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Sample records for coumarin ring derivatives

  1. A review of coumarin derivatives in pharmacotherapy of breast cancer.

    Science.gov (United States)

    Musa, Musiliyu A; Cooperwood, John S; Khan, M Omar F

    2008-01-01

    The coumarin (benzopyran-2-one, or chromen-2-one) ring system, present in natural products (such as the anticoagulant warfarin) that display interesting pharmacological properties, has intrigued chemists and medicinal chemists for decades to explore the natural coumarins or synthetic analogs for their applicability as drugs. Many molecules based on the coumarin ring system have been synthesized utilizing innovative synthetic techniques. The diversity oriented synthetic routes have led to interesting derivatives including the furanocoumarins, pyranocoumarins, and coumarin sulfamates (COUMATES), which have been found to be useful in photochemotherapy, antitumor and anti-HIV therapy, and as stimulants for central nervous system, antibacterials, anti-inflammatory, anti-coagulants, and dyes. Of particular interest in breast cancer chemotherapy, some coumarins and their active metabolite 7-hydroxycoumarin analogs have shown sulfatase and aromatase inhibitory activities. Coumarin based selective estrogen receptor modulators (SERMs) and coumarin-estrogen conjugates have also been described as potential antibreast cancer agents. Since breast cancer is the second leading cause of death in American women behind lung cancer, there is a strong impetus to identify potential new drug treatments for breast cancer. Therefore, the objective of this review is to focus on important coumarin analogs with antibreast cancer activities, highlight their mechanisms of action and structure-activity relationships on selected receptors in breast tissues, and the different methods that have been applied in the construction of these pharmacologically important coumarin analogs.

  2. Halogenated coumarin derivatives as novel seed protectants.

    Science.gov (United States)

    Brooker, N; Windorski, J; Bluml, E

    2008-01-01

    Development of new and improved antifungal compounds that are target-specific is backed by a strong Federal, public and commercial mandate. Many plant-derived chemicals have proven fungicidal properties, including the coumarins (1,2-Benzopyrone) found in a variety of plants such as clover, sweet woodruff and grasses. Preliminary research has shown the coumarins to be a highly active group of molecules with a wide range of antimicrobial activity against both fungi and bacteria. It is believed that these cyclic compounds behave as natural pesticidal defence molecules for plants and they represent a starting point for the exploration of new derivative compounds possessing a range of improved antifungal activity. Within this study, derivatives of coumarin that were modified with halogenated side groups were screened for their antifungal activity against a range of soil-borne plant pathogenic fungi. Fungi included in this in vitro screen included Macrophomina phaseolina (charcoal rot), Phytophthora spp. (damping off and seedling rot), Rhizoctonia spp. (damping off and root rot) and Pythium spp. (seedling blight), four phylogenetically diverse and economically important plant pathogens. Studies indicate that these halogenated coumarin derivatives work very effectively in vitro to inhibit fungal growth and some coumarin derivatives have higher antifungal activity and stability as compared to the original coumarin compound alone. The highly active coumarin derivatives are brominated, iodinated and chlorinated compounds and results suggest that besides being highly active, very small amounts can be used to achieve LD100 rates. In addition to the in vitro fungal inhibition assays, results of polymer seed coating compatibility and phytotoxicity testing using these compounds as seed treatments will also be reported. These results support additional research in this area of natural pesticide development.

  3. Coumarin derivatives, but not coumarin itself, cause skin irritation via topical delivery.

    Science.gov (United States)

    Pan, Tai-Long; Wang, Pei-Wen; Aljuffali, Ibrahim A; Leu, Yann-Lii; Hung, Yi-Yun; Fang, Jia-You

    2014-04-21

    Coumarin and its derivatives are widely employed as a fragrance in cosmetics and skin care products. The skin absorption level and possible disruption to the skin by topical application of coumarins were evaluated in this study. Percutaneous absorption of osthole, daphnoretin, coumarin, byakangelicin, and 7-hydroxycoumarin was assessed in vitro and in vivo. Skin physiology measurements and immunoblotting were utilized as methodologies for validating toxicity. The relationship between structures and permeation/toxicity of coumarins was elucidated. Both equimolar concentration and saturated solubility in 30% ethanol were used as the applied dose. Osthole with the most lipophilic characteristic demonstrated the greatest skin accumulation, followed by coumarin and 7-hydroxycoumarin. Coumarin was the permeant with the highest flux across the skin. The trend of in vivo deposition was consistent with that of the in vitro profiles. Skin uptake of osthole was 8-fold higher than that of coumarin. Hair follicles played a significant role as a pathway for transport of coumarin according to the examination of follicular accumulation. Osthole and 7-hydroxycoumarin slightly, but significantly, enhanced transepidermal water loss after a consecutive 5-day administration. The immunoblotting profiling verified the role of proliferation in skin damage induced by osthole, byakangelicin, and 7-hydroxycoumarin. The proliferation-related proteins examined in this work included glucose-regulated proteins, cytokeratin, and C-myc. Daphnoretin and coumarin showed a negligible alteration on protein biomarkers. The experimental results suggested that skin irritation caused by coumarins was mainly derived from the analogs but not from coumarin itself.

  4. Coumarin amide derivatives as fluorescence chemosensors for cyanide anions

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Qianqian [School of Material Science and Engineering, Shandong Provincial Key Laboratory of Preparation and Measurement of Building Materials, University of Jinan, Jinan 250022, Shandong (China); Liu, Zhiqiang [State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, Shandong (China); Cao, Duxia, E-mail: duxiacao@ujn.edu.cn [School of Material Science and Engineering, Shandong Provincial Key Laboratory of Preparation and Measurement of Building Materials, University of Jinan, Jinan 250022, Shandong (China); Guan, Ruifang, E-mail: mse_guanrf@ujn.edu.cn [School of Material Science and Engineering, Shandong Provincial Key Laboratory of Preparation and Measurement of Building Materials, University of Jinan, Jinan 250022, Shandong (China); Wang, Kangnan; Shan, Yanyan; Xu, Yongxiao; Ma, Lin [School of Material Science and Engineering, Shandong Provincial Key Laboratory of Preparation and Measurement of Building Materials, University of Jinan, Jinan 250022, Shandong (China)

    2015-07-01

    Four coumarin amide derivatives with 4-methyl coumarin or pyrene as terminal group have been synthesized. Their photophysical properties and recognition properties for cyanide anions have been examined. The results indicate that the compounds can recognize cyanide anions with obvious absorption and fluorescence spectra change, at the same time, obvious color and fluorescence change can be observed by naked eye. The in situ hydrogen nuclear magnetic resonance spectra and photophysical properties change confirm that Michael additions between the chemosensors and cyanide anions take place at the 4-position of coumarin. - Highlights: • Four coumarin amide derivatives with 4-methyl coumarin or pyrene as terminal group were synthesized. • The compounds can recognize cyanide anions with obvious absorption and fluorescence spectra change. • Michael additions between the chemosensors and cyanide anions take place at the 4-position of coumarin.

  5. Towards optimal dosing of coumarin derivatives: the role of pharmacogenetics

    NARCIS (Netherlands)

    van Schie, R.M.F.

    2013-01-01

    Coumarin derivatives are effective in the prevention and treatment of thromboembolic diseases. Examples of indications are atrial fibrillation and venous thromboembolism. Although coumarins are on the market for decades, it is still challenging to find the optimal dosage for each patient since couma

  6. Conversion of 3-Carbethoxy-4-methyl Coumarin Derivatives into Several New Annelated Coumarin Derivatives

    Institute of Scientific and Technical Information of China (English)

    BAKEER; HadeerMohammed

    2003-01-01

    The reaction of ethyl esters of 4-methyl-2-oxo-2H-l-benzo(naphtho) pyran.3-carboxylic acids (1) with aromatic aldehy-des in the presence of piperidine yielded 4-styryl-3-carboxami-dopiperidyl connmrin derivatives 4. The reaction of hydrazlne hydrate with 1 gave acetophenone hydrozone derivatives 5 and acetophenone azine derivatives 6. The reaction of 1 with prima-ry amines afforded compomlds 7—9. And the treatment of la with Grignard reagents afforded 3-aroyl-4-methyl coumarin derivatives 10.

  7. Synthesis and Spectroscopic Study of Coumarin Derivatives

    Institute of Scientific and Technical Information of China (English)

    YAO Chun-feng; ZENG He-ping

    2011-01-01

    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.

  8. Modulation of Drug Resistance in Staphylococcus aureus with Coumarin Derivatives

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    Rodrigo Santos Aquino de Araújo

    2016-01-01

    Full Text Available Semisynthetic and commercial coumarins were investigated for their antibacterial and adjuvant properties with antibiotic agents against norfloxacin, erythromycin, and tetracycline resistant Staphylococcus aureus as based on efflux mechanisms. The coumarins and certain commercial antibiotics had their Minimum Inhibitory Concentrations determined by broth microdilution assay against resistant S. aureus strains which overexpress efflux pump proteins. For evaluation of the modulatory activity, the antibiotics MICs were determined in the presence of the coumarin derivatives at subinhibitory concentration. Although the coumarins did not display relevant antibacterial activity (MIC ≥ 128 µg/mL, they did modulate the antibiotics activities. Various coumarins, especially the alkylated derivatives in combination with antibiotics at subinhibitory concentrations, modulated antibiotic activity, reducing the MIC for tetracycline and norfloxacin by 2 to 8 times. Polar Surface Area (PSA studies were performed and the fact that the presence of apolar groups is an important factor for the modulatory activity of coumarins was corroborated. Docking on the Penicillin-Binding Protein from MRSA identified that 18 is a potential ligand presenting low Ebinding. The results indicate that coumarin derivatives modulated antibiotic resistance and may be used as potential antibiotic adjuvants, acting by bacterial efflux pump inhibition in S. aureus.

  9. Synthesis of new condensed coumarin derivatives

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    Dekić Stojadin V.

    2007-01-01

    Full Text Available Reactions of 4-chloro-2-oxo-2H-chromene-3-carbonitrile (1 with 4-methylpyridin- 2-ylamine (2 and 6-methoxy-benzothiazol-2-ylamine (3 in acetonitrile containing a catalytic amount of triethylamine gave the new coumarin derivatives 7-imino-10-methyl-7H- 5-oxa-7a,12-diaza-benzo[a]anthracen-6-one (4 and 7-imino-10-methoxy-7H-5-oxa-12- thia-7a,13-diaza-indeno[1,2-b]phenanthren-6-one (5 in 52 and 39% yields, respectively. The novel compounds were subjected to acid hydrolysis giving the corresponding oxoderivatives 10-methyl-5-oxa-7a,12-diaza-benzo[a]anthracene-6,7-dione (6 and 10- methoxy-5-oxa-12-thia-7a,13-diaza-indeno[1,2-b]phenanthrene-6,7-dione (7 in 64 and 58% yields, respectively. The structural assignments of the synthesized compounds were based on elemental analyses, IR and proton NMR spectra. .

  10. Potential antibacterial activity of coumarin and coumarin-3-acetic acid derivatives.

    Science.gov (United States)

    Chattha, Fauzia Anjum; Munawar, Munawar Ali; Nisa, Mehrun; Ashraf, Mohammad; Kousar, Samina; Arshad, Shafia

    2015-05-01

    Coumarin and coumarin-3-acetic acid derivatives were synthesized by reacting phenols with malic acid, ethyl acetoacetate and ethyl acetylsuccinate in appropriate reaction conditions. All synthesized compounds were subjected to test for their antimicrobial activities against variety of gram positive (Bacillus subtilis, Staphylococcus aureus) and gram negative bacterial stains (Shigella sonnei, Escherichia coli) by agar dilution method. Several of them exhibited appreciable good antibacterial activity against the different strains of gram positive and gram negative bacteria. These findings suggest a great potential of these compounds for screening and use as antibacterial agents for further studies with a battery of bacteria.

  11. Fragmentation pathways of synthetic and naturally occurring coumarin derivatives by ion trap and quadrupole time-of-flight mass spectrometry.

    Science.gov (United States)

    Liang, Xianrui; Han, Xiaomei

    2015-09-15

    Synthetic and natural coumarin derivatives possess a wide range of biological activities. Fragmentation pathway studies are important in identifying both naturally occurring coumarins and synthetic coumarins with novel structures and properties. The fragmentation pathways of eleven coumarin derivatives are investigated by electrospray ionization (ESI) ion-trap mass spectrometry (ESI-ITMS(n) ) and ESI quadrupole time-of-flight mass spectrometry (QTOFMS) in positive mode. Compounds 1-9 in this study were newly synthesized in our laboratory. Compounds 10 and 11 were isolated from the root of Zanthoxylum armatum. The major fragmentation pathways for 11 coumarin derivatives are greatly affected by the heterocyclic ring structures and the side-chain substituents. Typical losses of small neutral molecules, such as CH3 CH2 OH, CH2 =CH2 , CO, and H2 O, are observed for compounds 1-5. Compounds 6-9 share similar fragmentation pathways through losses of CO, aromatic rings, and the coumarin skeleton. The main product ions at m/z 205, 219, and 220 observed for compounds 10 and 11 are produced by the loss of C5 H12 O2 , C4 H10 O2 , and the C4 H9 O2 radical, respectively. The fragmentation pathways of 11 coumarin derivatives are elucidated based on ITMS(n) and QTOFMS spectral data. Differences in the structures of the heterocyclic rings and side-chain substituents strongly affect the fragmentation pathways of the coumarins. The present results will facilitate further research into the fragmentation pathways and structural characterization of these classes of compounds with diverse structures. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

  12. Antimicrobial Properties of Newly Synthesized Derivatives of Coumarine

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    S. Govori

    2010-01-01

    Full Text Available Problem statement: Coumarins are well known for their biological activity. On the basis of that we have synthesized some new derivatives of coumarine and investigated their antimicrobial properties. Approach: 4-Heteroaryl-coumarin-3-carbaldehydes 4(a-d are synthesized by condensation of 4-chloro-coumarin-3-carbaldehydes 2 and corresponding heterorylamines 3(a-d under reflux reaction conditions. Antimicrobial properties of new coumarins 4(a-d are investigated and results are submitted for their activities against Staphylococcus aureus, Escherichia coli, Hafnia alvei, Pseudomonas aeruginosa and Enterobacter cloacae. Applying the Agar disc diffusion technique we measured diameters of the inhibition zone around discs which are previously wetted with N, N-DMF solution of compounds, 1, 3 and 5 mg L−1. Results: The inhibition zone depends from concentrations and also from sort of bacteria. The inhibition zone differ from 0 to 30mm. Two sort of bacteria, Hafnia alvei and Pseudomonas aeruginosa, are resistant to these new synthesized compounds. Conclusion: From results we may conclude that these derivates showed moderate to high activity against Staphylococcus aureus, Escherichia coli and Enterobacter cloaco. Compounds 4(a-d are more active against Staphylococcus aureus, E.coli and Enterobacter cloaco. Compounds 4(a-d are not active against Hafnia alvei and Pseudomonas aeruginosa.

  13. Paniculacin, a new coumarin derivative from Murraya paniculata.

    Science.gov (United States)

    Saeed, Sumayya; Shah, Shazia; Mehmood, Rashad; Malik, Abdul

    2011-08-01

    Paniculacin (1), a new coumarin derivative, has been isolated from the ethyl acetate soluble fraction of the ethanolic extract of Murraya paniculata along with umbelliferone, scopoletin, 4-hydroxybenzoic acid, trans-cinnamic acid, and β-sitosterol. Their structures were elucidated on the basis of spectral data.

  14. The Antioxidant Activity of New Coumarin Derivatives

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    Abu Bakar Mohamad

    2011-09-01

    Full Text Available The antioxidant activity of two synthesized coumarins namely, N-(4,7-dioxo-2-phenyl-1,3-oxazepin-3(2H,4H,7H-yl-2-(2-oxo-2H-chromen-4-yloxyacetamide 5 and N-(4-oxo-2-phenylthiazolidin-3-yl-2-(2-oxo-2H-chromen-4-yloxyacetamide 6 were studied with the DPPH, hydrogen peroxide and nitric oxide radical methods and compared with the known antioxidant ascorbic acid. Compounds 5 and 6 were synthesized in a good yield from the addition reaction of maleic anhydride or mercaptoacetic acid to compound 4, namely N'-benzylidene-2-(2-oxo-2H-chromen-4-yloxyacetohydrazide. Compound 4 was synthesized by the condensation of compound 3, namely 2-(2-oxo-2H-chromen-4-yloxy acetohydrazide, with benzaldehyde. Compound 3, however, was synthesized from the addition of hydrazine to compound 2, namely ethyl 2-(2-oxo-2H-chromen-4-yloxyacetate, which was synthesized from the reaction of ethyl bromoacetate with 4-hydroxycoumarin 1. Structures for the synthesized coumarins 2–6 are proposed on the basis of spectroscopic evidence.

  15. Predictive Modeling of Antioxidant Coumarin Derivatives Using Multiple Approaches: Descriptor-Based QSAR, 3D-Pharmacophore Mapping, and HQSAR

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    Indrani MITRA

    2016-09-01

    Full Text Available The inability of the systemic antioxidants to alleviate the exacerbation of free radical formation from metabolic outputs and environmental pollutants claims an urgent demand for the identification and design of new chemical entities with potent antioxidant activity. In the present work, different QSAR approaches have been utilized for identifying the essential structural attributes imparting a potential antioxidant activity profile of the coumarin derivatives. The descriptor-based QSAR model provides a quantitative outline regarding the structural prerequisites of the molecules, while 3D pharmacophore and HQSAR models emphasize the favourable spatial arrangement of the various chemical features and the crucial molecular fragments, respectively. All the models infer that the fused benzene ring and the oxygen atom of the pyran ring constituting the parent coumarin nucleus capture the prime pharmacophoric features, imparting superior antioxidant activity to the molecules. The developed models may serve as indispensable query tools for screening untested molecules belonging to the class of coumarin derivatives.

  16. Coumarin benzothiazole derivatives as chemosensors for cyanide anions.

    Science.gov (United States)

    Wang, Kangnan; Liu, Zhiqiang; Guan, Ruifang; Cao, Duxia; Chen, Hongyu; Shan, Yanyan; Wu, Qianqian; Xu, Yongxiao

    2015-06-05

    Four coumarin benzothiazole derivatives, N-(benzo[d]thiazol-2-yl)-2-oxo-2H-chromene-3-carboxamide (1), (Z)-N-(3-methylbenzo[d]thiazol-2(3H)-ylidene)-2-oxo-2H-chromene-3-carboxamide (2), 7-(diethylamino)-N-(benzo[d]thiazol-2-yl)-2-oxo-2H-chromene-3-carboxamide (3) and (Z)-7-(diethylamino)-N-(3-methylbenzo[d]thiazol-2(3H)-ylidene)-2-oxo-2H-chromene-3-carboxamide) (4), have been synthesized. Their crystal structures, photophysical properties in acetonitrile and recognition properties for cyanide anions have been investigated. All the compounds are generally planar, especially compound 1 exhibits perfect planarity with dihedral angle between benzothiazolyl group and coumarin group being only 3.63°. Coumarin benzothiazole compounds 1 and 3 can recognize cyanide anions by Michael addition reaction and compound 3 exhibits color change from yellow to colorless and green fluorescence was quenched completely, which can be observed by naked eye. Coumarin benzothiazolyliden compound 4 can recognize cyanide anions with fluorescence turn-on response based on the copper complex ensemble displacement mechanism.

  17. Coumarin benzothiazole derivatives as chemosensors for cyanide anions

    Science.gov (United States)

    Wang, Kangnan; Liu, Zhiqiang; Guan, Ruifang; Cao, Duxia; Chen, Hongyu; Shan, Yanyan; Wu, Qianqian; Xu, Yongxiao

    2015-06-01

    Four coumarin benzothiazole derivatives, N-(benzo[d]thiazol-2-yl)-2-oxo-2H-chromene-3-carboxamide (1), (Z)-N-(3-methylbenzo[d]thiazol-2(3H)-ylidene)-2-oxo-2H-chromene-3-carboxamide (2), 7-(diethylamino)-N-(benzo[d]thiazol-2-yl)-2-oxo-2H-chromene-3-carboxamide (3) and (Z)-7-(diethylamino)-N-(3-methylbenzo[d]thiazol-2(3H)-ylidene)-2-oxo-2H-chromene-3-carboxamide) (4), have been synthesized. Their crystal structures, photophysical properties in acetonitrile and recognition properties for cyanide anions have been investigated. All the compounds are generally planar, especially compound 1 exhibits perfect planarity with dihedral angle between benzothiazolyl group and coumarin group being only 3.63°. Coumarin benzothiazole compounds 1 and 3 can recognize cyanide anions by Michael addition reaction and compound 3 exhibits color change from yellow to colorless and green fluorescence was quenched completely, which can be observed by naked eye. Coumarin benzothiazolyliden compound 4 can recognize cyanide anions with fluorescence turn-on response based on the copper complex ensemble displacement mechanism.

  18. Study of Photophysical Properties on Newly Synthesized Coumarin Derivatives.

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    Sidarai, Ashok H; Desai, Vani R; Hunagund, Shirajahammad M; Basanagouda, Mahantesha; Kadadevarmath, Jagadish S

    2017-08-19

    Herein, we have studied the photophysical properties for three newly synthesized coumarin derivatives; 4-((2,6-dibromo-4-methylphenoxy)methyl)-2H-benzo[h]chromen-2-one (DMB), 4-((3,4-dihydro-6,7-dimethoxyisoquinolin-1-yl)methyl)-6-methyl-2H-chromen-2-one (DIM) and 4-((p-tolyloxy)methyl)-6-methoxy-2H-chromen-2-one (TMC). The absorption and emission spectra for above said molecules were recorded in different solvents at room temperature in order to calculate their ground and excited state dipole moments. The ground (μ g ) and excited state dipole (μ e ) moments of these coumarin derivatives were calculated using Lippert's, Bakshiev's and Kawski-Chamma-Viallet's equations by the solvatochromic shift method, which involves a variation of Stokes shift with the solvent dielectric constant and refractive index. Ground state dipole moments (μ g ) were also calculated from the Guggenheim method using the dielectric constant and refractive index of the solute molecule. The value of ground state dipole moment obtained from these two methods is well correlated. Further, it is notified that the excited state dipole moment is larger than the ground state dipole moment for all three solute molecules. It inferred that the excited state for above said molecules is more polar than the ground state. The present investigations may shine in the design of nonlinear optical materials. Graphical Abstract The photophysical properties for novel coumarin derivatives were studied in different solvents.Ground and excited state dipole moments were estimated by the solvatochromic shift method. The excited state dipole moment is greater than the ground state dipole moment in systems studied. The excited state is more polar than the ground state. The present investigation may be shine in the design of non linear optical materials.

  19. Recent developments of C-4 substituted coumarin derivatives as anticancer agents.

    Science.gov (United States)

    Dandriyal, Jyoti; Singla, Ramit; Kumar, Manvendra; Jaitak, Vikas

    2016-08-25

    Cancer is a prominent cause of death in global. Currently, the numbers of drugs that are in clinical practice are having a high prevalence of side effect and multidrug resistance. Researchers have made an attempt to expand a suitable anticancer drug that has no MDR and side effect. Coumarin scaffold became an attractive subject due to their broad spectrum of pharmacological activities. Coumarin derivatives extensively explored for anticancer activities as it possesses minimum side effect along with multi-drug reversal activity. Coumarin derivatives can act by various mechanisms on different tumor cell lines depending on substitution pattern of the core structure of coumarin. Substitution on coumarin nucleus leads to the search for more potent compounds. In this review, we have made an effort to give a synthetic strategy for the preparation of C-4 substituted coumarin derivatives as anticancer agents based on their mechanism of action and also discuss the SAR of the most active compound.

  20. Elucidation of the binding mechanism of coumarin derivatives with human serum albumin.

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    Archit Garg

    Full Text Available Coumarin is a benzopyrone which is widely used as an anti-coagulant, anti-oxidant, anti-cancer and also to cure arthritis, herpes, asthma and inflammation. Here, we studied the binding of synthesized coumarin derivatives with human serum albumin (HSA at physiological pH 7.2 by using fluorescence spectroscopy, circular dichroism spectroscopy, molecular docking and molecular dynamics simulation studies. By addition of coumarin derivatives to HSA the maximum fluorescence intensity was reduced due to quenching of intrinsic fluorescence upon binding of coumarin derivatives to HSA. The binding constant and free energy were found to be 1.957±0.01×10(5 M(-1, -7.175 Kcal M(-1 for coumarin derivative (CD enamide; 0.837±0.01×10(5 M(-1, -6.685 Kcal M(-1 for coumarin derivative (CD enoate, and 0.606±0.01×10(5 M(-1, -6.49 Kcal M(-1 for coumarin derivative methylprop (CDM enamide. The CD spectroscopy showed that the protein secondary structure was partially unfolded upon binding of coumarin derivatives. Further, the molecular docking studies showed that coumarin derivatives were binding to HSA at sub-domain IB with the hydrophobic interactions and also with hydrogen bond interactions. Additionally, the molecular dynamics simulations studies contributed in understanding the stability of protein-drug complex system in the aqueous solution and the conformational changes in HSA upon binding of coumarin derivatives. This study will provide insights into designing of the new inspired coumarin derivatives as therapeutic agents against many life threatening diseases.

  1. Synthesis, crystal structures and photoluminescence of anthracen- and pyrene-based coumarin derivatives.

    Science.gov (United States)

    Zhang, Hui; Tong, Hao; Zhao, Yuling; Yu, Tianzhi; Zhang, Peng; Li, Jianfeng; Fan, Duowang

    2015-11-01

    Two new anthracen- and pyrene-based coumarin derivatives, 3-(4-(anthracen-10-yl)phenyl)coumarin (4) and 3-(4-(pyrene-1-yl)phenyl)coumarin (5), were synthesized and characterized by FT-IR, (1)H NMR, element analysis and single crystal X-ray crystallography. The UV-vis absorption and photoluminescence spectra of these coumarin derivatives were investigated. The results show that compound 4 and 5 exhibit blue and blue-green emissions, respectively, under ultraviolet light excitation. Compared with the compound 4, the emission peak of compound 5 was bathochromically shifted by about 80 nm due to the more planar structure and larger π-conjugation.

  2. Crystal structures of three 6-substituted coumarin-3-carboxamide derivatives.

    Science.gov (United States)

    Gomes, Lígia R; Low, John Nicolson; Fonseca, André; Matos, Maria João; Borges, Fernanda

    2016-07-01

    Three coumarin derivatives, viz. 6-methyl-N-(3-methyl-phen-yl)-2-oxo-2H-chromene-3-carboxamide, C18H15NO3 (1), N-(3-meth-oxy-phen-yl)-6-methyl-2-oxo-2H-chromene-3-carboxamide, C18H15NO4 (2), and 6-meth-oxy-N-(3-meth-oxy-phen-yl)-2-oxo-2H-chromene-3-carboxamide, C18H15NO5 (3), were synthesized and structurally characterized. The mol-ecules display intra-molecular N-H⋯O and weak C-H⋯O hydrogen bonds, which probably contribute to the approximate planarity of the mol-ecules. The supra-molecular structures feature C-H⋯O hydrogen bonds and π-π inter-actions, as confirmed by Hirshfeld surface analyses.

  3. Design, synthesis and biological evaluation of novel coumarin thiazole derivatives as α-glucosidase inhibitors.

    Science.gov (United States)

    Wang, Guangcheng; He, Dianxiong; Li, Xin; Li, Juan; Peng, Zhiyun

    2016-04-01

    A new series of coumarin thiazole derivatives 7a-7t were synthesized, characterized by (1)H NMR, (13)C NMR and element analysis, evaluated for their α-glucosidase inhibitory activity. The majority of the screened compounds displayed potent inhibitory activities with IC50 values in the range of 6.24±0.07-81.69±0.39μM, when compared to the standard acarbose (IC50=43.26±0.19μM). Structure-activity relationship (SAR) studies suggest that the pattern of substitution in the phenyl ring is closely related to the biological activity of this class of compounds. Among all the tested molecules, compound 7e (IC50=6.24±0.07μM) was found to be the most active compound in the library of coumarin thiazole derivatives. Enzyme kinetic studies showed that compound 7e is a non-competitive inhibitor with a Ki of 6.86μM. Furthermore, the binding interactions of compound 7e with the active site of α-glucosidase were confirmed through molecular docking. This study has identified a new class of potent α-glucosidase inhibitors for further investigation.

  4. Synthesis and Antimicrobial Activity of New 4-Heteroarylamino Coumarin Derivatives Containing Nitrogen and Sulfur as Heteroatoms

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    Biljana R. Dekić

    2010-03-01

    Full Text Available Synthesis, spectral analysis and bioactivity of new coumarin derivatives are described in this paper. Eight new coumarin derivatives were synthesized in moderate to good yields by condensation of 4-chloro-3-nitrocoumarin and the corresponding heteroarylamine. The synthesized compounds were tested for their in vitro antimicrobial activity, in a standard disk diffusion assay, against thirteen strains of bacteria and three fungal strains. They have shown a wide range of activity - from one completely inactive compound to medium active ones.

  5. Cytotoxity of two new coumarin derivatives isolated from Launaea mucronata.

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    El-Sharkawy, Eman R; Mahmoud, Khaled

    2016-01-01

    The chloroform fraction of methanol (MeOH) extract of the aerial parts of Launaea mucronata was in vitro investigated for cytotoxicity against HCT116, HepG2 and MCF-7 cell lines, and resulted with IC50 = 20.0, 18.6 and 14.30 μg/mL, respectively. The chloroform fraction of the MeOH extract was subjected to further fractionation, which led to the isolation of two new coumarin compounds (6-isobutyl coumarin and 6-isobutyl-7-methyl- coumarin). The structures of the new compounds were elucidated by high field 1D and 2D NMR and ESI-MS spectroscopies. Low polar fractions revealed the isolation of other known triterpene compounds which were identified according to its spectral data and comparison with the literature. New coumarin compounds show high cytotoxicity against MCF-7, HCT116 and HepG2 cell lines.

  6. Phytotoxic Potential and Biological Activity of Three Synthetic Coumarin Derivatives as New Natural-Like Herbicides

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    Fabrizio Araniti

    2015-09-01

    Full Text Available Coumarin is a natural compound well known for its phytotoxic potential. In the search for new herbicidal compounds to manage weeds, three synthetic derivatives bearing the coumarin scaffold (1–3, synthesized by a carbonylative organometallic approach, were in vitro assayed on germination and root growth of two noxious weeds, Amaranthus retroflexus and Echinochloa crus-galli. Moreover, the synthetic coumarins 1–3 were also in vitro assayed on seedlings growth of the model species Arabidopsis thaliana to identify the possible physiological targets. All molecules strongly affected seed germination and root growth of both weeds. Interestingly, the effects of synthetic coumarins on weed germination were higher than template natural coumarin, pointing out ED50 values ranging from 50–115 µM. Moreover, all synthetic coumarins showed a strong phytotoxic potential on both Arabidopsis shoot and root growth, causing a strong reduction in shoot fresh weight (ED50 values ≤ 60 µM, accompanied by leaf development and a decrease in pigment content. Furthermore, they caused a strong alteration in root growth (ED50 values ≤ 170 µM and morphology with evident alterations in root tip anatomy. Taken together, our results highlight the promising potential herbicidal activity of these compounds.

  7. Novel macromolecules derived from coumarin: synthesis and antioxidant activity

    Science.gov (United States)

    Al-Amiery, Ahmed A.; Al-Majedy, Yasameen K.; Kadhum, Abdul Amir H.; Mohamad, Abu Bakar

    2015-07-01

    The rational design of 4-hydroxycoumarins with tailor-made antioxidant activities is required nowadays due to the wide variety of pharmacologically significant, structurally interesting of coumarins and researcher orientation toward green chemistry and natural products. A simple and unique coumarins have been achieved by reaction of 4-hydroxycoumarin with aromatic aldehyde accompanied with the creation of a macromolecules have 2-aminothiazolidin-4-one. The molecular structures of the compounds were characterized by the Fourier transformation infrared and Nuclear magnetic resonance spectroscopies, in addition to CHN analysis. The scavenging abilities of new compounds against stable DPPH radical (DPPH•) and hydrogen peroxide were done and the results show that the compounds exhibited high antioxidant activates.

  8. Synthetic studies of coumarin derivatives from o-hydroxybenzophenones with phenylacetic acid and acetic anhydride

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Soon Hee; Yang, Sung Yun [Ewha Womans Univ., Seoul (Korea, Republic of)

    1999-02-01

    The 8 coumarin derivatives have been synthesized from 8 starting materials(2-hydroxy-benzophenone, 2,2'-dihydroxybenzophenone, 2,4-dihydroxybenzophenone, 2-hydroxy-5-methylbenzophenone, 5-chloro-2-hydroxy-4-methylbenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-4'-dimethoxybenzophenone) with phenylacetic acid and Ac{sub 2}O/TEA in acetone at reflux temperature. The ratio of o-hydroxybenzophenone, phenylacetic acid, Ac{sub 2}O and TEA is 1:1:8:8 in acetone. Our results showed higher products yields of coumarin derivatives than Shama and Ray's method in previous papers. A new intermediate form was proposed to our mechanism of coumarin synthetic method.

  9. Inhibition effects of acetyl coumarines and thiazole derivatives on corrosion of zinc in acidic medium

    Indian Academy of Sciences (India)

    A V Shanbhag; T V Venkatesha; R A Prabhu; B M Praveen

    2011-06-01

    The corrosion inhibition characteristics of acetyl coumarine (AC), bromo acetyl coumarine (BAC) and thiazole derivatives (BTMQ and BTCQ) on the corrosion of zinc in 0.1 M HCl solution were investigated by weight loss, potentiodynamic polarization and impedance techniques. The inhibition efficiency increased with increase in inhibitor concentration upto 5 × 10-4 M, then gave almost same inhibition efficiency. The polarizationmeasurements indicated the mixed nature of inhibitors. The adsorption of compounds obeyed Langmuir’s adsorption isotherm. The thermodynamic functions for adsorption processes were evaluated.

  10. Studies on the antiplatelet and antithrombotic profile of anti-inflammatory coumarin derivatives.

    Science.gov (United States)

    Kontogiorgis, Christos; Nicolotti, Orazio; Mangiatordi, Giuseppe Felice; Tognolini, Massimiliano; Karalaki, Foteini; Giorgio, Carmine; Patsilinakos, Alexandros; Carotti, Angelo; Hadjipavlou-Litina, Dimitra; Barocelli, Elisabetta

    2015-12-01

    The interest towards coumarin-based structures stems from their polypharmacological profile. Herein, we present a series of Mannich bases and 7-azomethine-linked coumarin derivatives exhibiting antiplatelet and antithrombotic activities, in addition to the already known anti-inflammatory and antioxidant activities. Among others, compounds 15 and 16 were found to be the most potent and selective inhibitors of platelet aggregation whereas compound 3 also proved to be the most potent in the clot retraction assay. Structure-activity relationship studies were conducted to elucidate the molecular determinants responsible for the herein observed activities. The chance of inhibiting cyclooxygenase-1 was also investigated for evaluating the platelet aggregation induced by arachidonic acid. Taken together, these results suggest that the investigation of other targets connected to the antiplatelet activity, such as phosphodiesterase-3 (PDE3), could be a viable strategy to shed light on the polypharmacological profile of coumarin-based compounds. Docking simulations towards PDE3 were also carried out.

  11. Synthesis, and Fluorescence Properties of Coumarin and Benzocoumarin Derivatives Conjugated Pyrimidine Scaffolds for Biological Imaging Applications.

    Science.gov (United States)

    Al-Masoudi, Najim A; Al-Salihi, Niran J; Marich, Yossra A; Markus, Timo

    2015-11-01

    Series of coumarin and 5,6-benzomcomarin substituted pyrimidine derivatives 11-15 and 22-25 were synthesized, aiming to develop new imaging fluorescent agents. Analogously, treatment of 4-chloropyrimidine analog 16 with coumarin 3-carbohyrazide 5 under MWI condition followed by boiling with NH4OAc in HOAc furnished coumarin-1,2,4-triazolo-pyrimidine analog 18. The fluorescence property was investigated spectrophotometrically in MeOH with Rhodamine 6G as standard dye. All the compounds showed emission in the region between 331 and 495 nm. The quantum yield of all the compounds were found to be weak, except methyl benzocoumarin 3-carboxylate 22 which showed (ΦF = 0.98) in comparison to Rhodamine 6G as standard (ΦF = 0.95).

  12. Benchmark study of UV/Visible spectra of coumarin derivatives by computational approach

    Science.gov (United States)

    Irfan, Muhammad; Iqbal, Javed; Eliasson, Bertil; Ayub, Khurshid; Rana, Usman Ali; Ud-Din Khan, Salah

    2017-02-01

    A benchmark study of UV/Visible spectra of Simple coumarins and Furanocoumarins derivatives was conducted by employing the Density Functional Theory (DFT) and Time Dependent Density Functional Theory (TD-DFT) approaches. In this study the geometries of ground and excited states, excitation energy and absorption spectra were estimated by using the DFT functional CAM-B3LYP, WB97XD, HSEH1PBE, MPW1PW91 and TD-B3LYP with 6-31 + G (d,p) basis set. CAM-B3LYP functional was found to have close agreement with the experimental values of Furranocoumarin class of coumarins while MPW1PW91 gave close results for simple coumarins. This study provided an insight about the electronic characteristics of the selected compounds and provided an effective tool for developing and designing the better UV absorber compounds.

  13. Synthesis and Study of Novel Coumarin Derivatives Potentially Utilizable as Memory Media

    Directory of Open Access Journals (Sweden)

    Jana Donovalová

    2009-11-01

    Full Text Available Novel coumarin derivatives, 2-oxo-2H-chromenecarbaldehyde hydrazones were prepared by reaction of substituted 2-oxo-2H-chromenecarbaldehydes with N-aminoimides in ethanol in the presence of 4-toluenesulfonic acid as catalyst. The photochromic and thermochromic properties of the prepared compounds were investigated.

  14. One-pot four component synthesis of novel 3-furyl coumarin derivatives

    Indian Academy of Sciences (India)

    Venkata Prasad Jalli; Suvratha Krishnamurthy; Tetsuji Moriguchi; Akihiko Tsuge

    2016-02-01

    Efficient and facile synthesis of 3-furyl coumarin derivatives have been achieved by reaction of 4-chloro-3-formylcoumarin, secondary amines, dialkyl acetylenedicarboxylates and diversely substituted isocyanides using four component, one-pot reaction. All the products were isolated as yellow color fluorescent solids by column chromatography in quantitative yield and characterized with 1H NMR, 13C NMR, IR and FAB mass.

  15. Coumarin embryopathy

    Energy Technology Data Exchange (ETDEWEB)

    Struwe, F.E.; Reinwein, H.; Stier, R.

    1984-02-01

    Anticoagulant therapy using Coumarin derivatives (vitamin K antagonists) during early pregnancy may result in a characteristic embryopathy appearing as a phaenocopy of chondrodysplasia punctata (Conradi-Huenermann's disease). This has been suggested in advance by observations made in newborns of mothers who had been treated previously with Warfarin or Acenocoumon. Similar observations made in a newborn after the mother's treatment with Phencoumon in early pregnancy are described in this paper. Coumarin embryopathy is proposed as a common term.

  16. Supramolecular Photodimerization of Coumarins

    Directory of Open Access Journals (Sweden)

    Koichi Tanaka

    2012-02-01

    Full Text Available Stereoselective photodimerization of coumarin and its derivatives in supra-molecular systems is reviewed. The enantioselective photodimerization of coumarin and thiocoumarin in inclusion crystals with optically active host compounds is also described.

  17. Recent progress in the drug development of coumarin derivatives as potent antituberculosis agents.

    Science.gov (United States)

    Keri, Rangappa S; Sasidhar, B S; Nagaraja, Bhari Mallanna; Santos, M Amélia

    2015-07-15

    Tuberculosis (TB) is still a challenging worldwide health problem and mycobacterium tuberculosis (MTB) remains one of the most deadly human pathogens. TB is the second leading infectious cause of mortality today behind only HIV/AIDS. The impetus for developing new structural classes of antituberculosis drugs comes from the emergence of multi-drug resistant (MDR) strains. The development of MDR strains to commonly used drugs is due to, longer durations of therapy as results of resistance, and the resurgence of the disease in immune compromised patients. Therefore, there is an urgent need to explore new antitubercular (anti-TB) agents. Ironically, the low number of potentially new chemical entities which can act as anti-TB candidates is of great importance at present situation. Considering the severity of the problem, WHO has prepared a strategic plan in Berlin declaration 2007 to stop TB, globally. Among the oxygen heterocycles, coumarin derivatives are important motifs, which can be widely found in many natural products, and many of them displaying diverse biological activities. This spectacular spectrum of applications has intrigued organic and medicinal chemists for decades to explore the natural coumarins or their synthetic analogs for their applicability as anti-TB drugs. To pave the way for the future research, there is a need to collect the latest information in this promising area. In the present review, we collated published reports on coumarin derivatives to shed light on the insights on different types of methods reported for their preparations, characterizations and anti-TB applications, so that its full therapeutic potential class of compounds can be utilized for the treatment of tuberculosis. Therefore, the objective of this review is to focus on important coumarin analogs with anti-TB activities, and structure-activity relationships (SAR) for designing the better anti-TB agents. It is hoped that, this review will be helpful for new thoughts in the

  18. On the role of a coumarin derivative for sensing applications: Nucleotide identification using a micellar system.

    Science.gov (United States)

    Bettoschi, Alexandre; Ceglie, Andrea; Lopez, Francesco; Meli, Valeria; Murgia, Sergio; Tamburro, Manuela; Caltagirone, Claudia; Cuomo, Francesca

    2016-09-01

    The recognition of nucleotides is of crucial importance because they are the basic constituents of nucleic acids. The present study is focused on the selective interaction between a novel amphiphilic fluorophore containing coumarin and imidazole, CI (1-methyl-3-(12-((2-oxo-2H-chromen-7-yl)oxy)dodecyl)-1H-imidazol-3-ium bromide), and different nucleotide-monophosphates (NMPs). It was supposed that the solubilization of the low water soluble CI in a micelle system of hexadecyltrimethylammonium chloride (CTAC) would make the coumarin moiety of CI available to the interaction with the water-soluble NMPs. Changes in CTAC critical micelle concentration suggested that CI strongly interacted with the host cationic surfactant, thus forming a positively charged interface enriched with coumarin able to interact with the anionic NMPs. Steady-state fluorescence quenching revealed that CI/CTAC system was capable of distinguish between purine- and pyrimidine-based nucleotides. A modified Stern-Volmer equation permitted the use of a quenching model that accounted for the possible interactions between the micelles and the nucleotides. The data analysis allowed calculating selective parameters that differentiated according to the type of nucleotide either at 25 or 50°C. Our results established the utility of the novel coumarin derivative fluorophore, supported by the simple and suitable micellar systems, as a tool for DNA sensing applications.

  19. Synthesis and bioactivity of novel coumarin derivatives containing (E)-methyl 2-(methoxyimino)-2-phenylacetates

    Institute of Scientific and Technical Information of China (English)

    Ai Ying Guan; Chang Ling Liu; Zhi Nian Li; Ming Xing Zhang

    2011-01-01

    Ten coumarin derivatives containing (E)-methyl 2-(methoxyimino)-2-phenylacetate were synthesized and bioassayed. The compounds were identified by IR, 1H NMR and elemental analyses. The test results indicated that compound 5j (R1 is methyl and R2 is n-C6H13) was the optimal structure in this paper with good fungicidal activity against CDM (85%) at 6.25 mg/L concentration.

  20. Synthesis and properties of novel calix[4]arene derivatives bearing fluorogenic coumarin units

    Institute of Scientific and Technical Information of China (English)

    He Wen Wang; Ya Qing Feng; Jin Qiang Xue; Chan Xiao

    2008-01-01

    Four novel calix[4]arene derivatives 5-8 bearing four fluorogenic coumarin units attached via imino group acting also as binding sites at the upper rim have been prepared and characterized by IR, 1H NMR and MS. Compounds 5-8 adopt a cone conformation. Their complexation properties to different heavy and transition metal ions have been studied by UV-vis spectroscopy. Compounds 5, 6, 8 show selective recognition to Fe3+ and Cr3+.

  1. Synthesis, cholinesterase inhibition and molecular modelling studies of coumarin linked thiourea derivatives.

    Science.gov (United States)

    Saeed, Aamer; Zaib, Sumera; Ashraf, Saba; Iftikhar, Javeria; Muddassar, Muhammad; Zhang, Kam Y J; Iqbal, Jamshed

    2015-12-01

    Alzheimer's disease is among the most widespread neurodegenerative disorder. Cholinesterases (ChEs) play an indispensable role in the control of cholinergic transmission and thus the acetylcholine level in the brain is enhanced by inhibition of ChEs. Coumarin linked thiourea derivatives were designed, synthesized and evaluated biologically in order to determine their inhibitory activity against acetylcholinesterases (AChE) and butyrylcholinesterases (BChE). The synthesized derivatives of coumarin linked thiourea compounds showed potential inhibitory activity against AChE and BChE. Among all the synthesized compounds, 1-(2-Oxo-2H-chromene-3-carbonyl)-3-(3-chlorophenyl)thiourea (2e) was the most potent inhibitor against AChE with an IC50 value of 0.04±0.01μM, while 1-(2-Oxo-2H-chromene-3-carbonyl)-3-(2-methoxyphenyl)thiourea (2b) showed the most potent inhibitory activity with an IC50 value of 0.06±0.02μM against BChE. Molecular docking simulations were performed using the homology models of both cholinesterases in order to explore the probable binding modes of inhibitors. Results showed that the novel synthesized coumarin linked thiourea derivatives are potential candidates to develop for potent and efficacious acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitors.

  2. Inhibition of P-Glycoprotein Mediated Efflux of Paclitaxel by Coumarin Derivatives in Cancer Stem Cells: An In Silico Approach.

    Science.gov (United States)

    Tripathi, Anushree; Misra, Krishna

    2016-01-01

    P-glycoprotein (P-gp) is well known to cause multidrug resistance (MDR) in cancer cells. This MDR leads to cancer recurrence which is a major obstacle in cancer treatment. High P-gp expression has been observed in the population of cancer stem cells (CSCs) having self-renewal potential. Early detection and inhibition of these CSCs is directly beneficial to cancer treatment. In this study coumarin derivatives are used to inhibit efflux process and thereby enhance bioavailability of various drugs like paclitaxel (PTX). This drug is most commonly used for the treatment of cancers of breast, ovary, head and neck. Coumarin derivatives can be used to reduce the growth of breast cancer stem cells through P-gp mediated efflux inhibition and paclitaxel bioavailability enhancement. With the use of computational approaches including molecular docking simulation and pharmacophore study, few coumarin derivatives have been found to be more potential inhibitors of P-gp mediated efflux. Based on high affinity inhibitors, new coumarin derivatives have been designed and docked at active site cavity of P-gps. Some newly designed coumarin derivatives were found to be more potent due to their higher binding affinity towards target protein. The finding that newly designed coumarins can be exploited for inhibition of P-gp mediated efflux in order to enhance paclitaxel bioavailability and can inhibit breast cancer stem cell growth is significant for designing potent anticancer drugs.

  3. Synthesis and Photooxygenation of Furo[3,2-c]coumarin Derivatives as Antibacterial and DNA Intercalating Agent

    Institute of Scientific and Technical Information of China (English)

    Al-Sehemi, Abdullah G.; EI-Gogary, Sameh R.

    2012-01-01

    Syntheses of 2,3-dimethyl-4H-furo[3,2-c]coumarin and 3-phenyl-4H-furo[3,2-c]coumarin as angular furocou- marins were carried out through Williamson reaction of 4-hydroxycoumarin with a-haloketones followed by cycli- zation. Photooxygenation of the synthesized furocoumarin derivatives was performed and the photoproducts were isolated and characterized. The affinity of 2,3-dimethyl-4H-furo[3,2-c]coumarin towards DNA and the antibacterial activity were evaluated and compared with 8-methoxypsoralen (8-MOP).

  4. Novel coumarin-benzimidazole derivatives as antioxidants and safer anti-inflammatory agents.

    Science.gov (United States)

    Arora, Radha Krishan; Kaur, Navneet; Bansal, Yogita; Bansal, Gulshan

    2014-10-01

    Inspired from occurrence of anti-inflammatory activity of 3-substituted coumarins and antiulcer activity of various 2-substituted benzimidazoles, novel compounds have been designed by coupling coumarin derivatives at 3-position directly or through amide linkage with benzimidazole nucleus at 2-position. The resultant compounds are expected to exhibit both anti-inflammatory and antioxidant activities along with less gastric toxicity profile. Two series of coumarin-benzimidazole derivatives (4a-e and 5a-e) were synthesized and evaluated for anti-inflammatory activity and antioxidant activity. Compounds 4c, 4d and 5a displayed good anti-inflammatory (45.45%, 46.75% and 42.85% inhibition, respectively, versus 54.54% inhibition by indomethacin) and antioxidant (IC50 of 19.7, 13.9 and 1.2 µmol/L, respectively, versus 23.4 µmol/L for butylatedhydroxytoluene) activities. Evaluation of ulcer index and in vivo biochemical estimations for oxidative stress revealed that compounds 4d and 5a remain safe on gastric mucosa and did not induce oxidative stress in tissues. Calculation of various molecular properties suggests the compounds to be sufficiently bioavailable.

