Coumarin and eugenol ameliorate LPS-induced inflammation in RAW 264.7 cells via modulating the NLRP3 inflammasome pathway

Objective:To investigate the underlying mechanism of anti-inflammatory action of coumarin and eugenol in lipopolysaccharide(LPS)-stimulated RAW 264.7 cells.Methods:RAW 264.7 cells were treated with 2.5μg/mL of LPS,50μM of coumarin,and 50μM eugenol for 24 h.The viability of the cells was assessed using MTT assay.The production of nitric oxide was determined using Griess reagent and DCFH-DA was used to measure the production of reactive oxygen species.The protein expression of NLRP3,IL-1β,NF-κB,and cyclooxygenase 2 was assessed using Western blot analysis.Results:Coumarin and eugenol showed anti-inflammatory effects against LPS-induced inflammatory response by ameliorating the expression of NLRP3 inflammasome and NF-κB,which further led to a subsequent reduction in IL-1β,nitric oxide,and reactive oxygen species.Conclusions:Coumarin and eugenol exert their anti-inflammatory activities by modulating the NLRP3 inflammasome pathway and NF-κB.These compounds may have promising therapeutic applications for the treatment of various inflammatory diseases.

Self-assembly of coumarin molecules on plasma electrolyzed layer for optimizing the electrochemical performance of AZ31 Mg alloy

A novel inorganic-organic layer with outstanding corrosion resistance in a 3.5wt.% NaCl solution was fabricated by taking advantage of the unique interactions between coumarin (COM) molecules and the porous layer formed on Mg alloy. To achieve this aim, the AZ31 Mg alloy coated via microarc oxidation (MAO) coating was placed in an ethanolic solution of COM for 6 and 12 h at 25 ℃. By reducing the surface area exposed to the corrosive species, the donor-acceptor complexes produced by the particular interactions between the COM and MAO surface would successfully prevent the corrosion of Mg alloy substrate. The MAO layer would provide the ideal sites for the charge-transfer-induced physical and chemical locking, leading to uneven organic layer nucleation and crystal growth with a thatch-like structure. To evaluate the formation mechanism of such hybrid composites and highlight the key bonding modes between the COM and MAO, theoretical simulations were conducted.

Two New O-terpenoidal Coumarins, Excavacoumarin A and B from Clausena excavata

Two new O-terpenoidal coumarins named excavacoumarin A (2): B (3), and a known one 1 were isolated from the leaves of Clausena excavata Burm. f. (Rutaceae) collected in Xishuangbanna, Yunnan, Structure elucidation and unambiguous NMR assignments for the title compounds were carried out on the basis of 1D and 2D NMR experiments.

¹³C-NMR Data from Coumarins from Moraceae Family

Species from Moraceae family stand out in popular medicine and phytotherapy, have been for example used as expectorants, bronchodilators, anthelmintics and treatment of skin diseases, such as vitiligo, due to the presence of compounds with proven biological activity, as the coumarins. Coumarins are lactones with 1,2-benzopyrone basic structure, and are widely distributed in the plant kingdom, both in free form, and in glycosylated form. This work reports a literature review, describing the data of 13C NMR from 53 coumarins isolated from the family Moraceae, and data comparison between genera who presented photochemical studies, in order to contribute to the chemotaxonomy of this family.

A new angelol-type coumarin glucoside from Angelica pubescens

A new angelol-type coumarin glucoside, 6-[（1R,2R）-1, 2-dihydroxy-3-β-D-glucosyloxy-3-methylbutyl]-7-methoxycoumarin, was isolated from the roots of Angelica pubescens. Its structure was elucidated on the basis of spectral analysis.

Microwave promoted one-pot synthesis of 3-(2′-amino-3′-cyano-4′-arylpyrid-6′-yl)coumarins

A facile procedure for the synthesis of 3-（2′-amino-3′-cyano-4′-arylpyrid-6′-yl） coumarins are being reported starting from 3- acetylcoumarin, aromatic aldehydes and malononitrile. The reactions were carried out on microwave irradiation in good yield with short time and easy work-up. The structures of all the compounds have been confirmed on the basis of their analytical, IR, ^1H NMR, and mass spectral data.

The Synthesis of a Series of Phosphoryl Coumarins

Different hydroxy substituted coumarins were successfully phosphorylated with diisopropylphophite （DIPPH） by the Atherton-Todd reaction in 76-89% yields. Moreover, the reaction activities of different hydroxys of the coumarins in the Atherton-Todd reaction were studied.

