughness was also demonstrated by tensile test, pendulum hardness, pencil hardness and scratch resistance test. Furthermore, controlled UV irradiation of the polyurethane gave rise to a mechanical performance adjustment from reversible photo-crosslinking and scission of the coumarin molecules within the macromolecular structure. A 70% dimerization degree of the coumarin within the polyurethane film by UV light provided a partially reversible threefold higher tensile strength than that of the original biobased formulation as an effective tool to tune the response of biobased polyurethanes.Graphical

Bio-Based Photoreversible Networks Containing Coumarin Groups for Future Medical Applications.

Photocurable biomaterials that can be delivered as liquids and rapidly (within seconds) cured in situ using UV light are gaining increased interest in advanced medical applications. Nowadays, fabrication of biomaterials that contain organic photosensitive compounds have become popular due to their self-crosslinking and versatile abilities of changing shape or dissolving upon external stimuli. Special attention is paid to coumarin due to its excellent photo- and thermoreactivity upon UV light irradiation. Thus, by modifying the structure of coumarin to make it reactive with a bio-based fatty acid dimer derivative, we specifically designed a dynamic network that is sensitive to UV light and able to both crosslink and re-crosslink upon variable wave lengths. A simple condensation reaction was applied to obtain future biomaterial suitable for injection and photocrosslinking in situ upon UV light exposure and decrosslinking at the same external stimuli but at different wave lengths. Thus, we performed the modification of 7-hydroxycoumarin and condensation with fatty acid dimer derivatives towards a photoreversible bio-based network for future medical applications.

I2/DMSO mediated Cascade cyclization reaction of amino coumarins with aryl methyl ketones: Access to Dicoumarino‐fused [1,5]‐diazocine and pyrrolo‐coumarin scaffolds

AbstractAn easy metal‐free cascade cyclization of 4‐amino coumarin with aryl methyl ketone has been developed as a straightforward method for constructing coumarino‐fused [1,5]‐diazocines. This chemical transformation affords linearly fused structure of coumarin and 1,5‐diazocine with significant yield. Such complex hybrid diazocine skeletons can propose various bioactivities in drug design. The technique is highly appealing, sustainable, and economic since it is operationally simple and uses a catalytic quantity of iodine in presence of DMSO. In this protocol, DMSO functions both as a solvent and an oxidant. Again, the sustainability of this protocol is enhanced as it is devoid of any exogenous oxidant. Further functionalization of these diazocine moieties using metal catalyzed cross coupling techniques lead to several interesting scaffolds. Furthermore, these diazocine compounds can undergo a base‐controlled regioselective metal‐free Chan‐Lam type coupling reaction, yielding novel N‐arylated and O‐arylated products. Additionally, the formation of densely functionlized coumarin fused pyrrole scaffolds from 3‐aminocoumarin and aryl methyl ketone widens the practical applicabilty of this protocol. This pyrrolo‐coumarin frameworks are present in the bio‐active marine alkaloid, lamellarins.

Development of Two Efficient Dual‐Function Fluorescent Probes for Specific Recognition of Zn2+/H2S

AbstractIn this paper, two dual function fluorescent probes P1 and P2 with obvious fluorescence spectrum change were developed for the detection of Zn2+ and H2S. Density functional theory (DFT) was employed to investigate the detection mechanism. A further illustration of the fluorescence quenching mechanism was also studied by 1H NMR titration and UV‐Vis absorption spectroscopy. Both probes are new compounds containing coumarin structure as fluorophore. They can quantitatively detect Zn2+ and H2S in the concentration range from 0 to 50 μM with excellent selectivity and anti‐interference ability over many metal ions or anions. Most worthy is that probes P1 and P2 have better cell permeability with lower cytotoxicity, which can be used for fluorescence detection in MCF‐7 cells, as well as the detection of exogenous Zn2+ in organisms.