  5. Theoretical investigation of the substituent effects on the electronic and optical properties of 6-substituted coumarin derivatives

    Science.gov (United States)

    Bai, Yihui; Zhang, Fang; Ying, Jin; Wu, Yingzi

    2015-06-01

    The electronic structures, absorption and emission spectra of selected 6-substituted coumarins were investigated and compared with unsubstituted coumarin by using density functional theory (DFT) and time-dependent DFT (TD-DFT) methods with Gaussian 09 software package. Results revealed that the presented absorption and emission spectra were affected by the substituent groups apparently. The maximum absorption wavelength of a coumarin molecule can be shifted to a longer one by introducing a large conjugated substituent, an electron donating group or a group which can form a rigid structure with the parent moiety at 6-position. The lowest energy emission of a 6-substituted coumarin can be greatly red-shifted by modifying the substituent to one which can be strongly conjugated with the phenyl ring. A group which has a strongly electron-withdrawing effect may cause a large excitation intensity and a short wavelength in emission. Most selected molecules are predicted to give the lowest-energy emissions in the purple or blue light region, which are supposed to be selected and modified as purple or blue luminescent materials. 6-nitrocoumarin is predicted as an invisible fluorescent material. 6,7-benzocoumarin, which forms a rigid conjugated ring with the parent moiety, is expected to be modified as a green luminescent material. Many of these 6-substituted coumarins are expected to be potential candidates as large Stokes shift dyes for multicolor labeling and fluorescence-activated cell sorting (FACS), especially those molecules, which bear sbnd CONH2, sbnd CN, and sbnd CH3 respectively.

  6. Analysis of fluorescence quenching of coumarin derivatives by 4-hydroxy-TEMPO in aqueous solution.

    Science.gov (United States)

    Żamojć, Krzysztof; Wiczk, Wiesław; Zaborowski, Bartłomiej; Jacewicz, Dagmara; Chmurzyński, Lech

    2014-05-01

    The fluorescence quenching of different coumarin derivatives (7-hydroxy-4-methylcoumarin, 5,7-dimethoxycoumarin, 7-amino-4-methyl-3-coumarinylacetic acid, 7-ethoxy-4-methylcoumarin, 7-methoxycoumarin, 7-hydroxycoumarin, 7-hydroxy-4-methyl-3-coumarinylacetic acid and 7-amino-4-methylcoumarin) by 4-hydroxy-TEMPO in aqueous solutions at the room temperature was studied with the use of UV-Vis absorption spectroscopy as well as a steady-state and time-resolved fluorescence spectroscopy. In order to understand the mechanism of quenching the absorption and fluorescence emission spectra of all coumarins along with fluorescence decays were recorded under the action of 4-hydroxy-TEMPO. The Stern-Volmer plots (both from time-averaged and time-resolved measurements) displayed no positive (upward) deviation from a linearity. The fluorescence quenching mechanism was found to be entirely dynamic, what was additionally confirmed by the registration of Stern-Volmer plots at different temperatures. The Stern-Volmer quenching constants and bimolecular quenching rate constants were obtained for all coumarins studied at the room temperature. The findings demonstrate the possibility of developing an analytical method for the quantitative determination of the free radicals' scavenger, 4-hydroxy-TEMPO.

  7. Synthesis of (iso)quinoline, (iso)coumarin and (iso)chromene derivatives from acetylene compounds

    Science.gov (United States)

    Ryabukhin, D. S.; Vasilyev, A. V.

    2016-06-01

    Published data on the methods of synthesis of quinoline, isoquinoline, coumarin, isocoumarin, chromene and isochromene derivatives from acetylene compounds are summarized. The reactions catalyzed by metal complexes (Pd, Pt, Ru, Rh, Au, Ag, Ni, Cu, etc.) and transformations induced by various electrophilic reagents (Brynsted and Lewis acids) are considered. Moieties of the mentioned heterocyclic systems are present in many biologically active natural products and pharmaceutical agents. Besides, derivatives of these heterocycles are used in the manufacture of catalysts, dyes, perfumery and cosmetic products, corrosion inhibitors and so on. The bibliography includes 211 references.

  8. Synthesis and Biological Evaluation of Some New Coumarin Derivatives

    Directory of Open Access Journals (Sweden)

    M. Y. El-Kady

    2003-02-01

    Full Text Available Pyrimidino[5`,4`-6,5]-,pyridino[3`,2`-6,5]- and pyrrolo[3`,2`-5,6]4H-pyrano-[3,2-c][1]benzopyran-6-one derivatives (5-7 and 10 could be obtained via reaction of 2-amino-4-(p-bromophenyl-3-cyano(carboethoxy-4H,5H-pyrano[3,2-c][1]benzopyran-5-ones (3a,b with a variety of reagents. Alkylation of (3b with either 2-furoyl chloride or chloroacetyl chloride gave the 2-N-substituted derivatives (9a,b. Benzofurano[3,2-b]4H-pyran derivative (12 was also prepared. The antimicrobial activity of the prepared compounds was tested.

  9. Rational Design, Synthesis and Evaluation of Coumarin Derivatives as Protein-protein Interaction Inhibitors.

    Science.gov (United States)

    De Luca, Laura; Agharbaoui, Fatima E; Gitto, Rosaria; Buemi, Maria Rosa; Christ, Frauke; Debyser, Zeger; Ferro, Stefania

    2016-09-01

    Herein we describe the design and synthesis of a new series of coumarin derivatives searching for novel HIV-1 integrase (IN) allosteric inhibitors. All new obtained compounds were tested in order to evaluate their ability to inhibit the interaction between the HIV-1 IN enzyme and the nuclear protein lens epithelium growth factor LEDGF/p75. A combined approach of docking and molecular dynamic simulations has been applied to clarify the activity of the new compounds. Specifically, the binding free energies by using the method of molecular mechanics-generalized Born surface area (MM-GBSA) was calculated, whereas hydrogen bond occupancies were monitored throughout simulations methods.

  10. Formation and control of excimer of a coumarin derivative in Langmuir–Blodgett films

    Energy Technology Data Exchange (ETDEWEB)

    Chakraborty, Santanu; Bhattacharjee, D.; Hussain, Syed Arshad, E-mail: sa_h153@hotmail.com

    2014-01-15

    In this communication we report the formation and control of excimer of a coumerin derivative 7-Hydroxy-N-Octadecyl Coumarin-3-Carboxamide (7HNO3C) assembled onto Langmuir–Blodgett (LB) films. Surface pressure–area per molecule isotherm revealed that 7HNO3C formed stable Langmuir monolayer at the air–water interface. Spectroscoipic characterizations confirmed the formation of excimer of 7HNO3C in the LB film prepared at 20 mN/m surface pressure. The excimer band remains present even when 7HNO3C molecules are diluted with a long chain fatty acid stearic acid in LB films. The excimer formation of 7HNO3C can be controlled by incorporating clay particle laponite in the LB film. The excimer band is totally absent in the hybrid 7HNO3C–laponite LB films. In-situ fluorescence imaging microscopy and atomic force microscopy confirmed the incorporation of clay laponite onto LB films. -- Highlights: • Formation of Langmuir monolayer and Langmuir–Blodgett (LB) film of a coumarin derivative. • Presence of excimeric species in the LB film lifted at 20 mN/m surface pressure is confirmed from the spectroscopic studies. • Control of excimer formation by incorporating clay particle laponite on to the LB film. • In-situ fluorescence imaging microscopy and atomic force microscopy confirmed the incorporation of clay laponite onto LB films.

  11. Fungi as a source of natural coumarins production.

    Science.gov (United States)

    Costa, Tania Maria; Tavares, Lorena Benathar Ballod; de Oliveira, Débora

    2016-08-01

    Natural coumarins and derivatives are compounds that occur naturally in several organisms (plant, bacteria, and fungi) consisting of fused benzene and α-pyrone rings. These compounds show high technological potential applications in agrochemical, food, pharmaceuticals, and cosmetics industries. Therefore, the need for bulk production of coumarins and the advancement of the chemical and pharmaceutical industries led to the development of synthetic coumarin. However, biotransformation process, synthetic bioengineering, metabolic engineering, and bioinformatics have proven effective in the production of natural products. Today, these biological systems are recognized as green chemistry innovation and business strategy. This review article aims to report the potential of fungi for synthesis of coumarin. These microorganisms are described as a source of natural products capable of synthesizing many bioactive metabolites. The features, classification, properties, and industrial applications of natural coumarins as well as new molecules obtained by basidiomycetes and ascomycetes fungi are reported in order to explore a topic not yet discussed in the scientific literature.

  12. Sesquiterpene coumarin and sesquiterpene chromone derivatives from Ferula ferulaeoides (Steud.) Korov.

    Science.gov (United States)

    Meng, He; Li, Guoyu; Huang, Jian; Zhang, Ke; Wang, Hangyu; Wang, Jinhui

    2013-04-01

    Five novel compounds - three sesquiterpene coumarin derivatives, ferulin A (1), B (2), and C (3), and two sesquiterpene chromone derivatives, ferulin D (4) and E (5), together with eleven known compounds (6-16) have been isolated from the roots of Ferula ferulaeoides (Steud.) Korov. Their structures were established by comprehensive spectroscopic analysis. The biosynthetic pathways leading to these compounds were proposed. The cytotoxicity of all these isolates against HepG2, MCF-7, and C6 cancer cell lines was evaluated and compound 7 displayed the highest potency against HepG2, MCF-7, and C6 with IC50 values 39.9 μM, 37.7 μM, and 16.0 μM, respectively. Copyright © 2013 Elsevier B.V. All rights reserved.

  13. Jordan Higher Derivable Mappings on Rings

    Directory of Open Access Journals (Sweden)

    Mohammad Ashraf

    2014-01-01

    Full Text Available Let R be a ring. We say that a family of maps D={dn}n∈N is a Jordan higher derivable map (without assumption of additivity on R if d0=IR (the identity map on R and dn(ab+ba=∑p+q=n‍dp(adq(b+∑p+q=n‍dp(bdq(a hold for all a,b∈R and for each n∈N. In this paper, we show that every Jordan higher derivable map on a ring under certain assumptions becomes a higher derivation. As its application, we get that every Jordan higher derivable map on Banach algebra is an additive higher derivation.

  14. Synthesis, NMR characterization, X-ray structural analysis and theoretical calculations of amide and ester derivatives of the coumarin scaffold

    Science.gov (United States)

    Matos, Maria J.; Uriarte, Eugenio; Santana, Lourdes; Vilar, Santiago

    2013-06-01

    Compounds 1 (4-methyl-N-(coumarin-3-yl)benzamide) and 2 ((coumarin-3-yl)-4-methylbenzoate) were synthesized by linking the coumarin system (3-aminocoumarin or 3-hydroxycoumarin, respectively) to a p-toluoylchloride. 1H and 13C NMR and X-ray diffractometry determined the molecular structures of both derivatives. The X-ray results were compared to those obtained by conformational analysis followed by semiempirical methodologies (AM1 and PM3). The theoretical calculations yielded results reproducing the whole three-dimensional (3D) structure of both molecules in a good agreement with X-ray structural analysis. The global structures of the two compounds are very similar in the two studied environments, meaning that the structural determination in the gas phase can be extrapolated. A comparative study between compounds 1 and 2, based on the structural results, was carried out.

  15. Reversible photochemical modifications in dicarbene-derived metallacycles with coumarin pendants.

    Science.gov (United States)

    Han, Ying-Feng; Jin, Guo-Xin; Daniliuc, Constantin G; Hahn, F Ekkehardt

    2015-04-13

    Molecular rectangles were obtained from two bis(NHC) ligands, each featuring two terminal coumarin groups and two Ag(+), Au(+), or Cu(+) ions. Upon UV irradiation (λ=365 nm), the dinuclear complexes undergo photochemical modification through a [2+2] cycloaddition reaction of two adjacent coumarin moieties to give a macrocyclic tetra(NHC) ligand. The photodimerization of the coumarin pendants proceeds stereoselectively to give the syn-head-head isomers in all cases. Subsequent irradiation at λ=254 nm initiates a photocleavage reaction with reconstitution of the initial dinuclear complexes with coumarin pendants.

  16. Derivations, Products of Derivations, and Commutativity in Near-rings

    Institute of Scientific and Technical Information of China (English)

    Howard E. Bell; Nurcan Argac

    2001-01-01

    For a zero-symmetric 3-prime near-ring N, we study three kinds of conditions: (a) conditions involving two derivations d1, d2 which imply that d1 = 0 or d2 = 0; (b) conditions involving derivations which force (N, +) to be abelian or N to be a commutative ring; (c) the condition that dn (S) is multiplicatively central for some derivation d and subset S of N.

  17. Rapid Identification of Coumarins from Micromelum falcatum by UPLC-HRMS/MS and Targeted Isolation of Three New Derivatives

    Directory of Open Access Journals (Sweden)

    Eirini Kouloura

    2014-09-01

    Full Text Available Micromelum falcatum, a medicinal plant of the Rutaceae family, has been used in the Traditional Chinese Medicine (TCM mainly against colds and rheumatoid arthritis. Despite its traditional use the association of its constituents with possible anti-inflammatory activity has not been explored. During this study, a rapid UPLC-ESI(+-HRMS method was developed for the profiling of M. falcatum leave extracts and the targeted isolation of coumarin constituents. Based on chromatographic, spectroscopic and spectrometric features several 7-oxygenated coumarin derivatives were detected. After targeted isolation, eight coumarins, among them three new natural products, namely microfalcrin, microcoumaririn and micromelosidester, were purified using semi-preparative HPLC and unambiguously identified by 1 and 2D NMR. Furthermore, important spectrometric characteristics were revealed based on the HRMS and HRMS/MS spectra of the isolated 7-oxygenated coumarins facilitating their identification in complex mixtures. Finally, the anti-inflammatory properties of the extracts and representative compounds were evaluated by measuring the inhibition of the pro-inflammatory mediator NF-κB induction and nitric oxide (NO production.

  18. Synergistic of a coumarin derivative with potassium iodide on the corrosion inhibition of aluminum alloy in 1.0 M H2SO4

    Science.gov (United States)

    Mohamad, Abu Bakar; Kadhum, Abdul Amir H.; Al-Amiery, Ahmed A.; Ying, Lim Chai; Musa, Ahmed Y.

    2014-05-01

    Synergistic effects of the addition of KI on the corrosion inhibitive performance of a coumarin derivative on an aluminum alloy in 1.0 M H2SO4 at different temperatures were studied using various electrochemical measurements. Density functional theory was used to calculate the quantum chemical parameters of the coumarin derivative. The experimental results showed that the coumarin derivative is considered as a mixedtype inhibitor. The corrosion potential values were almost unchanged upon the addition of PBBC to the acidic solution. The inhibition efficiency increases with increasing inhibitor concentration and increases further in the presence of 6.02 mM KI but decreases significantly at higher temperature. The adsorption of PBBC obeyed the Langmuir isotherm, and being chemically adsorbed at lower temperatures, while physical adsorption is favoured at higher temperature. The theoretical results indicated that the coumarin derivative was adsorbed onto the surface of Al2024 through the sulfur, oxygen and nitrogen atoms.

  19. Rational Design of Coumarin Derivatives as CK2 Inhibitors by Improving the Interaction with the Hinge Region.

    Science.gov (United States)

    Zhang, Na; Chen, Wen-Juan; Zhou, Yue; Zhao, Hongtao; Zhong, Ru-Gang

    2016-01-01

    Design of novel coumarin derivatives as CK2 inhibitors were attempted by targeting the interaction with the hinge region. A set of substituents capable of forming a hydrogen bond or halogen bond with the hinge region were screened in silico, and trifluoromethyl emerges as a promising motif by forming favorable electrostatic interaction and a presumable halogen bond with the hinge region. As proof of concept, three trifluoromethyl derivatives of coumarin were synthesized and tested in vitro. The results indicated that replacement of methyl by trifluoromethyl leads to a modest 5-fold improvement in potency, with the most active compound being 0.4 µM. The newly designed compounds were further screened on one lung cancer cell line A549, showing low micromolar anti-proliferative activity.

  20. Synthesis and Characterization of Some New 4-Hydroxy-coumarin Derivatives

    Directory of Open Access Journals (Sweden)

    Yasameen K. Al-Majedy

    2014-08-01

    Full Text Available Some novel coumarins were synthesized starting from 4-hydroxycoumarin and methyl bromoacetate. The structures of the newly obtained compounds were confirmed by elemental analysis, mass, IR and NMR spectra.

  1. On Semiprime Rings with Generalized Derivations

    Directory of Open Access Journals (Sweden)

    Shakir Ali

    2010-09-01

    Full Text Available Let R be a ring and F and G be generalized derivations of R with associated derivations d and g respectively. In the present paper,we shall investigate the commutativity of semiprime ring R admitting generalized derivations F and G satisfying any one of the properties: (iF(xx = xG(x, (ii [F(x, d(y] = [x,y], (iii F([x,y] = [d(x, F(y], (iv d(xF(y = xy, (v F(x^2 = x^2, (vi [F(x,y] = [x,G(y], (vii F([x, y] = [F(x, y] + [d(y, x] and (viii F(x ◦ y = F(x ◦ y −d(y ◦ x for all x, y in some appropriate subset of R.

  2. Anti-Inflammatory Screening and Molecular Modeling of Some Novel Coumarin Derivatives

    Directory of Open Access Journals (Sweden)

    Radwan El-Haggar

    2015-03-01

    Full Text Available Coumarin and their derivatives have drawn much attention in the pharmacological and pharmaceutical fields due to their broad range and diverse biological activities. In the present work, starting from the 6-amino-7-hydroxy-4-methyl-2H-chromen-2-one, a series of 6-(substituted benzylamino-7-hydroxy-4-methyl-2H-chromen-2-ones 1–11 was synthesized and assessed for their anti-inflammatory activity using the carrageenan-induced hind paw edema method. Compounds 2, 3, 4 and 9 showed significant (p < 0.001 reduction of rat paw edema volume after 1 h from the administration of the carrageenan compared to the reference drug, indomethacin. On the other hand, compounds 4 and 8 showed the highest anti-inflammatory activity, surpassing indomethacin after 3 h with 44.05% and 38.10% inhibition, respectively. Additionally, a molecular docking study was performed against the COX enzyme using the MOE 10.2010 software.

  3. Synthesis, Structure-Activity Relationships (SAR and in Silico Studies of Coumarin Derivatives with Antifungal Activity

    Directory of Open Access Journals (Sweden)

    José M. Barbosa-Filho

    2013-01-01

    Full Text Available The increased incidence of opportunistic fungal infections, associated with greater resistance to the antifungal drugs currently in use has highlighted the need for new solutions. In this study twenty four coumarin derivatives were screened in vitro for antifungal activity against strains of Aspergillus. Some of the compounds exhibited significant antifungal activity with MICs values ranging between 16 and 32 µg/mL. The structure-activity relationships (SAR study demonstrated that O-substitutions are essential for antifungal activity. It also showed that the presence of a short aliphatic chain and/or electron withdrawing groups (NO2 and/or acetate favor activity. These findings were confirmed using density functional theory (DFT, when calculating the LUMO density. In Principal Component Analysis (PCA, two significant principal components (PCs explained more than 60% of the total variance. The best Partial Least Squares Regression (PLS model showed an r2 of 0.86 and q2cv of 0.64 corroborating the SAR observations as well as demonstrating a greater probe N1 interaction for active compounds. Descriptors generated by TIP correlogram demonstrated the importance of the molecular shape for antifungal activity.

  4. Synthesis and experimental-computational characterization of nonlinear optical properties of triazacyclopentafluorene-coumarin derivatives

    Science.gov (United States)

    García, Santiago; Vázquez, Juan L.; Rentería, Marvin; Aguilar-Garduño, Isis G.; Delgado, Francisco; Trejo-Durán, Mónica; García-Revilla, Marco A.; Alvarado-Méndez, Edgar; Vázquez, Miguel A.

    2016-12-01

    A series of novel 3-(2,2a,3-triazacyclopenta[jk]fluoren-1-yl)-2H-chromen-2-one derivatives 5a-c have been synthesized by [8 + 2] cycloaddition reaction between the corresponding 3-(imidazo[1,2-a]pyrimidines)-2-yl)-2H-chromen-2-one 4a-c with 2-(trimethylsilyl)phenyl triflates as benzyne precursor in 65-80% yields. The strategic incorporation of triazacyclopentafluorene group at the 3-position of the coumarin molecules resulted in dyes with excellent nonlinear optical properties. The nonlinear optical properties of third order (compounds 5a-c) were studied using Z-scan technique. The high nonlinear response is of 10-7 cm2/W order. The nonlinearity of the compounds is an indication of a promising material for applications at low power, such as optical switching, waveguides, nonlinear contrast phase, among others. Theoretical results of HOMO-LUMO gaps and oscillator strengths are used to rationalize the high efficiency of the novel compound in the nonlinear optical behavior. In particular, 5b displays the best nonlinear optical properties and at the same time the smaller HOMO-LUMO gap and the highest oscillator strength.

  5. Coumarins from the Herb Cnidium monnieri and Chemically Modified Derivatives as Antifoulants against Balanus albicostatus and Bugula neritina Larvae

    Directory of Open Access Journals (Sweden)

    Zhan-Chang Wang

    2013-01-01

    Full Text Available In the search for new environmental friendly antifouling (AF agents, four coumarins were isolated from the herbal plant Cnidium monnieri, known as osthole (1, imperatorin (2, isopimpinellin (3 and auraptenol (4. Furthermore, five coumarin derivatives, namely 8-epoxypentylcoumarin (5, meranzin hydrate (6, 2'-deoxymetranzin hydrate (7, 8-methylbutenalcoumarin (8, and micromarin-F (9 were synthesized from osthole. Compounds 1, 2, 4, 7 showed high inhibitory activities against larval settlement of Balanus albicostatus with EC50 values of 4.64, 3.39, 3.38, 4.67 μg mL−1. Compound 8 could significantly inhibit larval settlement of Bugula neritina with an EC50 value of 3.87 μg mL−1. The impact of functional groups on anti-larval settlement activities suggested that the groups on C-5' and C-2'/C-3' of isoamylene chian could affect the AF activities.

  6. Derivations and Generating Degrees in the Ring of Arithmetical Functions

    Indian Academy of Sciences (India)

    Alexandru Zaharescu; Mohammad Zaki

    2007-05-01

    In this paper we study a family of derivations in the ring of arithmetical functions of several variables over an integral domain, and compute the generating degrees of the ring of arithmetical functions over the kernel of these derivations.

  7. Power Cocentralizing Generalized Derivations on Prime Rings

    Indian Academy of Sciences (India)

    Vincenzo De Filippis

    2010-06-01

    Let be a prime ring, the Utumi quotient ring of $R,C=Z(U)$ the extended centroid of , a non-central Lie ideal of , and non-zero generalized derivations of . Suppose that there exists an integer $n≥ 1$ such that $(H(u)u-uG(u))^n=0$, for all $u\\in L$, then one of the following holds: (1) there exists $c\\in U$ such that $H(x)=xc,G(x)=cx;(2)R$ satisfies the standard identity $s_4$ and char ()=2; (3) satisfies $s4$ and there exist $a, b, c\\in U$, such that $H(x)=ax+xc,G(x)=cx+xb$ and $(a-b)^n=0$.

  8. A novel method for the synthesis of coumarin laser dyes derived from 3-(1H-benzoimidazol-2-yl coumarin-2-one under microwave irradiation

    Directory of Open Access Journals (Sweden)

    Ghasem Bakhtiari

    2014-12-01

    Full Text Available We want to achieve the synthesis of 3-(1H-benzoimidazol-2-yl-7-(diethylamino coumarin-2-one (1, 3-(1H-benzoimidazol-2-yl-7-(dimethylamino coumarin-2-one (2, 3-(1H-benzoimidazol-2-yl coumarin-2-one (3 that are important dyes in industries (Soko owska et al., 2001. Methods for the synthesis of some of these compounds have been the title in some pervious patents, but enough information about separation and purification of them was not clearly indicated. We carried out several methods for the synthesis of the mentioned compound and purification with different yields. Now, we can synthesise these dyes under microwave irradiation in solid phase and solvent free methods with 80% yield, which is a high and remarkable percentage.

  9. Study on DNA binding behavior and light switch effect of new coumarin-derived Ru(II) complexes

    Science.gov (United States)

    Liu, Xue-Wen; Shen, You-Ming; Li, Zhi-Xin; Zhong, Xiao; Chen, Yuan-Dao; Zhang, Song-Bai

    2015-10-01

    A new ligand mhcip (mhcip = 2-(4-methyl-7-hydroxyl-8-coumarinyl)imidazo[4,5-f]-[1,10]phenanthroline) and its ruthenium complexes, [Ru(L)2mhcip]2+ (L = bpy (2,2‧-bipyridine), phen (1,10-phenanthroline)), have been synthesized and characterized. The introduction of coumarin ring may play an important role in the strong fluorescence of the complexes. Intercalative binding mode between both complexes and CT-DNA was determined by UV-visible spectroscopy, fluorescence spectroscopy and viscosity measurements. The two complexes show efficient DNA photocleavage under irradiation at 365 nm. The cycling of light switch off and on has been achieved for both complexes through the introduction of Cu2+ and EDTA in the absence or presence of DNA.

  10. Synthesis of novel coumarin appended bis(formylpyrazole) derivatives: Studies on their antimicrobial and antioxidant activities.

    Science.gov (United States)

    Nagamallu, Renuka; Srinivasan, Bharath; Ningappa, Mylarappa B; Kariyappa, Ajay Kumar

    2016-01-15

    A series of novel coumarin pyrazole hybrids of biological interest were synthesized from the hydrazones, carbazones and thiocarbazones via Vilsmeier Haack formylation reaction. These intermediates and formyl pyrazoles were evaluated for antimicrobial and antioxidant activities. Among the series, compounds 6g and 6h showed excellent antimicrobial activity against different bacterial and fungal strains and compounds 7g, 7h were found to be potent antioxidant agents in both DPPH and hydroxyl radical scavenging assays. Further, detailed quantitative structure-activity relationship (QSAR) analysis indicated the molecular parameters that contribute to increased potency of inhibition. The above findings would further encourage our understanding in employing coumarin pyrazole hybrids as potential antibiotic agents for treating infections caused by pathogenic microbes and fungi. Further, it also paves the way for exploration of these compounds as potential therapeutic agents to treat conditions arising because of excessive oxidative damage.

  11. Novel oxime-bearing coumarin derivatives act as potent Nrf2/ARE activators in vitro and in mouse model.

    Science.gov (United States)

    Chang, Ken-Ming; Chen, Huang-Hui; Wang, Tai-Chi; Chen, I-Li; Chen, Yu-Tsen; Yang, Shyh-Chyun; Chen, Yeh-Long; Chang, Hsin-Huei; Huang, Chih-Hsiang; Chang, Jang-Yang; Shih, Chuan; Kuo, Ching-Chuan; Tzeng, Cherng-Chyi

    2015-12-01

    We have designed and synthesized certain novel oxime- and amide-bearing coumarin derivatives as nuclear factor erythroid 2 p45-related factor 2 (Nrf2) activators. The potency of these compounds was measured by antioxidant responsive element (ARE)-driven luciferase activity, level of Nrf2-related cytoprotective genes and proteins, and antioxidant activity. Among them, (Z)-3-(2-(hydroxyimino)-2-phenylethoxy)-2H-chromen-2-one (17a) was the most active, and more potent than the positive t-BHQ in the induction of ARE-driven luciferase activity. Exposure of HSC-3 cells to various concentrations of 17a strongly increased Nrf2 nuclear translocation and the expression level of Nrf2-mediated cytoprotective proteins in a concentration-dependent manner. HSC-3 cells pretreated with 17a significantly reduced t-BOOH-induced oxidative stress. In the animal experiment, Nrf2-mediated cytoprotective proteins, such as aldo-keto reductase 1 subunit C-1 (AKR1C1), glutathione reductase (GR), and heme oxygenase (HO-1), were obviously elevated in the liver of 17a-treated mice than that of control. These results suggested that novel oxime-bearing coumarin 17a is able to activate Nrf2/ARE pathway in vivo and are therefore seen as a promising candidate for further investigation.

  12. Influence of Polarity of Solvents on the Spectral Properties of Bichromophoric Coumarins

    Directory of Open Access Journals (Sweden)

    Henrieta Stankovicova

    2010-12-01

    Full Text Available Absorption and fluorescence spectra of bichromophoric coumarins were investigated in different solvents and in polymer matrices. These bichromophoric coumarins were composed of a coumarin dimethylamino-substituted at position 7 or unsubstituted coumarin and phthalimide or a 1,8-naphthylimide linked with an iminomethyl bridge to the position 3 or 8 of the coumarin ring. Absorption spectra of 7-dimethylamino derivatives in position 3 of coumarin were quite similar, exhibiting broad bands around 430-440 nm like the parent compound 7-dimethylaminocoumarin-3-carbaldehyde. For coumarin derivatives substituted in position 8, the absorption maximum was shifted to shorter wavelength as for derivatives without position 7 dimethylamino substitution. The most intense fluorescence was observed for 7-(N,N-dimethylamino-3-[(N-phtalimidoyliminomethyl]coumarin in polar solvent, while intense fluorescence was observed for 7-(N,N-dimethylamino-3-[N-(1,3-dioxobenz[de]isoquinolinyliminomethyl]-coumarin in non polar solvent (chloroform, comparable with the fluorescence of 7-amino-4-methylcoumarin. Spectral measurements of bichromophoric coumarins in polymer matrices revealed that the maxima lies in between those for chloroform and methanol yielding more intense fluorescence then in solutions. Completely different solvent effects were observed for 7-(N,N-dimethylamino-3-[N-(1,3-dioxobenz[de]isoquinolinylimino-methyl]coumarin and 7-(N,N-dimethylamino-3-[(N-phtalimidoyliminomethyl]coumarin. With addition of polar methanol the intensity of fluorescence decreases, yielding a Stern-Volmer-like constant of 0.54 dm3 mol−1 for 7-(N,N-dimethylamino-3-[N-(1,3-dioxo-benz[de]isoquinolinyliminomethyl]coumarin and an even higher one of 1.08 dm3 mol−1 for 7-dimethylaminocoumarin-3-carbaldehyde compared to the rather low one of 0.024 dm3 mol−1 for 7-amino-4-methylcoumarin. Contrary to this, addition of methanol under identical conditions brings about an increase in fluorescence

  13. Investigation of binding mechanism of novel 8-substituted coumarin derivatives with human serum albumin and α-1-glycoprotein.

    Science.gov (United States)

    Yeggoni, Daniel Pushpa Raju; Manidhar, Darla Mark; Suresh Reddy, Cirandur; Subramanyam, Rajagopal

    2016-09-01

    Coumarin molecules have biological activities possessing lipid-controlling activity, anti-hepatitis C activity, anti-diabetic, anti-Parkinson activity, and anti-cancer activity. Here, we have presented an inclusive study on the interaction of 8-substituted-7-hydroxy coumarin derivatives (Umb-1/Umb-2) with α-1-glycoprotein (AGP) and human serum albumin (HSA) which are the major carrier proteins in the human blood plasma. Binding constants obtained from fluorescence emission data were found to be KUmb-1=3.1 ± .01 × 10(4) M(-1), KUmb-2 = 7 ± .01 × 10(4) M(-1), which corresponds to -6.1 and -6.5 kcal/mol of free energy for Umb-1 and Umb-2, respectively, suggesting that these derivatives bind strongly to HSA. Also these molecules bind to AGP with binding constants of KUmb-1-AGP=3.1 ± .01 × 10(3) M(-1) and KUmb-2-AGP = 4.6 ± .01 × 10(3) M(-1). Further, the distance, r between the donor (HSA) and acceptor (Umb-1/Umb-2) was calculated based on the Forster's theory of non-radiation energy transfer and the values were observed to be 1.14 and 1.29 nm in Umb-1-HSA and Umb-2-HSA system, respectively. The protein secondary structure of HSA was partially unfolded upon binding of Umb-1 and Umb-2. Furthermore, site displacement experiments with lidocaine, phenylbutazone (IIA), and ibuprofen (IIIA) proves that Umb derivatives significantly bind to subdomain IIIA of HSA which is further supported by docking studies. Furthermore, Umb-1 binds to LYS402 with one hydrogen bond distance of 2.8 Å and Umb-2 binds to GLU354 with one hydrogen bond at a distance of 2.0 Å. Moreover, these molecules are stabilized by hydrophobic interactions and hydrogen bond between the hydroxyl groups of carbon-3 of coumarin derivatives.

  14. Growth until puberty after in utero exposure to coumarins

    NARCIS (Netherlands)

    Van Driel, D; Wesseling, J; Rosendaal, FR; Odink, RJ; Van der Veer, E; Gerver, WJ; Geven-Boere, LM; Sauer, PJJ

    2000-01-01

    Anticoagulation with coumarins is an effective therapy during pregnancy. Fetal exposure to coumarin derivatives during the first trimester, however, is associated with skeletal anomalies (warfarin or coumarin embryopathy). Information about long-term effects of prenatal coumarin exposure on the skel

  15. Isoquinoline-catalyzed reaction between 4-hydroxycoumarin or 4-hydroxy-6-methylpyran-1-one and dialkyl acetylene dicarboxylates: synthesis of coumarin and pyranopyrane derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Anary-Abbasinejad, Mohammad; Anaraki-Ardakani, Hossein; Mosslemin, Mohammad Hossein [Islamic Azad University, Yazd (Iran, Islamic Republic of). Dept. of Chemistry; Khavasi, Hamid Reza [Shahid Beheshti University, Tehran (Iran, Islamic Republic of). Dept. of Chemistry

    2010-07-01

    In this work we report the reaction between dialkyl acetylenedicarboxylates and enolic systems such as 5,5-dimethyl-1,3-cyclohexanedione, 1,3-cyclohexanedione, 4-hydroxycoumarin or 4-hydroxy-6-methylpyran-1-one in the presence of isoquinoline, which leads to new coumarin and pyranopyran derivatives. (author)

  16. New Coumarin Derivatives and Other Constituents from the Stem Bark of Zanthoxylum avicennae: Effects on Neutrophil Pro-Inflammatory Responses

    Directory of Open Access Journals (Sweden)

    Jih-Jung Chen

    2015-04-01

    Full Text Available Three new coumarin derivatives, 8-formylalloxanthoxyletin (1, avicennone (2, and (Z-avicennone (3, have been isolated from the stem bark of Zanthoxylum avicennae (Z. avicennae, together with 15 known compounds (4–18. The structures of these new compounds were determined through spectroscopic and MS analyses. Compounds 1, 4, 9, 12, and 15 exhibited inhibition (half maximal inhibitory concentration (IC50 values ≤7.65 µg/mL of superoxide anion generation by human neutrophils in response to formyl-l-methionyl-l-leucyl-l-phenylalanine/cytochalasin B (fMLP/CB. Compounds 1, 2, 4, 8 and 9 inhibited fMLP/CB-induced elastase release with IC50 values ≤8.17 µg/mL. This investigation reveals bioactive isolates (especially 1, 2, 4, 8, 9, 12 and 15 could be further developed as potential candidates for the treatment or prevention of various inflammatory diseases.

  17. Generalized Derivations with Nilpotent Values on Semiprime Rings

    Institute of Scientific and Technical Information of China (English)

    Feng WEI

    2004-01-01

    Let R be a semiprime ring, RF be its left Martindale quotient ring and I be an essential ideal of R. Then every generalized derivation u defined on I can be uniquely extended to a generalized derivation of RF. Furthermore, if there exists a fixed positive integer n such that μ(x)n = 0 for all x ∈ I, thenμ = 0.

  18. Separation of 20 coumarin derivatives using the capillary electrophoresis method optimized by a series of Doehlert experimental designs.

    Science.gov (United States)

    Woźniakiewicz, Michał; Gładysz, Marta; Nowak, Paweł M; Kędzior, Justyna; Kościelniak, Paweł

    2017-05-15

    The aim of this study was to develop the first CE-based method enabling separation of 20 structurally similar coumarin derivatives. To facilitate method optimization a series of three consequent Doehlert experimental designs with the response surface methodology was employed, using number of peaks and the adjusted time of analysis as the selected responses. Initially, three variables were examined: buffer pH, ionic strength and temperature (No. 1 Doehlert design). The optimal conditions provided only partial separation, on that account, several buffer additives were examined at the next step: organic cosolvents and cyclodextrin (No. 2 Doehlert design). The optimal cyclodextrin type was also selected experimentally. The most promising results were obtained for the buffers fortified with methanol, acetonitrile and heptakis(2,3,6-tri-O-methyl)-β-cyclodextrin. Since these additives may potentially affect acid-base equilibrium and ionization state of analytes, the third Doehlert design (No. 3) was used to reconcile concentration of these additives with optimal pH. Ultimately, the total separation of all 20 compounds was achieved using the borate buffer at basic pH 9.5 in the presence of 10mM cyclodextrin, 9% (v/v) acetonitrile and 36% (v/v) methanol. Identity of all compounds was confirmed using the in-lab build UV-VIS spectra library. The developed method succeeded in identification of coumarin derivatives in three real samples. It demonstrates a huge resolving power of CE assisted by addition of cyclodextrins and organic cosolvents. Our unique optimization approach, based on the three Doehlert designs, seems to be prospective for future applications of this technique.

  19. A New Synthetic Approach to Coumestan Derivatives

    Institute of Scientific and Technical Information of China (English)

    GONG, Deng-Huang; LI, Chao-Zhong; YUAN, Cheng-Ye

    2001-01-01

    A new method for the preparation of coumestan derivatives was described involving an intramolecular palladium-catalyzed ring closure reaction of coumarins obtained from condensation of substituted o-hydroxyphenylacetic acid and o-hydroxybenzaldehyde.

  20. Isolationand structure elucidation of coumarin and cinamate derivatives from Lycium ruthenicum

    Directory of Open Access Journals (Sweden)

    Hassan Valizadeh

    2014-10-01

    Full Text Available Lyciumspecies is a popular medicinal plant in the traditional Chinese medicine and Lycium ru-thenicum is a native medicinal plant of Iran. Lycium genus has several biologically important properties too. Investigation of chemical composition of ethyl acetate extract of this plant is the goal of this study. Two coumarins (Scopoletin and Sculetin and Methyl-2-hydroxy-4-undecanoxy-trans-cinamate were isolated and characterized as the major constituents using 1H NMR, 13C NMR and FT-IR spectroscopic data, MS spectrometry, elemental analysis and by comparison with the literature values. Phytochemical investigation of Lyciumruthenicum demonstrated the presence of important biologically active compounds. This is the first phyto-chemical study of this species in Iran.

  1. Antimycobacterial activity of novel hydrazide-hydrazone derivatives with 2H-chromene and coumarin scaffold.

    Science.gov (United States)

    Angelova, Violina T; Valcheva, Violeta; Vassilev, Nikolay G; Buyukliev, Rosen; Momekov, Georgi; Dimitrov, Ivan; Saso, Luciano; Djukic, Mirjana; Shivachev, Boris

    2017-01-15

    This study reports the synthesis of new 2H-chromene or coumarin based acylhydrazones, which were evaluated for their in vitro antimycobacterial activity against reference strain Mycobacterium tuberculosis H37Rv and compared to the first-line antituberculosis drugs, isoniazid (INH) and ethambutol (EMB). The most active compounds 7m (MIC 0.13μM), 7o (MIC 0.15μM) and 7k (MIC 0.17μM) demonstrated antimycobacterial activity at submicromolar concentration level and remarkably minimal associated cytotoxicity in the human embryonic kidney cell line HEK-293T. Structure-activity relationship for this class of compounds has been established. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Coumarin-fused coumarin: antioxidant story from N,N-dimethylamino and hydroxyl groups.

    Science.gov (United States)

    Xi, Gao-Lei; Liu, Zai-Qun

    2015-04-01

    Two coumarin skeletons can form chromeno[3,4-c]chromene-6,7-dione by sharing with the C ═ C in lactone. The aim of the present work was to explore the antioxidant effectiveness of the coumarin-fused coumarin via six synthetic compounds containing hydroxyl and N,N-dimethylamino as the functional groups. The abilities to quench 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonate) cationic radical (ABTS(+•)), 2,2'-diphenyl-1-picrylhydrazyl radical (DPPH), and galvinoxyl radical revealed that the rate constant for scavenging radicals was related to the amount of hydroxyl group in the scaffold of coumarin-fused coumarin. But coumarin-fused coumarin was able to inhibit DNA oxidations caused by (•)OH, Cu(2+)/glutathione (GSH), and 2,2'-azobis(2-amidinopropane hydrochloride) (AAPH) even in the absence of hydroxyl group. In particular, a hydroxyl and an N,N-dimethylamino group locating at different benzene rings increased the inhibitory effect of coumarin-fused coumarin on AAPH-induced oxidation of DNA about 3 times higher than a single hydroxyl group, whereas N,N-dimethylamino-substituted coumarin-fused coumarin possessed high activity toward (•)OH-induced oxidation of DNA without the hydroxyl group contained. Therefore, the hydroxyl group together with N,N-dimethylamino group may be a novel combination for the design of coumarin-fused heterocyclic antioxidants.

  3. Differential inhibition of cytochromes P450 3A4 and 3A5 by the newly synthesized coumarin derivatives 7-coumarin propargyl ether and 7-(4-trifluoromethyl)coumarin propargyl ether.

    Science.gov (United States)

    Sridar, Chitra; Kent, Ute M; Noon, Kate; McCall, Alecia; Alworth, Bill; Foroozesh, Maryam; Hollenberg, Paul F

    2008-11-01

    The abilities of 7-coumarin propargyl ether (CPE) and 7-(4-trifluoromethyl)coumarin propargyl ether (TFCPE) to act as mechanism-based inactivators of P450 3A4 and 3A5 in the reconstituted system have been investigated using 7-benzyloxy-4-(trifluoromethyl)coumarin (BFC) and testosterone as probes. CPE inhibited the BFC O-debenzylation activity of P450 3A4 in a time-, concentration-, and NADPH-dependent manner characteristic of a mechanism-based inactivator with a half-maximal inactivation (K(I)) of 112 microM, a maximal rate of inactivation (k(inact)) of 0.05 min(-1), and a t(1/2) of 13.9 min. Similarly, TFCPE inhibited the BFC O-debenzylation activity of P450 3A4 in a time-, concentration-, and NADPH-dependent manner with a K(I) of 14 microM, a k(inact) of 0.04 min(-1), and a t(1/2) of 16.5 min. Parallel losses of P450 3A4 enzymatic activity and heme were observed with both compounds as measured by high-performance liquid chromatography and reduced CO spectra. Interestingly, neither compound inhibited the BFC O-debenzylation activity of P450 3A5. Reactive intermediates of CPE and TFCPE formed by P450 3A4 were trapped with glutathione, and the resulting adducts were identified using tandem mass spectral analysis. Metabolism studies using TFCPE resulted in the identification of a single metabolite that is formed by P450 3A4 but not by P450 3A5 and that may play a role in the mechanism-based inactivation.

  4. On Prime Near-Rings with Generalized Derivation

    Directory of Open Access Journals (Sweden)

    Howard E. Bell

    2008-01-01

    Full Text Available Let N be a 3-prime 2-torsion-free zero-symmetric left near-ring with multiplicative center Z. We prove that if N admits a nonzero generalized derivation f such that f(N⊆Z, then N is a commutative ring. We also discuss some related properties.

  5. Sesquiterpene coumarins from Ferula gumosa.

    Science.gov (United States)

    Iranshahi, Mehrdad; Masullo, Milena; Asili, Ali; Hamedzadeh, Ali; Jahanbin, Bentolhoda; Festa, Michela; Capasso, Anna; Piacente, Sonia

    2010-11-29

    A new sesquiterpene coumarin, gumosin (1), two new sesquiterpene coumarin glycosides, gumosides A (2) and B (3), and 10 known compounds, namely, cauferoside (4), feselol (5), conferoside, ferilin, ferocaulidin, ligupersin A, conferol, and daucosterol, and the phenolic compounds acantrifoside E and 4-hydroxybenzoic acid 4-(6-O-sulfo)glucopyranoside, were isolated from a methanolic extract of Ferula gumosa roots. The structures of 1-3 were elucidated by spectroscopic data interpretation. The cytotoxic activity of the sesquiterpene coumarin derivatives was evaluated against a small panel of cancer cell lines.

  6. Characterization of Generalized Jordan Higher Derivations on Triangular rings

    CERN Document Server

    Qi, Xiaofei

    2011-01-01

    Let $\\mathcal A$ and $\\mathcal B$ be unital rings and $\\mathcal M$ be a $(\\mathcal A, \\mathcal B)$-bimodule, which is faithful as a left $\\mathcal A$-module and also as a right $\\mathcal B$-module. Let ${\\mathcal U}={\\rm Tri}(\\mathcal A, \\mathcal M, \\mathcal B)$ be the associated triangular ring. It is shown that every additive generalized Jordan (triple) higher derivation on $\\mathcal U$ is a generalized higher derivation.

  7. Synthesis and Use of Coumarin and Certain Derivative%香豆素及其衍生物的合成与用途

    Institute of Scientific and Technical Information of China (English)

    尚尔才

    2011-01-01

    Synthesis methods and the application of coumarin and certain derivative, especially their use in pesticide, medicine and laser dye were reviewed in this paper.%综述了香豆素和某些衍生物的合成方法及用途,主要介绍了其在农药、医药、香料及激光染料方面的应用。

  8. Selective Activation of Nociceptor TRPV1 Channel and Reversal of Inflammatory Pain in Mice by a Novel Coumarin Derivative Muralatin L from Murraya alata*

    OpenAIRE

    Wei, Ning-Ning; Lv, Hai-Ning; Wu, Yang; Yang, Shi-Long; Sun, Xiao-Ying; Lai, Ren; Yong JIANG; Wang, KeWei

    2015-01-01

    Coumarin and its derivatives are fragrant natural compounds isolated from the genus Murraya that are flowering plants widely distributed in East Asia, Australia, and the Pacific Islands. Murraya plants have been widely used as medicinal herbs for relief of pain, such as headache, rheumatic pain, toothache, and snake bites. However, little is known about their analgesic components and the molecular mechanism underlying pain relief. Here, we report the bioassay-guided fractionation and identifi...

  9. Easy Access to Coumarin Derivatives Using Alumina Sulfuric Acid as an Efficient and Reusable Catalyst under Solvent-Free Conditions

    Directory of Open Access Journals (Sweden)

    Ali Amoozadeh

    2013-01-01

    Full Text Available A new and efficient condition for the use of alumina sulfuric acid (ASA as a heterogeneous catalyst in the Pechmann condensation reaction in solvent-free condition for the formation of coumarins has been reported.

  10. Higher derivations on rings and modules

    Directory of Open Access Journals (Sweden)

    Paul E. Bland

    2005-01-01

    Full Text Available Let τ be a hereditary torsion theory on ModR and suppose that Qτ:ModR→ModR is the localization functor. It is shown that for all R-modules M, every higher derivation defined on M can be extended uniquely to a higher derivation defined on Qτ(M if and only if τ is a higher differential torsion theory. It is also shown that if τ is a TTF theory and Cτ:M→M is the colocalization functor, then a higher derivation defined on M can be lifted uniquely to a higher derivation defined on Cτ(M.

  11. Coumarin-thiazole and -oxadiazole derivatives: Synthesis, bioactivity and docking studies for aldose/aldehyde reductase inhibitors.

    Science.gov (United States)

    Ibrar, Aliya; Tehseen, Yildiz; Khan, Imtiaz; Hameed, Abdul; Saeed, Aamer; Furtmann, Norbert; Bajorath, Jürgen; Iqbal, Jamshed

    2016-10-01

    In continuation of our previous efforts directed towards the development of potent and selective inhibitors of aldose reductase (ALR2), and to control the diabetes mellitus (DM), a chronic metabolic disease, we synthesized novel coumarin-thiazole 6(a-o) and coumarin-oxadiazole 11(a-h) hybrids and screened for their inhibitory activity against aldose reductase (ALR2), for the selectivity against aldehyde reductase (ALR1). Compounds were also screened against ALR1. Among the newly designed compounds, 6c, 11d, and 11g were selective inhibitors of ALR2. Whereas, (E)-3-(2-(2-(2-bromobenzylidene)hydrazinyl)thiazol-4-yl)-2H-chromen-2-one 6c yielded the lowest IC50 value of 0.16±0.06μM for ALR2. Moreover, compounds (E)-3-(2-(2-benzylidenehydrazinyl)thiazol-4-yl)-2H-chromen-2-one (6a; IC50=2.94±1.23μM for ARL1 and 0.12±0.05μM for ARL2) and (E)-3-(2-(2-(1-(4-bromophenyl)ethylidene)hydrazinyl)thiazol-4-yl)-2H-chromen-2-one (6e; IC50=1.71±0.01μM for ARL1 and 0.11±0.001μM for ARL2) were confirmed as dual inhibitors. Furthermore, compounds 6i, 6k, 6m, and 11b were found to be selective inhibitors for ALR1, among which (E)-3-(2-(2-((2-amino-4-chlorophenyl)(phenyl)methylene)hydrazinyl)thiazol-4-yl)-2H-chromen-2-one (6m) was most potent (IC50=0.459±0.001μM). Docking studies performed using X-ray structures of ALR1 and ALR2 with the given synthesized inhibitors showed that coumarinyl thiazole series lacks the carboxylate function that could interact with the anionic binding site being a common ALR1/ALR2 inhibitors trait. Molecular docking study with dual inhibitor 6e also suggested plausible binding modes for the ALR1 and ALR2 enzymes. Hence, the results of this study revealed that coumarinyl thiazole and oxadiazole derivatives could act as potential ALR1/ALR2 inhibitors.