Coumarin 6平面荧光太阳能聚光器的制备与性能分析

以PMMA作为基质材料,以Coumarin 6作为荧光物质,采用掺杂方式制备出平面荧光太阳能聚光器。制备得到的Coumarin 6平面荧光太阳能聚光器的几何尺寸分别为50 mm×50 mm×5 mm与100 mm×100 mm×5mm,将太阳能电池粘贴于聚光器的输出端,通过测试聚光器对太阳能电池输出功率的影响测定Coumarin 6平面荧光太阳能聚光器的聚光特性。而为了研究掺杂浓度对聚光器聚光特性的影响,制备了7种不同浓度的Coumarin 6平面荧光太阳能聚光器,并分别测试了其聚光特性,得出最优化的掺杂浓度。

Synthesis and Biological Evaluation of Cyclic Imides with Coumarins and Azacoumarins

A series of new N-substituted cyclic imides of coumarins and azacoumarins have been synthesized. All the compounds were screened for their antibacterial and antifungal activities. α-Amylase enzyme inhibition activities of some N-substituted phthalimide derivatives have been explored. All the compounds were characterized by IR, 1H-NMR, and GC-MS.

A Novel Dimeric Coumarin from Clausena lenis

A novel dimeric coumarin (1), a dimeric of seselin named diseselin A, was isolated from the aerial part of Clausena lenis. The structure was elucidated based on the MS, 1D and 2D NMR data.

Three New Coumarins from Micromelum integerrimum

Three derivatives of micromelin, named hydramicromelins A-C (1-3), were isolated from the aerial part of Micromelum integerrimum (Buch.-Ham) Roem., respectively. Hydramicromelins A-C (1-3) were epimers which possessed the same plane structure and molecular formula. Their structures were elucidated based on MS and NMR data. The relative configurations of 1-3 were established by NOE analysis.

Anti-Alzheimer's disease potential of coumarins from Angelica decursiva and Artemisia capillaris and structure-activity analysis

Objective: To use structure-activity analysis to study the anti-Alzheimer's disease(anti-AD) activity of natural coumarins isolated from Angelica decursiva and Artemisia capillaries, along with one purchased coumarin(daphnetin). Methods: Umbelliferone, umbelliferone 6-carboxylic acid, scopoletin, isoscopoletin, 7-methoxy coumarin, scoparone, scopolin, and esculetin have been previously isolated; however 2'-isopropyl psoralene was isolated from Angelica decursiva for the first time to evaluate their inhibitory effects against acetylcholinesterase(ACh E), butyrylcholinesterase(BCh E), and β-site amyloid precursor protein cleaving enzyme 1(BACE1) enzyme activity. We scrutinized the potentials of coumarins as cholinesterase and BACE1 inhibitors via enzyme kinetics and molecular docking simulation. Results: Among the test compounds, umbelliferone 6-carboxylic acid, esculetin and daphnetin exhibited potent inhibitory activity against ACh E, BCh E and BACE1. Both esculetin and daphnetin have a catechol group and exhibit significant anti-AD activity against ACh E and BCh E. In contrast, presence of a sugar moiety and methoxylation markedly reduced the anti-AD activity of the coumarins investigated in this study. With respect to BACE1 inhibition, umbelliferone 6-carboxylic acid, esculetin and daphnetin contained carboxyl or catechol groups, which significantly contributed to their antiAD activities. To further investigate these results, we generated a 3D structure of BACE1 using Autodock 4.2 and simulated binding of umbelliferone 6-carboxylic acid, esculetin and daphnetin. Docking simulations showed that different residues of BACE1 interacted with hydroxyl and carboxylic groups, and the binding energies of umbelliferone 6-carboxylic acid, esculetin and daphnetin were negative(-4.58,-6.25 and-6.37 kcal/mol respectively). Conclusions: Taken together, our results suggest that umbelliferone 6-carboxylic acid, esculetin and daphnetin have anti-AD effects by inhibiting ACh E, BCh E and BACE1, which might be useful against AD.

Novel fluorescent chemosensor for Ag^+ based on coumarin fluorophore

A novel chemosensor 1 （CS1） bearing one coumarin and two carbodithioate groups was synthesized and its fluorescent sensing behavior toward metal ions was investigated. Ag^＋ addition to a CH3COCH3/H2O （3：7, v：v） solution of CS1 gave a significantly quenched fluorescence. Other ions including Pb^2＋, Zn^2＋, Cu^2＋, Ca^2＋, Cd^2＋, Co^2＋, Mg^2＋, Mn^2＋, Hg^2＋, Ag^＋, Ni^2＋ induced no or much smaller spectral changes. This constitutes an ON-OFF Ag^＋-selective fluorescent chemosensor.