  12. Synthesis and biological evaluation of novel phosphoramidate derivatives of coumarin as chitin synthase inhibitors and antifungal agents.

    Science.gov (United States)

    Ji, Qinggang; Ge, Zhiqiang; Ge, Zhixing; Chen, Kaizhi; Wu, Hualong; Liu, Xiaofei; Huang, Yanrong; Yuan, Lvjiang; Yang, Xiaolan; Liao, Fei

    2016-01-27

    A series of novel phosphoramidate derivatives of coumarin have been designed and synthesized as chitin synthase (CHS) inhibitors. All the synthesized compounds have been screened for their chitin synthase inhibition activity and antimicrobial activity in vitro. The bioactive assay manifested that most of the target compounds exhibited good efficacy against CHS and a variety of clinically important fungal pathogens. In particular, compound 7t with IC50 of 0.08 mM against CHS displayed stronger efficiency than the reference Polyoxin B with IC50 of 0.16 mM. In addition, the apparent Ki values of compound 7t was 0.096 mM while the Km of Chitin synthase prepared from Candida tropicalis was 3.86 mM for UDP-N-acetylglucosamine, and the result of the Ki showed that the compounds was a non-competitive inhibitor of the CHS. As far as the antifungal activity is concerned, compounds 7o, 7r and 7t were highly active against Aspergillus flavus with MIC values in the range of 1 μg/mL to 2 μg/Ml while the results of antibacterial screening showed that these compounds have negligible actions to the tested bacteria. These results indicated that the design of these compounds as antifungal agents was rational.

  13. Coumarin sulfonamides derivatives as potent and selective COX-2 inhibitors with efficacy in suppressing cancer proliferation and metastasis.

    Science.gov (United States)

    Lu, Xiao-Yuan; Wang, Zhong-Chang; Ren, Shen-Zhen; Shen, Fa-Qian; Man, Ruo-Jun; Zhu, Hai-Liang

    2016-08-01

    Cyclooxygenase-2 is frequently overexpression in malignant tumors and the product PGE2 promotes cancer cell progression and metastasis. We designed novel series of coumarin sulfonamides derivatives to improve biological activities of COX-2 inhibition and anticancer. Among them, compound 7t showed most powerful selective inhibitory and antiproliferative activity (IC50=0.09μM for COX-2, IC50=48.20μM for COX-1, IC50=0.36μM against HeLa cells), comparable to the control positive compound Celecoxib (0.31μM, 43.37μM, 7.79μM). Cancer cell apoptosis assay were performed and results indicated that compound 7t effectively fuels HeLa cells apoptosis in a dose and time-dependent manner. Moreover, 7t could significantly suppress cancer cell adhesion, migration and invasion which were essential process of cancer metastasis. Docking simulations results was further indicated that compound 7t could bind well to the COX-2 active site and guided a reasonable design of selective COX-2 inhibitor with anticancer activities in future.

  14. Statistical methods for estimating the probability of spontaneous abortion in observational studies--analyzing pregnancies exposed to coumarin derivatives.

    Science.gov (United States)

    Meister, Reinhard; Schaefer, Christof

    2008-09-01

    Spontaneous abortion rates are of general interest when investigating pregnancy outcome. In most studies observations are left truncated as pregnant women enter with a delay of several weeks after conception. Apart from spontaneous abortion pregnancy may end in induced abortion or live birth. These outcomes are considered as competing events (risks). Although statistical methods for handling this setting are available since more than 10 years, studies on pregnancy outcome after drug exposure usually report crude rates of spontaneous abortions, ignoring left truncation and competing risks. The authors propose simple methods which remove bias inherent to crude rates. The probability of spontaneous abortion is estimated using an event-history based approach for the subdistribution of competing risks that handles left truncation appropriately. Variance estimation enables the construction of approximate confidence intervals and of a simple test-statistic for comparing rates between different cohorts. The proposed methods are applied to a comparative prospective study on the association of spontaneous abortion and exposure to coumarin derivatives. The naive analysis using crude rates gives substantially different results than those based on the proposed methods, with up to a twofold change. Correctly incorporating left truncation into the analysis may increase the variance of the estimators, relative to an ideal sample where all pregnancies are followed from the time of conception. The consequences of such truncation for study design are discussed. Combining corrections for left truncation and competing risks offers a powerful method for analyzing miscarriage risk.

  15. 6种新型香豆素类衍生物的拉曼光谱研究%Raman spectra studies on six new coumarin derivatives

    Institute of Scientific and Technical Information of China (English)

    刘婵; 周吉; 刘丽娜; 任华华; 叶勇

    2013-01-01

    The coumarins have been widely used as the organic heterocyclic compounds .It has very high medicine value duce to its biological activities in preventing HIV , preventing cancer , lowering blood pressure and preventing arrhythmia .In this study ,six new derivatives of coumarin were synthesized by using the tertiary amine as catalyst ,and then these coumarin derivatives were characterized by Raman spectra .Besides ,the characteristic spectra of the compound were assigned and we discussed the effects of structure in different components on the Raman spectra .%  香豆素是一类应用很广泛的有机杂环化合物,具有抗 HIV、抗癌、降压、抗心律失常等多种生物活性,具有很高的药用价值。本实验利用叔胺催化,合成了6种新型香豆素衍生物,采用激光显微拉曼光谱对其结构进行研究,归属各化合物拉曼谱峰,并探讨分子结构差异对拉曼光谱的影响。

  16. Antitumor effect of a copper (II) complex of a coumarin derivative and phenanthroline on lung adenocarcinoma cells and the mechanism of action.

    Science.gov (United States)

    Zhu, Taofeng; Chen, Ruhua; Yu, Hao; Feng, Yan; Chen, Jianqiang; Lu, Qin; Xie, Jing; Ding, Weiliang; Ma, Tieliang

    2014-11-01

    In order to investigate the effect of a copper (II) complexes of a coumarin derivative and phenanthroline (hereinafter referred to as the coumarin-copper drug) on lung adenocarcinoma cells in vivo and in vitro, along with the mechanism of action, LA795 lung adenocarcinoma cells were treated with different concentrations of coumarin-copper drug. An MTT assay was performed to determine the cell proliferation ratio, cell apoptosis was detected by Annexin V/propidium iodide staining with flow cytometric analysis and western blot analysis was employed to evaluate the expression levels of apoptosis-associated proteins. In addition, an LA795 cell xenograft tumor model was established in nude mice, with mice receiving intraperitoneal injection once a week for three weeks of either 2 or 4 mg/kg in three divided doses coumarin‑copper drug, or phosphate‑buffered saline. The tumor growth curves were drawn and the tumor growth inhibition rates were calculated. The apoptotic index of subcutaneously transplanted tumor cells was determined by terminal deoxynucleotidyl‑transferase‑mediated dUTP nick end‑labeling assay. The coumarin-copper drug effectively inhibited the proliferation of LA795 cells in a dose‑ and time‑dependent manner, with the half maximal inhibitory concentration equaling 2.0 µmol/l. The coumarin-copper drug also significantly induced LA795 cell apoptosis in a time-dependent manner (P<0.05), which was accompanied by upregulation p35 and B-cell lymphoma-2 (Bcl-2)-associated X protein (Bax), and downregulation of Bcl-2. Furthermore, the coumarin‑copper drug significantly inhibited the growth of LA795 tumors in a dose dependent manner (P<0.05), in accordance with the apoptotic index. In conclusion, the coumarin-copper drug may inhibit the proliferation of LA795 cells through the induction of cell apoptosis, which may be associated with the upregulation of p53 and Bax, with concurrent downregulation of Bcl-2.

  17. Structure-Function Analysis of Mammalian CYP2B Enzymes Using 7-Substituted Coumarin Derivatives as Probes: Utility of Crystal Structures and Molecular Modeling in Understanding Xenobiotic Metabolism.

    Science.gov (United States)

    Shah, Manish B; Liu, Jingbao; Huo, Lu; Zhang, Qinghai; Dearing, M Denise; Wilderman, P Ross; Szklarz, Grazyna D; Stout, C David; Halpert, James R

    2016-04-01

    Crystal structures of CYP2B35 and CYP2B37 from the desert woodrat were solved in complex with 4-(4-chlorophenyl)imidazole (4-CPI). The closed conformation of CYP2B35 contained two molecules of 4-CPI within the active site, whereas the CYP2B37 structure demonstrated an open conformation with three 4-CPI molecules, one within the active site and the other two in the substrate access channel. To probe structure-function relationships of CYP2B35, CYP2B37, and the related CYP2B36, we tested the O-dealkylation of three series of related substrates-namely, 7-alkoxycoumarins, 7-alkoxy-4-(trifluoromethyl)coumarins, and 7-alkoxy-4-methylcoumarins-with a C1-C7 side chain. CYP2B35 showed the highest catalytic efficiency (kcat/KM) with 7-heptoxycoumarin as a substrate, followed by 7-hexoxycoumarin. In contrast, CYP2B37 showed the highest catalytic efficiency with 7-ethoxy-4-(trifluoromethyl)coumarin (7-EFC), followed by 7-methoxy-4-(trifluoromethyl)coumarin (7-MFC). CYP2B35 had no dealkylation activity with 7-MFC or 7-EFC. Furthermore, the new CYP2B-4-CPI-bound structures were used as templates for docking the 7-substituted coumarin derivatives, which revealed orientations consistent with the functional studies. In addition, the observation of multiple -Cl and -NH-π interactions of 4-CPI with the aromatic side chains in the CYP2B35 and CYP2B37 structures provides insight into the influence of such functional groups on CYP2B ligand binding affinity and specificity. To conclude, structural, computational, and functional analysis revealed striking differences between the active sites of CYP2B35 and CYP2B37 that will aid in the elucidation of new structure-activity relationships.

  18. Comparison of seven structurally related coumarins on the inhibition of Quorum sensing of Pseudomonas aeruginosa and Chromobacterium violaceum.

    Science.gov (United States)

    D'Almeida, R E; Molina, R D I; Viola, C M; Luciardi, M C; Nieto Peñalver, C; Bardón, A; Arena, M E

    2017-08-01

    Quorum sensing (QS) is a cell-to-cell signaling communication system that controls the virulence behavior of a broad spectrum of bacterial pathogens, participating also in the development of biofilms, responsible of the antibiotic ineffectiveness in many infections. Therefore, QS system is an attractive target for antimicrobial therapy. In this study, we compare the effect of seven structurally related coumarins against bacterial growth, biofilm formation and elastase activity of Pseudomonas aeruginosa. In addition, the anti-pathogenic capacity of the seven coumarins was evaluated on the wild type and the biosensor strain of Chromobacterium violaceum. The comparative study of coumarins showed that molecules with hydroxyl groups on the aromatic ring displayed higher activity on the inhibition of biofilm formation of P. aeruginosa over coumarins with substituents in positions 3 and 4 or without the double 3,4-bond. These 3 or 4-hydroxylated positions caused a decrease in the anti-biofilm activity obtained for coumarin. However, the hydroxyl group in position 3 of the pyrone ring was important for the inhibition of C. violaceum QS and elastolytic activity of P. aeruginosa. The effects observed were active independently of any effect on growth. According to our results, coumarin and its hydroxylated derivatives represent an interesting group of compounds to use as anti-virulence agents against the human pathogen P. aeruginosa. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. A one pot, three component synthesis of coumarin hybrid thiosemicarbazone derivatives and their antimicrobial evolution

    Directory of Open Access Journals (Sweden)

    Rajesh H. Vekariya

    2017-06-01

    Full Text Available A convenient, one-pot, multi-component protocol for the preparation of 2-(1-(2-oxo-2H-chromen-3-ylethylidenehydrazinecarbothioamide derivatives has been achieved. Here, firstly we have reported the synthesis of 3-acetyl-2H-chromen-2-one using starch sulfuric acid and cellulose sulfuric acid as biodegradable catalysts. Subsequently, we also carried out the reaction of isothiocynates, hydrazine hydrate and 3-acetyl-2H-chromen-2-one in the presence of catalytic amount of glacial acetic acid in refluxing ethanol to afford corresponding 2-(1-(2-oxo-2H-chromen-3-ylethylidenehydrazinecarbothioamide derivatives in high to excellent yields. All synthesized compounds were screened for antimicrobial activity. All compounds were found to show good to excellent activity against Escherichia coli MTCC 443.

  20. Morphology of the ring current derived from magnetic field observations

    Directory of Open Access Journals (Sweden)

    G. Le

    2004-04-01

    Full Text Available Our examination of the 20 years of magnetospheric magnetic field data from ISEE, AMPTE/CCE and Polar missions has allowed us to quantify how the ring current flows and closes in the magnetosphere at a variety of disturbance levels. Using intercalibrated magnetic field data from the three spacecraft, we are able to construct the statistical magnetic field maps and derive 3-dimensional current density by the simple device of taking the curl of the statistically determined magnetic field. The results show that there are two ring currents, an inner one that flows eastward at ~3 RE and a main westward ring current at ~4–7 RE for all levels of geomagnetic disturbances. In general, the in-situ observations show that the ring current varies as the Dst index decreases, as we would expect it to change. An unexpected result is how asymmetric it is in local time. Some current clearly circles the magnetosphere but much of the energetic plasma stays in the night hemisphere. These energetic particles appear not to be able to readily convect into the dayside magnetosphere. During quiet times, the symmetric and partial ring currents are similar in strength (~0.5MA and the peak of the westward ring current is close to local midnight. It is the partial ring current that exhibits most drastic intensification as the level of disturbances increases. Under the condition of moderate magnetic storms, the total partial ring current reaches ~3MA, whereas the total symmetric ring current is ~1MA. Thus, the partial ring current contributes dominantly to the decrease in the Dst index. As the ring current strengthens the peak of the partial ring current shifts duskward to the pre-midnight sector. The partial ring current is closed by a meridional current system through the ionosphere, mainly the field-aligned current, which maximizes at local times near the dawn and dusk. The closure currents flow in

  1. Novel Fluorescent Dyes Based on Coumarin System

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Seven novel fluorescent coumarin derivatives were synthesized from 7-diethylamino-4-chloro-3-formyl coumarin. The spectra of absorption, excitation and emission were dependent not only on the structures and also on the concentration of dyes. The PPP-MO predictions can only be consistent with the spectra in dilute solutions.

  2. On prime and semiprime near-rings with derivations

    Directory of Open Access Journals (Sweden)

    Nurcan Argaç

    1997-01-01

    Full Text Available Let N be a semiprime right near-ring, A a subset of N such that 0∈A and AN⫅A, and d a derivation of N The purpose of this paper is to prove that if d acts as a homomorphism on A or as an anti-homomorphism on A, then d(A={0}.

  3. Synthesis of some new carbonitriles and pyrazole coumarin derivatives with potent antitumor and antimicrobial activities.

    Science.gov (United States)

    Hafez, Omiama M Abdel; Nassar, Mahmoud I; El-Kousy, Salah M; Abdel-Razik, Ayman F; Sherien, M M Atalla; El-Ghonemy, Mai M

    2014-01-01

    3-Acetyl-4-hydroxycoumarin (2) was reacted with some aldehydes (4-chlorobenzaldehyde, 4-bromobenzaldehyde, 5-methylfurfural) to afford the chalcones (3a-c). Cyclization of these chalcones with malononitrile in the presence of ammonium acetate afforded pyridine carbonitriles (4a-c), while the cyclization reaction of chalcones (3a-c) with ethyl cyanoacetate afforded the oxopyridine carbonitriles (5a-c). On the other hand, the chalcones (3a-c) reacted with hydrazine hydrate in alcohol to yield pyrazoles (6a-c), but when the same reaction is carried out in the presence of acetic acid, the acetyl pyrazole derivatives (7a-c) were obtained. Finally, the reaction of the chalcones (3a-c) with phenylhydrazine afforded phenylpyrazole derivatives (8a-c). The structures of synthesized compounds were confirmed by their micro analysis and spectral data (IR, NMR and MS). Twelve samples were evaluated for the human breast adenocarcinoma cytotoxicity, three of them showed moderate activity, the rest of the samples showed weak cytotoxic activity (very high IC50), but for the hepatocarcinoma cell lines four samples showed weak cytotoxic effect, while the rest of the compounds showed very weak effect. For antimicrobial study, three compounds proved to be the most promising against tested bacterial organisms.

  4. Coumarin: a promising scaffold for anticancer agents.

    Science.gov (United States)

    Kaur, Manjinder; Kohli, Swarandeep; Sandhu, Sonali; Bansal, Yogita; Bansal, Gulshan

    2015-01-01

    Coumarin enjoys an important place in drug discovery process due to its presence in diversity of biologically active compounds. Many compounds of plant origin are derivatives of coumarin. Taking these natural products as lead, research groups across the globe have designed and synthesized numerous coumarin analogues for treatment of varied diseases. Cancer is one of the dreadful chronic diseases, and many drugs are available for its treatment. However, due to heterogeneity of cancer, the search is still on to develop drugs for specific types of cancers. The present review is an attempt to study various coumarin derivatives of natural as well as synthetic origins, which are identified or developed for the treatment of different types of cancers. Herein, we have classified various anticancer coumarin derivatives on the basis of their origin as well as substitution around it. These are discussed under the headings of natural, semi-synthetic and synthetic coumarin derivatives. The synthetic coumarin derivatives are further classified as mono-, di- and poly-substituted and fused coumarin derivatives. Of the six positions available for substituents on coumarin nucleus, only three positions (C-3, C-4 and C-7) are exploited for the selection of functional groups appropriate for anticancer activity. The other positions (C-5, C-6 and C-8) are either unexplored or very less exploited. The present review is expected to provide the medicinal chemists a guide to choose new functional groups for substitution at different positions of coumarin nucleus for development of novel compounds for the treatment of a specific type of cancer.

  5. Two benzoyl coumarin amide fluorescence chemosensors for cyanide anions

    Science.gov (United States)

    Wang, Zian; Wu, Qianqian; Li, Jiale; Qiu, Shuang; Cao, Duxia; Xu, Yongxiao; Liu, Zhiqiang; Yu, Xueying; Sun, Yatong

    2017-08-01

    Two new benzoyl coumarin amide derivatives with ortho hydroxyl benzoyl as terminal group have been synthesized. Their photophysical properties and recognition properties for cyanide anions in acetonitrile have also been examined. The influence of electron donating diethylamino group in coumarin ring and hydroxyl in benzoyl group on recognition properties was explored. The results indicate that the compounds can recognize cyanide anions with obvious absorption and fluorescence spectral change and high sensitivity. The import of diethylamine group increases smartly the absorption ability and fluorescence intensity of the compound, which allows the recognition for cyanide anions can be observed by naked eyes. The in situ hydrogen nuclear magnetic resonance spectra combining photophysical properties change and job's plot data confirm that Michael addition between the chemosensors and cyanide anions occurs. Molecular conjugation is interrupted, which leads to fluorescence quenching. At the same time, there is a certain extent hydrogen bond reaction between cyanide and hydroxyl group in the compounds, which is beneficial to the recognition.

  6. Derivatives containing both coumarin and benzimidazole potently induce caspase-dependent apoptosis of cancer cells through inhibition of PI3K-AKT-mTOR signaling.

    Science.gov (United States)

    Liu, Haitao; Wang, Yubin; Sharma, Ashok; Mao, Rui; Jiang, Na; Dun, Boying; She, Jin-Xiong

    2015-07-01

    Coumarins are a large family of compounds derived from a wide range of plants, fungi, and bacteria, and coumarin derivatives can have extremely variable structures and consequently diverse biological properties including antitumor activity. Compounds that bear a benzimidazole moiety are known to possess antitumor activity and a variety of other biological activities. High-throughput screening of a compound library identified a coumarin-containing and a benzimidazole-containing compound [#32, 7-(diethylamino)-3-(1-methyl-1H-benzimidazol-2-yl)-2H-chromen-2-one] that has potent anticancer activity. Evaluation of 17 additional analogs further identified three compounds with anticancer activity in 14 different human cancer cell lines. Fluorescence-activated cell sorting and western blotting analyses suggested that these compounds can induce caspase-dependent apoptosis. Real-time reverse transcriptase PCR analyses of 26 cancer-related genes revealed that seven genes (NPPB, ATF3, DDIT4, CDH10, TSPAN14, TXNIP, and AXL) were significantly upregulated and nine genes (PAGE4, LRP8, SNCAIP, IGFBP5, SLCO2A1, CLDN2, ESRRG, D2HGDH, and PDGFRA) were significantly downregulated. The most upregulated gene is natriuretic peptide precursor B (NPPB) or brain natriuretic peptide, which is increased by 7-, 27-, and 197-fold at 12, 24, and 48 h, respectively. The second most upregulated gene is ATF3, which is increased by 23-fold at the 48 h timepoint. PAGE4 and IGFBP5 are the two most downregulated genes, with a 17-fold reduction in both genes. The expression of several genes (DDIT4, PDGFRA, LRP8, IGFBP5) and western blotting data on key signaling proteins indicate that compound #32 significantly inhibits the PI3K-AKT-mTOR pathway, an intracellular signaling pathway critical in cell proliferation and apoptosis.

  7. Evaluation of Antifungal Activity and Mode of Action of New Coumarin Derivative, 7-Hydroxy-6-nitro-2H-1-benzopyran-2-one, against Aspergillus spp.

    Directory of Open Access Journals (Sweden)

    Felipe Queiroga Sarmento Guerra

    2015-01-01

    Full Text Available Aspergillus spp. produce a wide variety of diseases. For the treatment of such infections, the azoles and Amphotericin B are used in various formulations. The treatment of fungal diseases is often ineffective, because of increases in azole resistance and their several associated adverse effects. To overcome these problems, natural products and their derivatives are interesting alternatives. The aim of this study was to examine the effects of coumarin derivative, 7-hydroxy-6-nitro-2H-1-benzopyran-2-one (Cou-NO2, both alone and with antifungal drugs. Its mode of action against Aspergillus spp. Cou-NO2 was tested to evaluate its effects on mycelia growth and germination of fungal conidia of Aspergillus spp. We also investigated possible Cou-NO2 action on cell walls (0.8 M sorbitol and on Cou-NO2 to ergosterol binding in the cell membrane. The study shows that Cou-NO2 is capable of inhibiting both the mycelia growth and germination of conidia for the species tested, and that its action affects the structure of the fungal cell wall. At subinhibitory concentration, Cou-NO2 enhanced the in vitro effects of azoles. Moreover, in combination with azoles (voriconazole and itraconazole Cou-NO2 displays an additive effect. Thus, our study supports the use of coumarin derivative 7-hydroxy-6-nitro-2H-1-benzopyran-2-one as an antifungal agent against Aspergillus species.

  8. Thiol-chromene click chemistry: a coumarin-based derivative and its use as regenerable thiol probe and in bioimaging applications.

    Science.gov (United States)

    Yang, Yutao; Huo, Fangjun; Yin, Caixia; Zheng, Anmin; Chao, Jianbin; Li, Yingqi; Nie, Zongxiu; Martínez-Máñez, Ramón; Liu, Diansheng

    2013-09-15

    The synthesis and characterization of a coumarin-chromene (8, 9-dihydro-2H-cyclopenta[b]pyrano[2,3-f]chromene-2,10(7aH)-dione) (1) derivative and its use for thiol chemosensing in water was reported. Experimental details showed 1 acts as a probe for the detection of thiols including cysteine (Cys), homocysteine (Hcy) and glutathione (GSH), whereas amino acids which do not contain thiols induced no changes in UV-vis spectra and fluorescence emission properties of 1. A possible detection mechanism is a nucleophilic attack of thiols to the α,β-unsaturated ketone in 1 that resulted in a fluorescent coumarin derivative. Further studies showed that 1-thiol derivatives can be applied to the design of regenerative chemodosimeters for Cu(2+), Hg(2+) and Cd(2+) in water based on M(n+)-promoted desulfurization and recovery of 1. Furthermore, the optical properties of the probe and its Cys-addition product were theoretically studied. The ability of probe 1 to detect thiols in living cells (HepG2 cells) via an enhancement of the fluorescence was proved. Moreover, the applicability of 1 for the direct determination of biorelevant thiols in a complex matrix such as human plasma was also demonstrated. Copyright © 2013 Elsevier B.V. All rights reserved.

  9. Evaluation of Antifungal Activity and Mode of Action of New Coumarin Derivative, 7-Hydroxy-6-nitro-2H-1-benzopyran-2-one, against Aspergillus spp.

    Science.gov (United States)

    Guerra, Felipe Queiroga Sarmento; de Araújo, Rodrigo Santos Aquino; de Sousa, Janiere Pereira; Pereira, Fillipe de Oliveira; Mendonça-Junior, Francisco J B; Barbosa-Filho, José M; de Oliveira Lima, Edeltrudes

    2015-01-01

    Aspergillus spp. produce a wide variety of diseases. For the treatment of such infections, the azoles and Amphotericin B are used in various formulations. The treatment of fungal diseases is often ineffective, because of increases in azole resistance and their several associated adverse effects. To overcome these problems, natural products and their derivatives are interesting alternatives. The aim of this study was to examine the effects of coumarin derivative, 7-hydroxy-6-nitro-2H-1-benzopyran-2-one (Cou-NO2), both alone and with antifungal drugs. Its mode of action against Aspergillus spp. Cou-NO2 was tested to evaluate its effects on mycelia growth and germination of fungal conidia of Aspergillus spp. We also investigated possible Cou-NO2 action on cell walls (0.8 M sorbitol) and on Cou-NO2 to ergosterol binding in the cell membrane. The study shows that Cou-NO2 is capable of inhibiting both the mycelia growth and germination of conidia for the species tested, and that its action affects the structure of the fungal cell wall. At subinhibitory concentration, Cou-NO2 enhanced the in vitro effects of azoles. Moreover, in combination with azoles (voriconazole and itraconazole) Cou-NO2 displays an additive effect. Thus, our study supports the use of coumarin derivative 7-hydroxy-6-nitro-2H-1-benzopyran-2-one as an antifungal agent against Aspergillus species.

  10. Ethyl coumarin-3-carboxylate: synthesis and chemical properties

    Directory of Open Access Journals (Sweden)

    Bakr F. Abdel-Wahab

    2014-03-01

    Full Text Available Ethyl coumarin-3-carboxylate occupies an important position in the organic synthesis and is used in production of biologically active compounds. Thus, the data published over the last few years on the methods of synthesis and chemical properties of ethyl coumarin-3-carboxylate are reviewed here for the first time. The reactions were classified as coumarin ring reactions and ester group reactions, and some of these reactions have been applied successfully to the synthesis of biologically and industrially important compounds.

  11. A new coumarin glucoside, coumarins and alkaloids from Ruta corsica roots.

    Science.gov (United States)

    Bertrand, Cédric; Fabre, Nicolas; Moulis, Claude

    2004-03-01

    A new coumarin glucoside, 3'(S)-hydroxy-2',2'-dimethyl-dihydropyranocoumarin-8-beta-d-glucopyranosyl, one coumarin, five furanocoumarins, three bicoumarins, three quinoline alkaloids and one sinapoyl sucrose derivative have been isolated from the roots of Ruta corsica.

  12. Solvent-Free Synthesis of New Coumarins

    Directory of Open Access Journals (Sweden)

    Redah I. Al-Bayati

    2012-01-01

    Full Text Available A solvent-free synthesis of five series of coumarin derivatives using microwave assistant is presented herein. The synthesized compounds are fully characterized by UV-VIS, FT-IR, and NMR spectroscopy.

  13. New fluorescent probes of the hydroxyl radical: characterisation and modelization of the reactivity of coumarin derivatives with HO; Developpement de sondes fluorescentes du radical hydroxyle: caracterisation et modelisation de la reactivite de molecules derivees de la coumarine avec HO

    Energy Technology Data Exchange (ETDEWEB)

    Louit, G.

    2005-10-15

    The hydroxyl radical is involved in a wide range of different fields, from oxidative stress to atmospheric chemistry. In addition to the study of oxidative damage in biological media, the hydroxyl radical detection allows to perform a dosimetry when it is produced by ionising radiation. The aims of this work have been double: - to improve the detection of the hydroxyl radical by the design of new probes - to improve knowledge on the reactive pathways in which the hydroxyl radical is involved. We have studied the coumarin molecule, as well as 6 derivatives that we have synthesised, as fluorescent probes of the hydroxyl radical. Firstly, fluorescence spectroscopy and HPLC chromatography have allowed the evaluation of the sensibility and selectivity of detection of the probes. Consequently to this study, two applications have been developed, concerning the determination of rate constants by competition kinetics and bidimensional dosimetry. Secondly, we have studied the reactivity of the hydroxyl radical through the regioselectivity of its addition on the aromatic cycle. This problem was addressed by the combined use of experimental methods such as time resolved kinetics and HPLC along with interpretation from classical and ab initio modelization. (author)

  14. Design, synthesis and vasorelaxant evaluation of novel coumarin-pyrimidine hybrids.

    Science.gov (United States)

    Amin, Kamilia M; Awadalla, Fadi M; Eissa, Amal A M; Abou-Seri, Sahar M; Hassan, Ghaneya S

    2011-10-15

    The main objective of the present work depends on the hybridization of coumarin moiety as a vasorelaxant scaffold and pyrimidine ring with known potential cardiovascular activity in order to prepare some new potent antihypertensive candidates. Hence, two groups of pyrimidinyl coumarin derivatives were synthesized and evaluated for their vasorelaxing activity. These compounds were prepared via two routes; either preparation of the guanidinocoumarin 4 followed by a cocktail of cyclization reactions to yield a different array of 6-(substituted pyrimidin-2-yl)aminocoumarins 5-17, or through cyclization of the precursor chalcones 22a-g with guanidine hydrochloride to generate the corresponding final compounds, 8-(6-aryl-2-aminopyrimidin-4-yl)-7-methoxycoumarins 23a-g. The effect of these compounds and the coumarin intermediates 3, 4, 21 and 22a-g on nor-epinephrine induced contracture in thoracic rat aortic rings was investigated using prazocin as reference drug. Several derivatives showed promising activities either equal or even better than that of prazocin (IC(50) 0.487 mM). The most prospective compounds; the pyrimidinylamino coumarin derivatives 8, 17 (IC(50) 0.411, IC(50) 0.421 mM) and the chalcones 22b, 22e (IC(50) 0.371, 0.374 mM) that displayed the highest activity can be a base for lead optimization and simple but efficient design of new compounds. 2D-QSAR analysis was applied to find a correlation between the experimental vasorelaxant activities of the newly synthesized coumarin derivatives and their different physicochemical parameters. The result of this study showed that the increase in aqueous solubility while retaining good hydrophobic character of the overall molecule is the key for maintaining high relaxation activity.

  15. Existence and Posner's Theorem for α-derivations in Prime Near-rings

    Directory of Open Access Journals (Sweden)

    M. S. Samman

    2009-02-01

    Full Text Available In this paper we define α-derivation for near-rings and extend some results for derivations of prime rings or near-rings to a more general case for α-derivations of prime near-rings. To initiate the study of the theory, the existence of such derivation is shown by an example. It is shown that if d is an α-derivation of a prime near-ring N such that d commutes with α, then d2 = 0 implies d = 0. Also a Posner-type result on the composition of α-derivations is obtained.

  16. A novel coumarin-quinone derivative SV37 inhibits CDC25 phosphatases, impairs proliferation, and induces cell death.

    Science.gov (United States)

    Bana, Emilie; Sibille, Estelle; Valente, Sergio; Cerella, Claudia; Chaimbault, Patrick; Kirsch, Gilbert; Dicato, Mario; Diederich, Marc; Bagrel, Denyse

    2015-03-01

    Cell division cycle (CDC) 25 proteins are key phosphatases regulating cell cycle transition and proliferation by regulating CDK/cyclin complexes. Overexpression of these enzymes is frequently observed in cancer and is related to aggressiveness, high-grade tumors and poor prognosis. Thus, targeting CDC25 by compounds, able to inhibit their activity, appears a good therapeutic approach. Here, we describe the synthesis of a new inhibitor (SV37) whose structure is based on both coumarin and quinone moieties. An analytical in vitro approach shows that this compound efficiently inhibits all three purified human CDC25 isoforms (IC50 1-9 µM) in a mixed-type mode. Moreover, SV37 inhibits growth of breast cancer cell lines. In MDA-MB-231 cells, reactive oxygen species generation is followed by pCDK accumulation, a mark of CDC25 dysfunction. Eventually, SV37 treatment leads to activation of apoptosis and DNA cleavage, underlining the potential of this new type of coumarin-quinone structure.

  17. Evaluation of luminol chemiluminescence based on simultaneous introducing of coumarin derivatives as green fluorophores and chitosan-induced Au/Ag alloy nanoparticle as catalyst for the sensitive determination of glucose.

    Science.gov (United States)

    Chaichi, M J; Alijanpour, S O; Asghari, S; Shadlou, S

    2015-03-01

    We report herein the development of a novel chemiluminescence system based on simultaneous introducing of synthetic coumarin derivatives and chitosan-induced Au/Ag alloy NPs on the luminol CL system and suggest how it may be useful for determination of glucose. Chitosan-induced Au/Ag nanoalloys in the coumarin derivatives intensified-luminol CL system, in addition to catalyze CL reaction can make a change in the process of coumarin derivatives effect as fluorophore on the luminol CL system. This phenomenon is caused by interaction between active functional groups of coumarin derivatives and chitosan. The interaction strength depends on the coumarin derivatives' structure and their substituents. Considering the inevitable trend luminol radical and superoxide anion radical to absorption on the surface of the embedded Au/Ag nanoalloy in the chitosan matrix, it can be concluded that chitosan acts as a platform for all reagents involved in the CL reaction including coumarin derivatives, Au/Ag nanoalloy and luminol, and electron-transfer taking place on it; Placing all chemiluminescent reagents together on the chitosan network can lead to a powerful CL due to increasing rigidity of CL system. The most efficient coumarin derivative on the Au/Ag nanoalloy-fluorophore-luminol-H2O2 CL system, in relation to interaction capability with chitosan' functional groups, was selected and the CL condition in presence of it was optimized. Whereas the glucose oxidase-mediated oxidation of glucose yields gluconic acid and H2O2, under optimum condition the most efficient CL system was applied to detection of glucose due to enzymatically production of hydrogen peroxide. The linear response range of 1.5 × 10(-6)-5.0 × 10(-3) M and the detection limit (defined as the concentration that could be detected at the signal-to-noise ratio of 3) of 7.5 × 10(-7) M was found for the glucose standards. Also, the developed method was successfully applied to determination of glucose in

  18. Novel Coumarin Derivatives Containing 1,2,4-Triazole, 4,5-Dicyanoimidazole and Purine Moieties: Synthesis and Evaluation of Their Cytostatic Activity

    Directory of Open Access Journals (Sweden)

    Mladen Mintas

    2012-09-01

    Full Text Available We report here on the synthesis and in vitro anti-tumor effects of a series of novel 1,2,4-triazole (compounds 3–6, 4,5-dicyanoimidazole (compound 7, and purine (compounds 8–13 coumarin derivatives and their acyclic nucleoside analogues 14–18. Structures of novel compounds 3–18 were deduced from their 1H- and 13C-NMR and corresponding mass spectra. Results of anti-proliferative assays performed on a panel of selected human tumor cell lines revealed that compound 6 had moderate cytostatic activity against the HeLa cell line (IC50 = 35 µM, whereas compound 10 showed moderate activity against the HeLa (IC50 = 33 µM, HepG2 (IC50 = 25 µM and SW620 (IC50 = 35 µM cell lines. These compounds showed no cytotoxic effects on normal (diploid human fibroblasts.

  19. Synthesis, spectroscopic characterization and biological evaluation studies of Schiff's base derived from naphthofuran-2-carbohydrazide with 8-formyl-7-hydroxy-4-methyl coumarin and its metal complexes

    Science.gov (United States)

    Halli, M. B.; Sumathi, R. B.; Kinni, Mallikarjun

    2012-12-01

    Metal complexes of the type ML2, where M = Co(II), Ni(II), Cu(II), Zn(II), Cd(II), Hg(II) and L = Schiff's base derived from the condensation of naphthofuran-2-carbohydrazide with 8-formyl-7-hydroxy-4-methyl coumarin have been synthesized. The chelation of the complexes have been elucidated in the light of analytical, IR, UV-vis, 1H NMR, mass, ESR spectral data, thermal and magnetic studies. The measured molar conductance values indicate that, the complexes are non-electrolytic in nature. The redox behavior of one of the synthesized metal complexes was investigated by cyclic voltammetry. The Schiff's base and its metal complexes have been screened for their in vitro antibacterial and antifungal activities by MIC method. The DNA cleavage activities of all the complexes were studied by agarose gel electrophoresis method. In addition, the free ligand along with its complexes has been studied for their antioxidant activity.

  20. Multifunctional coumarin derivatives: monoamine oxidase B (MAO-B) inhibition, anti-β-amyloid (Aβ) aggregation and metal chelation properties against Alzheimer's disease.

    Science.gov (United States)

    Huang, Ming; Xie, Sai-Sai; Jiang, Neng; Lan, Jin-Shuai; Kong, Ling-Yi; Wang, Xiao-Bing

    2015-02-01

    A series of coumarin derivatives were designed, synthesized, and evaluated as novel multifunctional agents against Alzheimer's disease (AD). In vitro studies showed that most of these compounds exhibited significant potency to inhibit hMAO-B selectively and self-induced Aβ1-42 aggregation. In particular, compound 13 presented the greatest potential to inhibit hMAO-B (IC50=0.081μM, SI >1234) and good inhibition of Aβ1-42 aggregation (52.9% at 20μM). Moreover, compound 13 could function as a metal-chelator, penetrate the blood-brain barrier (BBB) and show low cell toxicity in rat pheochromocytoma (PC12) and SH-SY5Y cells. Taken together, these results suggested that compound 13 might be a promising multifunctional agent for AD treatment.

  1. A novel off–on fluorescence chemosensor for Ca{sup 2+} based on Rhodamine–Coumarin Schiff base derivative

    Energy Technology Data Exchange (ETDEWEB)

    An, Jun-mei [College of Chemistry and Chemical Engineering and State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000 (China); Yang, Zheng-yin, E-mail: yangzy@lzu.edu.cn [College of Chemistry and Chemical Engineering and State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000 (China); Yan, Mi-hui; Li, Tian-rong [College of Chemistry and Chemical Engineering and State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000 (China)

    2013-07-15

    A novel sensor, 7-Hydroxy-4-methylcoumarin-8-carbaldehyde-(rhodamine) hydrazone (l) has been synthesized and investigated as a fluorescence chemosensor for Ca{sup 2+} in acetonitrile. The compound is found preferential binding to Ca{sup 2+} in presence of large excess of other competitive ions with associated changes in its optical and fluorescence spectral behavior. Upon the addition of Ca{sup 2+}, an overall emission change of 64-fold was observed. Photoinduced electron transfer (PET) process, coupled with the intramolecular charge transfer (ICT) process, are proposed to explain the observed spectral response. -- Highlights: ► A novel fluorescent sensor based on rhodamine and coumarin has been synthesized to detect Ca{sup 2+}. ► Sensesor shows high sensitivity and selectivity to Ca{sup 2+} with detection limit of 30 ppb.► The sensor can distinguish Ca{sup 2+} and Mg{sup 2+} effectively.

  2. New Coumarin Derivatives as Anti-Breast and Anti-Cervical Cancer Agents Targeting VEGFR-2 and p38α MAPK.

    Science.gov (United States)

    Batran, Rasha Z; Dawood, Dina H; El-Seginy, Samia A; Ali, Mamdouh M; Maher, Timothy J; Gugnani, Kuljeet S; Rondon-Ortiz, Alejandro N

    2017-09-01

    Breast and cervical cancers are the most common gender-specific cancers affecting women worldwide. In this investigation, we highlighted the synthesis, VEGFR-2 and p38α MAPK inhibitory activity of new series of fluorinated coumarin-based derivatives featuring a variety of bioactive chemical moieties attached or fused to the coumarin nucleus at the 3 and/or 4 position. The bioactive inhibitors were further assessed for their anti-proliferative effect against human MCF-7 breast cancer and HeLa cervical cancer cell lines, respectively. Most of the tested compounds showed potent preferential inhibition effects against human VEGFR-2 and remarkable anticancer activities in the human breast cancer cell line MCF-7. Compounds 29, 24, and 2 displayed the highest inhibitory activity against VEGFR-2 (94% inhibition) and they were the most potent anticancer agents toward MCF-7 cancer cells with IC50 values of 7.90, 8.28, and 8.30 μg/mL, respectively. Compound 13 inhibited p38α MAPK phosphorylation with a significant reduction in % cell viability against HeLa cancer cells at 10 and 30 µM. Docking experiments carried out on VEGFR-2 and p38 MAPK crystallographic structures revealed that the active compounds bind to the active sites through H-bonds, arene-cation, and hydrophobic π-π interactions. QSAR analysis demonstrated considerable correlation coefficient (R(2)  = 0.76969) and root mean square error (RMSE = 0.10446) values. Also, the residual values between the experimental pIC50 and predicted pIC50 are very close, indicating the reliability of the established QSAR model. © 2017 Deutsche Pharmazeutische Gesellschaft.

  3. Melanogenesis stimulation in murine b16 melanoma cells by umberiferae plant extracts and their coumarin constituents.

    Science.gov (United States)

    Matsuda, Hideaki; Hirata, Noriko; Kawaguchi, Yoshiko; Yamazaki, Miho; Naruto, Shunsuke; Shibano, Makio; Taniguchi, Masahiko; Baba, Kimiye; Kubo, Michinori

    2005-07-01

    Melanogenesis stimulation activities of seven ethanolic extracts obtained from Umbelliferae plants used as Chinese crude drugs, namely the roots of Angelica dahurica BENTH. et HOOK., A. biserrata SHEN et YUAN, Notopterygium incisum TING, Heracleum lanatum MICHX., and H. candicans WALL., and the fruits of Cinidium monnieri (L.) CUSSON and C. formosanum YABE, were examined by using cultured murine B16 melanoma cells. Among them, the extract (5, 25 microg/ml) of H. lanatum showed a potent stimulatory effect on melanogenesis with significant enhancement of cell proliferation in a dose-dependent manner. The melanogenesis stimulatory effects of sixteen coumarins (1-16) isolated from the seven Umbelliferae crude drugs were also examined. Among them, linear-furocoumarins [psoralen (1), xanthotoxin (2), bergapten (3), and isopimpinellin (4)] and angular-furocoumarin [sphondin (13)] exhibited potent melanogenesis stimulation activity. From the view point of structure-activity relationships, it may be assumed that a linear-furocoumarin ring having a hydrogen and/or methoxyl group at 5 and 8 positions such as 1, 2, 3 and 4 was preferable for the melanogenesis stimulation activity. The introduction of a prenyl group into the furocoumarin ring was disadvantageous. Coumarin derivatives having a simple coumarin ring were inactive.

  4. Synthesis, Structural Elucidation, and Antibacterial Evaluation of Some New Molecules Derived from Coumarin, 1,3,4-Oxadiazole, and Acetamide

    Directory of Open Access Journals (Sweden)

    Shahid Rasool

    2016-01-01

    Full Text Available Because of the reported biological activities of coumarin, 1,3,4-oxadiazole, and acetamides, some new compounds incorporating these moieties were synthesized and evaluated for their biological potential against Gram-positive and Gram-negative bacteria. In the present work, 4-chlororesorcinol (1 and ethyl acetoacetate (2 were mixed in a strong acidic medium to synthesize 6-chloro-7-hydroxy-4-methyl-2-oxo-2H-chromene (3 which was subjected to the intermolecular cyclization after consecutive three steps to synthesize 5-[(6-chloro-4-methyl-2-oxo-2H-chromen-7-yloxy]methyl-1,3,4-oxadiazol-2-thiol (6. A series of acetamoyl electrophiles, 8a–o, were synthesized from aralkyl/alkyl/aryl amines, 7a–o, in an aqueous basic medium. The final compounds, 9a–o, were synthesized by the reaction of compounds 6 and 8a–o in DMF/NaH. The synthesized compounds were structurally elucidated by spectral data analysis of IR, 1H-NMR, and EIMS. The most of the synthesized compounds remained moderate to excellent antibacterial agents. The molecules, 9e, 9j, and 9k, were the most efficient ones against all the five bacterial strains taken into account.

  5. Synthesis and evaluation of 7-substituted coumarin derivatives as multimodal monoamine oxidase-B and cholinesterase inhibitors for the treatment of Alzheimer's disease.

    Science.gov (United States)

    Joubert, Jacques; Foka, Germaine B; Repsold, Benjamin P; Oliver, Douglas W; Kapp, Erika; Malan, Sarel F

    2017-01-05

    A series of 7-substituted coumarin derivatives were designed and synthesised to display ChE and MAO-B inhibitory activity. The compounds consisted out of a coumarin structure (MAO-B inhibitor) and benzyl-, piperidine-, N-benzylpiperidine- or p-bromo-N-benzylpiperizine moiety, resembling the N-benzylpiperidine function of donepezil (ChE inhibitor), connected via an alkyl ether linkage at the 7 position. The biological assay results indicated that all the compounds (1-25) displayed selective inhibition to hMAO-B over hMAO-A, with the benzyloxy series (1-8, 10-13) showing nano-molar hMAO-B inhibition (IC50: 0.5-73 nM). Limited ChE inhibitory activity was however observed for the benzyloxy series with the exception of 2 and especially 3 showing selective BuChE inhibition. From this series 3 showed the best multifunctional activity (eqBuChE IC50 = 0.96 μM, hMAO-A IC50 = 2.13 μM, hMAO-B IC50 = 0.0021 μM). Within the N-benzylpiperidine (16-19) and p-bromo-N-benzylpiperizine (21-24) series the compounds in general showed moderate ChE and MAO-B inhibitory activity. Of these compounds 19 was the most potent multifunctional agent showing good eeAChE and eqBuChE inhibition (IC50 = 9.10 μM and 5.90 μM, respectively), and relatively potent and selective hMAO-B inhibition (IC50 = 0.30 μM, SI = >33). Molecular modeling revealed that 19 was able to bind simultaneously to the CAS, mid-gorge and PAS sites of AChE and BuChE suggesting that it will be able to inhibit AChE induced Aβ aggregation. From this study, compounds that 3 and 19 can be considered as promising multifunctional lead compounds.

  6. Determination of electrostatic parameters of a coumarin derivative compound C17H13NO3 by x-ray and density functional theory

    Science.gov (United States)

    Youcef, Megrouss; Nadia, Benhalima; Rawia, Bahoussi; Nouredine, Boukabcha; Abdelkader, Chouaih; Fodil, Hamzaoui

    2015-10-01

    This work is devoted to the experimental determination of the electrostatic properties of the molecular 4-methyl-7-(salicylidene amino) coumarin (C17H13NC3) using high resolution x-ray diffraction data. The experimental results are compared with those obtained theoretically from calculation type ab initio. The experimental investigation is carried out using the molecular electron charge density distribution based on the multipolar model of Hansen and Coppens. However the theoretical calculations are conducted by using the molecular orbital B3LYP method and the Hartree-Fock (HF) approximation with the basis set 6-31G (d,p) implemented in the Gaussian program. In addition to the structural analysis, the thermal agitation is also analyzed in terms of rigid blocks to ensure a better precision of the results. Subsequently, the electrostatic atomic and molecular properties such as the net charges, the molecular dipolar moment to highlight the nature of charge transfer existing within the molecule studied are derived. Moreover, the obtained electrostatic potential enables the localization of the electropositive and the electronegative parts of the investigated molecule. The present work reports in detail the obtained electrostatic properties of this biologically important molecule.

  7. Determination of electrostatic parameters of a coumarin derivative compound C17H13NO3 by x-ray and density functional theory

    Institute of Scientific and Technical Information of China (English)

    Youcef Megrouss; Nadia Benhalima; Rawia Bahoussi; Nouredine Boukabcha; Abdelkader Chouaih; Fodil Hamzaoui

    2015-01-01

    This work is devoted to the experimental determination of the electrostatic properties of the molecular 4-methyl-7-(salicylidene amino) coumarin (C17H13NC3) using high resolution x-ray diffraction data. The experimental results are compared with those obtained theoretically from calculation type ab initio. The experimental investigation is carried out using the molecular electron charge density distribution based on the multipolar model of Hansen and Coppens. However the theoretical calculations are conducted by using the molecular orbital B3LYP method and the Hartree–Fock (HF) ap-proximation with the basis set 6-31G (d,p) implemented in the Gaussian program. In addition to the structural analysis, the thermal agitation is also analyzed in terms of rigid blocks to ensure a better precision of the results. Subsequently, the electrostatic atomic and molecular properties such as the net charges, the molecular dipolar moment to highlight the nature of charge transfer existing within the molecule studied are derived. Moreover, the obtained electrostatic potential enables the localization of the electropositive and the electronegative parts of the investigated molecule. The present work reports in detail the obtained electrostatic properties of this biologically important molecule.

  8. A highly efficient and selective turn-on fluorescent sensor for Hg2+, Ag+ and Ag nanoparticles based on a coumarin dithioate derivative.

    Science.gov (United States)

    El-Shekheby, Heba A; Mangood, Ahmed H; Hamza, Salem M; Al-Kady, Ahmed S; Ebeid, El-Zeiny M

    2014-03-01

    Based on chelation-enhanced fluorescence, a new fluorescent coumarin derivative probe 3(1-(7-hydroxy-4-methylcoumarin)ethylidene)hydrazinecarbodithioate for Hg(2+), Ag(+) and Ag nanoparticles is reported. Fluorescent probe acts as a rapid and highly selective "off-on" fluorescent probe and fluorescence enhancement by factors 5 to 12 times was observed upon selective complexation with Hg(2+), Ag(+) and Ag nanoparticles. The molar ratio plots indicated the formation of 1:1 complexes between Hg(2+) and Ag(+) with the probe. The linear response range covers a concentration range 0.1 × 10(-5) -1.9 × 10(-5) mol/L, 0.1 × 10(-5) -2.3 × 10(-5) mol/L and 0.146 × 10(-12) -2.63 × 10(-12) mol/L for Hg(2+), Ag(+) and Ag nanoparticles, respectively. The interference effect of some anions and cations was also tested.

  9. Producing fluorescent digital printing ink: Investigating the effect of type and amount of coumarin derivative dyes on the quality of ink

    Energy Technology Data Exchange (ETDEWEB)

    Ataeefard, Maryam, E-mail: ataeefard-m@icrc.ac.ir [Department of Printing Science and Technology, Institute for Color Science and Technology, P.O. Box 16765-654, Tehran (Iran, Islamic Republic of); Nourmohammadian, Farahnaz, E-mail: nour@icrc.ac.ir [Centre of Excellence for Colour Science and Technology, Institute for Colour Science and Technology, P.O. Box 16765-654, Tehran (Iran, Islamic Republic of); Department of Organic Colorants, Institute for Colour Science and Technology, P.O. Box 16765-654, Tehran (Iran, Islamic Republic of)

    2015-11-15

    The aim of this work is to produce a composite powder as a fluorescent ink for digital electrophotographic printing. Three benzoxazolyl and benzimidazolyl coumarin derivative dyes are used as fluorescent dyes that are incorporated into poly (styrene-co-a crylic acid) using eco-friendly emulsion aggregation (EA) approaches in several amounts with final application of fluorescent laser printing ink called toner. Fluorescence and daylight spectrophotometry is used for investigating the emission and reflectance properties of fluorescent toner. It was found that the relations between emission of fluorescent toners and the amount of dyes are non-linear. Particle size analysis, scanning electron microscopy, differential scanning calorimeter and thermal gravimetric analysis were used to study the size, shape, morphology and thermal properties of fluorescent toner particles. Results verify that the polarity of the dyes and their compatibility with the environment could affect the shape of the fluorescent toner. In addition, the results show that the fluorescent toner produced by the EA method has appropriate characteristics comparing to an industrial toner. - Highlights: Fluorescent digital printing ink produced via emulsion aggregation technique. Fluorescent ink for produced for electrophotographic printing. The relations between fluorescent emission and the amount of dyes are non-linear. Different dyes, show different behavior.

  10. Monte Carlo Method Based QSAR Modeling of Coumarin Derivates as Potent HIV‐1 Integrase Inhibitors and Molecular Docking Studies of Selected 4‐phenyl Hydroxycoumarins

    Directory of Open Access Journals (Sweden)

    Veselinović Jovana

    2014-06-01

    Full Text Available In search for new and promising coumarin compounds as HIV-1 integrase inhibitors, chemoinformatic methods like quantitative structure-activity relationships (QSAR modeling and molecular docking have an important role since they can predict desired activity and propose molecule binding to enzyme.

  11. A Convenient Ultrasound-Promoted Synthesis of Some New Thiazole Derivatives Bearing a Coumarin Nucleus and Their Cytotoxic Activity

    Directory of Open Access Journals (Sweden)

    Sobhi M. Gomha

    2012-08-01

    Full Text Available Successful implementation of ultrasound irradiation for the rapid synthesis of a novel series of 3-[1-(4-substituted-5-(aryldiazenylthiazol-2-ylhydrazonoethyl]-2H-chromen-2-ones 5ah, via reactions of 2-(1-(2-oxo-2H-chromen-3-ylethylidene thiosemicarbazide (2 and the hydrazonoyl halides 3(4, was demonstrated. Also, a new series of 5-arylidene-2-(2-(1-(2-oxo-2H-chromen-3-ylethylidenehydrazinylthiazol-4(5H-ones 10ad were synthesized from reaction of 2 with chloroacetic acid and different aldehydes. Moreover, reaction of 2-cyano-N'-(1-(2-oxo-2H-chromen-3-ylethylidene-acetohydrazide (12 with substituted benzaldehydes gave the respective arylidene derivatives 13ac under the conditions employed. The structures of the synthesized compounds were assigned based on elemental analyses and spectral data. Also, the cytototoxic activities of the thiazole derivative 5a was evaluated against HaCaT cells (human keratinocytes. It was found that compound 5a possess potent cytotoxic activity.

  12. Antibacterial Activity of Coumarine Derivatives Synthesized from 4-Chloro-chromen-2-one. The Comparison with Standard Drug.

    Directory of Open Access Journals (Sweden)

    Aziz Behrami

    2014-12-01

    Full Text Available This work reports the synthesis of some new derivatives from 4-Chloro-chromen-2-one and describe the results of antibacterial activity of purified compounds. Compounds 4-Butylamino-chromen-2-one (1a , 4-Butylamino-2-oxo-2H-chromene-3-sulfonyl chloride (2a , 4-Butylamino-2-oxo-2H-chromene-3-sulfonic acid (2-hydroxy-phenyl-amide (3a, 4-Butylamino-5-ethyl-2-oxo-7-(N'-phenyl-hydrazino-2H-chromene-3-sulfonic acid (2-hydroxy-phenyl-amide (4a , have been synthesized and characterized using melting points , IR spectra , 1H-NMR and 13C-NMR spectra. The antibacterial activity of synthesized compounds and streptomycin at concentractions of 1mg/ml, 3mg/ml and 5mg/ml , have been evaluated against three strains of bacterial culture; Staphylococcus aureus, E.coli and Klebsiella. The compounds show bacteriostatic and bactericidal activity.

  13. Syntheses of new 3-thiazolyl coumarin derivatives, in vitro α-glucosidase inhibitory activity, and molecular modeling studies.

    Science.gov (United States)

    Salar, Uzma; Taha, Muhammad; Khan, Khalid Mohammed; Ismail, Nor Hadiani; Imran, Syahrul; Perveen, Shahnaz; Gul, Sahib; Wadood, Abdul

    2016-10-21

    3-Thiazolylcoumarin derivatives 1-14 were synthesized via one-pot two step reactions, and screened for in vitro α-glucosidase inhibitory activity. All compounds showed inhibitory activity in the range of IC50 = 0.12 ± 0.01-16.20 ± 0.23 μM as compared to standard acarbose (IC50 = 38.25 ± 0.12 μM), and also found to be nontoxic. Molecular docking study was carried out in order to establish the structure-activity relationship (SAR) which demonstrated that electron rich centers at one and electron withdrawing centers at the other end of the molecules showed strong inhibitory activity. All the synthesized compounds were characterized by spectroscopic techniques such as EI-MS, HREI-MS, (1)H NMR and (13)C NMR. CHN analysis was also performed.

  14. A New and Efficient Method for the Synthesis of Novel 3-Acetyl Coumarins Oxadiazoles Derivatives with Expected Biological Activity

    Directory of Open Access Journals (Sweden)

    Abdullah Sulaiman Al-Ayed

    2014-01-01

    Full Text Available This paper presents the design of some novel 3-acetylcoumarin derivatives, based on minimal inhibitory concentration values (MICs previously obtained against some microorganism cultures, Gram positive and negative bacteria and fungi. Some of these molecules exhibited antibacterial activity against S. aureus, comparable to that of the standard used (impinem. The in vitro antioxidant activities of the novel 3-acetylcoumarin oxadiazoles were assayed by the quantitative 1,1-diphenyl-2-picrylhydrazyl (DPPH radical scavenging activity method. The compounds 5c,d proved to be the most active, showing the highest capacity to deplete the DPPH radicals. Structure elucidation of the products has been accomplished on the basis of IR, 1H-NMR, 13C-NMR, NOESY and HMBC NMR data.

  15. Determinação de cumarina em extrato fluido e tintura de guaco por espectrofotometria derivada de primeira ordem Determination of coumarin in fluid extract and tinture of "guaco" by first derivative spectrophotometry

    Directory of Open Access Journals (Sweden)

    Adriana de Carvalho Osório

    2004-12-01

    Full Text Available O objetivo do trabalho foi desenvolver um método de doseamento de cumarina (1,2-benzopirano em extrato fluido e tintura de guaco (Mikania glomerata Sprengel. O método desenvolvido foi por espectrofotometria derivada de primeira ordem, que se mostrou preciso, exato, reprodutível e de fácil execução.The objective of this work was to develop a method for coumarin(1,2-benzopyran dosage in fluid extract and tinture of "guaco" (Mikania glomerata Sprengel. First derivative spectrophotometry was developed and proved to be accurate, exact, reprodutive and of easy execution.

  16. Syntheses of Some 3-[1'( 1' H )-Substituent-pyrazol-5'-yl ] benzo [5,6] coumarins

    Institute of Scientific and Technical Information of China (English)

    EL-DEEN, Ibrahim Mohey; AL-WAKEEL, El-Sayed Ismail; El-MAWLA, Ahmed Gad

    2002-01-01

    3-[1' (1' H)-Substitueut-pyrazol-5'-yl] benzo [ 5, 6] coumarins and 3-(1' , 2 '-oxazol- 5 '- yl ) benzo [ 5 , 6 ] coumarin were prepared via condensation of 3-(2'-formyl-1'-chlorovinyl) benzo [ 5, 6]coumarin with hydrazine derivatives or hydroxylamine. Reaction of 3-[1' (1'H)-pyrazol-5'-yl] benzo[5, 6] coumarin with alkyl halides, olefinic compounds or acid chlorides are described.

  17. Computational and experimental evaluation of selective substitution of thiolated coumarin derivatives on gold nanoparticles: Surface enhancing Raman scattering and electrochemical studies

    Science.gov (United States)

    Mlambo, Mbuso; Harris, Richard A.; Mashazi, Philani; Sabela, Myalowenkosi; Kanchi, Suvardhan; Madikizela, Lawrence M.; Shumbula, Prince N.; Moloto, Nosipho; Hlatshwayo, Thulani T.; Mdluli, Phumlani S.

    2017-02-01

    Gold nanoparticles (AuNPs) of various sizes were prepared and treated with a mixture of HS-(CH2)11-NHCO-coumarin (act as Raman reporter) and HS-PEG-(CH2)11COOH (as co-stabilizer and also to attach biomarkers on activated sbnd COOH) to produce mixed monolayer protected clusters of gold (AuMMPCs). In this paper, we demonstrate the significance of the HS-(CH2)11-NHCO-coumarin concentration (percentage ratio) on the enhancement factor (EF), and the geometry of the adsorbed ligands on AuNPs of different sizes. The calculated EFs from Raman spectra reveal a significant decrease with an increase in AuNPs sizes. Molecular dynamics calculations were carried out to obtain the adsorption energies for different ratios of HS-PEG-(CH2)11COOH to HS-(CH2)11-NHCO-coumarin. It was found that molecules that adsorb strongly on the surface of the metal, underwent changes in their polarizability and consequently enhanced Raman intensities were observed, and this was in agreement with experimental data.

  18. Partitioning of π-electrons in rings of aza-derivatives of naphthalene

    Directory of Open Access Journals (Sweden)

    IVAN GUTMAN

    2007-07-01

    Full Text Available A recently proposed method for calculating the π-electron contents (EC of rings of heteroatom-containing polycyclic conjugated molecules was applied to the aza-derivatives of naphthalene. The main finding was that a nitrogen atom in position α (resp. β diminishes (resp. increases the EC-value of the respective ring. Such a regularity in the displacement of π-electrons can be (qualitatively rationali­zed by means of resonance-theoretical reasoning.

  19. Liquid Crystalline Thiadiazole Derivatives: Thiadiazole Derivatives Containing Pyridine Ring as Terminal Group

    Institute of Scientific and Technical Information of China (English)

    XU,Yah(徐艳); XU,Yan; ZHU,Zhi-Guo(朱志国)XU; ZHU,Zhi-Guo; XU,Zheng(徐正); XU,Zheng

    2001-01-01

    The synthesis and mesomorphic behavior of a new series of liquid crystals coutaining 1,3,4-thiadiazole and pyridine rings with-CH = N-central group are reported. All compounds ex hibit enantiotropic snectic A mesophase, but the Schiff' s base analogues hnve no mesomorphic behavior. The innuence of the pyridine ing and thiadiazole ring is discussed.

  20. Inhibitory Effect of Coumarin on Syntrophic Fatty Acid-Oxidizing and Methanogenic Cultures and Biogas Reactor Microbiomes.

    Science.gov (United States)

    Popp, Denny; Plugge, Caroline M; Kleinsteuber, Sabine; Harms, Hauke; Sträuber, Heike

    2017-07-01

    Coumarins are widely found in plants as natural constituents having antimicrobial activity. When considering plants that are rich in coumarins for biogas production, adverse effects on microorganisms driving the anaerobic digestion process are expected. Furthermore, coumarin derivatives, like warfarin, which are used as anticoagulating medicines, are found in wastewater, affecting its treatment. Coumarin, the structure common to all coumarins, inhibits the anaerobic digestion process. However, the details of this inhibition are still elusive. Here, we studied the impact of coumarin on acetogenesis and methanogenesis. First, coumarin was applied at four concentrations between 0.25 and 1 g · liter(-1) to pure cultures of the methanogens Methanosarcina barkeri and Methanospirillum hungatei, which resulted in up to 25% less methane production. Acetate production of syntrophic propionate- and butyrate-degrading cultures of Syntrophobacter fumaroxidans and Syntrophomonas wolfei was inhibited by 72% at a coumarin concentration of 1 g · liter(-1) Coumarin also inhibited acetogenesis and acetoclastic methanogenesis in a complex biogas reactor microbiome. When a coumarin-adapted microbiome was used, acetogenesis and methanogenesis were not inhibited. According to amplicon sequencing of bacterial 16S rRNA genes and mcrA genes, the communities of the two microbiomes were similar, although Methanoculleus was more abundant and Methanobacterium less abundant in the coumarin-adapted than in the nonadapted microbiome. Our results suggest that well-dosed feeding with coumarin-rich feedstocks to full-scale biogas reactors while keeping the coumarin concentrations below 0.5 g · liter(-1) will allow adaptation to coumarins by structural and functional community reorganization and coumarin degradation.IMPORTANCE Coumarins from natural and anthropogenic sources have an inhibitory impact on the anaerobic digestion process. Here, we studied in detail the adverse effects of the model

  1. Novel Synthesis of Hydrazide-Hydrazone Derivatives and Their Utilization in the Synthesis of Coumarin, Pyridine, Thiazole and Thiophene Derivatives with Antitumor Activity

    Directory of Open Access Journals (Sweden)

    Rafat M. Mohareb

    2010-12-01

    Full Text Available The reaction of cyanoacetyl hydrazine (1 with 3-acetylpyridine (2 gave the hydrazide-hydrazone derivative 3. The latter compound undergoes a series of heterocyclization reactions to give new heterocyclic compounds. The antitumor evaluation of the newly synthesized products against three cancer cell lines, namely breast adenocarcinoma (MCF-7, non-small cell lung cancer (NCI-H460 and CNS cancer (SF-268 was performed. Most of the synthesized compounds showed high inhibitory effects.

  2. Molecular origins of optoelectronic properties in coumarin dyes: toward designer solar cell and laser applications.

    Science.gov (United States)

    Liu, Xiaogang; Cole, Jacqueline M; Waddell, Paul G; Lin, Tze-Chia; Radia, Jignesh; Zeidler, Anita

    2012-01-12

    Coumarin derivatives are used in a wide range of applications, such as dye-sensitized solar cells (DSCs) and dye lasers, and have therefore attracted considerable research interest. In order to understand the molecular origins of their optoelectronic properties, molecular structures for 29 coumarin laser dyes are statistically analyzed. To this end, data for 25 compounds were taken from the Cambridge Structural Database and compared with data for four new crystal structures of coumarin laser dyes [Coumarin 487 (C(19)H(23)NO(2)), Coumarin 498 (C(16)H(17)NO(4)S), Coumarin 510 (C(20)H(18)N(2)O(2)), and Coumarin 525 (C(22)H(18)N(2)O(3))], which are reported herein. The competing contributions of different resonance states to the bond lengths of the 4- and 7-substituted coumarin laser dyes are computed based on the harmonic oscillator stabilization energy model. Consequently, a positive correlation between the contribution of the para-quinoidal resonance state and the UV-vis peak absorption wavelength of these coumarins is revealed. Furthermore, the perturbations of optoelectronic properties, owing to chemical substituents in these coumarin laser dyes, are analyzed: it is found that their UV-vis peak absorption and lasing wavelengths experience a red shift, as the electron-donating strength of the 7-position substituent increases and/or the electron-withdrawing strength of the 3- or 4-position substituent rises; this conclusion is corroborated by quantum-chemical calculations. It is also revealed that the closer the relevant substituents align with the direction of the intramolecular charge transfer (ICT), the larger the spectral shifts and the higher the molar extinction coefficients of coumarin laser dyes. These findings are important for understanding the ICT mechanism in coumarins. Meanwhile, all structure-property correlations revealed herein will enable knowledge-based molecular design of coumarins for dye lasers and DSC applications.

  3. Coumarin Push-Pull NLOphores with Red Emission: Solvatochromic and Theoretical Approach.

    Science.gov (United States)

    Lanke, Sandip K; Sekar, Nagaiyan

    2016-05-01

    A new class of red emitting extensively conjugated donor-π-acceptor type dyes bearing coumarin units are investigated for nonlinear optical properties. The photophysical behaviour and the relation between structure and properties of the coumarin "push-pull" derivatives were investigated based on solvatochromism and experimentally observed shifts in emission maxima. The electronic coupling for the electron transfer reaction for the coumarin dyes are calculated with the generalized Mulliken-Hush method. We evaluated non-linear optical (NLO) properties of coumarin dyes using both experimental solvent dependent shift method and computational method. All the investigated coumarin dyes are showing large value for first (β) and second hyperpolarizability (γ). Density functional theory [B3LYP/6-31G(d)] and time dependent density functional theory (TDDFT) computations have been employed to have more understanding of structural, molecular, electronic and photophysical parameters of the coumarin dyes.

  4. An Introductory Organic Chemistry Review Homework Exercise: Deriving Potential Mechanisms for Glucose Ring Opening in Mutarotation

    Science.gov (United States)

    Murdock, Margaret; Holman, R. W.; Slade, Tyler; Clark, Shelley L. D.; Rodnick, Kenneth J.

    2014-01-01

    A unique homework assignment has been designed as a review exercise to be implemented near the end of the one-year undergraduate organic chemistry sequence. Within the framework of the exercise, students derive potential mechanisms for glucose ring opening in the aqueous mutarotation process. In this endeavor, 21 general review principles are…

  5. Microwave Assisted Convenient One-Pot Synthesis of Coumarin Derivatives via Pechmann Condensation Catalyzed by FeF3 under Solvent-Free Conditions and Antimicrobial Activities of the Products

    Directory of Open Access Journals (Sweden)

    Vahid Vahabi

    2014-08-01

    Full Text Available A rapid and efficient solvent-free one-pot synthesis of coumarin derivatives by Pechmann condensation reactions of phenols with ethyl acetoacetate using FeF3 as a catalyst under microwave irradiation is described. This one-pot synthesis on a solid inorganic support provides the products in good yields. The newly synthesized compounds were systematically characterized by IR, 1H-NMR, 13C-NMR, MS and elemental CHN analyses. The proposed solvent-free microwave irradiation method using the environmentally friendly catalyst FeF3 offers the unique advantages of high yields, shorter reaction times, easy and quick isolation of the products, excellent chemoselectivity, and a one-pot, green synthesis. The products were screened for antimicrobial activity, and the results showed that the compounds reacted against all the tested bacteria.

  6. On prime and semiprime rings with generalized derivations and non-commutative Banach algebras

    Indian Academy of Sciences (India)

    MOHD ARIF RAZA; NADEEM UR REHMAN

    2016-08-01

    Let $R$ be a prime ring of characteristic different from 2 and $m$ a fixed positive integer. If $R$ admits a generalized derivation associated with a nonzero deviation $d$ such that $[F(x), d(y)]_m = [x, y]$ for all $x$, $y$ in some appropriate subset of $R$, then $R$ is commutative. Moreover, we also examine the case $R$ is a semiprime ring. Finally, we apply the above result to Banach algebras, and we obtain a non-commutative version of the Singer--Werner theorem.

  7. In utero exposure to coumarins and cognition at 8 to 14 years old

    NARCIS (Netherlands)

    van Driel, Dieneke; Wesseling, Judit; Sauer, Pieter J J; van der Veer, Eveline; Touwen, Bert C L; Smrkovsky, Mila

    2001-01-01

    Objective. To assess the cognitive abilities in school-aged children who have been exposed to coumarins in utero. Background. Coumarin derivatives are an effective option for anticoagulant therapy in pregnant women. However, case reports describe anomalies of the fetal central nervous system after i

  8. Microwave-assisted synthesis and antifungal activity of novel coumarin derivatives: Pyrano[3,2-c]chromene-2,5-diones.

    Science.gov (United States)

    Zhang, Rong-Rong; Liu, Jia; Zhang, Yu; Hou, Meng-Qing; Zhang, Ming-Zhi; Zhou, Fenger; Zhang, Wei-Hua

    2016-06-30

    A series of novel fused coumarin analogues pyrano[3,2-c]chromene-2,5-diones have been synthesized through an optimized microwave-assisted protocol. All target compounds were tested and evaluated for their antifungal activity against Botrytis cinerea, Colletotrichum copsica, Alternaria solani, Gibberella zeae and Rhizoctorzia solani. The bioassay results indicated that some of the compounds exhibited potent antifungal activities at concentration less than 50 ppm. For the compounds 5d, 6c and 7b, EC50 values against B. cinerea were as low as 0.141, 0.082 and 0.091 μM, respectively, which represents better antifungal activity than that of the commonly used fungicide Azoxystrobin. Compounds 5d (57%) and 6c (55%) also exhibited more effective control than Azoxystrobin (44%) against Colletotrichum capsica. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  9. RELATIONS OF DERIVATIVE ALGEBRA AND RING OF DIFFERENTIAL OPERATORS IN CHARACTERISTIC p>0

    Institute of Scientific and Technical Information of China (English)

    张江峰

    2002-01-01

    Let K be a field of characteristic p>0. We prove that the derivative algebra of K[x1,…,xn] is a proer subring of the ring of differential operators of K[x1,…,xn]. A concrete example is given to show that there is a differential operator of order p that does not belong to the derivative algebra. By these results, is follows that the derivative algebra is Morita equivalent to K[xp1,…,xpn], and hence its global homological dimension, Krull dimension, K0 group and some other properties are got.

  10. Climate variability of Late Pleistocene deglaciation in the North American midcontinent derived from tree rings

    Science.gov (United States)

    Panyushkina, Irina P.; Livina, Valerie N.; Leavitt, Steve W.; Mode, William N.

    2016-04-01

    High-resolution climatic proxies, such as tree rings spanning millennia, have excellent potential to describe high- and low-frequency variability of climate. In practice, however, although the number of Holocene millennium-length tree-ring records is still rather limited, they are especially rare for the Late Pleistocene warming period following the Last Glacial Maximum. Furthermore, detection of climatic variability in tree-ring data is hindered due to intricate methodology of chronology development that transforms changes in tree geometry and a variety of environmental responses of tree growth to a climatic signal. Following meticulous derivation of a new tree-ring chronology, we propose a novel approach to analyze annual, decadal, multi-decadal and centennial climate-related variability of floating tree rings dated back near the end of the Pleistocene. We have developed a 1400-year tree-ring width chronology of spruce from the Green Bay area (Wisconsin) dated from 14.5 ka to 13.1ka cal BP. This new North American midcontinent record is composed of 10 overlapped site chronologies and has two short gaps filled with linear interpolation. The Green Bay chronology covers most of the warm and moist Bølling-Allerød interstadial (14.7 ka -12.7 ka BP). Within the Bølling-Allerød interstadial, there were several abrupt and brief cooling excursions such as the Older Dryas with full-glacial-like temperature conditions. We have applied tipping point analysis to detect the changes of climate-system states during these turbulent times and obtained early warning signals in the tree-ring variance. The analysis detected four short-term bifurcations dated ca. 14,450 cal BP, 14,000 cal BP, 13,750-13,600 cal BP and 13,180-13,100 cal BP. The bifurcation events of the tree-ring record correspond well to the abrupt and short cooling temperature excursions of the Bølling-Allerød interstadial documented in δ18O and Ca of GRIP ice-core records, and the Laurentide ice sheet dynamics

  11. Current developments of coumarin compounds in medicinal chemistry.

    Science.gov (United States)

    Peng, Xin-Mei; Damu, Guri L V; Zhou, Cheng- He

    2013-01-01

    Coumarin compounds represent an important type of naturally occurring and synthetic oxygen-containing heterocycles with typical benzopyrone framework. This type of special benzopyrone structure enables its derivatives readily interact with a diversity of enzymes and receptors in organisms through weak bond interactions, thereby exhibit wide potentiality as medicinal drugs. So far, some coumarin-based drugs such as anticoagulant and antineurodegenerative agents have been extensively used in clinic. Coumarin-containing supramolecular medicinal agents as a new increasing expansion of supramolecular chemistry in pharmaceutical science have also been actively investigated in recent years. Coumarin-derived artificial ion receptors, fluorescent probes and biological stains are growing quickly and have a variety of potential applications in monitoring timely enzyme activity, complex biological events as well as accurate pharmacological and pharmacokinetic properties. This review provides a systematic summary and insight of the whole range of medicinal chemistry in the current developments of coumarin compounds as anticoagulant, antineurodegenerative, anticancer, antioxidative, antibacterial, antifungal, antiviral, antiparasitic, antiinflammatory and analgesic, antidiabetic, antidepressive and other bioactive agents as well as supramolecular medicinal drugs, diagnostic agents and pathologic probes, and biological stains. Some rational design strategies, structure-activity relationships and action mechanisms are discussed. The perspectives of the future development of coumarinbased medicinal chemistry are also presented.

  12. The antitumor effects of mitochondria-targeted 6-(nicotinamide methyl coumarin

    Directory of Open Access Journals (Sweden)

    Wang Huanan

    2016-01-01

    Full Text Available Cancer is the second leading cause of death worldwide. Traditional antitumor drugs exhibit severe cytotoxic and side effects. Lung cancer needs new and more effective treatment approaches. Coumarin derivatives can act on various tumor cells and show anti-proliferative activity through various mechanisms, including mitochondrial signaling cascades that regulate development and apoptosis of cells. Mitochondria-targeted coumarin derivatives have not been reported yet. Taking advantage of the fact that cancer cells frequently have higher mitochondria membrane potential, we synthesized a mitochondria-targeted 6-(nicotinamide methyl coumarin by coupling 6-methyl coumarin to nicotinamide. Our results demonstrate that 6-(nicotinamide methyl coumarin preferentially kills A549 cells through inducing A549 cells apoptosis, mediated by increasing ROS level and causing mitochondrial depolarization. Strikingly, the viability of the A31 cells treated with 6-(nicotinamide methyl coumarin did not decrease, indicating that 6-(nicotinamide methyl coumarin preferentially accumulates in A549 cells and A549 cells are much more susceptible to 6-(nicotinamide methyl coumarin treatment compared with A31 cells.

  13. A new unsymmetrical azine derivative based on coumarin group as dual-modal sensor for CN- and fluorescent "OFF-ON" for Zn2 +

    Science.gov (United States)

    Hu, Jing-Han; Sun, You; Qi, Jing; Li, Qiao; Wei, Tai-Bao

    2017-03-01

    A simple chemosensor YS based on coumarin group was designed and synthesized. Its structure was determined by single crystal X-ray diffraction analysis. In the presence of cyanide the sensor showed an immediate visible change in color from colorless to pale yellow by naked-eyes and produced a strong blue fluorescence rapidly in DMSO/H2O (3:7, v/v). The detection limit on fluorescence response of the sensor to CN- is down to 1.69 × 10- 7 M. In addition YS could show fluorescence turn-on response rapidly for Zn2 + over other metals ions such as Fe3 +, Hg2 +, Ag+, Ca2 +, Cu2 +, Co2 +, Ni2 +, Cd2 +, Pb2 +, Cr3 + and Mg2 + in aqueous solutions. Notably, this sensor served as a molecular switch, which was controlled by Zn2 + and EDTA cyclically. Test strips based on YS were fabricated, which could act as a convenient and efficient CN- and Zn2 + test kit. This chemosensor could achieve the detection of two ions, which need not depend on two different sensors.

  14. Semisynthesis and insecticidal activity of some fraxinellone derivatives modified in the B ring.

    Science.gov (United States)

    Guo, Yong; Qu, Huan; Zhi, Xiaoyan; Yu, Xiang; Yang, Chun; Xu, Hui

    2013-12-11

    A series of novel fraxinellone derivatives modified at the C-1 or C-8 position in the B ring were prepared as insecticidal agents against the pre-third-instar larvae of oriental armyworm, Mythimna separata Walker at 1 mg/mL. Five key steric configurations of compounds 2, 3, and 8f,g,j were further determined by single-crystal X-ray diffraction. It was found that the kinds and the amount of the reduction products of fraxinellone were related to the molar ratio between the reduction agent Red-Al and the substrate fraxinellone. Among all of the derivatives, compounds 2 and 8i,j,o displayed more promising insecticidal activity than their precursors fraxinellone and toosendanin. The preliminary structure-activity relationships revealed that the lactone (B-ring) of fraxinellone contributed to the observed insecticidal activity; the double bond at the C-2 position of fraxinellone was not necessary for the insecticidal activity; conversion of the oxygen atom of carbonyl group on the lactone of fraxinellone to a sulfur one does not improve the insecticidal activity; introduction of electron-withdrawing groups on the phenyl ring of 8f, to the benzoyloxy series, could result in more potent compounds.

  15. Synthesis of coumarin or ferrocene labeled nucleosides via Staudinger ligation

    Directory of Open Access Journals (Sweden)

    Kois Pavol

    2006-11-01

    Full Text Available Abstract Background Reaction of azides with triaryl phosphines under mild conditions gives iminophosphoranes which can react with almost any kind of electrophilic reagent, e.g. aldehydes/ketones to form imines or esters to form amides. This so-called Staudinger ligation has been employed in a wide range of applications as a general tool for bioconjugation including specific labeling of nucleic acids. Results A new approach for the preparation of labeled nucleosides via intermolecular Staudinger ligation is described. Reaction of azidonucleosides with triphenylphosphine lead to iminophosphorane intermediates, which react subsequently with derivatives of coumarin or ferrocene to form coumarin or ferrocene labeled nucleosides. Fluorescent properties of coumarin labeled nucleosides are determined. Conclusion New coumarin and ferrocene labeled nucleosides were prepared via intermolecular Staudinger ligation. This reaction joins the fluorescent coumarin and biospecific nucleoside to the new molecule with promising fluorescent and electrochemical properties. The isolated yields of products depend on the structure of azidonucleoside and carboxylic acids. A detailed study of the kinetics of the Staudinger ligation with nucleoside substrates is in progress.

  16. Regioselective Nucleophilic Ring Opening of Epoxides and Aziridines derived from Homoallylic Alcohols

    DEFF Research Database (Denmark)

    Tanner, David Ackland; Groth, Thomas

    1997-01-01

    The regioselectivity of nucleophilic ring opening of some 3,4-epoxy and 3,4-aziridino alcohols has been studied. The nucleophiles chosen were complex hydrides (LiAlH4, Red-Al and DIBAL) and Lipshutz- or Gilman-type organocuprate reagents. The C-4 substituent in the substrates was varied in order...... to study steric and electronic effects on the ring opening reactions. For alkyl substituents at C-4, most of the results can be explained on the basis of intramolecular delivery of the nucleophile to C-3 via a six-membered transition state, leading to 1,4-diols or 1,4-amino alcohol derivatives. In general...

  17. AIE Based Coumarin Chromophore - Evaluation and Correlation Between Solvatochromism and Solvent Polarity Parameters.

    Science.gov (United States)

    Lanke, Sandip K; Sekar, Nagaiyan

    2016-03-01

    A new class of red emitting extensively conjugated donor-π-acceptor type dyes bearing coumarin units have been synthesized by condensation of 7-(diethylamino)-2-oxo-2 H-chromene-3-carbaldehyde with different active methylenes. All the dyes are characterized by (1)H NMR, (13)C NMR and HRMS spectroscopy. The photophysical behaviour and the relation between structure and properties of the coumarin "push-pull" derivatives were investigated experimentally. The dyes exhibited positive solvatochromism and solvatofluorism in solution of varying polarity. These coumarin dyes show aggregation induced emission properties with red emitting fluorescence. They show absorption in the range of 501-528 and emission in the range of 547-630 nm. We evaluated photophysical properties of coumarin dyes using solvotochromism and solvent dependent shift in the emission wavelength. All the synthesized coumarin dyes COS1-COS4 are showing very good solvatochromic properties.

  18. Synthesis and characterization of tunable coumarin- linked glasses as new class of organic/inorganic phosphors

    Energy Technology Data Exchange (ETDEWEB)

    Luridiana, Alberto; Pretta, Gianluca; Secci, Francesco; Frongia, Angelo [Dipartimento di Scienze Chimiche e Geologiche, Università degli Studi di Cagliari, Complesso universitario di Monserrato, SS 554, bivio per Sestu, Monserrato (Canada) (Italy); Chiriu, Daniele; Carbonaro, Carlo Maria; Corpino, Riccardo [Dipartimento di Fisica, Università degli Studi di Cagliari, Complesso universitario di Monserrato, SS 554, bivio per Sestu, Monserrato (Canada) (Italy); Ricci, Pier Carlo, E-mail: carlo.ricci@dsf.unica.it [Dipartimento di Fisica, Universitá degli Studi di Cagliari, S.P. Monserrato-Sestu Km 0,700, 09042 Monserrato (Canada) (Italy)

    2014-10-21

    It is well known that stilbene with a trans conformation is highly fluorescent. From the viewpoint of molecular structure, coumarins bear a carbon-carbon double bond which is fixed as trans conformation as in trans-stilbene through a lactone structure. This can help to avoid the trans-cis transformation of the double bond under ultraviolet (UV) irradiation as observed in stilbene compounds and results in strong fluorescence and high fluorescence quantum yield and photostability in most of coumarin derivatives. Herein we report some preliminary results about the synthesis and spectroscopic characterization of tunable coumarins and the development of a new linkage protocol for the obtainment of monolayer coumarin-covalently linked glasses. The resulting organic/inorganic coumarin/silica based Self-Assembled Monolayer (SMA) film is proposed as new phosphors for the substituting of critical raw materials, like rare earths, in photonics applications.

  19. Synthesis and Sensing Applications of Fluorescent 3-Cinnamoyl Coumarins

    Science.gov (United States)

    Yadav, Preeti; Gill, Hardeep Singh; Chand, Karam; Li, Lian; Kumar, Jayant; Sharma, Sunil K.

    2015-01-01

    We have synthesized two novel fluorescent 3-(4-diethylaminocinnamoyl) coumarins that exhibit fluorescence quenching upon exposure to a nerve agent simulant, diethylchlorophosphate (DCP), providing a basis for rapid and sensitive DCP chemosensing. Furthermore, these coumarin derivatives display two-photon fluorescence upon illumination with near-infrared laser pulses and their two-photon (TP) absorption cross-section was evaluated. The potential for TP bio-imaging of these compounds was investigated by their cellular uptake in HeLa cells by TP confocal microscopy. PMID:26703600

  20. Synthesis and Sensing Applications of Fluorescent 3-Cinnamoyl Coumarins

    Directory of Open Access Journals (Sweden)

    Preeti Yadav

    2015-12-01

    Full Text Available We have synthesized two novel fluorescent 3-(4-diethylaminocinnamoyl coumarins that exhibit fluorescence quenching upon exposure to a nerve agent simulant, diethylchlorophosphate (DCP, providing a basis for rapid and sensitive DCP chemosensing. Furthermore, these coumarin derivatives display two-photon fluorescence upon illumination with near-infrared laser pulses and their two-photon (TP absorption cross-section was evaluated. The potential for TP bio-imaging of these compounds was investigated by their cellular uptake in HeLa cells by TP confocal microscopy.

  1. Coumarins of Matricaria chamomilla L.: aglycones and glycosides.

    Science.gov (United States)

    Petruľová-Poracká, Veronika; Repčák, Miroslav; Vilková, Mária; Imrich, Ján

    2013-11-01

    The identity and quantity of coumarin-like compounds in leaves and anthodia of Matricaria chamomilla L. were studied by LC-DAD and NMR. So far, two monosubstituted coumarins, herniarin and umbelliferone, and two herniarin precursors were identified therein. In this paper, two other coumarin glycosides and one aglycone were confirmed. Skimmin (umbelliferone-7-O-β-d-glucoside), daphnin (daphnetin-7-O-β-d-glucoside) and daphnetin (7,8-dihydroxycoumarin) were found for the first time in diploid and tetraploid leaves and anthodia of M. chamomilla L. Daphnetin is known as a strong sensitizer, so this compound and its glycosidic derivative can contribute to the allergic potential of chamomile. Commercial chamomile preparations were tested for their presence.

  2. Coumarin: A Privileged Scaffold for the Design and Development of Antineurodegenerative Agents.

    Science.gov (United States)

    Jameel, Ehtesham; Umar, Tarana; Kumar, Jitendra; Hoda, Nasimul

    2016-01-01

    Drug development for neurodegenerative diseases (NDs) is foremost task for the medicinal chemists in the 21st century. Coumarins are exemplary of an assorted and aptitudinally useful set of drugs. Coumarins play a momentous role in several pharmacological and medicinal aspects. Its analogues are anticipated to play a significant role in the development of new therapeutic leads for NDs. Their promising applications in the field of ND medication are exemplified by clinical candidates such as nodakenin that have been potent for demoting memory impairment. Apart from ND, clinically used anticoagulant warfarin, anticoagulant dicoumarol, and antibiotic coumermycin, novobiocin and chartesium grab the interest of researchers in coumarins. It would be worthwhile to look at the different biological processes that could cause neurodegeneration, thereby establishing a link with distinct coumarin derivatives to serve the purpose of medication. This review undertakes estimation of the wide spectrum of studies focusing coumarin to the domain of drug research for ND. Herein, we search for multitarget coumarin-based inhibitors and their scope for NDs. Future challenges in coumarin-based drug development have been discussed, and emphases have been laid on the future perspectives of coumarins as possible drugs in the future for the treatment of NDs.

  3. Mito-methyl coumarin, a novel mitochondria-targeted drug with great antitumor potential was synthesized.

    Science.gov (United States)

    Wang, Huanan; Xu, Wenqing

    2017-07-15

    Due to higher transmembrane potential of tumor cells, enhanced accumulation of cationic drugs in tumor mitochondria has been attributed to a higher (more negative inside) mitochondrial transmembrane potential compared with normal cells, emerging researchers are focus on developing mitochondria-targeted antitumor drugs. Coumarins showed great potential on antitumor, but mitochondria-targeted coumarin derivatives have not been reported. In the present study, we synthesized mitochondria-targeted-methyl coumarin (mito-methyl coumarin) through coupling 6-methyl coumarin to TPP. We confirmed that mito-methyl coumarin inhibited HeLa cells proliferation selectively, induced ROS generation, reduced mitochondrial membrane potential, promoted mitochondria Ca(2+) accumulation, decreased mitochondria mass and induced HeLa cells apoptosis, but methyl coumarin did not. These results demonstrate that we succeed in synthesizing a novel mitochondria-targeted drug, mito-methyl coumarin, which is effective in inhibiting HeLa cells proliferation and inducing HeLa cells apoptosis through promoting ROS generation and mitochondria Ca(2+) accumulation. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Compositions of Generalized Derivations in Prime Rings%素环中广义子的复合

    Institute of Scientific and Technical Information of China (English)

    马晶; 徐晓伟

    2008-01-01

    Let R be a prime ring with a non-central Lie ideal L.In the present paper we show that if the composition DG of two generalized derivations D and G is zero on L,then DG must be zero on R.And we get all the possibilities for the composition of a couple of generalized derivations to be zero on a non-central Lie ideal of a prime ring.

  5. Photoprotective effect of coumarin and 3-hydroxycoumarin in sea urchin gametes and embryonic cells.

    Science.gov (United States)

    de Araujo Leite, Jocelmo Cássio; de Castro, Tainá Myra Xavier; Barbosa-Filho, José Maria; de Siqueira-Junior, José Pinto; Marques-Santos, Luis Fernando

    2015-05-01

    Ultraviolet radiation B (UVB) represents 5% of all solar UV radiation and chronic exposure can induce harmful biological responses, including skin cancer. Prospection of new drugs with photoprotective properties and less toxic effects is constant and natural products have been the main options in this field. Coumarins are a group of natural phenolic compounds that shows several pharmacological activities. The aim of present work was to investigate the effect of coumarin and six derivatives in sea urchin gametes and zygotes exposed to UVB. Embryonic development assay was used to monitor UVB embryotoxicity. Firstly, we demonstrated that coumarin inhibited first embryonic cell division from 5 μM (EC50 = 52.9 μM) and its derivatives showed an embryotoxic effect ten times higher. Then, gametes or zygotes were treated with coumarin compounds before or after UVB exposure (UVB doses ranged from 0.056 to 0.9 kJm(-2)). Pretreatment of gametes or zygotes with coumarin or 3-hydroxycoumarin (1 μM, both) decreased UVB embryotoxic effect. Protective effect of the compounds was observed only when cells were treated previous to UVB exposure. Coumarin derivatives 4-hydroxycoumarin, 6-hydroxycoumarin, 7-hydroxycoumarin, 6,7-dihydroxycoumarin and 6-methoxy-7-hydroxycoumarin did not exhibit photoprotective activity. Our data provides evidences that coumarin and 3-hydroxycoumarin can be a promising class of photoprotective drugs.

  6. A Note on Derivations of Higher Order and Commutativity of Prime Rings

    Institute of Scientific and Technical Information of China (English)

    Tsai-Lien Wong

    2003-01-01

    One question posed by Chung and Luh is answered. Namely, let R be a prime ring with center Z and d a non-zero derivation of R. Suppose xdn - xam ∈ Z for all x ∈ R, where n > m are fixed non-negative integers. Then R is commutative if any one of the following conditions is satisfied: (I) m = 0;(ii) m = 1, n > 1 an even integer, and charR ≠ 2; (iii) m = 2, n > 2 an odd integer, and char R ≠ 2.

  7. Commutativity conditions on derivations and Lie ideals $\\sigma$-prime rings

    CERN Document Server

    Oukhtite, L; Taoufiq, L

    2009-01-01

    Let $R$ be a 2-torsion free $\\sigma$-prime ring, $U$ a nonzero square closed $\\sigma$-Lie ideal of $R$ and let $d$ be a derivation of $R$. In this paper it is shown that: 1) If $d$ is centralizing on $U$, then $d = 0$ or $U \\subseteq Z(R)$. 2) If either $d([x, y]) = 0$ for all $x, y \\in U$, or $[d(x), d(y)] = 0$ for all $x, y \\in U$ and $d$ commutes with $\\sigma$ on $U$, then $d = 0$ or $U \\subseteq Z(R)$.

  8. 21 CFR 189.130 - Coumarin.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Coumarin. 189.130 Section 189.130 Food and Drugs... Direct Addition or Use as Human Food § 189.130 Coumarin. (a) Coumarin is the chemical 1,2-benzopyrone... synthesized. It has been used as a flavoring compound. (b) Food containing any added coumarin as such or as...

  9. Coumarin-Containing Polymers for High Density Non-Linear Optical Data Storage

    Directory of Open Access Journals (Sweden)

    Denis Gindre

    2016-01-01

    Full Text Available Optical data storage was performed with various thin polymer films containing coumarin-based derivatives and by using femtosecond laser pulses as well as two-photon absorption processes. Exploring the photodimerization attribute of coumarin derivatives and using appropriate irradiation wavelengths, recording/erasing processes could be carried out in the same area. Second harmonic generation microscopy was used to read the stored information.

  10. 香豆素杯[4]芳烃的合成及其锌(Ⅱ)配合物的光谱%Synthesis of Coumarin- Calix[ 4 ] arene Derivative and Spectral Properties of Its Zn(Ⅱ) Complex

    Institute of Scientific and Technical Information of China (English)

    王飞; 张晓梅; 徐国财

    2011-01-01

    为探寻对过渡金属离子具有配合作用的新型超分子配体,将杯[4]芳烃经醚化、氨解得到的中间体3与香豆素-3-甲酰氯反应,合成了新的合香豆素片段的杯[4]芳烃配体H2L,用1 HNMR、13CNMR、IR、MS( Maldi - Tof)表征其结构.H2L与醋酸锌反应,获得了相应锌(Ⅱ)配合物(LZn),元素分析及MS( ESI)分析结果表明,LZn的化学组成为L(ZnAc)2·2H2O.研究了锌(Ⅱ)配合物的UV和IR吸收光谱性质,还测定了它的荧光强度.结果表明,与H2L相比,锌(Ⅱ)配合物分子中共轭体系增大且平面刚性增加.%In order to seek a new supramolecular ligand with the capacity for coordination to transition metal I-ons, a new calix[4]arene derivative H2L with coumarin sections was synthesized by the reaction of coumarin -3 -formyl chloride with intermediater 3 prepared by etherification firstly and then ammonolysis of calix[4]arene, and its structure was characterized by 1HNMR, 13C NMR, IR and MS (Maldi -Tof). Reacting H2L with zinc acetate could produce a Zn(II) complex (LZn) , and the chemical composition of LZn was L(ZnAc)2 · 2H2O determined by elementary analysis and MS (ESI). Using IR and UV, the absorption spectra of LZn were studied, and the fluorescence intensity was examined also. Results showed that conjugation system in LZn was enlarged and plane rigidity increased by comparison with those in H2L.

  11. Cytotoxic Coumarins from the Bark of Mammea siamensis.

    Science.gov (United States)

    Ngo, Ngoc Trang Nhu; Nguyen, Vy Thuy; Vo, Hoa Van; Vang, Ole; Duus, Fritz; Ho, Thuy-Duong Huynh; Pham, Hung Dinh; Nguyen, Lien-Hoa Dieu

    2010-11-01

    A new geranylated coumarin, (E)-4-(1-hydroxypropyl)-5,7-dihydroxy-6-(3,7-dimethyl-2,6-octadienyl)-8-(3-methyl-1-oxobutyl)coumarin (named surangin D), was isolated from the bark of Mammea siamensis collected in Vietnam, along with four known coumarins, surangins B and C, and theraphins B and C, and seven xanthones, 1,7-dihydroxyxanthone, 7-hydroxy-1-methoxyxanthone, 1,7-dimethoxyxanthone, 1,7-dimethoxy-6-hydroxyxanthone, 1,6,7-trihydroxyxanthone, 1,3,7-trihydroxyxanthone, and 1,7-dihydroxy-3-methoxyxanthone. Their structures were determined by spectroscopic methods (mainly 1D- and 2D-NMR) and preparation of methylated derivatives. The four coumarins, surangins C and D and theraphins B and C, were tested for inhibition of cell proliferation in DLD-1 (colon cancer), MCF-7 (breast adenocarcinoma), HeLa (human cervical cancer) and NCI-H460 (human lung cancer) cell lines using the sulforhodamine B (SRB) assay. In all four cell lines, theraphin C showed the strongest activity (IC₅₀ in the range of 1.6-5.7 µM). Testing the anti-proliferative effect of the methylated derivatives showed reduced cellular effects of all derivatives, indicating that the number and position of free hydroxyl groups were very important for the anti-proliferative effect.

  12. Synthesis of New Tricyclic and Tetracyclic Fused Coumarin Sulfonate Derivatives and Their Inhibitory Effects on LPS-Induced Nitric Oxide and PGE2 Productions in RAW 264.7 Macrophages: Part 2.