Silica triflate as an efficient reagent for the solvent-free synthesis of coumarins

Silica triflate, as a new silica-based reagent, can be used for the efficient synthesis of 4-substituted coumarins via a Pechmann reaction under solvent-free reaction conditions. All reactions were performed at 80 ℃ in good to high yields.

Synthesis and Self-assembling of Coumarin-based Low-molecular Weight Organogelators

Four coumarin derivatives（4a-4d） with different alkoxy chains were synthesized. It was found that compound 4d showed a better gelation ability than the other compounds, for example, it could self-assemble into organogels in various organic fluids via ultrasound treatment or heating-cooling process, whereas compound 4c could only gel in a few mixed solvents and compounds 4a, 4b could not form organogel. The results from fluorescent and FT-IR spectra indicate that π-π interaction had an effect on the formation of the organogels of compound 4d besides H-bonding and van der Waals interaction, which were the driving forces for the self-assembling of compound 4c in gel state. The gel of compound 4d in toluene could emit strong fluorescence under UV irradiation and the [2＋2] cyclo-addition was suggested by ^1H NMR and fluorescence spectroscopy. This light-sensitive organogel might find application in optical materials.

Synthesis and Spectroscopic Study of Coumarin Derivatives

Five new coumarin amide derivatives were synthesized with coupling reagent,the structures of which were characterized by IR,1H NMR,13C NMR,MS and element analysis.Their spectral properties were studied in dichloromethane,in N,N-dimethylformamide（DMF） and in solid state.Solvent polarity has less influence on the UV-Vis maximum absorption at about 430 nm.The maximum emission wavelengths change from 464 nm to 474 nm in dichloromethane,from 476 nm to 482 nm in DMF and from 521 nm to 548 nm in solid state,respectively.The fluorescence intensities of compounds 8 and 9 were extremely strong in solvents or in solid state.Compounds 8 and 9 exhibited high fluorescenct quantumn yields in solution compared to compounds 4 ＂7.The fluorescence lifetimes of all the compounds in solvents were measured.

SO₄^2-/SnO₂-Catalyzed C3-alkylation of 4-hydroxycoumarin with secondary benzyl alcohols and <i>O</i>-alkylation with <i>O</i>-acetyl compounds

Sulfated tin oxide (STO) has been found to be an efficient reusable solid superacid catalyst for C3-alkylation and O-alkylation of 4-hydroxycoumarins with benzylic, allylic alcohols/and corresponding acetates respectively, in acetic acid under reflux conditions with good yield of products.

A new coumarin from Wikstroemia indica (L.) C.A.Mey

A new coumarin was obtained from the stems and roots of Wikstroemia indica （L.） C. A. Mey. Its structure was elucidated as methyl 3-（2-hydroxy-4-（7-hydroxy-6-methoxy-2-oxo-2H-chromen-3-yloxy） phenyl） propanoate by spectroscopic methods.

Prenylated Coumarins from Heracleum stenopterum,Peucedanum praeruptorum,Clausena lansium,and Murraya paniculata

Four hitherto unknown prenylated coumarins,namely 600-O-b-D-apiofuranosylapterin(1),40-O-isobutyroylpeguangxienin(2),6-(3-methyl-2-oxobutyroyl)-7-methoxycoumarin(3),and 6-hydroxycoumurrayin(4),were isolated from the ethanol extract of Heracleum stenopterum,Peucedanum praeruptorum,Clausena lansium,and Murraya paniculata,respectively.Their chemical structures were established on the basis of extensive spectroscopic analysis.Compound 2 exhibited in vitro cytotoxic activity against five human cancer cell lines(HL-60,A-549,SMMC-7721,MCF-7,and SW-480)with IC50 values ranging from 15.9 to 23.2μM.

Design and Synthetic Scheme of Water Dispersible Graphene Oxide-Coumarin Complex for Ultra-Sensitive Fluorescence Based Detection of Copper (Cu2+) Ion in Aqueous Environment

Copper oxides and its salts are now widely used as pesticides to control fungal and bacterial diseases of field crops. Copper toxicity is often a major contributor of human health problems caused through accumulation of excess copper ions in various organs via drinking water, fruits and vegetables. So, detection and estimation of cupric ions in biological organs, drinking water, fruits and vegetables are extremely important. Recently, a fluorescence based sensor using coumarin dye (high quantum yield) has been proposed to detect micromolar Cu++ ion in biological organs. But major problem with coumarin dye is that it is insoluble in water and undergoes dye-dye aggregation in organic solvents. We proposed here a synthetic scheme of preparation of graphene oxide conjugated coumarin dye derivative which would be water dispersible and expected to be an ideal candidate for Cu2+ ion estimation in biological organs and drinking water.