    Science.gov (United States)

    El-Gamal, Mohammed I; Lee, Woo-Seok; Shin, Ji-Sun; Oh, Chang-Hyun; Lee, Kyung-Tae; Choi, Jungseung; Myoung, Nohsun; Baek, Daejin

    2016-11-01

    The synthesis of a new series of 21 fused coumarin derivatives is described, and the biological evaluation of their in vitro antiinflammatory effects as inhibitors of lipopolysaccharide (LPS)-induced nitric oxide (NO) and prostaglandin E2 (PGE2 ) production in RAW 264.7 macrophages. The target compounds 1a-u were first tested for cytotoxicity to determine a non-toxic concentration for antiinflammatory screening, so that the inhibitory effects against NO and PGE2 production would not be caused by cytotoxicity. Compounds 1f and 1p were the most active PGE2 inhibitors with IC50 values of 0.89 and 0.95 µM, respectively. Western blot and cell-free COX-2 screening showed that their effects were due to inhibition of both COX-2 protein expression and COX-2 enzyme activity. Their IC50 values against the COX-2 enzyme were 0.67 and 0.85 µM, respectively, which is more potent than etoricoxib. The selectivity indexes of compounds 1f and 1p against COX-2 compared to COX-1 were 41.1 and 42.5, respectively. Compound 1f showed strong inhibitory effects at 5 µM concentration on COX-2 mRNA expression in LPS-induced RAW 264.7 macrophages. Moreover, the tricyclic compounds 1l and 1n as well as the tetracyclic analog 1u were the most potent NO inhibitors, with one-digit micromolar IC50 values. They showed dose-dependent inhibition of inducible nitric oxide synthase (iNOS) protein expression. The tetracyclic derivative 1u was the most potent inhibitor of NO production. It also exhibited a strong inhibitory effect on iNOS mRNA expression in LPS-induced RAW 264.7 macrophages.

  13. A new synthetic protocol for coumarin amino acid

    Directory of Open Access Journals (Sweden)

    Xinyi Xu

    2013-02-01

    Full Text Available The hydrochloride of the racemic amino acid (2-(7-hydroxycoumarin-4-ylethylglycine, which can serve as a fluorescent probe in proteins, and two halogen derivatives of it, were synthesized by using a new synthetic protocol in five steps. It is less costly and relatively easy to prepare this kind of fluorescent amino acid with the new synthetic method. Furthermore, it can be applied to synthesize other derivatives of the coumarin amino acid with some specific properties.

  14. A coumarin-specific prenyltransferase catalyzes the crucial biosynthetic reaction for furanocoumarin formation in parsley.

    Science.gov (United States)

    Karamat, Fazeelat; Olry, Alexandre; Munakata, Ryosuke; Koeduka, Takao; Sugiyama, Akifumi; Paris, Cedric; Hehn, Alain; Bourgaud, Frédéric; Yazaki, Kazufumi

    2014-02-01

    Furanocoumarins constitute a sub-family of coumarin compounds with important defense properties against pathogens and insects, as well as allelopathic functions in plants. Furanocoumarins are divided into two sub-groups according to the alignment of the furan ring with the lactone structure: linear psoralen and angular angelicin derivatives. Determination of furanocoumarin type is based on the prenylation position of the common precursor of all furanocoumarins, umbelliferone, at C6 or C8, which gives rise to the psoralen or angelicin derivatives, respectively. Here, we identified a membrane-bound prenyltransferase PcPT from parsley (Petroselinum crispum), and characterized the properties of the gene product. PcPT expression in various parsley tissues is increased by UV irradiation, with a concomitant increase in furanocoumarin production. This enzyme has strict substrate specificity towards umbelliferone and dimethylallyl diphosphate, and a strong preference for the C6 position of the prenylated product (demethylsuberosin), leading to linear furanocoumarins. The C8-prenylated derivative (osthenol) is also formed, but to a much lesser extent. The PcPT protein is targeted to the plastids in planta. Introduction of this PcPT into the coumarin-producing plant Ruta graveolens showed increased consumption of endogenous umbelliferone. Expression of PcPT and a 4-coumaroyl CoA 2'-hydroxylase gene in Nicotiana benthamiana, which does not produce furanocoumarins, resulted in formation of demethylsuberosin, indicating that furanocoumarin production may be reconstructed by a metabolic engineering approach. The results demonstrate that a single prenyltransferase, such as PcPT, opens the pathway to linear furanocoumarins in parsley, but may also catalyze the synthesis of osthenol, the first intermediate committed to the angular furanocoumarin pathway, in other plants.

  15. An alternative derivation of ring-polymer molecular dynamics transition-state theory

    CERN Document Server

    Hele, Timothy J H

    2016-01-01

    In a previous article [J. Chem. Phys. 138, 084108 (2013)], we showed that the transition-state-theory ($t\\rightarrow 0_+$) limit of ring-polymer molecular dynamics rate-theory (RPMD-TST) is also the $t\\rightarrow 0_+$ limit of a new type of quantum flux-side time-correlation function, in which the dividing surfaces are invariant to imaginary-time translation; in other words, that RPMD-TST is a $t\\rightarrow 0_+$ quantum transition-state theory (QTST). Recently, Jang and Voth [J. Chem. Phys. 144, 084110 (2016)] rederived this quantum $t\\rightarrow 0_+$ limit, and claimed that it gives instead the centroid-density approximation. Here we show that the $t\\rightarrow 0_+$ limit derived by Jang and Voth is in fact RPMD-TST.

  16. Synthesis and insecticidal activity of new deoxypodophyllotoxin derivatives modified in the D-ring.

    Science.gov (United States)

    Wang, Juanjuan; Yu, Xiang; Zhi, Xiaoyan; Xu, Hui

    2014-09-15

    In continuation of our program aimed at the discovery of new natural-product-based insecticidal agents, twenty-six deoxypodophyllotoxin derivatives modified in the D-ring were synthesized and evaluated as insecticidal agents against the pre-third-instar larvae of oriental armyworm, Mythimna separata (Walker) in vivo at 1 mg/mL. The configuration of three compounds 3, 4, and IIIi was unambiguously determined by single-crystal X-ray diffraction. It demonstrated that aminolysis of deoxypodophyllotoxin in the presence of pyrrolidine and piperidine could result in complete inversion of the configuration of the carbonyl group at its C-2 position. Five compounds IIa, IIi-k, and IIIh showed the equal or higher insecticidal activity than toosendanin. Especially IIj displayed the most potent insecticidal activity with the final mortality rate of 65.5%.

  17. Studies toward bivalent κ opioids derived from salvinorin A: heteromethylation of the furan ring reduces affinity

    Directory of Open Access Journals (Sweden)

    Thomas A. Munro

    2013-12-01

    Full Text Available The recent crystal structure of the κ-opioid receptor (κ-OR revealed, unexpectedly, that the antagonist JDTic is a bivalent ligand: in addition to the orthosteric pocket occupied by morphinans, JDTic also occupies a distinct (allotopic pocket. Mutagenesis data suggest that salvinorin A (1 also binds to this allotopic pocket, adjacent to the aspartate residue that anchors the basic nitrogen atom of classical opiates (Asp138. It has been suggested that an H-bond donor appended to 1 might interact with Asp138, increasing affinity. Such a bivalent ligand might also possess altered functional selectivity. Based on modeling and known N-furanylmethyl opioid antagonists, we appended H-bond donors to the furan ring of 1. (Dimethylaminomethyl groups at C-15 or C-16 abolished affinity for κ-OR. Hydroxymethylation at C-16 was tolerated, but 15,16-bis-hydroxymethylation was not. Since allosteric modulators may go undetected in binding assays, we also tested these and other low-affinity derivatives of 1 for allosteric modulation of dynorphin A in the [35S]GTPγS assay. No modulation was detected. As an alternative attachment point for bivalent derivatives, we prepared the 2-(hydroxyethoxymethyl ether, which retained high affinity for κ-OR. We discuss alternative design strategies for linked, fused or merged bivalent derivatives of 1.

  18. Studies toward bivalent κ opioids derived from salvinorin A: heteromethylation of the furan ring reduces affinity.

    Science.gov (United States)

    Munro, Thomas A; Xu, Wei; Ho, Douglas M; Liu-Chen, Lee-Yuan; Cohen, Bruce M

    2013-12-20

    The recent crystal structure of the κ-opioid receptor (κ-OR) revealed, unexpectedly, that the antagonist JDTic is a bivalent ligand: in addition to the orthosteric pocket occupied by morphinans, JDTic also occupies a distinct (allotopic) pocket. Mutagenesis data suggest that salvinorin A (1) also binds to this allotopic pocket, adjacent to the aspartate residue that anchors the basic nitrogen atom of classical opiates (Asp138). It has been suggested that an H-bond donor appended to 1 might interact with Asp138, increasing affinity. Such a bivalent ligand might also possess altered functional selectivity. Based on modeling and known N-furanylmethyl opioid antagonists, we appended H-bond donors to the furan ring of 1. (Dimethylamino)methyl groups at C-15 or C-16 abolished affinity for κ-OR. Hydroxymethylation at C-16 was tolerated, but 15,16-bis-hydroxymethylation was not. Since allosteric modulators may go undetected in binding assays, we also tested these and other low-affinity derivatives of 1 for allosteric modulation of dynorphin A in the [(35)S]GTPγS assay. No modulation was detected. As an alternative attachment point for bivalent derivatives, we prepared the 2-(hydroxyethoxy)methyl ether, which retained high affinity for κ-OR. We discuss alternative design strategies for linked, fused or merged bivalent derivatives of 1.

  19. Syntheses of cytotoxic novel arctigenin derivatives bearing halogen and alkyl groups on aromatic rings.

    Science.gov (United States)

    Yamauchi, Satoshi; Wukirsari, Tuti; Ochi, Yoshiaki; Nishiwaki, Hisashi; Nishi, Kosuke; Sugahara, Takuya; Akiyama, Koichi; Kishida, Taro

    2017-09-01

    The new lignano-9,9'-lactones (α,β-dibenzyl-γ-butyrolactone lignans), which showed the higher cytotoxicity than arctigenin, were synthesized. The well-known cytotoxic arctigenin showed activity against HL-60 cells (EC50=12μM), however, it was inactive against HeLa cells (EC50>100μM). The synthesized (3,4-dichloro, 2'-butoxy)-derivative 55 and (3,4-dichloro, 4'-butyl)-derivative 66 bearing the lignano-9,9'-lactone structures showed the EC50 values of 10μM and 9.4μM against HL-60 cells, respectively. Against HeLa cells, the EC50 value of the derivative 66 was 27μM. By comparing the activities with the corresponding 9,9'-epoxy structure (tetrahydrofuran compounds), the importance of the lactone structure of 55 and 66 for the higher activities was shown. The substituents on the aromatic ring of the lignano-9,9'-lactones affected the cytotoxicity level, observing more than 10-fold difference. Copyright © 2017. Published by Elsevier Ltd.

  20. Trypanocidal constituents in plants: 7. Mammea-type coumarins

    Directory of Open Access Journals (Sweden)

    Ricardo Reyes-Chilpa

    2008-08-01

    Full Text Available Calophyllum brasiliense and Mammea americana (Clusiaceae are two trees from the tropical rain forests of the American continent. A previous screening showed high trypanocidal activity in the extracts of these species. Several mammea-type coumarins, triterpenoids and biflavonoids were isolated from the leaves of C. brasiliense. Mammea A/AA was obtained from the fruit peels of M. americana. These compounds were tested in vitro against epimastigotes and trypomastigotes of Trypanosoma cruzi, the etiologic agent of Chagas disease. The most potent compounds were mammea A/BA, A/BB, A/AA, A/BD and B/BA, with MC100 values in the range of 15 to 90 g/ml. Coumarins with a cyclized ,-dimethylallyl substituent on C-6, such as mammea B/BA, cyclo F + B/BB cyclo F, and isomammeigin, showed MC100 values > 200 g/ml. Several active coumarins were also tested against normal human lymphocytes in vitro, which showed that mammea A/AA and A/BA were not toxic. Other compounds from C. brasiliense, such as the triterpenoids, friedelin, canophyllol, the biflavonoid amentoflavone, and protocatechuic and shikimic acids, were inactive against the epimastigotes. The isopropylidenedioxy derivative of shikimic acid was inactive, and its structure was confirmed by X-ray diffraction. Our results suggest that mammea-type coumarins could be a valuable source of trypanocidal compounds.

  1. 香豆素衍生物荧光探针的合成及性能研究%The study of synthesis and properties of coumarin derivative fluorescence probe

    Institute of Scientific and Technical Information of China (English)

    张权; 陈文生; 褚洪潮

    2013-01-01

    以香豆素衍生物为基本原料合成了一种新型荧光分子探针TK.通过研究荧光分子探针TK在中性缓冲溶液中对金属离子的识别性能.结果显示,TK可以选择性荧光猝灭识别Cu2+、Fe3+.TK与Fe3+络合后,TK在351nm处的荧光峰强度发生猝灭,猝灭幅度为31%;与Cu2络合后,TK在474nm的荧光峰强度几乎完全猝灭,猝灭幅度达97%.经定量分析显示,TK与Cu2+形成了1∶1型络合物.通过金属离子竞争实验表明,常见的金属离子均不干扰TK对Cu2+的检测.%TK,a new fluorescence molecular probe was synthesized through coumarin derivatives which were regarded as the basic raw materials.The recognition performance of TK for metal ions was studied in the neutral buffer solution.The results showed that TK can recognize Cu2+ and Fe3+ selectively with fluorescence quenching.After synthesis with Fe3+,the fluorescence intensity of TK at 351 nm was quenched of 31% ; after synthesis with Cu2 +,the fluorescence intensity at 474 nm was almost completely quenched,the quenching rate reached 97%.The quantitative analysis showed that TK formed a 1∶1 coordination compound with Cu2+ The competitive experiments of metal ions showed that the detection of TK for Cu2+ was not disturbed by common metal ions.

  2. New Psychoactive Substances: Chemistry, Pharmacology, Metabolism, and Detectability of Amphetamine Derivatives With Modified Ring Systems.

    Science.gov (United States)

    Welter-Luedeke, Jessica; Maurer, Hans H

    2016-02-01

    In recent years, new amphetamine derivatives with modified ring systems were sold and consumed as new drugs of abuse. They belong together with other new drugs of abuse classes to the so-called new psychoactive substances (NPS). The chemistry, pharmacology, toxicology, metabolism, and toxicokinetics are shortly discussed of camfetamine, 3 methylphenyl-amphetamines (2-MA, 3-MA, and 4-MA), 2-methiopropamine (2-MPA), and 5-(2-aminopropyl)benzofuran (5-APB), 6-(2-aminopropyl)benzofuran (6-APB, so-called "benzofury") and their N-methyl derivatives 5-MAPB and 6-MAPB. Only a rough assessment of the pharmacology and toxicology NPS can be performed in most cases using published data of analogs, trip reports, and described clinical cases. Accordingly, they all act more or less as central nervous stimulants mainly by increasing the concentration of the neurotransmitters noradrenaline, dopamine, and serotonin (5-HT) by inducing their release and reuptake inhibition. Thus, the acute toxicity is associated with the sympathomimetic effects, such as mydriasis, hyperthermia, hypertension, tachycardia, insomnia, and anxiety. With the exception of 5- and 6-APB, these NPS were extensively metabolized by N-demethylation and/or aromatic hydroxylation catalyzed by various cytochrome P450 isoenzymes followed by partial glucuronidation and/or sulfation. For urinalysis, the unchanged drugs and/or the nor-metabolites are the main targets.

  3. Cytotoxic activity of a synthetic deoxypodophyllotoxin derivative with an opened D-ring.

    Science.gov (United States)

    Chen, Chuan; Wang, Cui-Cui; Wang, Zhong; Geng, Wen-Yue; Xu, Hui; Song, Xiao-Mei; Luo, Du-Qiang

    2016-05-01

    Podophyllotoxin and its synthetic derivatives are valuable medicinal agents that have antitumor, insecticidal, and antifungal properties. We previously synthesized a deoxypodophyllotoxin derivative with an opened D-ring (DPD) exhibiting potent insecticidal activity. This article was firstly performed to identify the cytotoxicity of DPD toward human cancer cell lines (SGC7901, HeLa, and A549) and normal cell line (HEK293T) using MTT assay. DPD showed potent cytotoxicity against human cancer lines (HeLa and A549) and less cytotoxicity against normal cell lines HEK293T. DPD could also induce the cell cycle arrest at G2/M phase in HeLa cells and significantly increase the phosphorylation (Tyr 15) of CDC2 leading to inactivation of CDC2. The effects of DPD on cellular microtubule networks were detected using immunofluorescence technique in HeLa cells. The immunofluorescence results showed DPD influenced the arrangement and organization of cellular microtubule networks in HeLa cells. Microtubules are long, hollow cylinders made up of polymerized tubulin dimers. Total microtubules were separated after DPD treatment. Western blot results showed that the free polymerized tubulin dimers were obviously increased after DPD treatment. DPD may be a good drug candidate with the therapeutic potential to human cancer by affecting microtubule polymerization.

  4. Evaluation of Halogenated Coumarins for Antimosquito Properties

    Directory of Open Access Journals (Sweden)

    Venugopala K. Narayanaswamy

    2014-01-01

    Full Text Available Mosquitoes are the major vectors of parasites and pathogens affecting humans and domestic animals. The widespread development of insecticide resistance and negative environmental effects of most synthetic compounds support an interest in finding and developing alternative products against mosquitoes. Natural coumarins and synthetic coumarin analogues are known for their several pharmacological properties, including being insecticidal. In the present study halogenated coumarins (3-mono/dibromo acetyl, 6-halogenated coumarin analogues were screened for larvicidal, adulticidal, and repellent properties against Anopheles arabiensis, a zoophilic mosquito that is one of the dominant vectors of malaria in Africa. Five compounds exerted 100% larval mortality within 24 h of exposure. All coumarins and halogenated coumarins reversibly knocked down adult mosquitoes but did not kill them after 24 h of exposure. Repellent properties could not be evidenced. Five compounds were considered potential larvicidal agents for further research and development, while adulticidal activity was considered only mild to moderate.

  5. Light-Induced Reversible Self-Assembly of Gold Nanoparticles Surface-Immobilized with Coumarin Ligands.

    Science.gov (United States)

    He, Huibin; Feng, Miao; Chen, Qidi; Zhang, Xinqi; Zhan, Hongbing

    2016-01-18

    A novel light-induced reversible self-assembly (LIRSA) system is based on the reversible photodimerization and photocleavage of coumarin groups on the surface of gold nanoparticles (AuNPs) in THF solution. Facilitated by coumarin groups, light irradiation at 365 nm triggers the stable assembly of monodisperse AuNPs; the resulting self-assembly system can be disassembled back to the disassembled state by a relatively short exposure to benign UV light. The reversible self-assembly cycle can be repeated 4 times. A specific concentration range of coumarin ligand and the THF solvent were identified to be the two predominant factors that contribute to the LIRSA of AuNPs. This is the first successful application of reversible photodimerization based on a coumarin derivative in the field of AuNP LIRSA. This LIRSA system may provide unique opportunities for the photoregulated synthesis of many adjustable nanostructures and devices.

  6. Synthesis of 4H-chromene, coumarin, 12H-chromeno[2,3-d]pyrimidine derivatives and some of their antimicrobial and cytotoxicity activities.

    Science.gov (United States)

    Sabry, Nermien M; Mohamed, Hany M; Khattab, Essam Shawky A E H; Motlaq, Shymaa S; El-Agrody, Ahmed M

    2011-02-01

    Condensation of 3-N,N-diethylaminophenol (1) with α-cyanocinnamonitriles (2a-c) and ethyl α-cyanocinnamates (2d-f) provided compounds 3a-f and 4a-c. 12H-Chromeno[2,3-d]pyrimidine derivatives 6, 11-13 and 16 were obtained by treatment of 4H-chromene compounds (3) with different electrophiles followed by nucleophilic reagents. Structures of these compounds were established on the basis of IR, UV, 1H NMR, 13C NMR and MS data. Some of the new compounds were evaluated for antimicrobial and cytotoxicity activities. Copyright © 2010 Elsevier Masson SAS. All rights reserved.

  7. Synthesis, biological evaluation and molecular docking of novel chalcone-coumarin hybrids as anticancer and antimalarial agents.

    Science.gov (United States)

    Pingaew, Ratchanok; Saekee, Amporn; Mandi, Prasit; Nantasenamat, Chanin; Prachayasittikul, Supaluk; Ruchirawat, Somsak; Prachayasittikul, Virapong

    2014-10-06

    A new series of chalcone-coumarin derivatives (9-19) linked by the 1,2,3-triazole ring were synthesized through the azide/alkyne dipolar cycloaddition. Hybrid molecules were evaluated for their cytotoxic activity against four cancer cell lines (e.g., HuCCA-1, HepG2, A549 and MOLT-3) and antimalarial activity toward Plasmodium falciparum. Most of the synthesized hybrids, except for analogs 10 and 16, displayed cytotoxicity against MOLT-3 cell line without affecting normal cells. Analogs (10, 11, 16 and 18) exhibited higher inhibitory efficacy than the control drug, etoposide, in HepG2 cells. Significantly, the high cytotoxic potency of the hybrid 11 was shown to be non-toxic to normal cells. Interestingly, the chalcone-coumarin 18 was the most potent antimalarial compound affording IC50 value of 1.60 μM. Molecular docking suggested that the cytotoxicity of reported hybrids could be possibly due to their dual inhibition of α- and β-tubulins at GTP and colchicine binding sites, respectively. Furthermore, falcipain-2 was identified to be a plausible target site of the hybrids given their antimalarial potency.

  8. Binding of coumarins to human serum albumin. Study by equilibrium dialysis; Union de cumarinas a seroalbumina humana. Estudio por dialisis en el equilibrio

    Energy Technology Data Exchange (ETDEWEB)

    Zaton Lopez, A.M.L.; Ferrer Lopez, J.M. [Departamento de Bioquimica y Biologia Molecular, Universidad del Pais Vasco, Facultad de Farmacia, Vitoria (Spain)

    1995-12-31

    In order to find the typical structure of ligands that could displace the binding of warfarin on human serum albumin, the binding parameters of several coumarin derivatives have been compared. Warfarin, hydroxy coumarin, coumarin, acetyl coumarin and chromanol, bind to two different sites on seroalbumin. In the primary binding site, the affinity for the 4-hydroxyl compounds (4-chromanol, warfarin and 4-hidroxycoumarin) are larger than for coumarin and 3-acetyl coumarin. this high-affinity binding site, warfarin binding site, is the region in which the specific binding of warfarin and 4-hydroxybenzopyrans occurs. the 4-chromanol is the smallest ligand which binds to seroalbumin with high-affinity, and its structure is typical in ligands which specifically bind to the warfarin binding site. (Author) 23 refs.

  9. Effect and their mechanism of action of copper(Ⅱ) complexes with coumarin derivatives on lung cancer in vivo and vitro%香豆素缩氨基酸型曼尼西碱香豆素类铜药物体内外抗肺癌增殖及其作用机制

    Institute of Scientific and Technical Information of China (English)

    朱涛峰; 陈如华; 杨宏峰; 冯艳; 陆勤; 虞浩; 陈建强

    2013-01-01

    Objective To investigate effect of the copper (Ⅰ) complexes with coumarin derivatives (coumarin-copper drugs) on lung cancer cell (A549 cell line) in vivo and vitro and its mechanism of action.Methods A549 cells were treated with different concentrations of the coumarin-copper drugs,MTT assay was performed to determine cell ratio.Cell apoptosis was detected by Annexin V/PI flow cytometry.Western blot was performed to evaluate the protein expression of caspase-3.The subcutaneous transplantable tumor model of A549 cell in nude mice was established.The nude mice in each group received corresponding treated.The growth curves of the tumor were drawn and the tumor growth inhibition rates were calculated.The apoptosis index of subcutaneously transplanted tumor cells was served by TUNEL.Results Coumarin-copper drugs effectively inhibited the proliferation of A549 in a dose-and-time dependent manner,and the IC50 was 2.0 μmol/L.Coumarin-copper drugs could induce the apoptosis of A549 cells in a dose dependent way (P < 0.05),which was accompany with upregulation of caspase-3.Coumarin copper drugs effectively inhibited the growth of A549 tumor in a dose dependent manner,kept company with the apoptosis index of A549 tumor (P <0.05).Conclusions Coumarin copper drugs may inhibit the proliferation of A549 cells through inducing cell apoptosis,which should be related to the up-regulation of caspase-3.%目的 研究香豆素缩氨基酸型曼尼西碱金属香豆素类铜药物(简称香豆素类铜药物)在体内外抗肺腺癌A549细胞的生物学活性.方法 不同浓度香豆素类铜药物干预A549细胞,用MTT法、Annexin V/PI及Western blot进行检测体外抗肺癌活性.建立A549荷瘤裸鼠模型后,经过香豆素类铜药物的干预,绘制肿瘤生长曲线并计算肿瘤干预的抑瘤率,通过TUNEL法检测体内肿瘤细胞凋亡.结果 香豆素类铜药物以浓度时间依赖性方式有效地抑制A549细胞增殖,抑制A549细胞活力的IC50为2

  10. An Engel Condition with Derivation for Multilinear Polynomials in Prime Rings

    Institute of Scientific and Technical Information of China (English)

    Vincenzo De Filippis; Onofrio Mario Di Vincenzo

    2002-01-01

    Let R be a prime algebra without non-zero nil right ideals over a commutative ring K, f(x1,..., xn) a multilinear polynomial in n variables over K, and d a non-zero derivation of R such that for any r1,..., rn ∈ R, there exists k = k(r1, ... ,rn)≥1 such that [d(f(r1,...,rn)),f(r1,... ,rn)]k = 0. If char(R)= 0, then f(x1,..., xn) is a polynomial central-valued on R. If char(R) = p > 2and f(x1,..., xn) is not a polynomial identity in p × p matrices of characteristic p, then R satisfies Sn+2(x1,... ,xn+2), and for any r1,... ,rn ∈ R, there exists t = t(r1,...,rn) ≥1 such that fpt (r1,...,rn) ∈ Z(R). Moreover, if Z(R) is finite, then f(x1,...., xn) is central-valued on R.

  11. Preparation and Antimicrobial Activity of s-Triazine Hydrazones of 7-Hydroxy Coumarin and Their Metal Complexes

    Directory of Open Access Journals (Sweden)

    G. R. Jani

    2009-01-01

    Full Text Available Metal complexes of 7-hydroxy coumarin hydrazone of s-triazine derivatives derived from 7-hydroxy-8-aceto-N-(4',6’-dichloro-1',3',5'-s-triazine coumarin hydrazone and transition metals have been synthesized and screened for their antibacterial, antifungal and antiseptic activity. The geometry of the complexes has been proposed. The ligand system co-ordinates with the metal ion in a bidentate manner through the nitrogen atom of hydrazone group.

  12. Generalized Derivations of Formal Triangular Matrix Rings%形式三角矩阵环的广义导子

    Institute of Scientific and Technical Information of China (English)

    谢乐平

    2011-01-01

    利用代数方法,得到了形式三角矩阵环Tri(A,M,B)的广义导子可以由环A,B的广义导子和(A,B)-双模M的广义拟线性映射表示的结论,同时由此结论推得形式三角矩阵环Tri(A,M,B)的导子的结构.%Generalized derivations of the formal triangular matrix ring Tri(A, M, B) are obtained by generalized derivations of A,B and a generalized fitting-linear mapping of M by using algebraic method. Using this result, the structure form of the derivations of the formal triangular'matrix ring Tri(A, M, B) is obtained.

  13. Three cases of ring chromosome 2, one derived from a paternal 2/6 translocation.

    Science.gov (United States)

    Maraschio, P; Danesino, C; Garau, A; Saputo, V; Vigi, V; Volpato, S

    1979-04-27

    Two cases of primary ring chromosome 2 and one case of a ring secondary to a paternal 2/6 translocation are described and compared with a fourth case of ring 2 from the literature. The breakpoints in two cases are identical and the same as the breakpoint on chromosome 2 in the composite 2/6 ring. The three primary rings have a number of symptoms in common, but other cases are needed to identify a possible deletion syndrome. The levels of the enzyme MDH-1 were within the normal range in Cases 1 and 2. Thus we localised the locus for MDH-1 to segment 2p23 leads to p25; this had previously been localised to segment p23 leads to pter.

  14. Coumarin Based Neutral Sensor for Biologically Important Anions

    Institute of Scientific and Technical Information of China (English)

    SHAO Jie

    2011-01-01

    A coumarin Shiff-base derivative,salicylaldehyde-N-(6-phenylazo-coumarin-3-formyl)-hydrazone(1),was obtained by simple organic synthesis from cheap and commercially available starting materials.Sensor 1 exhibits a very weak fluorescence emission,however,in the presence of acetate ions “turn-on” fluorescence is observed,which results from binding-induced conformational restriction of the fluorophore.Importantly,sensor 1 can also be used as colorimetric chemosensor for the anions with strong basicity,which is easily observed from yellow to red by naked eyes.Consequently,compound l can behave as a colorimetric and fluorescence sensor for biologically important F,CH3COO and H2PO4- in the presence of the other anions tested such as Cl-,Br- and I- in dimethyl sulfoxide(DMSO).

  15. Synthesis of 2-azetidinones substituted coumarin derivative

    Directory of Open Access Journals (Sweden)

    Jha Mukesh S.

    2012-01-01

    Full Text Available α-Naphthol is converted into 4-methylbenzo[h]chromen-2-one by reacting with ethyl acetoacetate in the presence of bismuth trichloride which is then oxidized to 2-oxo-2H-benzo[h]chromene-4-carbaldehyde and then condensed with aromatic primary amines to give Schiff bases (3a-3d. These Schiff bases are then reacted with acid chlorides in the presence of base in toluene to give 1, 3, 4-substituted 2-azetidinones.

  16. Vasorelaxing activity of two coumarins from Murraya paniculata leaves.

    Science.gov (United States)

    Cuong, Nguyen Manh; Khanh, Pham Ngoc; Duc, Ho Viet; Huong, Tran Thu; Tai, Bui Huu; Binh, Nguyen Quoc; Durante, Miriam; Fusi, Fabio

    2014-01-01

    In the search for novel chemical scaffolds leading to potential antihypertensive agents, the methanol extract of Murraya paniculata leaves was assessed for its effects on isolated rat aorta rings. The vasorelaxing effect of the chloroform fraction of the methanol plant extract was the most potent for its vasorelaxing activity on rat aorta rings contracted by 60 mM K(+) (K60). Two coumarins were isolated from the chloroform fraction: the novel kimcuongin (1) and the known murracarpin (2). Their structures were determined from spectroscopic evidences including (1)H- and (13)C-NMR, correlation spectroscopy (COSY), nuclear Overhauser effect spectroscopy (NOESY), heteronuclear multiple bond correlation (HMBC), heteronuclear single quantum correlation (HSQC), and high resolution mass spectrometry (HR-MS). Kimcuongin and, to a lesser extent, murracarpin, showed vasorelaxing activity with IC50 values of 37.7 µM and 139.3 µM, respectively. The coumarins kimcuongin and murracarpin may thus represent a novel class of vasodilators of natural source.

  17. Synthesis and Fluorescence Properties of Coumarin Glycosides and Triazoylglycosides

    Institute of Scientific and Technical Information of China (English)

    WU Zheng; FU Xin-ling; YANG Nan; WANG Qiu-an

    2013-01-01

    Four coumarin glycosides(1-4) and four coumarin triazoylglycosides(5-8) were synthesized by phase transfer catalytic glycosylation and copper-catalyzed azide-alkyne cycloaddition(CuAAC) respectively from 4-methyl-7-hydroxyl coumarin(4-methylumbelliferone).The structures were characterized by 1H NMR,MS or IR.The fluorescent properties of the coumarin glycosides and triazoylglycosides were studied in different solvents and compared to those of 4-methyl-7-hydroxyl coumarin.

  18. Sesquiterpene coumarins from Ferula fukanensis and their pro-inflammatory cytokine gene expression inhibitory effects.

    Science.gov (United States)

    Motai, Tsunetake; Daikonya, Akihiro; Kitanaka, Susumu

    2013-01-01

    Six new sesquiterpene coumarin derivatives, fukanefuromarin H-M (1-6), were isolated from an 80% aqueous methanol extract of the roots of Ferula fukanensis. The structures were elucidated on the basis of spectroscopic evidence, particularly heteronuclear multiple-bond connectivity (HMBC) and high-resolution MS. The sesquiterpene coumarin derivatives inhibited nitric oxide (NO) and inducible NO synthase (iNOS), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) gene expression in a murine macrophage-like cell line (RAW264.7), which was activated by lipopolysaccharide (LPS) and recombinant mouse interferon-γ (IFN-γ).

  19. A facile synthetic route to diazepinone derivatives via ring closing metathesis and its application for human cytidine deaminase inhibitors.

    Science.gov (United States)

    Kim, Minkyoung; Gajulapati, Kondaji; Kim, Chorong; Jung, Hwa Young; Goo, Jail; Lee, Kyeong; Kaur, Navneet; Kang, Hyo Jin; Chung, Sang J; Choi, Yongseok

    2012-12-04

    A variety of diazepinone derivatives were prepared from α-amino acids and amino alcohols by a new synthetic methodology based on ring closing metathesis as a key step. The diazepinones were coupled with ribose derivatives to afford novel diazepinone nucleosides. Among them, (4R)-1-ribosyl-4-methyl-3,4-dihydro-1H-1,3-diazepin-2(7H)-one (3) showed a potent inhibitory effect (K(i) = 145.97 ± 4.87 nM) against human cytidine deaminase.

  20. Ring Cleavage Reactions of Methyl α-D-Allopyranoside Derivatives with Phenylboron Dichloride and Triethylsilane

    Directory of Open Access Journals (Sweden)

    Yuusuke Ito

    2011-12-01

    Full Text Available In the course of our studies on the regioselective carbon-oxygen bond cleavage of the benzylidene acetal group of hexopyranosides with a reducing agent, we found that a combination of a Lewis acid and a reducing agent triggered a ring-opening reaction of the pyranose ring of methyl α-D-allopyranosides. The formation of an acyclic boronate ester by the attachment of a hydride ion at C-1 indicated that the unexpected endocyclic cleavage of the bond between the anomeric carbon atom and the pyranose ring oxygen atom proceeded via an oxacarbenium ion intermediate produced by the chelation between O5/O6 of the pyranoside and the Lewis acid, followed by nucleophile substitution with a hydride ion at C1.

  1. 含叔胺结构高光响应性香豆素衍生物的设计合成%Design and Synthesis of Highly Photo-Crosslinkable Coumarin Derivatives Containing Aromatic Tertiary Amine

    Institute of Scientific and Technical Information of China (English)

    江金强; 代鹏; 宗奕吾; 刘晓亚; 张胜文; 陈明清

    2009-01-01

    以环氧氯丙烷为桥接,将具有较强给电子能力的芳叔胺(ATA)结构引入香豆素衍生物C分子中,通过芳叔胺结构的光化学促进作用加速香豆素基元的光二聚反应.用紫外(UV)和荧光(FL)光谱等手段对该香豆素衍生物进行表征.结果表明,芳叔胺结构的引入可有效增强香豆素基元在260-400 nm之间的吸收.紫外点光源光二聚反应实验表明,芳叔胺结构的引入使香豆素基元的光响应性能得以大幅增强,在相同光照条件下,其在匀速反应区间内对光照时间的依赖性的斜率高达6.47,光二聚反应程度达到80%时所需光照时间仅为29 s.%Using epichlorohydrin as bridged unit, the aromatic tertiary amine (ATA) was introduced to prepare the highly photo-crosslinkable coumarin compound C and to accelerate the photo-dimerization of coumarin unit. Ultraviolet (UV) and fluorescence (FL) spectra were used to evaluate the coumarin C. It was found that the introduced ATA could enhance the absorption between 260-400 nm. The spot UV irradiation experiments showed that, after being bridged with ATA, the coumarin C would gain a highly photo-dimerization with a high slope of 6.47 in the uniform photo-reaction, and a short time of 29 s to gain 80% photo-dimerization.

  2. Synthesis of 1H-Indol-3-ylpyrazole Derivatives from 1,3,5-Triketones and Arylhydrazines: One-Pot Construction of Pyrazole and Indole Rings

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sung Hwan; Kim, Se Hee; Kim, Ko Hoon; Kim, Jae Nyoung [Chonnam National Univ., Gwangju (Korea, Republic of); Lee, Sang Ku [Immune Modulator Research Center, Daejeon (Korea, Republic of)

    2013-11-15

    The reaction of 1,3,5-triketones and arylhydrazines provided indolylpyrazole derivatives in a one-pot reaction in good to moderate yields. Both the pyrazole and indole rings were constructed simultaneously with phenylhydrazine, RCOCH{sub 2}CO- moiety for the pyrazole and the remaining -CH{sub 2}COR part for the indole ring.

  3. Synthesis and Cytotoxicity of Derivatives of Fluorouracil Conjugated with Three-membered Ring

    Institute of Scientific and Technical Information of China (English)

    WANG, Le; ZHANG, Yunxiao; TAO, Jingchao

    2009-01-01

    A novel series of 3-membered ring fluorouracil conjugates including cyclopropylmethyl fluorouracil and (2,3- epoxypropyl) fluorouracil conjugates were synthesized via selective protection, and their structures were confirmed by IR, 1H NMR and HRMS. Cytotoxicities in vitro of these conjugates were evaluated. Compounds 7, 8, 12 and 13 have shown cytotoxicities against Ec9706 cells in different degrees.

  4. Synthesis and Biological Evaluation of Novel Benzimidazole Derivatives Bearing a Heterocyclic Ring at 4/5 Position

    Energy Technology Data Exchange (ETDEWEB)

    Wubulikasimu, Reyila; Yang, Yanbing; Xue, Fei; Luo, Xianjin; Shao, Dongping [Shanghai Jiaotong Univ., Shanghai (China); Li, Yuhuan; Gao, Rongmei [Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing (China); Ye, Weidong [Zhejiang Medicine Co. Ltd., Zhejiang (China)

    2013-08-15

    A series of novel benzimidazole derivatives bearing a heterocyclic ring as oxadiazole (21-32), thiadiazole (33-34), triazole (35-36) were synthesized and evaluated for their activities against Coxsackie virus B3 and B6 in Vero cells. Compounds 21-26, 31-36 with moieties of 2'-pyridyl, 3'-pyridyl and 4'-pyridyl at the 2-position and oxadiazoles, thiadiazole, or triazole substituent at the 4- or 5-position generally displayed activities against CVB3 and CVB6. Especially compound 24 (IC{sub 50} = 1.08 μg/mL, SI = 61.7 against CVB3) was the promising candidate as lead compound for anti-enteroviral drug. It was observed in the incorporation of heterocyclic rings in benzimidazole at the 5-position could enhance their biological activities.

  5. Biologically active sesquiterpene coumarins from Ferula species.

    Science.gov (United States)

    Nazari, Zeinab Esmail; Iranshahi, Mehrdad

    2011-03-01

    Extracts from different species of the genus Ferula (Apiaceae) have had various biomedical applications for many centuries. Many biological features of this genus such as cytotoxicity, antibacterial, antiviral, P-glycoprotein (P-gp) inhibitory and antiinflammatory activity have been attributed to sesquiterpene coumarins; structures containing a common coumarin group and a sesquiterpene moiety. This both highlights the importance of sesquiterpene coumarins as biologically active natural products and necessitates further studies on these compounds. Taking into account the versatile biological properties of compounds isolated from Ferula and the unprecedented interest in the application of natural products as a new generation of therapeutics, the present review will discuss reports on biological activities of sesquiterpene coumarins of the genus Ferula, from 1990 onwards.

  6. Optical properties of coumarins containing copolymers

    Science.gov (United States)

    Skowronski, L.; Krupka, O.; Smokal, V.; Grabowski, A.; Naparty, M.; Derkowska-Zielinska, B.

    2015-09-01

    We investigate the optical properties such as absorption coefficient, refractive index, real and imaginary parts of dielectric function and energy band gap of coumarin-containing copolymers thin films by means of spectroscopic ellipsometry (SE) combined with transmittance measurements (T) and atomic force microscopy (AFM). We found that the optical properties of coumarin-containing copolymers strongly depend from length of alkyl spacer as well as the type of substitution in coumarin moiety. In our case the refractive index as well as the energy band gap of coumarin-containing copolymer decrease with increase the length of alkyl spacer. Additionally, the lengthening of the alkyl spacer brings the bathochromic shifts of the absorption spectra towards longer wavelengths.

  7. Effect of five-membered ring and heteroatom substitution on charge transport properties of perylene discotic derivatives: A theoretical approach

    Science.gov (United States)

    Navarro, Amparo; Fernández-Liencres, M. Paz; Peña-Ruiz, Tomás; García, Gregorio; Granadino-Roldán, José M.; Fernández-Gómez, Manuel

    2016-08-01

    Density functional theory calculations were carried out to investigate the evolvement of charge transport properties of a set of new discotic systems as a function of ring and heteroatom (B, Si, S, and Se) substitution on the basic structure of perylene. The replacement of six-membered rings by five-membered rings in the reference compound has shown a prominent effect on the electron reorganization energy that decreases ˜0.2 eV from perylene to the new carbon five-membered ring derivative. Heteroatom substitution with boron also revealed to lower the LUMO energy level and increase the electron affinity, therefore lowering the electron injection barrier compared to perylene. Since the rate of the charge transfer between two molecules in columnar discotic systems is strongly dependent on the orientation of the stacked cores, the total energy and transfer integral of a dimer as a disc is rotated with respect to the other along the stacking axis have been predicted. Aimed at obtaining a more realistic approach to the bulk structure, the molecular geometry of clusters made up of five discs was fully optimized, and charge transfer rate and mobilities were estimated for charge transport along a one dimensional pathway. Heteroatom substitution with selenium yields electron transfer integral values ˜0.3 eV with a relative disc orientation of 25°, which is the preferred angle according to the dimer energy profile. All the results indicate that the tetraselenium-substituted derivative, not synthetized so far, could be a promising candidate among those studied in this work for the fabrication of n-type semiconductors based on columnar discotic liquid crystals materials.

  8. Compound list: coumarin [Open TG-GATEs

    Lifescience Database Archive (English)

    Full Text Available coumarin CMA 00027 ftp://ftp.biosciencedbc.jp/archive/open-tggates/LATEST/Human/in_vitro/coum...arin.Human.in_vitro.Liver.zip ftp://ftp.biosciencedbc.jp/archive/open-tggates/LATEST/Rat/in_vitro/coum...arin.Rat.in_vitro.Liver.zip ftp://ftp.biosciencedbc.jp/archive/open-tggates/LATEST/Rat/in_vivo/Liver/Single/coum...-tggates/LATEST/Rat/in_vivo/Liver/Repeat/coumarin.Rat.in_vivo.Liver.Repeat.zip ...

  9. Sesquiterpene coumarins from seeds of Ferula sinkiangensis.

    Science.gov (United States)

    Li, Guangzhi; Li, Xiaojin; Cao, Li; Zhang, Lijing; Shen, Liangang; Zhu, Jun; Wang, Junchi; Si, Jianyong

    2015-06-01

    A new sesquiterpene coumarin with a novel sesquiterpene carbon framework, Sinkiangenorin D, and ten known sesquiterpene coumarins were isolated from the seeds of Ferula sinkiangensis. The structures of these compounds, including the relative stereochemistry, were elucidated on the basis of spectroscopic data. All of the isolated compounds were tested against the AGS, HeLa, and K562 human cancer cell lines and showed cytotoxic activities with 50% inhibitory concentration values between 12.7 and 226.6 μM.

  10. Corrosion Inhibition of Imidazoline Derivates with Benzene Rings on Mild Steel in CO2-Saturated Brine Solution

    Institute of Scientific and Technical Information of China (English)

    CHEN Guo-hao; ZHAO Jing-mao

    2012-01-01

    Corrosion inhibition of three imidazoline derivates with different numbers of benzcne rings,namely 2-phenyl-1-ethylamino imidazoline(CI-1),2-phcnyl-1-ethylamino-1-methylbenzyl quaternary imidazoline(CI-12) and 2-phcnyl-1-bcnzoyl ethylamino imidazoline(CI-13),on mild steel in CO2-saturated brine solution was evaluated by mass-loss method and potentiodynamic polarization method.The results show that the three imidazoline derivates can inhibit CO2 corrosion effectively with CI-12 ranking the highest.They mainly restrain the anodic dissolution and act as anodic-type inhibitors.The adsorptions of these derivates on the mild steel surface follow the Langmuir adsorption isothermal equation and belong to chemical adsorption.

  11. Coumarin or benzoxazinone based novel carbonic anhydrase inhibitors: synthesis, molecular docking and anticonvulsant studies.

    Science.gov (United States)

    Karataş, Mert Olgun; Uslu, Harun; Sarı, Suat; Alagöz, Mehmet Abdullah; Karakurt, Arzu; Alıcı, Bülent; Bilen, Cigdem; Yavuz, Emre; Gencer, Nahit; Arslan, Oktay

    2016-10-01

    Among many others, coumarin derivatives are known to show human carbonic anhydrase (hCA) inhibitory activity. Since hCA inhibition is one of the underlying mechanisms that account for the activities of some antiepileptic drugs (AEDs), hCA inhibitors are expected to have anti-seizure properties. There are also several studies reporting compounds with an imidazole and/or benzimidazole moiety which exert these pharmacological properties. In this study, we prepared fifteen novel coumarin-bearing imidazolium and benzimidazolium chloride, nine novel benzoxazinone-bearing imidazolium and benzimidazolium chloride derivatives and evaluated their hCA inhibitory activities and along with fourteen previously synthesized derivatives we scanned their anticonvulsant effects. As all compounds inhibited purified hCA isoforms I and II, some of them also proved protective against Maximal electroshock seizure (MES) and ScMet induced seizures in mice. Molecular docking studies with selected coumarin derivatives have revealed that these compounds bind to the active pocket of the enzyme in a similar fashion to that previously described for coumarin derivatives.

  12. Rings, chains and helices: new antimicrobial silver coordination compounds with (iso-)nicotinic acid derivatives.

    Science.gov (United States)

    Chevrier, Inès; Sagué, Jorge L; Brunetto, Priscilla S; Khanna, Nina; Rajacic, Zarko; Fromm, Katharina M

    2013-01-07

    Complexes with silver ions have great potential for applications in medicine. Appropriate bidentate ligands, binding to silver ions, are able to generate coordination polymers as well as molecular entities as a function of ligand flexibility, conformation and length. Here we present the continuation of our previous studies in this field with ligands based on oligomers of polyethylene glycol, functionalized at both ends with either nicotinic or isonicotinic acid. The structures of three ligands and nine new coordination compounds are presented. A large variety of structures are obtained as a function of counterion, solvent and ligand-to-metal ratio, such as isolated rings, offset stacked rings, parallel chains and entangled chains, and their antimicrobial properties as well as biocompatibility are assessed.

  13. Immobilising effect of Ruta graveolens L. on human spermatozoa: coumarin compounds are involved.

    Science.gov (United States)

    Naghibi Harat, Z; Lakpour, N; Sadeghipoor, H R; Kamalinejad, M; Eshraghian, M R; Naghibi, B; Akhondi, M M; Binaafar, S; Sadeghi, M R

    2015-12-01

    This study was designed to find out Ruta graveolens L. functional components, which have immobilisation effect on human spermatozoa for contraceptive use. A five-step fractionation method was used to derive different components from rue aqueous extract by using hexane, chloroform, ethanol, acetone and ultrapure water. Gas chromatography-mass spectrophotometery (GC-MS) of all fractions and the aqueous extract were performed to determine the chemical components. The immobilisation assay and membrane integrity test were also performed with four different coumarins, which were found in GC-MS in a concentration of 10 μm. Hexane, chloroform, acetone and ethanol fractions could significantly decrease motility of sperms within the first and the second hours. Hexane fraction had also significant immediate effect. The aqueous fraction had no effect on sperm motility. Meanwhile, GC-MS revealed that aqueous extract and effective fractions had similar coumarin compounds. We performed the immobilisation assay on four different coumarins, which were found in GC-MS in a concentration of 10 μm. Reduction of sperm motility was only significant for xanthotoxin. In the sperm viability and membrane integrity tests, hexane and ethanolic fractions could impair sperm vitality significantly, in contrast to coumarins. These results indicated that a part of immobilising effect of rue could be due to its coumarins. The possible mechanism could be blocking of spermatozoa potassium channels.

  14. Partitioning of p-electrons in rings of diaza-derivatives of acenes

    Directory of Open Access Journals (Sweden)

    SONJA STANKOVIC

    2008-05-01

    Full Text Available A few years ago, a method was proposed for assessing the p-electron content (EC of rings in heteroatom-containing benzenoid molecules. In this work, the effect of two nitrogen atoms at the opposite sides of a linear benzenoid molecule on the partitioning of its p-electrons was investigated. The results obtained can be explained by means of resonance-theoretical arguments.

  15. The use of Full Earth Rotation Vector Derived from Ring Laser Data

    Science.gov (United States)

    Hugentobler, Urs; Schreiber, Ulrich; Panafidina, Natascha; Gebauer, André

    2017-04-01

    Current active ring laser technology demonstrates the capability to measure variations of the rotation of the Earth. The large ring laser gyroscope "G" at the Geodetic Observatory Wettzell, Germany, shows a stability which allows the measurement of the wobble of the Earth axis. Earth rotation currently is determined routinely in the framework of the International Earth Rotation and Reference Systems Service (IERS) using space geodetic techniques such as Global Navigation Satellite Systems (GNSS), Satellite Laser Ranging (SLR), and Very Long Baseline Interferometry (VLBI). These techniques measure the rotation of the Earth kinematically by determining the motion of ground stations with respect to space objects, i.e., based on a technique also called "stellar compass". Ring laser gyroscopes on the other hand measure Earth rotation locally based on the observation of inertial accelerations, i.e., based on a technique also called "inertial compass". The fundamentally different measurement principles complement each other. It is, e.g., well known that forced polar motion, the so called Oppolzer terms, are not observable by space geodetic techniques due to strong correlation with the motion of the Earth axis in space. For the same reason the determination of subdaily Earth rotation parameters with space geodetic techniques is prone to strong systematic errors while exact knowledge of such terms is relevant, e.g., to determine high quality orbits of GNSS satellites. This presentation shall highlight the potential of the ring laser technology as additional sensor for monitoring Earth rotation, in particular with the upcoming capability to measure the full Earth rotation vector.

  16. Biocatalytic resolution of benzyl glycidyl ether and its derivates by Talaromyces flavus: effect of phenyl ring substituents on enantioselectivity.

    Science.gov (United States)

    Wei, Chun; Chen, Yunyun; Shen, Honglei; Wang, Shan; Chen, Lin; Zhu, Qing

    2012-08-01

    Talaromyces flavus containing a constitutive epoxide hydrolase (EH) resolved racemic benzyl glycidyl ether and nine derivatives into their (R)-enantiomers. After optimization of the fermentation conditions, the specific EH activity and biomass concentration were improved from 13.5 U/g DCW and 14.8 g DCW/l to 26.2 U/g DCW and 31.3 g DCW/l, respectively, with final values for e.e. ( s ) of 96 % and E of 13 with (R)-benzyl glycidyl ether. Substituents on the phenyl ring, however, gave low enantioselectivities.

  17. Synthesis and Structure-Activity Relationships of Imidazole-Coumarin Conjugates against Hepatitis C Virus

    Directory of Open Access Journals (Sweden)

    Shwu-Chen Tsay

    2016-02-01

    Full Text Available A series of new conjugated compounds with a –SCH2– linkage were synthesized by chemical methods from imidazole and coumarin derivatives. The experimental results indicate that of the twenty newly synthesized imidazole–coumarin conjugates, three of them exhibited appealing EC50 values (5.1–8.4 μM and selective indices >20 against hepatitis C virus. Their potency and selectivity were increased substantially by modification of their structure with two factors: imidazole nucleus with a hydrogen atom at the N(1 position and coumarin nucleus with a substituent, such as Cl, F, Br, Me, and OMe. These guidelines provide valuable information for further development of conjugated compounds as anti-viral agents.

  18. Synthesis and Structure-Activity Relationships of Imidazole-Coumarin Conjugates against Hepatitis C Virus.

    Science.gov (United States)

    Tsay, Shwu-Chen; Lin, Shu-Yu; Huang, Wen-Chieh; Hsu, Ming-Hua; Hwang, Kuo Chu; Lin, Chun-Cheng; Horng, Jia-Cherng; Chen, I-Chia; Hwu, Jih Ru; Shieh, Fa-Kuen; Leyssen, Pieter; Neyts, Johan

    2016-02-18

    A series of new conjugated compounds with a -SCH₂- linkage were synthesized by chemical methods from imidazole and coumarin derivatives. The experimental results indicate that of the twenty newly synthesized imidazole-coumarin conjugates, three of them exhibited appealing EC50 values (5.1-8.4 μM) and selective indices >20 against hepatitis C virus. Their potency and selectivity were increased substantially by modification of their structure with two factors: imidazole nucleus with a hydrogen atom at the N(1) position and coumarin nucleus with a substituent, such as Cl, F, Br, Me, and OMe. These guidelines provide valuable information for further development of conjugated compounds as anti-viral agents.

  19. Quantitative structure-toxicity relationship study of some natural and synthetic coumarins using retention parameters

    Directory of Open Access Journals (Sweden)

    Rabtti El Hadi M.A.

    2012-01-01

    Full Text Available Four lipophilicity descriptors (RM0, b, C0, PC1 for twelve coumarine derivatives were determined by reversed-phase thin-layer chromatography in order to analyze which descriptor best describes the lipophilicity of coumarines investigated. Moreover, possible chemical toxicity of coumarins, expressed as the probability of a compound to cause organ-specific health effects, was calculated using ACD/Tox Suite program. The quantitative relationships between toxicity and molecular descriptors, including experimentally determined lipophilicity descriptors obtained in current study, were investigated using partial least square regression. The best models were obtained for kidney and liver health effects. Quantitative structure-toxicity relationship models revealed the importance of electric polarization descriptors, size descriptors and lipophilicity descriptors. Obtained models were used for the selection of the structural features of the compounds that are significantly affecting their absorption, distribution, metabolism, excretion, and toxicity. [Acknowledgements. This work has been supported by the Ministry of Education and Science of Serbia, Grant 172017.

  20. Current developments of coumarin-based anti-cancer agents in medicinal chemistry.

    Science.gov (United States)

    Emami, Saeed; Dadashpour, Sakineh

    2015-09-18

    Cancer is one of the leading health hazards and the prominent cause of death in the world. A number of anticancer agents are currently in clinical practice and used for treatment of various kinds of cancers. There is no doubt that the existing arsenal of anticancer agents is insufficient due to the high incidence of side effects and multidrug resistance. In the efforts to develop suitable anticancer drugs, medicinal chemists have focused on coumarin derivatives. Coumarin is a naturally occurring compound and a versatile synthetic scaffold possessing wide spectrum of biological effects including potential anticancer activity. This review article covers the current developments of coumarin-based anticancer agents and also discusses the structure-activity relationship of the most potent compounds.

  1. Pharmacogenetic-guided dosing of coumarin anticoagulants : Algorithms for warfarin, acenocoumarol and phenprocoumon

    NARCIS (Netherlands)

    Verhoef, Talitha I.; Redekop, William K.; Daly, Ann K.; Van Schie, Rianne M F; De Boer, Anthonius; Maitland-Van Der Zee, Anke Hilse

    2014-01-01

    Coumarin derivatives, such as warfarin, acenocoumarol and phenprocoumon are frequently prescribed oral anticoagulants to treat and prevent thromboembolism. Because there is a large inter-individual and intra-individual variability in dose-response and a small therapeutic window, treatment with couma

  2. Oxalic acid catalyzed solvent-free one pot synthesis of coumarins

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Oxalic acid was found to be an efficient catalyst for Pechmann condensation, which includes the reaction between phenols and β-keto esters leading to formation of coumarin derivatives. The advantages of present methods are the use of cheap and easy available catalyst, solvent-free reaction conditions, better yields and shorter reaction time.

  3. The Relation between Hepatotoxicity and the Total Coumarin Intake from Traditional Japanese Medicines Containing Cinnamon Bark.

    Science.gov (United States)

    Iwata, Naohiro; Kainuma, Mosaburo; Kobayashi, Daisuke; Kubota, Toshio; Sugawara, Naoko; Uchida, Aiko; Ozono, Sahoko; Yamamuro, Yuki; Furusyo, Norihiro; Ueda, Koso; Tahara, Eiichi; Shimazoe, Takao

    2016-01-01

    Cinnamon bark is commonly used in traditional Japanese herbal medicines (Kampo medicines). The coumarin contained in cinnamon is known to be hepatotoxic, and a tolerable daily intake (TDI) of 0.1 mg/kg/day, has been quantified and used in Europe to insure safety. Risk assessments for hepatotoxicity by the cinnamon contained in foods have been reported. However, no such assessment of cinnamon bark has been reported and the coumarin content of Kampo medicines derived from cinnamon bark is not yet known. To assess the risk for hepatotoxicity by Kampo medicines, we evaluated the daily coumarin intake of patients who were prescribed Kampo medicines and investigated the relation between hepatotoxicity and the coumarin intake. The clinical data of 129 outpatients (18 male and 111 female, median age 58 years) who had been prescribed keishibukuryogankayokuinin (TJ-125) between April 2008 and March 2013 was retrospectively investigated. Concurrent Kampo medicines and liver function were also surveyed. In addition to TJ-125, the patients took some of the other 32 Kampo preparations and 22 decoctions that include cinnamon bark. The coumarin content of these Kampo medicines was determined by high performance liquid chromatography (HPLC). TJ-125 had the highest daily content of coumarin (5.63 mg/day), calculated from the daily cinnamon bark dosage reported in the information leaflet inserted in each package of Kampo medicine. The coumarin content in 1g cinnamon bark decoction was 3.0 mg. The daily coumarin intake of the patients was 0.113 (0.049-0.541) mg/kg/day, with 98 patients (76.0%) exceeding the TDI. Twenty-three patients had an abnormal change in liver function test value, but no significant difference was found in the incidence of abnormal change between the group consuming less than the TDI value (6/31, 19.4%) and the group consuming equal to or greater than the TDI value (17/98, 17.3%). In addition, no abnormal change related to cinnamon bark was found for individual

  4. The Relation between Hepatotoxicity and the Total Coumarin Intake from Traditional Japanese Medicines Containing Cinnamon Bark

    Science.gov (United States)

    Iwata, Naohiro; Kainuma, Mosaburo; Kobayashi, Daisuke; Kubota, Toshio; Sugawara, Naoko; Uchida, Aiko; Ozono, Sahoko; Yamamuro, Yuki; Furusyo, Norihiro; Ueda, Koso; Tahara, Eiichi; Shimazoe, Takao

    2016-01-01

    Cinnamon bark is commonly used in traditional Japanese herbal medicines (Kampo medicines). The coumarin contained in cinnamon is known to be hepatotoxic, and a tolerable daily intake (TDI) of 0.1 mg/kg/day, has been quantified and used in Europe to insure safety. Risk assessments for hepatotoxicity by the cinnamon contained in foods have been reported. However, no such assessment of cinnamon bark has been reported and the coumarin content of Kampo medicines derived from cinnamon bark is not yet known. To assess the risk for hepatotoxicity by Kampo medicines, we evaluated the daily coumarin intake of patients who were prescribed Kampo medicines and investigated the relation between hepatotoxicity and the coumarin intake. The clinical data of 129 outpatients (18 male and 111 female, median age 58 years) who had been prescribed keishibukuryogankayokuinin (TJ-125) between April 2008 and March 2013 was retrospectively investigated. Concurrent Kampo medicines and liver function were also surveyed. In addition to TJ-125, the patients took some of the other 32 Kampo preparations and 22 decoctions that include cinnamon bark. The coumarin content of these Kampo medicines was determined by high performance liquid chromatography (HPLC). TJ-125 had the highest daily content of coumarin (5.63 mg/day), calculated from the daily cinnamon bark dosage reported in the information leaflet inserted in each package of Kampo medicine. The coumarin content in 1g cinnamon bark decoction was 3.0 mg. The daily coumarin intake of the patients was 0.113 (0.049–0.541) mg/kg/day, with 98 patients (76.0%) exceeding the TDI. Twenty-three patients had an abnormal change in liver function test value, but no significant difference was found in the incidence of abnormal change between the group consuming less than the TDI value (6/31, 19.4%) and the group consuming equal to or greater than the TDI value (17/98, 17.3%). In addition, no abnormal change related to cinnamon bark was found for individual

  5. Synoptic-scale circulation patterns during summer derived from tree rings in mid-latitude Asia

    Science.gov (United States)

    Seim, Andrea; Schultz, Johannes A.; Leland, Caroline; Davi, Nicole; Byambasuren, Oyunsanaa; Liang, Eryuan; Wang, Xiaochun; Beck, Christoph; Linderholm, Hans W.; Pederson, Neil

    2016-11-01

    Understanding past and recent climate and atmospheric circulation variability is vital for regions that are affected by climate extremes. In mid-latitude Asia, however, the synoptic climatology is complex and not yet fully understood. The aim of this study was to investigate dominant synoptic-scale circulation patterns during the summer season using a multi-species tree-ring width (TRW) network comprising 78 sites from mid-latitude Asia. For each TRW chronology, we calculated an atmospheric circulation tree-ring index (ACTI), based on 1000 hPa geopotential height data, to directly link tree growth to 13 summertime weather types and their associated local climate conditions for the period 1871-1993. Using the ACTI, three groups of similarly responding tree-ring sites can be associated with distinct large-scale atmospheric circulation patterns: 1. growth of drought sensitive trees is positively affected by a cyclone over northern Russia; 2. temperature sensitive trees show positive associations to a cyclone over northwestern Russia and an anticyclone over Mongolia; 3. trees at two high elevation sites show positive relations to a zonal cyclone extending from mid-latitude Eurasia to the West Pacific. The identified synoptic-scale circulation patterns showed spatiotemporal variability in their intensity and position, causing temporally varying climate conditions in mid-latitude Asia. Our results highlight that for regions with less pronounced atmospheric action centers during summer such as the occurrence of large-scale cyclones and anticyclones, synoptic-scale circulation patterns can be extracted and linked to the Northern Hemisphere circulation system. Thus, we provide a new and solid envelope for climate studies covering the past to the future.

  6. The Synthesis of a Series of Phosphoryl Coumarins

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    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.

  7. SCREENING OF SYNTHETIC NEW HETEROCYCLIC DERIVATIVES OF 3- FORMYL-4-HYDROXYCOUMARIN FOR ANTI-INFLAMMATORY ACTIVITY IN ALBINO RATS

    OpenAIRE

    RAZI AHMAD, MOHAMMAD ASAD ZEBA N SIDDIQUI, ANIL KUMAR

    2013-01-01

    Coumarins have multiple biological activities; various coumarin-related derivatives arerecognized as inhibitors of the lipoxygenase and cycloxygenase pathways of arachidonatemetabolism. Several natural or synthetic coumarins with various hydroxyl and other substituteswere found to inhibit lipid peroxidation and to scavenge hydroxyl radical and superoxide anionand to influence processes involving free radical mediated injury. The heterocyclic derivatives of3-formyl-4-hydoxycoumarin were found ...

  8. [Microcirculatory consequences of a venous striction in the rat. Effect of a coumarine-rutine association].

    Science.gov (United States)

    Laemmel, E; Stücker, O; Pons, C; Duverger, J P; Dedieu, F; Leutenegger, E

    1998-06-01

    The aim of this study was to investigate the consequences of a venous striction on capillary red blood cell distribution and venular blood return and the effect of a coumarin derivative-rutoside combination. The study was conducted, in vivo, in the rat cremaster muscle using intravital microscopy. The striction lasted thirty minutes and was obtained by clamping the epigastric vein. This mechanical constraint was sufficient to induce microcirculatory modifications without disrupting microvessels. Before the striction (t-5 min), the velocities and diameters of the veins and arteries were comparable in all groups. After the striction (t5 min), in the control group, venous blood flow decreased by 60%, from 0.48 +/- 0.09 mm3/s (t-5 min) to 0.20 +/- 0.06 mm3/s (t5 min). The results showed that after thirty minutes reperfusion, venular blood flow in the control animals was only 34% of initial blood flow. The mean red blood cell velocity dropped by 56%, the percentage of low perfused capillaries increased from 7.5% to 50%. Treatment of animals with a coumarin derivative-rutoside combination, particularly at 4 mg/kg coumarin derivative-100 mg/kg rutoside, has significantly improved the microcirculation. After thirty minutes reperfusion venular blood flow was 60% and the percentage of low perfused capillaries was only 10%. The effect seemed to be more pronounced for rutoside than coumarin derivatives. The interest of this study was to set up an experimental model of a venous striction not too severe to induce micro-hemorrages but enough to modify microcirculation. This model was used to quantify the beneficial effects of a coumarin derivative-rutoside combination.

  9. 带有广义导子的素环%Prime Rings with Generalized Derivations

    Institute of Scientific and Technical Information of China (English)

    黄述亮; 傅士太

    2008-01-01

    The concept of derivations and generalized inner derivations has been generalized as an additive function δ: R→ R satisfying δ(xy) = δ(x)y + xd(y) for all x,y∈R,where d is a derivation on R.Such a function δis called a generalized derivation.Suppose that U is a Lie ideal of R such that u2 ∈ U for all u ∈U.In this paper,we prove that U(C)Z(R) when one of the following holds:(1)δ([u,v]) = uov (2)δ([u,v]) + uov=O(3)δ(uov) =[u,v](4)δ(uov) +[u,v]= O for all u,v ∈U.

  10. Creation of localized spins in graphene by ring-opening of epoxy derived hydroxyl.

    Science.gov (United States)

    Chen, Jie; Zhang, Weili; Sun, Yuanyuan; Zheng, Yongping; Tang, Nujiang; Du, Youwei

    2016-05-26

    Creation of high-density localized spins in the basal plane of graphene sheet by introduction of sp(3)-type defects is considered to be a potential route for the realization of high-magnetization graphene. Theoretical and experimental studies confirmed that hydroxyl can be an effective sp(3)-type candidate for inducing robust magnetic moment. However, the artificial generation of hydroxyl groups for creating high-density spins on the basal plane of graphene sheet is very scarce. Here we demonstrate that high-content hydroxyl groups can be generated on the basal plane of graphene oxide (GO) sheet by ring opening of epoxy groups. We show that by introduction of 10.74 at.% hydroxyl groups, the density of localized spins of GO can be significantly increased from 0.4 to 5.17 μB/1000 C. Thus, this study provided an effective method to obtain graphene with high-density localized spins.

  11. Synthesis and Antibacterial Activities of Novel 4-Hydroxy-7-hydroxy- and 3-Carboxycoumarin Derivatives

    Directory of Open Access Journals (Sweden)

    Lin-Wen Lee

    2012-09-01

    Full Text Available Coumarin derivatives are used as fluorescent dyes and medicines. They also have some notable physiological effects, including the acute hepatoxicity and carcinogenicity of certain aflatoxins, the anticoagulant action of dicoumarol, and the antibiotic activity of novobicin and coumerymycin A1. Because the number of drug resistant strains is increasing at present, the synthesis of new antibacterial compounds is one of the critical methods for treating infectious diseases. Therefore, a series of coumarin-substituted derivatives, namely 4-hydroxy- and 7-hydroxycoumarins, and 3-carboxycoumarins were synthesized. 4-Hydroxycoumarin derivatives 4a–c underwent rearrangement reactions. Both 4- and 7-hydroxycoumarins were treated with activated aziridines which produced series of ring-opened products 7, 8, 10, and 11. 3-Carboxy-coumarin amide dimer derivatives 14–21 were prepared by reacting aliphatic alkylamines and alkyldiamines with PyBOP and DIEA. In this study, we use a new technique called modified micro-plate antibiotic susceptibility test method (MMAST, which is more convenient, more efficient, and more accurate than previous methods and only a small amount of the sample is required for the test. Some of the compounds were produced by reactions with acid anhydrides and demonstrated the ability to inhibit Gram-positive microorganisms. The dimer derivatives displayed lower antibacterial activities.

  12. Inhibitory activity of coumarins from Artemisia capillaris against advanced glycation endproduct formation.

    Science.gov (United States)

    Jung, Hyun Ah; Park, Jin Ju; Islam, Md Nurul; Jin, Seung Eun; Min, Byung-Sun; Lee, Je-Hyun; Sohn, Hee Sook; Choi, Jae Sue

    2012-06-01

    Since glycation can lead to the onset of diabetic complications due to chronic hyperglycemia, several indigenous Artemisia species were evaluated as potential inhibitors of advanced glycation endproducts (AGE). Among them, the Artemisia capillaris plant demonstrated the highest AGE inhibitory activity. Repeated column chromatography was performed to isolate a new acylated flavonoid glycoside, acacetin-7-O-(6″-O-acetyl)-β-D-glucopyranosyl-(1→2)[α-L-rhamnopyranosyl]-(1→6)-β-D-glucopyranoside, along with 11 known flavonoids (acacetin-7-O-β-D-glucopyranosyl-(1→2)[α-L-rhamnopyranosyl]-(1→6)-β-D-glucopyranoside, linarin, quercetin, hyperoside, isorhamnetin, isorhamnetin 3-galactoside, isorhamnetin 3-glucoside, isorhamnetin 3-arabinoside, isorhamnetin 3-robinobioside, arcapillin, and cirsilineol), six coumarins (umbelliferone, esculetin, scopoletin, scopolin, isoscopolin, and scoparone), and two phenolic derivatives (4,5-di-O-caffeoylquinic acid and chlorogenic acid). In determining the structure-activity relationship (SAR), it was found that the presence and position of hydroxyl group of test coumarins (coumarin, esculin, isoscopoletin, daphnetin, 4-methylcoumarin, and six isolated coumarins) may play a crucial role in AGE inhibition. A free hydroxyl group at C-7 and a glucosyl group instead of a methoxyl group at C-6 are two important parameters for the inhibitory potential of coumarins on AGE formation. A. capillaris and five key AGE inhibitors, including 4,5-di-Ocaffeoylquinic acid, umbelliferone, esculetin, esculin, and scopoletin, were identified as potential candidates for use as therapeutic or preventive agents for diabetic complications and oxidative stress-related diseases. We understand this to be the first detailed study on the SAR of coumarins in AGE inhibition.

  13. 交换环上一些线性李代数的导子%Derivations of Certain Linear Lie Algebras over Commutative Rings

    Institute of Scientific and Technical Information of China (English)

    偶世坤; 王登银; 夏春光

    2009-01-01

    Let L be the symplectic algebra or the orthogonal algebra over a commutative ring R, h the maximal torus of L consisting of all diagonal matrices in L, and b the standard Borel subalgebra of L containing h. In this paper, we first determine the intermediate algebras between h and b, then for such an intermediate algebra, we give an explicit description on its derivations, provided that R is a commutative ring with identity and 2 is invertible in R.

  14. Investigation of supramolecular architectures of bent-shaped pyridine derivatives: from a three-ring crystalline compound towards five-ring mesogens

    CERN Document Server

    Trišović, Nemanja; Rogan, Jelena; Poleti, Dejan; Tóth-Katona, Tibor; Salamonczyk, Miroslaw; Jákli, Antal; Fodor-Csorba, Katalin

    2016-01-01

    In searching for novel photoactive liquid crystals, we have synthesized a series of five-ring pyridine-based bent-core compounds bearing different substituents at the peripheral phenyl rings (CH3O, Cl and NO2). Their mesomorphic behaviour has been investigated by polarizing optical microscopy, differential scanning calorimetry and X-ray scattering, and then compared with the unsubstituted parent compound. The introduction of the methoxy groups at the peripheral phenyl rings of the bent core results in a non-mesomorphic compound, whereas the chloro- and nitro-substituted compounds form enantiotropic B1-like phases. Significant changes of the textures and transition temperatures of the mesophase have been observed under UV light. The presented investigation of the mesomorphic properties of the synthesized compounds, coupled with analysis of the molecular packing of the related three-ring compounds, will help to design self-organized molecules suitable for UV indicators.

  15. Structural, electrochemical and theoretical study of a new chalcone derivative containing 3-thiophene rings

    Science.gov (United States)

    Baggio, Ricardo; Brovelli, Francisco; Moreno, Yanko; Pinto, Marcela; Soto-Delgado, Jorge

    2016-11-01

    The title chalcone, 1,3-di(thiophene-3-yl)prop-2-en-1-one (C11H8OS2) is an essentially planar molecular with its terminal thiophene rings subtending an angle of 8.9°. The crystal structure consists in the π··π stacking of molecules defining columns along [010], further linked along c by non conventional Csbnd H⋯O bonds, thus determining broad planar arrays parallel to (100). In addition, there are weak S⋯S contacts connecting these weakly interacting 2D substructures. The experimental results obtained from single crystal X-ray diffraction data and the theoretical geometry calculated by molecular mechanics are in good agreement. Electrochemical records reveal an anodic profile with an unsymmetrical irreversible peak at 1.77 V and a shoulder at 1.62 V vs SCE, a behavior interpretable as due to the oxidation of reactive sites present in the molecule. On the other hand, the electrochemical reduction shows a narrow peak at -1.58 V vs SCE, a fact attributable to the carbonyl group. Finally, the values for the energy involved in the departure/arrival of electrons from border orbitals, as calculated using DFT, is compared with experimental data from cyclic voltammetry.

  16. Synthesis and antitumor activity evaluation of new 2-(4-aminophenyl)benzothiazole derivatives bearing different heterocyclic rings.

    Science.gov (United States)

    Yurttaş, Leyla; Tay, Funda; Demirayak, Şeref

    2015-06-01

    Twenty-five new N-[4-(benzothiazole-2-yl)phenyl]acetamide derivatives bearing different heterocyclic ring systems were synthesized using 2-(4-aminophenyl)benzothiazole structure as a pharmacophoric group. Final compounds were screened for their potential antitumor activity in vitro against approximately 60 human tumor cell lines derived from nine neoplastic diseases at National Cancer Institute, USA. 2-(4-Aminophenyl)benzothiazole structure was prepared by the reaction of 4-aminobenzoic acid and 2-aminothiophenol in polyphosphoric acid using microwave irradiation. After acetylation reaction, amide compounds 2a and 2b were obtained, which were then reacted with 2-mercapto(benz)imidazole/benzothiazole/benzoxazole derivatives in acetone with the presence of potassium carbonate to gain final compounds (3-27). Among all tested compounds, compound 10, namely N-[4-(benzothiazole-2-yl)-3-chlorophenyl]-2-[(benzimidazole-2-yl)thio]acetamide, and compound 16, namely N-[4-(benzothiazole-2-yl)phenyl]-2-[(1,5-diphenyl-1H-imidazole-2-yl)thio]acetamide, were found to be of considerable anticancer activity against some cancer cell lines.

  17. Metabolic detoxification determines species differences in coumarin-induced hepatotoxicity.

    Science.gov (United States)

    Vassallo, Jeffrey D; Hicks, Sarah M; Daston, George P; Lehman-McKeeman, Lois D

    2004-08-01

    for nearly half of all CE metabolites in rat and mouse, whereas the GSH conjugate represented only 10% of the metabolites in human cytosol. In mouse, o-HPAA represented the major ring-opened metabolite, accounting for the remaining 50% of metabolites, and in human cytosol, o-HPAA was the major metabolite, representing nearly 90% of all CE metabolites. In contrast, no o-HPAA was detected in rats, whereas o-HPE represented a major metabolite. Collectively, these in vitro data implicate o-HPA detoxification through oxidation to o-HPAA as the major determinant of species differences in coumarin-induced hepatotoxicity.

  18. Flavonoids and coumarins from Hieracium pilosella L. (Asteraceae

    Directory of Open Access Journals (Sweden)

    Tadeusz Krzaczek

    2011-04-01

    Full Text Available Typical chromatographic methods were successfully applied to isolate nine flavonoid compounds and two coumarin glycosides from the inflorescences and the herb of Hieracium pilosella L. Repeated column chromatography, occasionally paper chromatography and recrystallization made the separation of three flavonoid aglycones and six glycosides - possible. Coumarin glycosides were isolated by preparative thin layer chromatography. Subsequent UV, NMR and MS analyses have led to identification of the following flavonoid derivatives: known for the species - apigenin, luteolin, luteolin 7-O- ß-glucopyranoside, luteolin 4’-O-ß-glucopyranoside, isoetin 7-O-ß- -glucopyranoside, isoetin 4’-O-ß-glucuronide and new for the species – kaempferol 3-methyl ether and apigenin 7-O-ß-glucopyranoside. Third isoetin glycoside contained two different sugar moieties: xylose and glucose, probably attached to the hydroxyl groups at C-4’ or C-4’ and C-2’(or 5’ of an aglycone. Umbelliferone 7-O-ß-glucopyranoside (skimmin and new for the genus Hieracium esculetin 7-O-ß-glucopyranoside (cichoriin were determined by NMR and MS methods.

  19. Accumulation of coumarins in Arabidopsis thaliana.

    Science.gov (United States)

    Kai, Kosuke; Shimizu, Bun-ichi; Mizutani, Masaharu; Watanabe, Ken; Sakata, Kanzo

    2006-02-01

    The biosynthesis of coumarins in plants is not well understood, although these metabolic pathways are often found in the plant kingdom. We report here the occurrence of coumarins in Arabidopsis thaliana ecotype Columbia. Considerably high levels of scopoletin and its beta-d-glucopyranoside, scopolin, were found in the wild-type roots. The scopolin level in the roots was approximately 1200nmol/gFW, which was approximately 180-fold of that in the aerial parts. Calli accumulated scopolin at a level of 70nmol/gFW. Scopoletin and scopolin formation were induced in shoots after treatment with either 2,4-dichlorophenoxyacetic acid (at 100microM) or a bud-cell suspension of Fusarium oxysporum. In order to gain insight into the biosynthetic pathway of coumarins in A. thaliana, we analyzed coumarins in the mutants obtained from the SALK Institute collection that carried a T-DNA insertion within the gene encoding the cytochrome P450, CYP98A3, which catalyzes 3'-hydroxylation of p-coumarate units in the phenylpropanoid pathway. The content of scopoletin and scopolin in the mutant roots greatly decreased to approximately 3% of that in the wild-type roots. This observation suggests that scopoletin and scopolin biosynthesis in A. thaliana are strongly dependent on the 3'-hydroxylation of p-coumarate units catalyzed by CYP98A3. We also found that the level of skimmin, a beta-d-glucopyranoside of umbelliferone, was slightly increased in the mutant roots.

  20. Two new coumarins from Murraya paniculata.

    Science.gov (United States)

    Saied, Sumayya; Nizami, Shaikh Sirajuddin; Anis, Itrat

    2008-01-01

    Two new coumarins, murrmeranzin (1) and murralonginal (2), together with four known compounds minumicrolin (3), murrangatin (4), meranzin hydrate (5) and hainanmurpanin (6) have been isolated from the aerial parts of Murraya paniculata. The structures of these compounds were determined through spectral analysis. Minumicrolin (3) showed mild butyrylcholinesterase inhibition activity.

  1. Synthesis and evaluation of 4-substituted coumarins as novel acetylcholinesterase inhibitors.

    Science.gov (United States)

    Razavi, Seyyede Faeze; Khoobi, Mehdi; Nadri, Hamid; Sakhteman, Amirhossein; Moradi, Alireza; Emami, Saeed; Foroumadi, Alireza; Shafiee, Abbas

    2013-06-01

    A series of 4-hydroxycoumarin derivatives were designed and synthesized as new acetylcholinesterase (AChE) inhibitors which could be considered for Alzheimer's disease therapeutics. Among the 19 coumarin-derived compounds tested toward Electrophorus electricus acetylcholinesterase (eelAChE) and horse serum butyrylcholinesterase (eqBChE), N-(1-benzylpiperidin-4-yl)acetamide derivative 4m displayed highest AChE inhibitory activity (IC50 = 1.2 μM) and good selectivity (37 times). The docking study of the most potent compound 4m, indicated that Phe330 is responsible for ligand recognition and trafficking by forming π-cation interaction with benzylpiperidine moiety. Furthermore, the formation of an additional π-π interaction between coumarin moiety and Trp279 of peripheral anionic site could stabilize the ligand in the active site resulting in more potent inhibition of the enzyme. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  2. In vitro inhibition effect of some coumarin compounds on purified human serum paraoxonase 1 (PON1).

    Science.gov (United States)

    Gokce, Basak; Gencer, Nahit; Arslan, Oktay; Karatas, Mert Olgun; Alici, Bulent

    2016-08-01

    Human serum paraoxonase 1 (PON1; EC 3.1.8.1) is a high-density lipoprotein associated, calcium-dependent enzyme that hydrolyses aromatic esters, organophosphates and lactones and can protect the low-density lipoprotein against oxidation. In this study, in vitro effect of some hydroxy and dihydroxy ionic coumarin derivatives (1-20) on purified PON1 activity was investigated. Among these compounds, derivatives 11-20 are water soluble. In investigated compounds, compounds 6 and 13 were found the most active (IC50 = 35 and 34 µM) for PON1, respectively. The present study has demonstrated that PON1 activity is very highly sensitive to studied coumarin derivatives.

  3. Interaction of coumarin with calf thymus DNA: deciphering the mode of binding by in vitro studies.

    Science.gov (United States)

    Sarwar, Tarique; Rehman, Sayeed Ur; Husain, Mohammed Amir; Ishqi, Hassan Mubarak; Tabish, Mohammad

    2015-02-01

    DNA is the major target for a wide range of therapeutic substances. Thus, there has been considerable interest in the binding studies of small molecules with DNA. Interaction between small molecules and DNA provides a structural guideline in rational drug designing and in the synthesis of new and improved drugs with enhanced selective activity and greater clinical efficacy. Plant derived polyphenolic compounds have a large number of biological and pharmacological properties. Coumarin is a polyphenolic compound which has been extensively studied for its diverse pharmacological properties. However, its mode of interaction with DNA has not been elucidated. In the present study, we have attempted to ascertain the mode of binding of coumarin with calf thymus DNA (Ct-DNA) through various biophysical techniques. Analysis of UV-visible absorbance spectra and fluorescence spectra indicates the formation of complex between coumarin and Ct-DNA. Several other experiments such as effect of ionic strength, iodide induced quenching, competitive binding assay with ethidium bromide, acridine orange and Hoechst 33258 reflected that coumarin possibly binds to the minor groove of the Ct-DNA. These observations were further supported by CD spectral analysis, viscosity measurements, DNA melting studies and in silico molecular docking.

  4. Biogas production from coumarin-rich plants--inhibition by coumarin and recovery by adaptation of the bacterial community.

    Science.gov (United States)

    Popp, Denny; Schrader, Steffi; Kleinsteuber, Sabine; Harms, Hauke; Sträuber, Heike

    2015-09-01

    Plants like sweet clover (Melilotus spp.) are not suitable as fodder for cattle because of harmful effects of the plant secondary metabolite coumarin. As an alternative usage, the applicability of coumarin-rich plants as substrates for biogas production was investigated. When coumarin was added to continuous fermentation processes codigesting grass silage and cow manure, it caused a strong inhibition noticeable as decrease of biogas production by 19% and increase of metabolite concentrations to an organic acids/alkalinity ratio higher than 0.3(gorganic acids) gCaCO3 (-1). Microbial communities of methanogenic archaea were dominated by the genera Methanosarcina (77%) and Methanoculleus (11%). This community composition was not influenced by coumarin addition. The bacterial community analysis unraveled a divergence caused by coumarin addition correlating with the anaerobic degradation of coumarin and the recovery of the biogas process. As a consequence, biogas production resumed similar to the coumarin-free control with a biogas yield of 0.34 LN g(volatile solids) (-1) and at initial metabolite concentrations (∼ 0.2 g(organic acids) gCaCO3 (-1)). Coumarin acts as inhibitor and as substrate during anaerobic digestion. Hence, coumarin-rich plants might be suitable for biogas production, but should only be used after adaptation of the microbial community to coumarin.

  5. Bismuth triflate:A highly efficient catalyst for the synthesis of bio-active coumarin compoundsvia one-pot multi-component reaction

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    A series of coumarin-chalcone hybrid compounds and coumarins linked to pyrazoline was synthe-sized in good yield and short time using a simple and efficient method. This method involved the one-pot reaction of salicylaldehyde, an α-ketoester and an aromatic aldehyde (in the case of the coumarin-chalcone derivatives) in addition to hydrazine hydrate (in the case of the pyrazolyl cou-marins) in the presence of a catalytic amount of bismuth triflate [Bi(OTf)3, 5 mol%]. The synthesized compounds showed scavenging activity towards the free radical 2,2-diphenyl-1-picrylhydrazyl. All compounds were characterized using IR,1H NMR and13C NMR spectroscopy.

  6. A new coumarin from stem bark of Mesua hexapetala.

    Science.gov (United States)

    Karunakaran, Thiruventhan; Ee, Gwendoline Cheng Lian; Teh, Soek Sin; Daud, Shaari; Mah, Siau Hui; Lim, Chan Kiang; Jong, Vivien Yi Mian; Awang, Khalijah

    2016-07-01

    A new alkylated coumarin derivative, hexapetarin (1) along with three other xanthones, trapezifolixanthone (2), cudraxanthone G (3) and 1,3,7-trihydroxy-2,4-di (3-methyl-2-butenyl)xanthone (4), and four common triterpenoids, friedelin (5), stigmasterol (6), beta-sitosterol (7) and gamma-sitosterol (8) were isolated from the stem bark of Mesua hexapetala (Clusiaceae), a plant, native to Malaysia. The structures of these compounds were elucidated and determined using spectroscopic techniques such as NMR and MS. Anti-inflammatory activity assay indicated hexapetarin (1) to possess moderate anti-inflammatory activity, while 1,3,7-trihydroxy-2,4-di (3-methyl-2-butenyl)xanthone (4) gave very good activity.

  7. 3,4-二苯基香豆素衍生物的合成及其促自然杀伤细胞活性研究%Synthesis of 3,4-Biphenyl Coumarin Derivatives and Their Promoting Effects on the Killing Activity of Natural Killing Cell

    Institute of Scientific and Technical Information of China (English)

    陈华; 周利凯; 李帅; 姚玉超; 谷云景; 李春晓; 李娜; 孟明; 李小六

    2013-01-01

    以水杨酸为起始原料,经Fridel-Crafts酰基化反应、微波促进的Perkin反应和两步亲核取代反应,合成了具有氨基烷氧侧链的3,4-二苯基香豆素衍生物1a~1e.初步生物活性测试表明,化合物1a~1e能显著促进自然杀伤细胞杀伤活性,具有较强的免疫调节活性.%A series of novel 3,4-biphenyl coumarin derivatives containing an amino side chain 1a~1e were synthesized using salicylic acid as starting material via Fridel-Crafts acylation, then the microwave-assisted Perkin reaction and double SN2 substitution reactions. The preliminary biological evaluation showed that compounds 1a~1e had significant promoting effects on the killing activity of natural killer cell, and hold potential as immunomodulating agents.

  8. Anti-inflammatory new coumarin from the Ammi majus L.

    Science.gov (United States)

    Selim, Yasser Abdelaal; Ouf, Nabil Hassan

    2012-01-12

    Investigation of the aerial parts of the Egyptian medicinal plant Ammi majus L. led to isolation of new coumarin, 6-hydroxy-7-methoxy-4 methyl coumarin (2) and 6-hydroxy-7-methoxy coumarin (3); this is the first time they have been isolated from this plant. The structures of the compounds (2 &3) were elucidated by spectroscopic data interpretation and showed anti-inflammatory and anti-viral activity. GRAPHICAL An efficient, one-new coumarin (2) was isolated from the aerial parts of the A. Majus L. was evaluated for their anti-viral and anti-inflammatory activities.

  9. Two new coumarin glycosides from Chimonanthus nitens.

    Science.gov (United States)

    Li, Qi-Ji; Wang, Ming-Li; Yang, Xiao-Sheng; Ma, Lin; Hao, Xiao-Jiang

    2013-01-01

    Two new coumarin glycosides, namely nitensosides A-B (1-2), together with six known compounds, scopolin (3), 5,6,7-trimethoxycoumarin (4), d-calycanthine (5), calycanthoside (6), xeroboside (7), and scopoletin (8), were isolated from Chimonanthus nitens. The structures of the new compounds were elucidated by comprehensive analysis of IR, MS, and NMR spectroscopic data. Compounds 3, 4, 7, and 8 showed moderate inhibitory activity against Micrococcus luteus.

  10. Genetically encoded fluorescent coumarin amino acids

    Science.gov (United States)

    Wang, Jiangyun; Xie, Jianming; Schultz, Peter G.

    2010-10-05

    The invention relates to orthogonal pairs of tRNAs and aminoacyl-tRNA synthetases that can incorporate the coumarin unnatural amino acid L-(7-hydroxycoumarin-4-yl) ethylglycine into proteins produced in eubacterial host cells such as E. coli. The invention provides, for example but not limited to, novel orthogonal synthetases, methods for identifying and making the novel synthetases, methods for producing proteins containing the unnatural amino acid L-(7-hydroxycoumarin-4-yl)ethylglycine and related translation systems.

  11. A new sesquiterpenoid coumarin from Ferula assafoetida.

    Science.gov (United States)

    Ghosh, Anindita; Banerji, Avijit; Mandal, Suvra; Banerji, Julie

    2009-08-01

    The gum resin of Ferula assafoetida Linn. afforded one new sesquiterpene, asimafoetida 1 and three known sesquiterpenoid coumarins. The structure has been established from extensive 2D NMR spectral studies as 7'-[7-(1R,3S)-5-Hydroxy-6,6-dimethyl-2-methylene-cyclohexyl]-9-methyl-9-pentenyl]oxy]-2H-1-benzopyran-2-one. The other three known compounds are ferulic acid, farnesiferol A and farnesiferol C.

  12. A new coumarin glycoside from Daphne giraldii

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A new coumarin glycoside was isolated from the ethanol extract of the barks of stem of Daphne giraldii Nitsche. Its structure was defined as daphnetin 8-O-β-D-glucopyranosyl-(1 → 6)-β-D-glucopyranoside on the basis of spectral evidences.(C) 2007 Wei Dong Zhang. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

  13. Genetically encoded fluorescent coumarin amino acids

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jiangyun [San Diego, CA; Xie, Jianming [San Diego, CA; Schultz, Peter G [La Jolla, CA

    2012-06-05

    The invention relates to orthogonal pairs of tRNAs and aminoacyl-tRNA synthetases that can incorporate the coumarin unnatural amino acid L-(7-hydroxycoumarin-4-yl)ethylglycine into proteins produced in eubacterial host cells such as E. coli. The invention provides, for example but not limited to, novel orthogonal synthetases, methods for identifying and making the novel synthetases, methods for producing proteins containing the unnatural amino acid L-(7-hydroxycoumarin-4-yl)ethylglycine and related translation systems.

  14. Synthesis of imidacloprid derivatives with a chiral alkylated imidazolidine ring and evaluation of their insecticidal activity and affinity to the nicotinic acetylcholine receptor.

    Science.gov (United States)

    Nishiwaki, Hisashi; Kuriyama, Mituhiro; Nagaoka, Hikaru; Kato, Akira; Akamatsu, Miki; Yamauchi, Satoshi; Shuto, Yoshihiro

    2012-11-01

    A series of imidacloprid (IMI) derivatives with an alkylated imidazolidine ring were asymmetrically synthesized to evaluate their insecticidal activity against adult female housefly, Musca domestica, and affinity to the nicotinic acetylcholine receptor of the flies. The bulkier the alkyl group, the lower was the receptor affinity, but the derivatives methylated and ethylated at the R-5-position of the imidazolidine ring were equipotent to the unsubstituted compound. Quantitative structure-activity relationship (QSAR) analysis of the receptor affinity demonstrated that the introduction of a substituent into the imidazolidine ring was fundamentally disadvantageous, but the introduction of a substituent at the R-5-position was permissible in the case of its small size. The binding model of the synthesized derivatives with the receptor supported the QSAR analysis, indicating the existence of space for a short alkyl group around the R-5-position in the ligand-binding site. In addition, positive correlation was observed between the insecticidal activity and receptor affinity, suggesting that the receptor affinity was the primary factor in influencing the insecticidal activity even if the imidazolidine ring was modified.

  15. Heavy atom quenched coumarin probes for sensitive and selective detection of biothiols in living cells.

    Science.gov (United States)

    Ji, Wengang; Ji, Yuzhuo; Jin, Qingqing; Tong, Qingxiao; Tang, Xinjing

    2015-07-07

    A series of turn-on fluorescent probes with halogen acetyl amide at the 3-position of coumarin derivatives were synthesized. Fluorescence of these probes was efficiently quenched by heavy halogen atoms (Br and I, not Cl), which could be successfully used for selective detection of biothiols with the sensitivity of Cys > GSH > Hcy and much higher than thiol containing proteins. These represent the smallest fluorescence quenchers in designing fluorescent probes for detecting both endogenous and exogenous biothiols in living cells.

  16. Synthesis and antitumor activity of duocarmycin derivatives: modification at C-8 position of A-ring pyrrole compounds bearing the simplified DNA-binding groups.

    Science.gov (United States)

    Amishiro, N; Nagamura, S; Murakata, C; Okamoto, A; Kobayashi, E; Asada, M; Gomi, K; Tamaoki, T; Okabe, M; Yamaguchi, N; Yamaguchi, K; Saito, H

    2000-02-01

    A series of the 8-O-substituted A-ring pyrrole derivatives of duocarmycin bearing the simplified DNA-binding moieties such as cinnamoyl or heteroarylacryloyl groups were synthesized, and evaluated for in vitro anticellular activity against HeLa S3 cells and in vivo antitumor activity against murine sarcoma 180 in mice. In addition, the stability of the 8-O-substituted analogues in aqueous solution and the conversion to their active form (cyclopropane compound) from the 8-O-substituted analogues in mice or human serum were examined. The 8-O-substituted A-ring pyrrole derivatives bearing the simplified DNA-binding moieties showed remarkably potent in vivo antitumor activity and low peripheral blood toxicity compared with the 8-O-substituted A-ring pyrrole derivatives having the trimethoxyindole skeleton in segment-B (Seg-B), which were equal to 8-O-[(N-methylpiperazinyl)carbonyl] derivatives of 4'-methoxycinnamates and 4'-methoxy-beta-heteroarylacrylates. Moreover, among 8-O-substituted analogues, several compounds can be chemically or enzymatically converted to their active form in human serum. This result indicated that new 8-O-substituted derivatives were different prodrugs from KW-2189 and 8-O-substituted analogues being the same type of prodrug as KW-2189.

  17. Self-assembly properties of semiconducting donor-acceptor-donor bithienyl derivatives of tetrazine and thiadiazole-effect of the electron accepting central ring.

    Science.gov (United States)

    Zapala, Joanna; Knor, Marek; Jaroch, Tomasz; Maranda-Niedbala, Agnieszka; Kurach, Ewa; Kotwica, Kamil; Nowakowski, Robert; Djurado, David; Pecaut, Jacques; Zagorska, Malgorzata; Pron, Adam

    2013-11-26

    Scanning tunneling microscopy was used to study the effect of the electron-accepting unit and the alkyl substituent's position on the type and extent of 2D supramolecular organization of penta-ring donor-acceptor-donor (DAD) semiconductors, consisting of either tetrazine or thiadiazole central acceptor ring symmetrically attached to two bithienyl groups. Microscopic observations of monomolecular layers on HOPG of four alkyl derivatives of the studied adsorbates indicate significant differences in their 2D organizations. Ordered monolayers of thiadiazole derivatives are relatively loose and, independent of the position of alkyl substituents, characterized by large intermolecular separation of acceptor units in the adjacent molecules located in the face-to-face configuration. The 2D supramolecular architecture in both derivatives of thiadiazole is very sensitive to the alkyl substituent's position. Significantly different behavior is observed for derivatives of tetrazine (which is a stronger electron acceptor). Stronger intermolecular DA interactions in these adsorbates generate an intermolecular shift in the monolayer, which is a dominant factor determining the 2D structural organization. As a consequence of this molecular arrangement, tetrazine groups (A segments) face thiophene rings (D segments) of the neighboring molecules. Monolayers of tetrazine derivatives are therefore much more densely packed and characterized by similar π-stacking of molecules independently of the position of alkyl substituents. Moreover, a comparative study of 3D supramolecular organization, deduced from the X-ray diffraction patterns, is also presented clearly confirming the polymorphism of the studied adsorbates.

  18. Melamine-formaldehyde resin supported H+: A mild and inexpensive reagent for synthesis of coumarins under mild conditions

    Institute of Scientific and Technical Information of China (English)

    Ramin Rezaei; Leila Dorosty; Maryam Rajabzadeh; Reza Khalifeh

    2011-01-01

    Melamine-formaldehyde resin supported H+ is used as an efficient catalyst in the Pechmann condensation reaction of phenols with β-ketoesters, in solvent-free media leading to the formation of coumarin derivatives using conventional heating and microwave irradiation in excellent yields with good purity.

  19. A click approach to novel D-ring-substituted 16α-triazolylestrone derivatives and characterization of their antiproliferative properties.

    Directory of Open Access Journals (Sweden)

    Judit Molnár

    Full Text Available A simple and efficient synthesis of novel, D-ring substituted estrone derivatives containing a 16α-triazolyl moiety is described. Two epimeric azido alcohols (16α-azido-17α-hydroxy and 16α-azido-17β-hydroxy of estra-1,3,5(10-triene-3-methyl ether were prepared, followed by copper(I-catalyzed azide-alkyne cycloaddition with various terminal alkynes. The steroidal triazoles were obtained in high yields and their activities against three human cancer cell lines (HeLa, MCF7 and A431 were screened. The most effective analogs were submitted to additional experiments in order to characterize their antiproliferative properties. As evidenced by flow cytometry, the selected steroids induced a disturbance in the HeLa cell cycle in a concentration- and exposure-dependent manner, through an increase of the hypodiploid population (subG1 and a cell cycle arrest in the G2/M phase. A noncancerous human fibroblast cell line (MRC5 was used to determine the selectivities of these compounds. Fluorescent microscopy after Hoechst 33258 - propidium iodide (HOPI double staining revealed nuclear condensation and disturbed cell membrane integrity. The enhanced activities of caspase-3 and caspase-9 without activation of caspase-8 in the treated cells indicated the activation of the intrinsic pathway of apoptosis. The levels of cell cycle regulators (CDK1, cyclin B1/B2 and cdc25B were decreased and the ratio Bax/Bcl-2 was increased 24 h after the treatment of HeLa cells (determined at an mRNA level by means of an RT-PCR technique. Under the same conditions, two agents elicited substantially increased degrees of phosphorylation of stathmin, as evidenced by Western blotting. The presented results demonstrate that these steroids can be regarded as appropriate structural scaffolds for the design and synthesis of further steroid analogs as innovative drug candidates with good efficacy.

  20. 香豆素类化合物在肿瘤治疗上的应用%Application of Anticancer Drugs with Coumarin Structures

    Institute of Scientific and Technical Information of China (English)

    黄月芬

    2015-01-01

    Coumarins are a group of compounds with anα-benzopyrone structure.In recent years,the researchers have explored the influence of coumarins on enzymes and cell pathways related to the metabolism of tumor cells,and isolated or synthesized many structurally specific coumarin derivatives with excellent anti-tumor activity,which proves adequately the importance of coumarin skeleton in the research and development of anticancer drugs.In this paper, we reviewed the application of many natural and synthetic coumarins which are classified by classical coumarin struc-tures on exploring new anticancer drugs.%香豆素( Coumarins)的基本结构是苯骈α-吡喃酮的一类化合物。近年来研究者报道了在肿瘤细胞信号转导通路和代谢的影响上香豆素具有的作用,从而发现了香豆素类化合物具有的抗肿瘤活性,并充分证明了目前香豆素类化合物在抗癌药物研发中的重要性。本文以香豆素的基本结构进行分类,对香豆素类化合物的抗肿瘤作用的研究进展进行综述。

  1. Genetic variation in the metabolism of coumarin in mouse liver

    NARCIS (Netherlands)

    Lovell, D.P.; Iersel, van M.P.L.S.; Walters, D.G.; Price, R.J.; Lake, B.G.

    1999-01-01

    The metabolism of 50 μM [3-14C] coumarin to polar products separated by high performance liquid chromatography (HPLC) and covalently bound metabolites in liver microsomes was compared in a series of inbred strains of mice. Coumarin metabolism to total polar products was higher in female than male mi

  2. 40 CFR 721.2155 - Alkoxyamino-alkyl-coumarin (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkoxyamino-alkyl-coumarin (generic... Substances § 721.2155 Alkoxyamino-alkyl-coumarin (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as...

  3. Radioiodination of 2,3-dimethyl-4H-furo[3,2-c]coumarin and biological evaluation in solid tumor bearing mice.

    Science.gov (United States)

    Abd Elhalim, S M; Ibrahim, I T

    2014-10-22

    Compound 2,3-dimethyl-4H-furo[3,2-c]coumarin is a coumarin derivative that could be labeled with (125)I. The process of labeling was started using 1mg of the compound, 50µg CAT oxidizing agent, 30min as reaction time at pH with a yield about 95%. The (125)I-coumarin derivative was stable for about 48h. Radiochemical purity of the labeled compound was performed by electrophoresis and HPLC. The labeled compound was separated with purity about 95%. Tumor transplantation to produce a solid tumor in the right leg of albino mice was made by intramuscular injection of 2×10(6) EAC (Ehrlish acittes carcinoma cells). Biodistribution study of (125)I-coumarin derivative revealed that the uptake in tumor bearing leg was over 5% at 1h and 4h post-injection. This uptake encourages the use of (123)I-coumarin derivative in imaging of tumor sites.

  4. Synthesis and Study of Second-order Nonlinear Optical Properties of 3-Substituted-6- (substituted-phenylazo) coumarins

    Institute of Scientific and Technical Information of China (English)

    SONG Hua-Can; WEN Huan; LIANG Dong; SUN Yi-Feng

    2003-01-01

    @@ It has attracted a lot of attentions to synthesize and investigate the behaviors of organic second-order nonlinear optical (NLO) materials. [1,2] We have ever reported that acridine derivatives ,[3] 4-substituted-benzylideneoxazol-5(4H)-one[4] and 4,4′-di-styryl-biphenyl derivatives[5] possess good second-order NLO properties. Coumarin derivatives are good organic optical materials and azobenzene derivatives possess a higher second-order nonlinear polarization values, however, there are few reports about the study on the synthetic method, optical behavior, especially,second-order NLO properties of 3-substitued-6-(substituted-phenylazo) coumarin derivatives. Therefore, a series of the following compounds were prepared in order to investigate their NLO behavior.

  5. In-vitro antibacterial, antifungal and cytotoxic activities of some coumarins and their metal complexes.

    Science.gov (United States)

    Rehman, Saeed U; Chohan, Zahid H; Gulnaz, Farzana; Supuran, Claudiu T

    2005-08-01

    A series of new antibacterial and antifungal coumarin-derived compounds and their transition metal complexes [cobalt (II), copper (II), nickel (II) and zinc (II)] have been synthesized, characterized and screened for their in vitro antibacterial activity against Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa, Salmonella typhi, Shigella dysenteriae, Bacillus cereus, Corynebacterium diphtheriae, Staphylococcus aureus and Streptococcus pyogenes bacterial strains and for in vitro antifungal activity against Trichophyton longifusus, Candida albicans, Aspergillus flavus, Microsporum canis, Fusarium solani, Candida glaberata. The results of these studies show the metal complexes to be more antibacterial and antifungal as compared to the uncomplexed coumarins. The brine shrimp bioassay was also carried out to study their in vitro cytotoxic properties.

  6. A fluorescent coumarin-thiophene hybrid as a ratiometric chemosensor for anions: Synthesis, photophysics, anion sensing and orbital interactions

    Science.gov (United States)

    Yanar, Ufuk; Babür, Banu; Pekyılmaz, Damla; Yahaya, Issah; Aydıner, Burcu; Dede, Yavuz; Seferoğlu, Zeynel

    2016-03-01

    A colorimetric and fluorimetric fluorescent chemosensor (CT-2), having a coumarin ring as a signaling unit and an acetamido thiophene ring as an H-donor receptor, has been synthesized from amino derivative (CT-1) of CT-2 for the purpose of recognition of anions in DMSO. The absorption and emission maxima were both determined for the fluorescent dye in different solvents. Both hypsochromic shift at the absorption maximum, and quenching of fluorescence after interactions between the anions and the receptoric part, were observed. This phenomenon was explained using orbital interactions based on quantum chemical calculations. The selectivity and sensitivity of CT-2 for F-, Cl-, Br-, I-, AcO-, CN-, H2PO4-, HSO4- and ClO4- anions were determined with spectrophotometric, fluorimetric and 1H NMR titration techniques and it was found that CT-2 be utilized for the detection of CN-, F- and AcO- in the presence of other ions as competitors. Color and fluorescence changes visible to the naked eye and under UV (365 nm) were observed upon addition of CN-, F- and AcO- to the solution of chemosensor (CT-2) in DMSO. The sensor showed no colorimetric and fluorimetric response for the anions such as Cl-, Br-, I-, H2PO4-, HSO4-, and ClO4-. However, 1H NMR titration shows that the chemosensor was more sensitive to CN-, than F- and AcO- at the stochiometric ratio of 1:2.5 respectively. Additionally, the compounds CT-1 and CT-2 showed good thermal stability for practical applications.

  7. Turning-On of Coumarin Phosphorescence in Acetylacetonato Platinum Complexes of Cyclometalated Pyridyl-Substituted Coumarins

    Directory of Open Access Journals (Sweden)

    Andrej Jackel

    2015-04-01

    Full Text Available Two pyridine-functionalized coumarins differing with respect to the site of pyridine attachment to the coumarin dye (3 in L1 or 7 in L2 and with respect to the presence (L1 or absence (L2 of a peripheral NMe2 donor were prepared and used as cyclometalating ligands towards the Pt(acac fragment. X-ray crystal structures of complexes 1 and 2 show strong intermolecular interactions by π-stacking and short Pt∙∙∙Pt or C-H∙∙∙O hydrogen bonding that result in the formation of sheetlike packing patterns. The NMe2 donor substituent has a profound influence on the absorption and emission properties of the free coumarin dyes; L1 emits strongly while L2 is only weakly emissive. On binding to Pt(acac the strong fluorescence of L1 is partially quenched while coumarin phosphorescence is observed from cyclometalated L1 and L2. The ligand-centered nature of the LUMO was confirmed by IR spectroelectrochemistry while the assignment of the phosphorescence emission as ligand-based rests on the vibrational structuring, the negligible solvatochromism, the small temperature-induced Stokes shifts on cooling to 77 K, the emission lifetimes, and strong oxygen quenching. (TD-DFT calculations confirm our experimental results and provide an assignment of the electronic transitions and the spin density distributions in the T1 state.

  8. Evaluation of Whole Tree Growth Increment Derived from Tree-Ring Series for Use in Assessments of Changes in Forest Productivity across Various Spatial Scales

    OpenAIRE

    Metsaranta, Juha M.; Bhatti, Jagtar S.

    2016-01-01

    The inherent predictability of inter-annual variation in forest productivity remains unknown. Available field-based data sources for understanding this variability differ in their spatial resolution, temporal resolution, and typical units of measure. Nearly all other tree and forest characteristics are in practice derived from measurements of diameter at breast height (DBH). Therefore, diameter increment reconstructed annually from tree-ring data can be used to estimate annual growth incremen...

  9. Cytoprotective Effect of Caffeic Acid Phenethyl Ester (CAPE) and Catechol Ring-Fluorinated CAPE Derivatives Against Menadione-Induced Oxidative Stress in Human Endothelial Cells

    Science.gov (United States)

    2006-03-31

    chlorogenic acid , and rosmari- nic acid did not display any cytoprotective effect in this assay at 15 lM (data not shown). Within the same pas- sage of HUVEC...Cytoprotective effect of caffeic acid phenethyl ester (CAPE) and catechol ring-fluorinated CAPE derivatives against menadione-induced oxidative...accepted 13 March 2006 Available online 31 March 2006 Abstract—Caffeic acid phenethyl ester (CAPE), a natural polyphenolic compound with many

  10. Preparation of some new coumarin dyes

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Series of coumarins containing heterocyclic substituent in 3-position were prepared.Sulfonyl chloride, a reactive group, was drawn into the heterocycle, and further condensed withamines to give series of new compounds that contain N-alkyl sulfamide. The spectral propertiesand dyeing character of these new dyes are discussed. A bathochromic shift (10 nm), enhancedfastness in light and sublimation (1-2 grade) and larger molar extinction coefficient (increase 104L ·mol-1 ·cm-1) are apparent with these new compounds. In the meantime, larger solubility appearswith these new compounds.

  11. Synthesis and carbonic anhydrase inhibitory properties of amino acid - coumarin/quinolinone conjugates incorporating glycine, alanine and phenylalanine moieties.

    Science.gov (United States)

    Küçükbay, F Zehra; Küçükbay, Hasan; Tanc, Muhammet; Supuran, Claudiu T

    2016-12-01

    N-Protected amino acids (Gly, Ala and Phe) were reacted with amino substituted coumarin and quinolinone derivatives, leading to the corresponding N-protected amino acid-coumarin/quinolinone conjugates. The carbonic anhydrase (CA, EC 4.2.1.1) inhibitory activity of the new compounds was assessed against various human (h) isoforms, such as hCA I, hCA II, hCA IV and hCA XII. The quinolinone conjugates were inactive as enzyme inhibitors, whereas the coumarins were ineffective hCA I/II inhibitors (KIs > 50 μM) but were submicromolar hCA IV and XII inhibitors, with inhibition constants ranging between 92 nM and 1.19 μM for hCA IV, and between 0.11 and 0.79 μM for hCA XII. These coumarin derivatives, as many others reported earlier, thus show an interesting selective inhibitory profile for the membrane-bound over the cytosolic CA isoforms.

  12. A series of Keggin-based compounds constructed by conjugate ring-rich pyrazine and quinoxaline derivatives.

    Science.gov (United States)

    Tian, Aixiang; Tian, Yan; Ning, Yali; Hou, Xue; Ni, Huaiping; Ji, Xuebin; Liu, Guocheng; Ying, Jun

    2016-09-21

    Through the use of conjugate ring-rich pyrazine and quinoxaline derivatives, five new Keggin polymolybdate based compounds, [Ag(I)3L(1)2(H2O)2(PMo12O40)] (1), [Ag(I)4L(1)5(SiMo12O40)] (2), [Ag(I)6L(2)6(PMo12O40)2] (3), [Ag(I)2L(2)2(C16H36N)2](SiMo12O40)] (4), [Cu(I)3L(2)3(PMo12O40)] (5) (L(1) = 2,3-diphenylpyrazine, L(2) = 2,3-diphenylquinoxaline, C16H36N = tetrabutylammonium), were synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction. In compound 1, three Ag(I) ions are fused by two L(1) molecules to form a [Ag3L(1)2](3+) subunit, and these subunits link the PMo12 anions to construct two kinds of 1D chains (I and II). Chains I and II connect to each other by sharing the same PMo12 anions and a 2D grid-like layer is built. The asymmetric unit of compound 2 is linked to form a dimer by sharing Ag ions, and a 1D double strand is formed. The SiMo12 anions connect adjacent 1D double strands through Ag3-O23 bonds and a 2D network is built. In compound 3, there exists a 1D ladder-like double chain with PMo12 anions as linking bars. A 2D layer is formed by linkage Ag2-O24 between adjacent chains. In compound 4, the PMo12 anions act as inorganic linkages to connect adjacent zigzag chains through Ag1-O3 bonds to construct a 2D grid-like layer. In compound 5 two Cu(I)-L(2) lines are fused by PMo12 anions to build a 1D ladder-like chain. Additionally, the electrochemical and photocatalytic properties of the title compounds have been studied.

  13. In vitro inhibition effect of some dihydroxy coumarin compounds on purified human serum paraoxonase 1 (PON1).

    Science.gov (United States)

    Erzengin, Mahmut; Basaran, Ismet; Cakir, Umit; Aybey, Aynur; Sinan, Selma

    2012-11-01

    Human serum paraoxonase 1 (PON1; EC 3.1.8.1) is a high-density lipoprotein associated, calcium-dependent enzyme that hydrolyses aromatic esters, organophosphates and lactones and can protect the low-density lipoprotein against oxidation. In this study, in vitro inhibition effect of some dihydroxy coumarin compounds namely 6,7-dihydroxy-3-(2-methylphenyl)-2H-chromen-2-one (A), 6,7-dihydroxy-3-(3-methylphenyl)-2H-chromen-2-one (B) and 6,7-dihydroxy-3-(4-methylphenyl)-2H-chromen-2-one (C) on purified PON1 were investigated by using paraoxon as a substrate. PON1 was purified using two-step procedures, namely ammonium sulphate precipitation and Sepharose-4B-L-tyrosine-1-naphthylamine hydrophobic interaction chromatography. The purified enzyme had a specific activity of 11.76 U/mg. The dihydroxy coumarin derivatives of A and B compounds inhibited PON1 enzyme activity in a noncompetitive inhibition manner with K(i) of 0.0080±0.256 and 0.0003±0.018 mM values, respectively. C compound exerted an uncompetitive inhibition of PON1 enzyme activity with K(i) of 0.0010±0.173 mM. Moreover, dihydroxy coumarin derivatives of A, B and C compounds were effective inhibitors on purified human serum PON1 activity with IC(50) of 0.012, 0.022 and 0.003 mM values, respectively. IC(50) value of unsubstituted 6,7 dihydroxy coumarin was found as 0.178 mM. The present study has demonstrated that PON1 activity is very highly sensitive to studied coumarin derivatives.

  14. Simultaneous determination of 12 coumarins in bamboo leaves by HPLC.

    Science.gov (United States)

    Wang, Shuying; Tang, Feng; Yue, Yongde; Yao, Xi; Wei, Qi; Yu, Jin

    2013-01-01

    A simple, rapid, and sensitive HPLC-UV method was developed for qualitative and quantitative analysis of 12 coumarin compounds (skimin, scopolin, scopoletin, umbelliferone, 6,7-dimethoxycoumarin, coumarin, psoralen, xanthotoxin, 5,7-dimethoxycoumarin, pimpinellin, imperatorin, and osthole) in bamboo leaves. The samples were extracted with ethanol-water (70 + 30, v/v) by ultrasonication and purified by Florisil SPE. The method was validated for linearity, LOD, LOQ, accuracy, precision, and recovery. The standard curves in the corresponding ranges had good linearity. LOD was at the range of 0.19 to 0.85 mglkg and LOQ 0.64 to 2.82 mg/kg. The values of RSD for accuracy and intraday and interday precision were less than 3%, except for 6,7-dimethoxycoumarin. Recoveries from spiked samples at 30, 20, and 10 mg/kg in Dendrocalamus giganteus Munro were higher than 70%, except for scopoletin, 6,7-dimethoxycoumarin, and coumarin. The method was validated using field-collected samples taken from Beijing and Changning Counties, SiChuan, China. Six coumarins, namely, skimin, scopolin, scopoletin, umbelliferone, coumarin, and pimpinellin, were found in the extracts of 11 species of bamboo leaves. The concentrations of total coumarins were in the range of 8.67 to 99.2 mg/kg. The maximum concentration of total coumarins was found in Bambusa pervariabilis, and the minimum was in

  15. Antiproliferative evaluation of terpenoids and terpenoid coumarins from Ferulago macrocarpa (Fenzl Boiss. fruits

    Directory of Open Access Journals (Sweden)

    Seyed-Ebrahim Sajjadi

    2015-01-01

    Full Text Available Background: Ferulago macrocarpa is a plant used as flavoring agent and protectant in the food industry and as a folk medicinal plant in Iran with no available information on its chemical identity. Ferulago spp. showed to contain biologically terpenoids and coumarins. Objective: The objective was to isolate and characterize terpenoids and coumarins from the acetone extract of F. macrocarpa fruits and to evaluate their antiproliferative effects on several cell lines. Materials and Methods: A series of normal and reverse phase gravity and high-performance liquid chromatography analyses were used to purify constituents. Compounds 1-5 and 7 were evaluated for their cytotoxic effects on MCF-7, HT-29 and H-1299 cell lines. Results: Six compounds including bornyl acetate (1, 1,10-di-epi-cubenol (2, stigmasterol (3 and three coumarins grandivittin (4, prantschimgin (5 and 4"-hydroxygrandivittin (7 along with mixtures of feruloyl derivatives (6a-6c have been purified. Their structures were established by spectroscopic methods including nuclear magnetic resonance and MS analyses. Compound 2 showed moderate cytotoxicity effect with IC 50 values of 5.0 and 6.7 mM on MCF-7 and HT-29, respectively. Conclusion: 1,10-di-epi-Cubenol could be considered as a potential proliferation inhibitor of MCF-7 and HT-29 cell lines.

  16. Total Synthesis of Six 3,4-Unsubstituted Coumarins

    Directory of Open Access Journals (Sweden)

    Wenqing Gao

    2013-12-01

    Full Text Available In this article we describe a new methodology for the total synthesis of 3,4-unsubstituted coumarins from commercially available starting materials. Six examples were prepared, including five naturally occurring coumarins—7-hydroxy-6,8-dimethoxy-coumarin (isofraxidin, 7-hydroxy-6-methoxycoumarin (scopoletin, 6,7,8-trimethoxy-coumarin, 6,7-dimethoxycoumarin (scoparone, and 7,8-dihydroxycoumarin (daphnetin and one synthetic coumarin, 7-hydroxy-6-ethoxycoumarin. Moreover, five important o-hydroxybenzaldehyde intermediates were also obtained, namely 2,4-dihydroxy-3,5-dimethoxybenzaldehyde, 2,4-dihydroxy-5-methoxybenzaldehyde, 5-ethoxy-2,4-dihydroxy-benzaldehyde, 2-hydroxy-3,4,5-trimethoxybenzaldehyde, and 2-hydroxy-4,5-dimethoxy-benzaldehyde. The method developed herein involves just three or four steps and allows for the rapid synthesis of these important molecules in excellent yields. This is the first synthesis of 6,7,8-trimethoxycoumarin and 7-hydroxy-6-ethoxycoumarin.

  17. A potential low-coumarin cinnamon substitute: Cinnamomum osmophloeum leaves.

    Science.gov (United States)

    Yeh, Ting-Feng; Lin, Chun-Ya; Chang, Shang-Tzen

    2014-02-19

    The essential oils from leaves of Taiwan's indigenous cinnamon (Cinnamomum osmophloeum ct. cinnamaldehyde) have similar constituents as compared to that from commercial bark cinnamons. This indigenous cinnamon has been proven to have excellent bioactivities. To understand whether this indigenous cinnamon contains a high level of the hepatotoxic compound, coumarin, as often seen in Cassia cinnamons, current research focused on determining the coumarin content in this indigenous cinnamon and screening the low-coumarin clones. The results demonstrated that the coumarin contents in all tested indigenous cinnamon clones were much lower than that found in Cassia cinnamons. In addition, this indigenous cinnamon contains about 80% (w/w) of cinnamaldehyde and 0.4-2.7% (w/w) of eugenol in its leaf essential oils. This combination could provide this indigenous cinnamon a better shelf life compared to that of regular commercial cinnamons. These results suggested that leaves of this indigenous cinnamon could be a potential resource for a safer cinnamon substitute.

  18. Synthesis and plant-growth regulatory activities of novel imine derivatives containing 1H-1,2,4-triazole and thiazole rings

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Eleven new imine derivatives 6 containing 1H-1,2,4-triazole and thiazole rings were synthesized by the condensation of 5-((1H- 1,2,4-triazol-1-yl)methyl)-4-tert-butylthiazol-2-amine with various substituted benzaldehydes.The structures of the title compounds were characterized by ~1H NMR,MS and elemental analysis.The plant-growth regulatory activities of these compounds were evaluated.The primary bioassay results indicated that these target compounds exhibited promising plant-growth regulatory activities...

  19. Two New Coumarins from Fraxinus chinensis Rexb.

    Institute of Scientific and Technical Information of China (English)

    Dong-Mei Zhang; Li-Li Wang; Jia Li; Li-Hong Hu

    2007-01-01

    The ethanol extract of the stem bark of Fraxinus chinensis Roxb. showed good inhibitory bioactivity against VEGF receptor-1 kinase (IC50:13.8 μg/mL). In order to find new and bioactive compounds, the chemical constituents of the stem bark of F. chinensis were investigated and two new coumarins, namely 6'-O-sinapinoyl esculin (compound 1) and 6'-O-vanillyl esculin (compound 2), together with eleven known compounds (compounds 3-13) were isolated.The structures of the two new compounds were identified by their physicochemical properties and spectral analysis, particularly one- and two-dimens ional nuclear magnetic resonance spectral methods. The known compound, oleuropein (compound 11), exhibited moderate activity (IC50:(8.7 ± 1.3) μmol/L) to inhibit VEGF receptor-1 kinase.

  20. Bioactive sesquiterpene coumarins from Ferula pseudalliacea.

    Science.gov (United States)

    Dastan, Dara; Salehi, Peyman; Reza Gohari, Ahmad; Ebrahimi, Samad Nejad; Aliahmadi, Atousa; Hamburger, Matthias

    2014-08-01

    One new and five known sesquiterpene coumarins were isolated from the roots of Ferula pseudalliacea. The structures were elucidated by 1D and 2D NMR, and HR-ESIMS data as 4'-hydroxy kamolonol acetate (1), kamolonol (2), szowitsiacoumarin A (3), farnesiferon B (4), farnesiferol C (5), and flabellilobin A (6). The absolute configuration of compounds 1, 2, and 4 was established by comparison of experimental and simulated electronic circular dichroism spectra using time dependence density function theory. 4'-Hydroxy kamolonol acetate and kamolonol showed antibacterial activity against Heliobacter pylori and Staphylococcus aureus at a concentration of 64 µg/mL. Kamolonol, 4'-hydroxy kamolonol acetate, and farnesiferon B displayed a cytotoxic activity in HeLa cells, with an IC50 of 3.8, 4.5, and 7.7 µM, respectively.

  1. Coumarins from the leaves of Bambusa pervariabilis McClure.

    Science.gov (United States)

    Sun, Jia; Yue, Yong-De; Tang, Feng; Guo, Xue-Feng

    2010-03-01

    A new pyrone-coumarin, 7,8-dihydroxy-3-(3-hydroxy-4-oxo-4H-pyran-2-yl)-2H-chromen-2-one (1), along with two known coumarins, scopoletin (2) and scopolin (3), was isolated from the 95% EtOH extract of the leaves of Bambusa pervariabilis McClure. Their structures were determined on the basis of spectroscopic techniques and chemical methods.

  2. 基于四甲基久洛尼定为原料的香豆素衍生物的合成%Synthesis of Coumarin Derivatives Based on Tetramethy Cjuloidine as Raw Material

    Institute of Scientific and Technical Information of China (English)

    吴华彪; 韩亮; 祖晓燕; 李郁锦; 叶青; 高建荣

    2014-01-01

    以间氨基苯酚和溴代异戊烯为起始原料经过亲核取代制备了N,N-二(3-甲基-2-丁烯)-3-羟基苯胺氢溴酸盐,通过亲电取代关环合成了8-羟基-1,1,7,7-四甲基久洛尼定,再经Vilsmeir-Haack反应引入醛基获得了9-甲酰基-8-羟基-1,1,7,7-四甲基久洛尼定,总收率为25.7%。对N,N-二(3-甲基-2-丁烯)-3-羟基苯胺氢溴酸盐的合成进行了工艺探索,结果表明当间氨基苯酚和溴代异戊烯投料比为1:2,CaCO3为缚酸剂时得到的收率较佳。以9-甲酰基-8-羟基-1,1,7,7-四甲基久洛尼定为原料,分别与噻吩乙腈、对溴苯乙腈进行缩合反应制备得到3-芳基香豆素衍生物,对其结构进行了核磁鉴定,并对其紫外光谱进行了测试。%N,N-Bis (3-methyl-2-butene)-3-hydroxyanilin hydrobromide was prepared from m-aminophenol and 1-bromo-3-methyl-2-butene via nucleophilic substitution reaction at first. Then 8-hydrox-y-1,1,7,7-tetramethyljulolidine was synthesized by electrophilic substitution. And aldehyde group was intro-duced to prepare 9-formyl-8-hydroxy-1,1,7,7-tetramethyljulolidine through Vilsmeir-Haack reaction. Reac-tion conditions for synthesis of N,N-bis (3-meyhyl-2-butene)-3-hydroxyanilin hydrobromide was explored, and the results showed that when the ratio of m-aminophenol and 1-bromo-3-methyl-2-butene was 1:2 and calcium carbonate was used as acid-binding agent, the yield was optimum. Then 9-formyl-8-hydroxy-1,1,7,7-tetramethyljulolidine reacted with 2-thiopheneacetonitrile or 4-bromophenylacetonitrile to prepare two 3-arylcoumarin derivatives. The structure of the derivative and products were identified by 1H NMR spectroscopy. And the UV spectra of target products were tested.

  3. [Allelopathy effects of ferulic acid and coumarin on Microcystis aeruginosa].

    Science.gov (United States)

    Guo, Ya-Li; Fu, Hai-Yan; Huang, Guo-He; Gao, Pan-Feng; Chai, Tian; Yan, Bin; Liao, Huan

    2013-04-01

    The inhibitory effects and allelopathy mechanism of ferulic acid and coumarin on Microcystis aeruginosa were investigated by measuring the D680 value, the content of chlorophyll-a, the electrical conductivity (EC) and superoxide anion radical O*- value. Ferulic acid and coumarin had allelopathic effects on the growth of M. aeruginosa and promoted the physiological metabolism at low concentrations while inhibited the metabolism at high concentrations. Obvious inhibitory effects were observed when the concentration of ferulic acid or coumarin was over 100 mg x L(-1). The average inhibitory rates reached 80.3% and 58.0% after six days when the concentration of ferulic acid or coumarin was 200 mg x L(-1). The content of chlorophyll-a was decreased while the EC value and O2*- concentration were promoted by higher concentrations of ferulic acid or coumarin, suggesting that the growth of algae was inhibited probably by the damage of cell membrane, increase in the content of O2*- and decrease in the content of chlorophyll-a. In addition, seed germination test elucidated that Ferulic acid was safer than Coumarin.

  4. Cytotoxic Activity of Some Novel Dicoumarin Derivatives in vitro

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hui; YU Tian-zhi; ZHAO Yu-ling; FAN Duo-wang; DING Lan; ZHANG Shi-dong

    2009-01-01

    Some novel dicoumarin derivatives, triethylene-glycol dibenzo[5,6] coumarin-3-carboxylate(1a). PEG (600) dibenzo[5,6]coumarin-3-carboxylate(1b), triethylene-glycol di[7-(N,N'-diethylamino)]-coumarin-3-carboxy-late(2a), were synthesized. The cytotoxic effect of these compounds, along with benzo[5,6]coumarin-3-carboxylic acid(1) and 7-(N,N'-diethylamino)-coumarin-3-carboxylic acid(2), against the SGC-7901 cell lines were determined by Sulforhodamine B(SRB) assay. The preliminary cytotoxicity screening process revealed that the investigated dicoumarin derivatives induced 50% inhibition of the cell viability of SGC-7901 cells at micromolar concentrations. Compound 2a was proved superior to compound la according to the IC_(50) values obtained and the agent with PEG moiety has more contribution to cell-killing ability of the molecules than the remaining agents.

  5. Application of chitin and chitosan as elicitors of coumarins and fluoroquinolone alkaloids in Ruta graveolens L. (common rue).

    Science.gov (United States)

    Orlita, Aleksandra; Sidwa-Gorycka, Matylda; Paszkiewicz, Monika; Malinski, Edmund; Kumirska, Jolanta; Siedlecka, Ewa M; Łojkowska, Ewa; Stepnowski, Piotr

    2008-10-01

    Common rue (Ruta graveolens L.) accumulates various types of secondary metabolites, such as coumarins furanocoumarins, acridone and quinolone alkaloids and flavonoids. Elicitation is a tool extensively used for enhancing secondary-metabolite yields. Chitin and chitosan are examples of elicitors inducing phytoalexin accumulation in plant tissue. The present paper describes the application of chitin and chitosan as potential elicitors of secondary-metabolite accumulation in R. graveolens shoots cultivated in vitro. The simple coumarins, linear furanocoumarins, dihydrofuranocoumarins and fluoroquinolone alkaloids biosynthesized in the presence of chitin and chitosan were isolated, separated and identified. There was a significant increase in the growth rate of R. graveolens shoots in the presence of either chitin or chitosan. Moreover, the results of the elicitation of coumarins and alkaloids accumulated by R. graveolens shoots in the presence of chitin and chitosan show that both compounds induced a significant increase in the concentrations of nearly all the metabolites. Adding 0.01% chitin caused the increase in the quantity (microg/g dry weight) of coumarins (pinnarin up to 116.7, rutacultin up to 287.0, bergapten up to 904.3, isopimpinelin up to 490.0, psoralen up to 522.2, xanhotoxin up to 1531.5 and rutamarin up to 133.7). The higher concentration of chitosan (0.1%) induced production of simple coumarins (pinnarin up to 116.7 and rutacultin up to 287.0), furanocoumarins (bergapten up to 904.3, isopimpinelin up to 490.0, psoralen up to 522.2, xanhotoxin up to 1531.5) and dihydrofuranocoumarins (chalepin up to 18 and rutamarin up to 133.7). Such a dramatic increase in the production of nearly all metabolites suggests that these compounds may be participating in the natural resistance mechanisms of R. graveolens. The application of chitin- and chitosan-containing media may be considered a promising prospect in the biotechnological production of xanthotoxin

  6. Coumarin pretreatment alleviates salinity stress in wheat seedlings.

    Science.gov (United States)

    Saleh, Ahmed Mahmoud; Madany, M M Y

    2015-03-01

    The potentiality of COU to improve plant tolerance to salinity was investigated. Wheat grains were primed with COU (50 ppm) and then grown under different levels of NaCl (50, 100, 150 mM) for two weeks. COU pretreatment improved the growth of wheat seedling under salinity, relative to COU-untreated seedlings, due to the accumulation of osmolytes such as soluble sugars and proline. Moreover, COU treatment significantly improved K(+)/Na(+) ratio in the shoots of both salt stressed and un-stressed seedlings. However, in the roots, this ratio increased only under non-salinity. In consistent with phenylalanine ammonia lyase (PAL), phenolics and flavonoids were accumulated in COU-pretreated seedlings under the higher doses of salinity, relative to COU-untreated seedlings. COU primed seedlings showed higher content of the coumarin derivative, scopoletin, and salicylic, chlorogenic, syringic, vanillic, gallic and ferulic acids, under both salinity and non-salinity conditions. Salinity stress significantly improved the activity of peroxidase (POD) in COU-pretreated seedlings. However, the effect of COU on the total antioxidant capacity (TAC) was only obtained at the highest dose of NaCl (150 mM). The present results suggest that COU pretreatment could alleviate the adverse effect of salinity on the growth of wheat seedlings through enhancing, at least partly, the osmoregulation process and antioxidant defense system.

  7. Artificial evolution of coumarin dyes for dye sensitized solar cells.

    Science.gov (United States)

    Venkatraman, Vishwesh; Abburu, Sailesh; Alsberg, Bjørn Kåre

    2015-11-07

    The design and discovery of novel molecular structures with optimal properties has been an ongoing effort for materials scientists. This field has in general been dominated by experiment driven trial-and-error approaches that are often expensive and time-consuming. Here, we investigate if a de novo computational design methodology can be applied to the design of coumarin-based dye sensitizers with improved properties for use in Grätzel solar cells. To address the issue of synthetic accessibility of the designed compounds, a fragment-based assembly is employed, wherein the combination of chemical motifs (derived from the existing databases of structures) is carried out with respect to user-adaptable set of rules. Rather than using computationally intensive density functional theory (DFT)/ab initio methods to screen candidate dyes, we employ quantitative structure-property relationship (QSPR) models (calibrated from empirical data) for rapid estimation of the property of interest, which in this case is the product of short circuit current (Jsc) and open circuit voltage (Voc). Since QSPR models have limited validity, pre-determined applicability domain criteria are used to prevent unacceptable extrapolation. DFT analysis of the top-ranked structures provides supporting evidence of their potential for dye sensitized solar cell applications.

  8. Vascular ring

    Science.gov (United States)

    ... subclavian and left ligamentum ateriosus; Congenital heart defect - vascular ring; Birth defect heart - vascular ring ... Vascular ring is rare. It accounts for less than 1% of all congenital heart problems. The condition ...

  9. Photochemistry of 1,4-Dihydropyridine Derivatives: Diradical Formation, Delocalization and Trapping as a Route to Novel Tricyclic and Tetracyclic Nitrogen Heterocyclic Ring Systems

    Directory of Open Access Journals (Sweden)

    Nader A. Al-Jalal

    2016-06-01

    Full Text Available Irradiation of an acetonitrile solution of 4-aryl-3,5-dibenzoyl-1,4-dihydropyridine derivatives 1a–c and maleimides 2a–c using medium pressure Hg-arc lamp (λ > 290 nm afforded three different cycloadducts 4, 5, 6 in addition to the oxidation products 3. These results indicate that compounds 1a–c undergoes intermolecular cycloaddition reaction through three biradical intermediates and behave photochemically different than those reported previously for the analogous 3,5-diacetyl and 3,5-dicarboxylic acid derivatives. The present work also offers simple access to novel tricyclic and tetracyclic nitrogen heterocyclic ring systems of potential biological and synthetic applications. The structure of the photoproducts was established spectroscopically and by single crystal X-ray crystallography.

  10. Anticholinesterase activity evaluation of alkaloids and coumarin from stems of Conchocarpus fontanesianus

    Directory of Open Access Journals (Sweden)

    Rodrigo S. Cabral

    2012-04-01

    Full Text Available Conchocarpus fontanesianus (A. St.-Hill. Kallunki & Pirani, Rutaceae, popularly known as pitaguará, is a native and endemic tree from São Paulo and Rio de Janeiro States, Brazil. Based in the information that anticholinesterasic derivatives could act as new prototypes to treatment of Alzheimer disease, this work describes the fractionation guided by evaluation of the anticholinesterase activity of the ethanolic stems extract from C. fontanesianus. This procedure afforded the alkaloids dictamnine (1, γ-fagarine (2, skimianine (3, and 2-phenyl-1-methyl-4-quinolone (4, as well as the coumarin marmesin (5.

  11. Synthesis of modified pyridine and bipyridine substituted coumarins as potent antimicrobial agents

    Directory of Open Access Journals (Sweden)

    Lad Hemali B.

    2015-01-01

    Full Text Available In search for new antimicrobial agents a series of new modified pyridine and bipyridine substituted coumarins 5a-y was designed and synthesized by adopting molecular hybridization strategy. All the synthesized compounds were evaluated for their in vitro antimicrobial activity using broth dilution method against selected bacterial (Gram-positive and Gram-negative and fungal strains. Compounds 5a, 5f, 5g, 5n, 5r, 5t, 5w, 5x and 5y demonstrated promising antibacterial activity while other derivatives showed comparable activity to standard drugs used as reference.

  12. Novel coumarin-based fluorescent probe for selective detection of Cu(II)

    Science.gov (United States)

    Bekhradnia, Ahmadreza; Domehri, Elham; Khosravi, Masome

    2016-01-01

    We report an efficient and convenient method for preparing nitro-3-carboxamide coumarin derivatives, proposed as novel fluorescent chemosensor, through microwave irradiation. This compound can be used as fluorescent probe for Cu2+ with selectivity over other metal ions in aqueous solution. The fluorescence of 6-nitro-N-[2-(dimethylamino)ethyl]-2-oxo-2H-chromene-3-carboxamide(3) is the highest in the presence of Cu2+, with stronger excitation at λ = 320 nm than for the other cations tested.

  13. Synthesis of new conjugated coumarin-benzimidazole hybrids and their anticancer activity.

    Science.gov (United States)

    Paul, Kamaldeep; Bindal, Shweta; Luxami, Vijay

    2013-06-15

    A series of novel coumarin-benzimidazole hybrids, 3-(1H-benzo[d]imidazol-2-yl)-7-(substituted amino)-2H-chromen-2-one derivatives of biological interest were synthesized. Six out of the newly synthesized compounds were screened for in vitro antitumor activity against preliminary 60 tumor cell lines panel assay. A significant inhibition for cancer cells was observed with compound 8 (more than 50% inhibition) compared with other compounds and active known drug 5-fluorouracil (in some cell lines) as positive control. Compound 8 displayed appreciable anticancer activities against leukemia, colon cancer and breast cancer cell lines.

  14. Synthesis and biological activity of some heterocyclic compounds containing quinoxaline and coumarin moieties

    Directory of Open Access Journals (Sweden)

    M. E. ABD EL-FATTAH

    2000-02-01

    Full Text Available 2,3-Dichloroquinoxaline (2 condensed with 7,8-dihydroxy-4-methylcoumarin to give the 1,4-dioxane derivative 4. 2.3-Dichloroquinoxaline (2 reacted with 4-hydroxycoumarin, 7-hydroxy-4-methylcoumarin and acyl hydrazide 13 to give either the 2,3-(dicoumarin-4-yloxyquinoxaline (6 or the 2,3-di-(4-methylcoumarin-7-yloxyquinoxaline (7 or the 2-chloro-3-(coumarin-4-yloxyquinoxaline (8 or the 2-chloro-3-(4-methylcoumarin-7-yloxy quinoxaline (9 or the ditriazoloquinoxaline 14 or the oxa-diazinoquinoxaline 16, depending on the relative ratios of the reactants and the reaction conditions.

  15. Interest of antioxidant agents in parasitic diseases. The case study of coumarins.

    Science.gov (United States)

    Figueroa-Guiñez, Roberto; Matos, Maria João; Vazquez-Rodriguez, Saleta; Santana, Lourdes; Uriarte, Eugenio; Borges, Fernanda; Olea-Azar, Claudio; Maya, Juan Diego

    2015-01-01

    Tropical parasitic diseases, especially those produced by protozoan parasites, are a major public health problem in many countries, and their impact in the health burden is significant. Oxidative processes proved to be related to these diseases, being the antioxidant agents promising therapeutic solutions for them. Therefore, this review provides an overview of published manuscripts regarding both activities. In particular, the interest of the coumarin derivatives as antioxidant agents with application in parasitic diseases is discussed in this manuscript. The recent findings in this field are highlighted.

  16. Synthesis and biological activity of some heterocyclic compounds containing quinoxaline and coumarin moieties

    OpenAIRE

    M. E. ABD EL-FATTAH; I. M. EL-DEEN

    2000-01-01

    2,3-Dichloroquinoxaline (2) condensed with 7,8-dihydroxy-4-methylcoumarin to give the 1,4-dioxane derivative 4. 2.3-Dichloroquinoxaline (2) reacted with 4-hydroxycoumarin, 7-hydroxy-4-methylcoumarin and acyl hydrazide 13 to give either the 2,3-(dicoumarin-4-yloxy)quinoxaline (6) or the 2,3-di-(4-methylcoumarin-7-yloxy)quinoxaline (7) or the 2-chloro-3-(coumarin-4-yloxy)quinoxaline (8) or the 2-chloro-3-(4-methylcoumarin-7-yloxy) quinoxaline (9) or the ditriazoloquinoxaline 14 or the oxa-diazi...

  17. Synthesis, Leishmanicidal and Cytotoxic Activity of Triclosan-Chalcone, Triclosan-Chromone and Triclosan-Coumarin Hybrids

    OpenAIRE

    Elver Otero; Sebastián Vergara; Robledo, Sara M.; Wilson Cardona; Miguel Carda; Vélez,Ivan D; Carlos Rojas; Felipe Otálvaro

    2014-01-01

    Twelve hybrids derived from triclosan were obtained via Williamson etherification of O-triclosan alkyl bromide plus chalcone and O-coumarin or O-chromone alkyl bromide plus triclosan, respectively. Structures of the products were elucidated by spectroscopic analysis. The synthesized compounds were evaluated for antileishmanial activity against L. (V) panamensis amastigotes. Cytotoxic activity was also evaluated against mammalian U-937 cells. Compounds 7–9 and 17, were active against Leishmani...

  18. Synthesis and Antimicrobial Activity of Some Novel Chalcones of 2-Hydroxy -1-Acetonapthone and 3-Acetyl Coumarin

    OpenAIRE

    2006-01-01

    Five novel chalcones were synthesised by condensing 2-hydroxy-1-acetonaphthone with aldehyde derivatives in dilute ethanolic potassium hydroxide solution at room temperature according to Claisen-Schmidt condensation and another five novel chalcones were prepared by refluxing 3-acetyl coumarin with aldehydes in the presence of piperidine in ethanol. All these compounds were characterised by means of their IR, 1H NMR spectroscopic data and microanalyses. The antimicrobial activity of these comp...

  19. Synthesis and Antimicrobial Activity of Some Novel Chalcones of 2-Hydroxy -1-Acetonapthone and 3-Acetyl Coumarin

    Directory of Open Access Journals (Sweden)

    Y. Rajendra Prasad

    2006-01-01

    Full Text Available Five novel chalcones were synthesised by condensing 2-hydroxy-1-acetonaphthone with aldehyde derivatives in dilute ethanolic potassium hydroxide solution at room temperature according to Claisen-Schmidt condensation and another five novel chalcones were prepared by refluxing 3-acetyl coumarin with aldehydes in the presence of piperidine in ethanol. All these compounds were characterised by means of their IR, 1H NMR spectroscopic data and microanalyses. The antimicrobial activity of these compounds were evaluated by the cup plate method.

  20. A fluorescent receptor assay for benzodiazepines using coumarin labeled desethylflumazenil as ligand

    NARCIS (Netherlands)

    Janssen, M.J; Ensing, K; de Zeeuw, R.A

    2001-01-01

    This article describes a novel nonisotopic receptor assay for benzodiazepines with fluorescence detection, As labeled ljgand (coumarin-labeled desethylflumazenil, CLDEF), a metabolite of the benzodiazepine antagonist flumazenil (desetheylflumazenil, Ro15-3890) has been coupled to a coumarin fluoroph

  1. Tetracyclic triterpenoids and terpenylated coumarins from the bark of Ailanthus altissima ("Tree of Heaven").

    Science.gov (United States)

    Hong, Zhi-Lai; Xiong, Juan; Wu, Shi-Biao; Zhu, Jing-Jing; Hong, Jun-Lin; Zhao, Yun; Xia, Gang; Hu, Jin-Feng

    2013-02-01

    Tetracyclic triterpenoids (named as altissimanins A-E, 1-5) and a terpenylated coumarin (denominated as altissimacoumarin G, 6), along with fifteen known compounds (7-21) were isolated from the bark of Ailanthus altissima. Structures of compounds 1-6 were established by spectroscopic methods and chemical transformations. Altissimanin A (1) is a tirucallane-type triterpenoid bearing an uncommon oxetane ring in the side-chain, while altissimanins D (4) and E (5) are two unprecedented dimers each consisting of one tirucallane-type and one dammarane-type triterpenoid moiety. All the isolates were evaluated for their cytotoxic effects against a small panel of human cancer cell lines. Copyright © 2012 Elsevier Ltd. All rights reserved.

  2. Spectral and quantum-mechanical characterizations of 7-amino-4-trifluoromethyl coumarin

    Science.gov (United States)

    Benchea, Andreea Celia; Gaina, Marius; Dorohoi, Dana Ortansa

    2017-01-01

    Coumarins are crystalline compounds utilized in pharmaceutical, food and cosmetic industries. Our study refers to quantum-mechanical and spectral characterization of 7-amino-4-trifluoromethyl coumarin (7-NH2-4-CF3-coumarin or coumarin 151) in order to estimate its stability, reactivity and biological activity. The contribution of different types of interactions to the spectral shifts in homogeneous solutions and the limits in which the excited state dipole moment of the studied molecule can vary are established by solvatochromic study.

  3. Is worst-case scenario streamflow drought underestimated in British Columbia? A multi-century perspective for the south coast, derived from tree-rings

    Science.gov (United States)

    Coulthard, Bethany; Smith, Dan J.; Meko, David M.

    2016-03-01

    Recent streamflow droughts in south coastal British Columbia have had major socioeconomic and ecological impacts. Increasing drought severity under projected climate change poses serious water management challenges, particularly in the small coastal watersheds that serve as primary water sources for most communities in the region. A 332-year dendrohydrological record of regionalized mean summer streamflow for four watersheds is analyzed to place recent drought magnitudes in a long-term perspective. We present a novel approach for optimizing tree-ring based reconstructions in small watersheds in temperate environments, combining winter snow depth and summer drought sensitive proxies as model predictors. The reconstruction model, estimated by regression of observed flows on Tsuga mertensiana ring-width variables and a tree-ring derived paleorecord of the Palmer Drought Severity Index, explains 64% of the regionalized streamflow variance. The model is particularly accurate at estimating lowest flow events, and provides the strongest annually resolved paleohydrological record in British Columbia. The extended record suggests that since 1658 sixteen natural droughts have occurred that were more extreme than any within the instrumental period. Flow-duration curves show more severe worst-case scenario droughts and a higher probability of those droughts in the long-term reconstruction than in the hydrometric data. Such curves also highlight the value of dendrohydrology for probabilistic drought assessment. Our results suggest current water management strategies based on worst-case scenarios from historical gauge data likely underestimate the potential magnitudes of natural droughts. If the low-flow magnitudes anticipated under climate change co-occur with lowest possible natural flows, streamflow drought severities in small watersheds in south coastal British Columbia could exceed any of those experienced in the past ∼350 years.

  4. Ring blowers. Ring blower

    Energy Technology Data Exchange (ETDEWEB)

    Nakahara, Y.; Okamura, T.; Takahashi, M. (Fuji Electric Co. Ltd., Tokyo (Japan))

    1991-06-10

    Features, structures and several products of ring blowers were outlined. The ring blower is featured by its medium characteristics because it is higher in air pressure than a turboblower and larger in airflow than a vane blower, and it is applicable flexibly to not only air blasting but various industrial fields such as suction transfer. As several products corresponding to various fields, the followings were outlined: the low noise type with optimum shapes of inlet, outlet and casing cover for reducing noises by 10 dB or more, the heat resistant, water-tight and explosion-proof types suitable for severe environmental conditions, the multi-voltage type for every country served at different voltages, the high air pressure type with two pressure rise stages, and the large airflow type with a wide impeller. In addition, as special use products, the glass fiber reinforced unsatulated polyester ring blower for respiration apparatus, and the variable speed blushless DC motor-driven one for medical beds were outlined. 2 refs., 9 figs., 1 tab.

  5. Zirconium and hafnium complexes bearing pyrrolidine derived salalen-type {ONNO} ligands and their application for ring-opening polymerization of lactides.

    Science.gov (United States)

    Duan, Yu-Lai; Hu, Zhi-Jian; Yang, Bo-Qun; Ding, Fei-Fei; Wang, Wei; Huang, Yong; Yang, Ying

    2017-08-29

    The reactions of pyrrolidine derived salalen-type {ONNO} ligands (S)-L(1-3)-H2 with 1 equiv. M(O(i)Pr)4(HO(i)Pr) (M = Zr or Hf) in diethyl ether yielded complexes [L(1-3)M(O(i)Pr)2] (L = L(1), M = Zr (1); L = L(2), M = Zr (2), Hf (3); L = L(3), M = Zr (4), Hf (5)). All of these complexes were well characterized by NMR spectroscopy, elemental analyses and single-crystal X-ray analysis in the case of complexes 1 and 3-5. X-ray structural determination revealed that these complexes were analogous mononuclear species and had a similar structure in which the metal centers were six-coordinated to two oxygen atoms and two nitrogen atoms of one ligand and two oxygen atoms of two isopropoxy groups. All of these complexes efficiently initialized the ring-opening polymerization of lactides to afford polymers with controlled molecular weight and narrow polydispersity. Furthermore, the ring-opening polymerization of rac-lactide catalyzed by complexes 1-5 afforded isotactic-enriched polymers in solution (Pm = 0.74-0.80) and under melt conditions (Pm = 0.63-0.72).

  6. Ring-shaped silafluorene derivatives as efficient solid-state UV-fluorophores: synthesis, characterization, and photoluminescent properties.

    Science.gov (United States)

    Cai, Yuanjing; Samedov, Kerim; Dolinar, Brian S; Albright, Haley; Guzei, Ilia A; Hu, Rongrong; Zhang, Chaocan; West, Robert

    2014-10-20

    Four ring-shaped silafluorene-containing compounds (1-4) were synthesized and characterized as potentially promising monomers for fluorescent polymers. Their optical properties in solution and solid state (thin film and powder) were studied. These compounds have low quantum yields in solution (Φ(fl)=0.13-0.15) with fluorescence maxima at about 355 nm, but high quantum yields in the solid state (powder, Φ(fl)=0.35-0.54) with fluorescence maxima at about 377 and 488 nm. Influence of the substituents and the number of silafluorene units in 1-4 on their optical properties was investigated. Extensive study of the X-ray crystal structures of 1-4 was undertaken to analyze and qualitatively estimate the role, extent, and influence of silafluorene moieties' interactions on solid-state fluorescent properties. Excited state UV/Vis and theoretical molecular orbital (MO) calculations were performed to explore possible fluorescence mechanisms and differences in quantum yields among these compounds.

  7. Structure and tautomerism of cyclopentadiene derivatives. I. Reversible migrations of a nitro group in the cyclopentadiene ring

    Energy Technology Data Exchange (ETDEWEB)

    Mikhailov, I.E.; Kompan, O.E.; Struchkov, Yu.T.; Minkin, V.I.; Dushenko, G.A.; Klenkin, A.A.; Olekhnovich, L.P.

    1987-10-20

    Intramolecular migrations of the nitro group around the perimeter of the five-membered ring, which take place during the mutual transformations of 5-nitro-5-alkyl-1,2,3,4- and 5-nitro-2-alkyl-1,3,4,5-tetramethoxycarbonylcyclopentadienes with a free energy of activation (..delta..G/sup= //sub 298/) of 100.2-111.2 kJ/mole, were detected and investigated by PMR spectroscopy. The effect of steric and electronic factors on the activation parameters of the rearrangements of the nitro group and also on the position of equilibrium between the isomers formed during the rearrangements was studied. The structure of such isomers was proved by x-ray crystallographic analysis for the case of 5-nitro-5-methyl-1,2,3,4- and 5-nitro-2-methyl-1,3,4,5-tetramethoxycarbonylcyclopentadienes and also 5-nitro-1,2,3,4,5-pentamethoxycarbonylcyclopentadiene. The /sup 1/H NMR spectra were obtained on a Tesla BS-487C spectrometer at 80 MHz with adiabatic signal transmission in chlorobenzene solutions.

  8. Tetrapeptide-coumarin conjugate 3D networks based on hydrogen-bonded charge transfer complexes: gel formation and dye release.

    Science.gov (United States)

    Guo, Zongxia; Gong, Ruiying; Jiang, Yi; Wan, Xiaobo

    2015-08-14

    Oligopeptide-based derivatives are important synthons for bio-based functional materials. In this article, a Gly-(L-Val)-Gly-(L-Val)-coumarin (GVGV-Cou) conjugate was synthesized, which forms 3D networks in ethanol. The gel nanostructures were characterized by UV-vis spectroscopy, FT-IR spectroscopy, X-ray diffraction (XRD), SEM and TEM. It is suggested that the formation of charge transfer (CT) complexes between the coumarin moieties is the main driving force for the gel formation. The capability of the gel to encapsulate and release dyes was explored. Both Congo Red (CR) and Methylene Blue (MB) can be trapped in the CT gel matrix and released over time. The present gel might be used as a functional soft material for guest encapsulation and release.

  9. Coumarin-based fluorescence hybrid silica material used for selective detection and absorption of Hg2+ in aqueous media

    Science.gov (United States)

    Meng, Qingtao; Jia, Hongmin; Wang, Cuiping; Zhao, Hongbin; Lu, Gonghao; Hu, Zhizhi; Zhang, Zhiqiang; Duan, Chunying

    2014-11-01

    An inorganic-organic hybrid fluorescence material (C-SBA-15) was prepared by covalent immobilization of a coumarin derivative within the channels of SBA-15. The characterization results of XRD, TEM micrographs, FT-IR and UV-vis demonstrate that coumarin is successfully grafted onto the inner surface of SBA-15 and its organized structure is preserved. C-SBA-15 can detect Hg2+ with high selectivity to Pb2+, Zn2+, Cu2+, Mn2+, Cd2+, Co2+, Ag+, Fe3+, Ni2+, K+, Na+, Ca2+, Mg2+ and Li+ in water. Furthermore, the fluorogenical response is reversible by treating with EDTA and do not vary over a broad pH range (5.0-10.5). C-SBA-15 features more outstanding absorbing capacity for Hg2+ among other HTM ions in water.

  10. Triazole tethered C5-curcuminoid-coumarin based molecular hybrids as novel antitubulin agents: Design, synthesis, biological investigation and docking studies.

    Science.gov (United States)

    Singh, Harbinder; Kumar, Mandeep; Nepali, Kunal; Gupta, Manish K; Saxena, Ajit K; Sharma, Sahil; Bedi, Preet Mohinder S

    2016-06-30

    Keeping in view the confines allied with presently accessible antitumor agents and success of C5-curcuminoid based bifunctional hybrids as novel antitubulin agnets, molecular hybrids of C5-curcuminoid and coumarin tethered by triazole ring have been synthesized and investigated for in-vitro cytotoxicity against THP-1, COLO-205, HCT-116 and PC-3 human tumor cell lines. The results revealed that the compounds A-2 to A-9, B-2, B-3, B-7 showed significant cytotoxic potential against THP-1, COLO-205 and HCT-116 cell lines, while the PC-3 cell line among these was found to be almost resistant. Structure activity relationship revealed that the nature of Ring X and the length of carbon-bridge (n) connecting triazole ring with coumarin moiety considerably influence the activity. Methoxy substituted phenyl ring as Ring X and two carbon-bridges were found to be the ideal structural features. The most potent compounds (A-2, A-3 and A-7) were further tested for tubulin polymerization inhibition. Compound A-2 was found to significantly inhibit the tubulin polymerization (IC50 = 0.82 μM in THP-1 tumor cells). The significant cytotoxicity and tubulin polymerization inhibition by A-2 was further rationalized by docking studies where it was docked at the curcumin binding site of tubulin.

  11. Design and Synthesis of a Coumarin-based Acidichromic Colorant

    Directory of Open Access Journals (Sweden)

    Ding-Yah Yang

    2007-07-01

    Full Text Available This paper describes the fine-tuning of the acidichromic properties of a coumarin-containing colorant 1 by incorporation of electron-donating and electron-withdrawing substituents on the coumarin moiety. Colorant 1 can undergo two distinct and reversible color changes under both strongly acidic and basic conditions, but not in the presence of gaseous ammonia. The results indicated that the bromo-substituted compound 5b changes from red to yellow when exposed to gaseous ammonia, both in solution and on polycarbonate film, suggesting that an electron-withdrawing group at the 7-position of the coumarin moiety made the enolic hydrogen on 5b more susceptible to deprotonation by a base than in the unsubstituted compound 1.

  12. SYNTHESIS OF SOME CINNAMIC ACID DERIVATIVES: EFFECT OF GROUPS ATTACHED ON AROMATIC RING TO THE REACTIVITY OF BENZALDEHYDE

    Directory of Open Access Journals (Sweden)

    Marcellino Rudyanto

    2010-06-01

    Full Text Available Synthesis of cinnamic acid and its six derivatives has been done by employing Knoevenagel reaction. Benzaldehyde, 4-butylbenzaldehyde, 4-t-butylbenzaldehyde, 4-butoxybenzaldehyde, 4-phenylbenzaldehyde, 5-bromo-2,4-dimethoxybenzaldehyde, and 5-bromo-2,3-dimethoxybenzaldehyde were reacted with malonic acid in pyridine – piperidine to give cinnamic acid (85,3%, 4-butylcinnamic acid (69,3%, 4-t-butylcinnamic acid (77,7%, 4-butoxycinnamic acid (64,5%, 4-phenylcinnamic acid (65,5%, 5-bromo-2,4-dimethoxycinnamic acid (53,2% and 5-bromo-2,4-dimethoxycinnamic acid (57,2%, respectively. It was disclosed that 4-alkyl, 4-alkoxy, 4-aryl, dan 2-alkoxy groups decrease the reactivity of carbonyl carbon of benzaldehyde.   Keywords: cinnamic acid, cinnamic acid derivatives, Knoevenagel reaction

  13. A 200-year reconstruction of Kocasu River (Sakarya River Basin, Turkey) streamflow derived from a tree-ring network

    Science.gov (United States)

    Güner, Hüseyin Tuncay; Köse, Nesibe; Harley, Grant L.

    2017-03-01

    The Sakarya River Basin (SRB) contains one of the most important agricultural areas for Turkey. Here, we use a network of 18 tree-ring chronologies and present a reconstruction of the mean June-July Kocasu River discharge, one of the main channels in the SRB, during the period 1803-2002 CE, and place the short period of instrumental flows (since 1953 CE) into historical context. Over the past two centuries, we found 33 dry and 28 wet events and observed the longest wet period between the years 1880 and 1920. The driest years were 1845 and 1873, and the wettest years were 1859 and 1960. Our reconstruction showed that the extreme short-term drought events that occurred in recent years were minor compared to the severity and duration of droughts that occurred previous to instrumental data. We found four pre-instrumental severe and sustained low streamflow events during the periods 1819-1834, 1840-1852, 1861-1875, and 1925-1931, during which historical records show reduced agricultural production, death, famine, plague, economic crisis, and widespread human migrations. More concerning, however, are current hydroclimate conditions in the SRB, marked by decadal-scale mean flows that dip below the long-term mean (1803-1953) in the late 1970s and have since failed to recover. With the Mediterranean region currently likely experiencing the worst drought in the past ca 1000 years due to human-induced climate change, the future outlook of water resource availability in the SRB could prove catastrophic for human and natural systems.

  14. A 200-year reconstruction of Kocasu River (Sakarya River Basin, Turkey) streamflow derived from a tree-ring network

    Science.gov (United States)

    Güner, Hüseyin Tuncay; Köse, Nesibe; Harley, Grant L.

    2016-08-01

    The Sakarya River Basin (SRB) contains one of the most important agricultural areas for Turkey. Here, we use a network of 18 tree-ring chronologies and present a reconstruction of the mean June-July Kocasu River discharge, one of the main channels in the SRB, during the period 1803-2002 CE, and place the short period of instrumental flows (since 1953 CE) into historical context. Over the past two centuries, we found 33 dry and 28 wet events and observed the longest wet period between the years 1880 and 1920. The driest years were 1845 and 1873, and the wettest years were 1859 and 1960. Our reconstruction showed that the extreme short-term drought events that occurred in recent years were minor compared to the severity and duration of droughts that occurred previous to instrumental data. We found four pre-instrumental severe and sustained low streamflow events during the periods 1819-1834, 1840-1852, 1861-1875, and 1925-1931, during which historical records show reduced agricultural production, death, famine, plague, economic crisis, and widespread human migrations. More concerning, however, are current hydroclimate conditions in the SRB, marked by decadal-scale mean flows that dip below the long-term mean (1803-1953) in the late 1970s and have since failed to recover. With the Mediterranean region currently likely experiencing the worst drought in the past ca 1000 years due to human-induced climate change, the future outlook of water resource availability in the SRB could prove catastrophic for human and natural systems.

  15. Evaluation of antioxidant properties of monoaromatic derivatives of pulvinic acids.

    Science.gov (United States)

    Habrant, Damien; Poigny, Stéphane; Ségur-Derai, Muriel; Brunel, Yves; Heurtaux, Benoît; Le Gall, Thierry; Strehle, Axelle; Saladin, Régis; Meunier, Stéphane; Mioskowski, Charles; Wagner, Alain

    2009-04-23

    The natural mushroom pigment Norbadione A and three other pulvinic acids were shown by our group to display very efficient antioxidant properties by comparison with a collection of potent molecules including catechols, flavonoids, stilbenes, or coumarins. Despite numerous publications on robust and straightforward synthetic access to pulvinic acids by us and others, no report has been made to unravel the structure-activity relationships that govern the striking antioxidant activity. Herein is presented the synthesis of 18 diverse pulvinic acid derivatives and the study of their radical scavenging capacities by four different assays. The influence of each of the two phenyl rings, of their substituents and of the lateral chain on the antioxidant properties, was explored to reveal a simplified structure of excellent activity. These results, along with the absence of cytotoxicity, make the synthesized compounds interesting to evaluate for several biological activities and especially for anti-inflammatory effects and skin protection against UV induced oxidative stress.

  16. Neptune's ring system.

    Science.gov (United States)

    Porco, C. C.; Nicholson, P. D.; Cuzzi, J. N.; Lissauer, J. J.; Esposito, L. W.

    The authors review the current state of knowledge regarding the structure, particle properties, kinematics, dynamics, origin, and evolution of the Neptune rings derived from Earth-based and Voyager data. Neptune has a diverse system of five continuous rings - 2 broad (Galle and Lassell) and 3 narrow (Adams, Le Verrier, and Arago) - plus a narrow discontinuous ring sharing the orbit of one of its ring-region satellites, Galatea. The outermost Adams ring contains the only arcs observed so far in Voyager images. The five arcs vary in angular extent from ≡1° to ≡10°, and exhibit internal azimuthal structure with typical spatial scales of ≡0.5°. All five lie within ≡40° of longitude. Dust is present throughout the Neptune system and measureable quantities of it were detected over Neptune's north pole. The Adams ring (including the arcs) and the Le Verrier ring contain a significant fraction of dust. The Neptune ring particles are probably red, and may consist of ice "dirtied" with silicates and/or some carbon-bearing material. A kinematic model for the arcs derived from Voyager data, the arcs' physical characteristics, and their orbital geometry and phasing are all roughly in accord with single-satellite arc shepherding by Galatea, though the presence of small kilometer-sized bodies embedded either within the arcs or placed at their Lagrange points may explain some inconsistencies with this model.

  17. Quenching of coumarin emission by CdSe and CdSe/ZnS quantum dots: Implications for fluorescence reporting

    Energy Technology Data Exchange (ETDEWEB)

    Baride, Aravind [Department of Chemistry, University of South Dakota, Vermillion, SD 57069 (United States); Engebretson, Daniel [Biomedical Engineering, University of South Dakota, Vermillion, SD 57069 (United States); Berry, Mary T. [Department of Chemistry, University of South Dakota, Vermillion, SD 57069 (United States); Stanley May, P., E-mail: smay@usd.edu [Department of Chemistry, University of South Dakota, Vermillion, SD 57069 (United States)

    2013-09-15

    The photoinduced release of highly fluorescent 7-diethylamino coumarin (7DEAC) from CdSe quantum dots (QD) modified with a thiocinnamate ligand (11-mercapto undecyl-E-3-(4-(N,N-diethylamino)-2-hydroxy phenyl) propenoate, [4DEATC]) has been previously described. Coumarin fluorescence was used to ‘report’ the photochemical reaction. The current study quantifies the quenching effect of the QDs on the coumarin emission in this system. A systematic study is presented on the quenching of 7DEAC by CdSe and CdSe/ZnS quantum dots capped with 2-[2-(2-methoxyethoxy)ethoxy] ethanethiol (PEG-thiol). A new method for the functionalization of CdSe and CdSe/ZnS QDs with PEG-thiol was developed, which does not require isolation of the as-synthesized QDs. Stern–Volmer analysis was applied to quantify the effect of the PEG-CdSe and PEG-CdSe/ZnS on 7DEAC emission. The Stern–Volmer constant, K{sub SV}, was shown to be inversely proportional to temperature for quenching by PEG-CdSe, and the fluorescence lifetime of 7DEAC was shown to be independent of PEG-CdSe concentration. Room-temperature K{sub SV} values were similar for the PEG-CdSe and PEG-CdSe/ZnS quenchers. The large magnitude of K{sub SV}, the temperature dependence of K{sub SV}, the lifetime data, and the similarity of K{sub SV} values for the core and core–shell QD quenchers are all consistent with a static quenching mechanism. Assuming a static quenching mechanism, the temperature dependence of the coumarin-QD binding constant, K{sub b}, was used to estimate the ΔH and ΔS for the binding process. -- Highlights: • Quenching of a coumarin derivative by CdSe and CdSe/ZnS quantum dots is demonstrated • Stern–Volmer analysis is performed as a function of temperature • Fluorescence lifetime analysis was used to support Stern–Volmer analysis • Data overwhelmingly support quenching via a Static Mechanism • Quenching of coumarin by quantum dots is significant and must be considered in any release and report

  18. Saturn's Rings

    Science.gov (United States)

    Cuzzi, J. N.

    2014-12-01

    The rings are changing before our eyes; structure varies on all timescales and unexpected things have been discovered. Many questions have been answered, but some answers remain elusive (see Cuzzi et al 2010 for a review). Here we highlight the major ring science progress over the mission to date, and describe new observations planned for Cassini's final three years. Ring Composition and particle sizes: The rings are nearly all water ice with no other ices - so why are they reddish? The C Ring and Cassini Division are "dirtier" than the more massive B and A Rings, as shown by near-IR and, recently, microwave observations. Particle sizes, from stellar and radio occultations, vary from place to place. Ring structure, micro and macro: numerous spiral density waves and ubiquitous "self-gravity wakes" reveal processes which fostered planet formation in the solar system and elsewhere. However, big puzzles remain regarding the main ring divisions, the C Ring plateau structures, and the B Ring irregular structure. Moonlets, inside and out, seen and unseen: Two gaps contain sizeable moonlets, but more gaps seem to contain none; even smaller embedded "propeller" objects wander, systematically or randomly, through the A ring. Rubble pile ringmoons just outside the rings may escaped from the rings, and the recently discovered "Peggy" may be trying this as we watch. Impact bombardment of the rings: Comet fragments set the rings to rippling on century-timescales, and boulders crash through hourly; meanwhile, the constant hail of infalling Kuiper belt material has a lower mass flux than previously thought. Origin and Age of the Rings: The ring mass and bombardment play key roles. The ring mass is well known everywhere but in the B Ring (where most of it is). New models suggest how tidal breakup of evolving moons may have formed massive ancient rings, of which the current ring is just a shadow. During its last three years, the Cassini tour profile will allow entirely new

  19. Fourier transform infrared spectroscopy for irradiation coumarin doped polystyrene polymer films by alpha ray

    Directory of Open Access Journals (Sweden)

    Mahasin F. Hadi Al-Kadhemy

    2016-07-01

    Full Text Available FTIR spectroscopy has been in use broadly to study microscopic areas in polymers for the last years. The FTIR transmission spectra of coumarin laser dye, polystyrene and coumarin doped polystyrene films with different doping ratio of coumarin solution have been studied. These spectra measured and explained for all films before and after Alpha irradiation with different irradiation times. All samples prepared by casting method. FTIR corroborate chemical bonds of coumarin dye molecules and polystyrene films by producing an IR absorption spectrum when increasing doping ratio of coumarin solution and when irradiation by Alpha source. There are some bonds disappeared after irradiation.

  20. Red emitting NLOphoric 3-styryl coumarins: Experimental and computational studies

    Science.gov (United States)

    Tathe, Abhinav B.; Sekar, Nagaiyan

    2016-01-01

    The coumarin molecules are versatile fluorophores and can be modified synthetically to give desired properties. The molecules studied have 4-cyano group as an assistance to original chromophore and imparts a red shift. These coumarins were expected to show good non-linear optical (NLO) properties. The experimental and theoretical methods were employed to determine their NLO properties. Directional components of hyperpolarizabilities were calculated and showed a variation according to the placement of electron pulling groups. Studied molecules show a very high (494-794 times of urea) total first order hyperpolarizability. The NLO properties of the molecules were found to be solvent dependant.

  1. Synthesis and biological activity of two pregnane derivatives with a triazole or imidazole ring at C-21.

    Science.gov (United States)

    Silva-Ortiz, Aylin Viviana; Bratoeff, Eugene; Ramírez-Apan, María Teresa; García-Becerra, Rocío; Ordaz-Rosado, David; Noyola-Martínez, Nancy; Castillo-Bocanegra, Rafael; Barrera, David

    2016-05-01

    Pregnane derivatives are studied as agents for the treatment of different hormone-dependent diseases. The biological importance of these steroids is based on their potential use against cancer. In this study, we report the synthesis, characterization and biological activity of two pregnane derivatives with a triazole (3β-hydroxy-21-(1H-1,2,4-triazol-1-yl)pregna-5,16-dien-20-one; T-OH) or imidazole (3β-hydroxy-21-(1H-imidazol-1-yl)pregna-5,16-dien-20-one; I-OH) moieties at C-21. These derivatives were synthesized from 16-dehydropregnenolone acetate. The activity on cell proliferation of the compounds was measured on three human cancer cells lines: prostate cancer (PC-3), breast cancer (MCF7) and lung cancer (SK-LU-1). The cytotoxic and antiproliferative effects of T-OH and I-OH were assessed by using SBR and XTT methods, respectively. The gene expressions were evaluated by real time PCR. In addition, results were complemented by docking studies and transactivation assays using an expression vector to progesterone and androgen receptor. Results show that the two compounds inhibited the three cell lines proliferation in a dose-dependent manner. Compound I-OH downregulated the gene expression of the cyclins D1 and E1 in PC-3 and MFC7 cells; however, effect upon Ki-67, EAG1, BIM or survivin genes was not observed. Docking studies show poor interaction with the steroid receptors. Nevertheless, the transactivation assays show a weak antagonist effect of I-OH on progesterone receptor but not androgenic or antiandrogenic actions. In conclusion, the synthesized compounds inhibited cell proliferation as well as genes key to cell cycle of PC-3 and MCF7 cell lines. Therefore, these compounds could be considered a good starting point for the development of novel therapeutic alternatives to treat cancer.

  2. Dietary vitamin K intake and stability of anticoagulation with coumarins: evidence derived from a clinical trial El consumo de vitamina K y la estabilidad de la anticoagulación con cumarínicos: evidencia derivada de ensayo clínico

    Directory of Open Access Journals (Sweden)

    P. Zuchinali

    2012-12-01

    Full Text Available Background: Dietary vitamin K intake has been considered a major factor that influences stability of oral anticoagulation (OA with coumarins. Few studies have evaluated the relationship between amounts of dietary vitamin K intake and stability of anticoagulation. Objective: To assess whether high dietary vitamin K intake is associated to stability of International Normalized Ratio (INR of the prothrombin time. Methods: We performed a sub-analysis of a randomized clinical trial involving outpatients from the anticoagulation clinic of a university hospital. INR and vitamin K intake were prospectively collected at baseline, 15, 30, 60 and 90 days after randomization. Patients were considered with a stable anticoagulation when their INR coefficient of variation was less than 10%. Dietary vitamin K intake was assessed by a food frequency questionnair and a score of intake was derived. Results: We studied 132 patients on chronic OA (57 ± 13 years; 55% males; 23 patients (17% were achieved stable anticoagulation. Stable and unstable patients had no significant differences in baseline characteristics. The dietary vitamin K score over the entire follow-up for stable patients was significantly lower than that for unstable patients (p = 0.012. Discussion: Our findings suggest that INR stability could be achieved with relatively low amounts of dietary vitamin K.Introducción: El consumo dietético de vitamina K ha sido considerado un factor importante que influye en la estabilidad de la anticoagulación oral (AO con cumarina. Pocos estudios han evaluado la relación entre el consumo dietético de vitamina K y la estabilidad de la anticoagulación. Objetivo: Evaluar la relación existente entre la alta ingesta de vitamina K y el mantenimiento de la estabilidade del la Razón Normalizada Internacional RNI. Métodos: Se realizó una subanálisis de un ensayo clínico aleatorizado con pacientes ambulatórios de la clínica de anticoagulación de un hospital

  3. Substituent and ring effects on enthalpies of formation: 2-methyl- and 2-ethylbenzimidazoles versus benzene- and imidazole-derivatives

    Science.gov (United States)

    Jiménez, Pilar; Roux, María Victoria; Dávalos, Juan Z.; Temprado, Manuel; Ribeiro da Silva, Manuel A. V.; Ribeiro da Silva, Maria Das Dores M. C.; Amaral, Luísa M. P. F.; Cabildo, Pilar; Claramunt, Rosa M.; Mó, Otilia; Yáñez, Manuel; Elguero, José

    The enthalpies of combustion, heat capacities, enthalpies of sublimation and enthalpies of formation of 2-methylbenzimidazole (2MeBIM) and 2-ethylbenzimidazole (2EtBIM) are reported and the results compared with those of benzimidazole itself (BIM). Theoretical estimates of the enthalpies of formation were obtained through the use of atom equivalent schemes. The necessary energies were obtained in single-point calculations at the B3LYP/6-311+G(d,p) on B3LYP/6-31G* optimized geometries. The comparison of experimental and calculated values of benzenes, imidazoles and benzimidazoles bearing H (unsubstituted), methyl and ethyl groups shows remarkable homogeneity. The energetic group contribution transferability is not followed, but either using it or adding an empirical interaction term, it is possible to generate an enormous collection of reasonably accurate data for different substituted heterocycles (pyrazole-derivatives, pyridine-derivatives, etc.) from the large amount of values available for substituted benzenes and those of the parent (pyrazole, pyridine) heterocycles.

  4. Hydrogenation of coumarin to octahydrocoumarin over a Ru/C catalyst

    Institute of Scientific and Technical Information of China (English)

    Dana Bílková; Petr Jansa; Iva Paterová; Libor Červený

    2015-01-01

    The production of octahydrocoumarin, which can serve as a replacement for toxic coumarin, was investigated using 5% Ru on active carbon (Ru/C) as the catalyst for the hydrogenation of couma-rin. The hydrogenation was studied by optimizing the reaction conditions (pressure, solvent and coumarin concentration). The activity and selectivity of the Ru/C catalyst were compared for dif-ferent solvents. The mechanism of coumarin hydrogenation was deduced. The formation of side products was explained. The optimal hydrogenation reaction conditions were: 130 °C, 10 MPa, 60 wt% coumarin in methanol, and 0.5 wt% (based on coumarin) of Ru/C catalyst. At the complete conversion of coumarin, the selectivity to the desired product was 90%.

  5. Gustatory Receptors Required for Avoiding the Toxic Compound Coumarin in Drosophila melanogaster.

    Science.gov (United States)

    Poudel, Seeta; Lee, Youngseok

    2016-04-30

    Coumarin is a phenolic compound that mainly affects the liver due to its metabolization into a toxic compound. The deterrent and ovicidal activities of coumarin in insect models such as Drosophila melanogaster have been reported. Here we explore the molecular mechanisms by which these insects protect themselves and their eggs from this toxic plant metabolite. Coumarin was fatal to the flies in a dosage-dependent manner. However, coumarin feeding could be inhibited through activation of the aversive gustatory receptor neurons (GRNs), but not the olfactory receptor neurons. Furthermore, three gustatory receptors, GR33a, GR66a, and GR93a, functioned together in coumarin detection by the proboscis. However, GR33a, but not GR66a and GR93a, was required to avoid coumarin during oviposition, with a choice of the same substrates provided as in binary food choice assay. Taken together, these findings suggest that anti-feeding activity and oviposition to avoid coumarin occur via separate mechanisms.

  6. Study of excitation energy transfer from Coumarin102(donor) to Coumarin6(acceptor) doped in poly-methyl methacrylate (PMMA) thin film

    Science.gov (United States)

    Singh, Khushboo; Negi, Gauri; Joshi, G. C.

    2015-05-01

    Energy transfer from Coumarin102 to Coumarin6 has been studied. It is observed that energy transfer begins at relatively larger donor acceptor separations than the critical transfer distance for efficient dipole-dipole energy transfer by Forster mechanism. For Coumarin 102 and Coumarin 6 dye pair, the energy transfer parameters, viz overlap integral(J(λ)) and Förster distance(R0), equaling 3.4x10-13M-1cm3 and 58.7(Å), respectively have been obtained. Migration through donor-donor interaction is suggested to be the possible mechanism and Huber model has been applied to calculate the transfer rate.

  7. Vortex rings

    Energy Technology Data Exchange (ETDEWEB)

    Akhmetov, D.G. [Lavrentiev Institute of Hydrodynamics, Novosibirsk (Russian Federation)

    2009-07-01

    This book presents a comprehensive coverage of the wide field of vortex rings. The book presents the results of systematic experimental investigations, theoretical foundation, as well as the practical applications of vortex rings, such as the extinction of fires at gushing gas and oil wells. All the basic properties of vortex rings as well as their hydrodynamic structures are presented. Special attention is paid to the formation and motion of turbulent vortex rings. (orig.)

  8. Ring-alkyl connecting group effect on mesogenic properties of p-carborane derivatives and their hydrocarbon analogues

    Directory of Open Access Journals (Sweden)

    Aleksandra Jankowiak

    2009-12-01

    Full Text Available The effect of the phenyl–alkyl connecting group on mesogenic properties of several series of isostructural compounds containing p-carborane (A and B, bicyclo[2.2.2]octane (C, and benzene (D was investigated using thermal and optical methods. Results demonstrated that mesophase stability in the series containing A–D follows the order (AlkCH2CH2– < (AlkOOC– < (AlkCH2O– < (AlkCOO–. Surprisingly, the connecting groups (AlkCH2CH2– and (AlkOOC– destabilize the mesophase significantly stronger for carboranes (A and B than for carbocyclic derivatives (C and D. Analysis indicates that this effect may have quadrupolar and conformational origin.

  9. Evaluation of Whole Tree Growth Increment Derived from Tree-Ring Series for Use in Assessments of Changes in Forest Productivity across Various Spatial Scales

    Directory of Open Access Journals (Sweden)

    Juha M. Metsaranta

    2016-12-01

    Full Text Available The inherent predictability of inter-annual variation in forest productivity remains unknown. Available field-based data sources for understanding this variability differ in their spatial resolution, temporal resolution, and typical units of measure. Nearly all other tree and forest characteristics are in practice derived from measurements of diameter at breast height (DBH. Therefore, diameter increment reconstructed annually from tree-ring data can be used to estimate annual growth increments of wood volume, but the accuracy and precision of these estimates requires assessment. Annual growth estimates for n = 170 trees sampled for whole stem analysis from five tree species (jack pine, lodgepole pine, black spruce, white spruce, and trembling aspen in Western Canada were compared against increments derived from breast height measurements only. Inter-annual variability of breast height and whole tree growth increments was highly correlated for most trees. Relative errors varied by species, diameter class, and the equation used to estimate volume (regional vs. national. A simple example of the possible effect of this error when propagated to the stand level is provided.

  10. Synthesis and quantitative structure-activity relationship (QSAR) study of novel 4-acyloxypodophyllotoxin derivatives modified in the A and C rings as insecticidal agents.

    Science.gov (United States)

    He, Shuzhen; Shao, Yonghua; Fan, Lingling; Che, Zhiping; Xu, Hui; Zhi, Xiaoyan; Wang, Juanjuan; Yao, Xiaojun; Qu, Huan

    2013-01-23

    In continuation of our program aimed at the discovery and development of natural-product-based insecticidal agents, we have synthesized three series of novel 4-acyloxy compounds derived from podophyllotoxin modified in the A and C rings, which is isolated as the main secondary metabolite from the roots and rhizomes of Podophyllum hexandrum . Their insecticidal activity was preliminarily evaluated against the pre-third-instar larvae of Mythimna separata in vivo. Compound 9g displayed the best promising insecticidal activity. It revealed that cleavage of the 6,7-methylenedioxy group of podophyllotoxin will lead to a less active compound and that the C-4 position of podophyllotoxin was the important modification location. A quantitative structure-activity relationship (QSAR) model was developed by genetic algorithm combined with multiple linear regression (GA-MLR). For this model, the squared correlation coefficient (R(2)) is 0.914, the leave-one-out cross-validation correlation coefficient (Q(2)(LOO)) is 0.881, and the root-mean-square error (RMSE) is 0.024. Five descriptors, BEHm2, Mor14v, Wap, G1v, and RDF020e, are likely to influence the biological activity of these compounds. Among them, two important ones are BEHm2 and Mor14v. This study will pave the way for further design, structural modification, and development of podophyllotoxin derivatives as insecticidal agents.

  11. Synthesis, biological activity evaluation and molecular docking studies of novel coumarin substituted thiazolyl-3-aryl-pyrazole-4-carbaldehydes.

    Science.gov (United States)

    Vaarla, Krishnaiah; Kesharwani, Rajesh Kumar; Santosh, Karnewar; Vedula, Rajeswar Rao; Kotamraju, Srigiridhar; Toopurani, Murali Krishna

    2015-12-15

    A novel series of coumarin substituted thiazolyl-3-aryl-pyrazole-4-carbaldehydes (4a-o) were synthesized via an efficient, one-pot multicomponent approach involving 3-(2-bromoacetyl)coumarins (1a-g), thiosemicarbazide (2) and substituted acetophenones (3a-c) utilizing Vilsmeier-Haack reaction condition with good yields. The title compounds structure was elucidated by spectroscopic data (IR, NMR and Mass) and elemental analysis. All the synthesized compounds were screened for their in vitro cytotoxic activity against MCF-7, DU-145 and HeLa cell lines and studied detailed about molecular interaction of probable target protein human microsomal cytochrome CYP450 2A6 using docking simulation. These coumarin derivatives were exhibiting moderate to appreciable cytotoxic activities. The compounds 4m and 4n exhibited significant cytotoxic activity with IC50 values having 5.75 and 6.25μM against HeLa cell line. Similarly compound 4n also exhibiting good anti cancer property and antibacterial activity against DU-145 cell line and Gram negative bacterial strains.

  12. The effect of β-saturated pyrrolic rings on the electronic structures and aromaticity of magnesium porphyrin derivatives: a density functional study.

    Science.gov (United States)

    Wan, Liang; Qi, Dongdong; Zhang, Yuexing

    2011-09-01

    Density functional theory (DFT) calculation on the molecular structures, molecular orbitals, electronic absorption spectra, and magnetic properties of magnesium porphyrin (MgPor) and a series of five hydrogenated magnesium porphyrin complexes with different number of β-saturated pyrrolic rings, namely MgPor-β-1Hy, MgPor-β-opp-2Hy, MgPor-β-adj-2Hy, MgPor-β-3Hy, and MgPor-β-4Hy, clarifies the red-shift of the lowest energy absorption band from chlorophyll a to bacteriochlorophyll and reveals the strong chemical stability for both of them. The energy levels of highest occupied molecular orbitals (HOMO) and HOMO-1 for MgPor are reversed upon hydrogenation at β-positions (2 and 3, 7 and 8, 12 and 13, and 17 and 18) of porphyrin ring. Along with the increase of β-saturated pyrrolic rings from 1, 2, 3, to 4, the HOMO energy increases from -4.78 eV to -3.10 eV in a regular manner. In contrast, the lowest unoccupied molecular orbitals (LUMO) energy levels of MgPor, MgPor-β-1Hy, and MgPor-β-opp-2Hy are very similar with each other. As a result, the lowest energy absorption band involving main transition from HOMO to LUMO is red-shifted from MgPor-β-1Hy to MgPor-β-opp-2Hy which is representative of chlorophyll a and bacteriochlorophyll, respectively. Natural hydroporphyrins represented by MgPor, MgPor-β-1Hy, and MgPor-β-opp-2Hy have turned out to be aromatic and stable enough, in good accordance with the ubiquity of their derivatives in the nature. In contrast, MgPor-β-adj-2Hy, MgPor-β-3Hy, and MgPor-β-4Hy with relatively weak aromaticity seem to be unstable and therefore were not found in nature.

  13. Modified Newton's rings: II

    CERN Document Server

    Chaitanya, T Sai; Krishna, V Sai; Anandh, B Shankar; Umesh, K S

    2010-01-01

    In an earlier work (Shankar kumar Jha, A Vyas, O S K S Sastri, Rajkumar Jain & K S Umesh, 'Determination of wavelength of laser light using Modified Newton's rings setup', Physics Education, vol. 22, no.3, 195-202(2005)) reported by our group, a version of Newton's rings experiment called Modified Newton's rings was proposed. The present work is an extension of this work. Here, a general formula for wavelength has been derived, applicable for a plane of observation at any distance. A relation between the focal length and the radius curvature is also derived for a plano-convex lens which is essentially used as a concave mirror. Tracker, a video analysis software, freely downloadable from the net, is employed to analyze the fringes captured using a CCD camera. Two beams which give rise to interference fringes in conventional Newton's rings and in the present setup are clearly distinguished.

  14. 4-Trifluoromethyl-substituted coumarins with large Stokes shifts: synthesis, bioconjugates, and their use in super-resolution fluorescence microscopy.

    Science.gov (United States)

    Schill, Heiko; Nizamov, Shamil; Bottanelli, Francesca; Bierwagen, Jakob; Belov, Vladimir N; Hell, Stefan W

    2013-12-02

    Bright and photostable fluorescent dyes with large Stokes shifts are widely used as sensors, molecular probes, and light-emitting markers in chemistry, life sciences, and optical microscopy. In this study, new 7-dialkylamino-4-trifluoromethylcoumarins have been designed for use in bioconjugation reactions and optical microscopy. Their synthesis was based on the Stille reaction of 3-chloro-4-trifluoromethylcoumarins and available (hetero)aryl- or (hetero)arylethenyltin derivatives. Alternatively, the acylation of 2-trifluoroacetyl-5-dialkylaminophenols with available (hetero)aryl- or (hetero)arylethenylacetic acids followed by intramolecular condensation afforded coumarins with 3-(hetero)aryl or 3-[2-(hetero)aryl]ethenyl groups. Hydrophilic properties were provided by the introduction of a sulfonic acid residue or by phosphorylation of a primary hydroxy group attached at C-4 of the 2,2,4-trimethyl-1,2-dihydroquinoline fragment fused to the coumarin fluorophore. For use in immunolabeling procedures, the dyes were decorated with an (activated) carboxy group. The positions of the absorption and emission maxima vary in the ranges 413-480 and 527-668 nm, respectively. The phosphorylated dye, 9,CH=CH-2-py,H, with the 1-(3-carboxypropyl)-4-hydroxymethyl-2,2-dimethyl-1,2-dihydroquinoline fragment fused to the coumarin fluorophore bearing the 3-[2-(2-pyridyl)ethenyl] residue (absorption and emission maxima at 472 and 623 nm, respectively) was used in super-resolution light microscopy with stimulated emission depletion and provided an optical resolution better than 70 nm with a low background signal. As a result of their large Stokes shifts, good fluorescence quantum yields, and adequate photostabilities, phosphorylated coumarins enable two-color imaging (using several excitation sources and a single depletion laser) to be combined with subdiffractional optical resolution.

  15. In vitro metabolism of gestodene in target organs: formation of A-ring reduced derivatives with oestrogenic activity.

    Science.gov (United States)

    Lemus, A E; Santillán, R; Damián-Matsumura, P; García, G A; Grillasca, I; Pérez-Palacios, G

    2001-04-13

    Gestodene (13beta-ethyl-17alpha-ethynyl-17beta-hydroxy-4,5-gonadien-3-one), the most potent progestin ever synthesized, stimulates breast cancer cell growth through an oestrogen receptor-mediated mechanism, and its use in hormonal contraception has been associated with side effects attributable to oestrogenic actions. These observations have remained controversial, since gestodene does not bind to the oestrogen receptor or exert oestrogen-like activities. Recently, we have demonstrated that non-phenolic gestodene derivatives interact with oestrogen receptors and induce oestrogenic effects in cell expression systems. To assess whether gestodene is biotransformed to metabolites with intrinsic oestrogenic potency, [3H]- and [14C]-labelled gestodene were incubated in vitro with rat anterior pituitary, hypothalamus and ventral prostate homogenates under different experimental conditions. The most remarkable finding was the isolation and identification of 3beta,5alpha-tetrahydrogestodene and 3alpha,5alpha-tetrahydrogestodene as metabolic conversion products of gestodene, presumably with 5alpha-dihydrogestodene as intermediate. The overall results seem to indicate that the weak oestrogenic effects attributable to gestodene could be mediated by its tetrahydro metabolites.

  16. An efficient methodology for the synthesis of 3-styryl coumarins

    Energy Technology Data Exchange (ETDEWEB)

    Martins, Sergio M.A.; Pereira, Antonio M.D.R.L. [Centro de Quimica, Departamento de Quimica, Universidade de Evora, Evora (Portugal); Branco, Paula C.S. [REQUIMTE, Departamento de Quimica, Universidade Nova de Lisboa, Caparica (Portugal)

    2012-04-15

    Regioselective and highly efficient Heck arylation of 3-vinyl-6,7-dimethoxycoumarin has been developed to afford 3-styryl coumarins in good to very high yields. The increase in conjugation reflects on the absorbance of the synthesized compounds revealing all pronounced bathochromic shifts and hyperchromic effects. (author)

  17. Nitroketene dithioacetal chemistry: Synthesis of coumarins incorporating nitrothiophene moiety

    Indian Academy of Sciences (India)

    H Surya Prakash Rao; K Vasantham

    2011-07-01

    Alkylation of dipotassium 2-nitro-1,1-ethylenedithiolate 1 with ethyl 4-chloroacetoacetate 6 in a mixture of MeOH-H2O (2:1) furnished highly functionalized 3-nitrothiophene 5. Pechmann condensation of 5 with 2-hydroxybenzaldehydes 8a-i, 10 furnished coumarin-3-nitrothiophene conjugates 9a-i, 11.

  18. Probing the binding of coumarins and cyclothialidines to DNA gyrase

    DEFF Research Database (Denmark)

    Kampranis, S C; Gormley, N A; Tranter, R

    1999-01-01

    DNA gyrase is the target of a number of antibacterial agents, including the coumarins and the cyclothialidines. To extend our understanding of the mechanism of action of these compounds, we have examined the previously published crystal structures of the complexes between the 24 kDa fragment of Gyr...

  19. A coumarin-based colorimetric fluorescent probe for hydrogen sulfide

    Indian Academy of Sciences (India)

    Yanqiu Yang; Yu Liu; Liang Yang; Jun Liu; Kun Li; Shunzhong Luo

    2015-03-01

    A coumarin-based fluorescent probe for selective detection of hydrogen sulfide (H2S) is presented. This `off–on’ probe exhibited high selectivity towards H2S in aqueous solution with a detection limit of 30 nM. Notably, because of its dual nucleophilicity, the probe could avoid the interference of thiols and other sulfur containing compounds.

  20. Overanticoagulation associated with combined use of lactulose and coumarin anticoagulants.

    NARCIS (Netherlands)

    Visser, L.E.; Penning-van Beest, F.J.A.; Wilson, J.H.; Vulto, A.G.; Kasbergen, A.A.H.; Smet, P.A.G.M. de; Hofman, A.W.I.M.; Stricker, B.H.C.

    2004-01-01

    Some medical textbooks on drug interactions take note of the potential interaction between laxatives and coumarin anticoagulants, but epidemiological evidence that this interaction is of practical importance is lacking. We conducted a follow-up study in a large population-based cohort to investigate

  1. Terpenylated coumarins as SIRT1 activators isolated from Ailanthus altissima

    DEFF Research Database (Denmark)

    Dao, Trong-Tuan; Tran, Tien-Lam; Kim, Jayeon;

    2012-01-01

    Four new terpenylated coumarins (1-4) were isolated from the stem bark of Ailanthus altissima by bioactivity-guided fractionation using an in vitro SIRT1 deacetylation assay. Their structures were identified as (2'R,3'R)-7-(2',3'-dihydroxy-3',7'-dimethylocta-6'-enyloxy)-6,8-dimethoxycoumarin (1), 6......,8-dimethoxy-7-(3',7'-dimethylocta-2',6'-dienyloxy)coumarin (2), (2'R,3'R,6'R)-7-(2',3'-dihydroxy-6',7'-epoxy-3',7'-dimethyloctaoxy)-6,8-dimethoxycoumarin (3), and (2'R,3'R,4'S,5'S)-6,8-dimethoxy-7-(3',7'-dimethyl-4',5'-epoxy-2'-hydroxyocta-6'-enyloxy)coumarin (4). Compounds 1-4 strongly enhanced SIRT1...... activity in an in vitro SIRT1-NAD/NADH assay and an in vivo SIRT1-p53 luciferase assay. These compounds also increased the NAD-to-NADH ratio in HEK293 cells. The present results suggest that terpenylated coumarins from A. altissima have a direct stimulatory effect on SIRT1 deacetylation activity and may...

  2. Genetic and environmental factors affecting the coumarin anticoagulant level

    NARCIS (Netherlands)

    L.E. Visser (Loes)

    2004-01-01

    textabstractThis introductory chapter has illustrated that various factors, such as genetic factors, drugs, diet and intercurrent diseases may affect anticoagulation levels. Most of the clinical and pharmacological data related to coumarin anticoagulants have so far been obtained from studying warfa

  3. Coumarin incorporated triazoles: a new class of anticonvulsants.

    Science.gov (United States)

    Bhat, Mashooq A; Al-Omar, Mohammed A

    2011-01-01

    A series of coumarin incorporated 1,2,4- triazole compounds (1-14) were evaluated for their possible anticonvulsant and neurotoxic properties, log P values, pharmacophoric mapping and three dimensional structure analysis. Compound (6) with para-fluoro substitution showed significant anticonvulsant activity.

  4. Coumarins and Chromones from ’Lomatium macrocarpum’,

    Science.gov (United States)

    Roots of Lomatium macrocarpum (Hook. and Arn.)C. and R. yielded osthol(7-methoxy-8-(3-methyl-2-butenyl)-coumarin) and a chromone , 2-methyl-5-hydroxy...6(3-methyl-2-butenyl)-7-methoxychromone, identified spectroscopically and by synthesis. The serial parts of the plant also contained this chromone

  5. Current perspectives on dental patients receiving coumarin anticoagulant therapy.

    Science.gov (United States)

    Herman, W W; Konzelman, J L; Sutley, S H

    1997-03-01

    Despite approximately 40 years of experience with oral anticoagulant drugs, controversy still exists about the safety of dental treatment in a patient receiving this therapy. The authors review the topic in depth and offer detailed recommendations for the dental management of patients receiving coumarin anticoagulant therapy.

  6. Alkaloids and Coumarins from the Leaves of Amyris diatripa.

    Science.gov (United States)

    Laguna, A

    1984-02-01

    The alkaloids edulinine and (+/-) isoplatydesmine were isolated from the leaves of Amyris diatripa, being the first report of the presence of alkaloids in species of this genus. The presence of coumarins in the plant was also shown by isolation of psoralen, bergapten, marmesin, ulopterol and suberenol.

  7. Terpenylated coumarins as SIRT1 activators isolated from Ailanthus altissima.

    Science.gov (United States)

    Dao, Trong-Tuan; Tran, Tien-Lam; Kim, Jayeon; Nguyen, Phi-Hung; Lee, Eun-Hee; Park, Junsoo; Jang, Ik-Soon; Oh, Won-Keun

    2012-07-27

    Four new terpenylated coumarins (1-4) were isolated from the stem bark of Ailanthus altissima by bioactivity-guided fractionation using an in vitro SIRT1 deacetylation assay. Their structures were identified as (2'R,3'R)-7-(2',3'-dihydroxy-3',7'-dimethylocta-6'-enyloxy)-6,8-dimethoxycoumarin (1), 6,8-dimethoxy-7-(3',7'-dimethylocta-2',6'-dienyloxy)coumarin (2), (2'R,3'R,6'R)-7-(2',3'-dihydroxy-6',7'-epoxy-3',7'-dimethyloctaoxy)-6,8-dimethoxycoumarin (3), and (2'R,3'R,4'S,5'S)-6,8-dimethoxy-7-(3',7'-dimethyl-4',5'-epoxy-2'-hydroxyocta-6'-enyloxy)coumarin (4). Compounds 1-4 strongly enhanced SIRT1 activity in an in vitro SIRT1-NAD/NADH assay and an in vivo SIRT1-p53 luciferase assay. These compounds also increased the NAD-to-NADH ratio in HEK293 cells. The present results suggest that terpenylated coumarins from A. altissima have a direct stimulatory effect on SIRT1 deacetylation activity and may serve as lead molecules for the treatment of some age-related disorders.

  8. A new angelol-type coumarin glucoside from Angelica pubescens

    Institute of Scientific and Technical Information of China (English)

    Xi Fei Ding; Xu Feng; Yun Fa Dong; Xing Zeng Zhao; Yu Chen; Ming Wang

    2008-01-01

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

  9. Ring theory

    CERN Document Server

    Rowen, Louis H

    1991-01-01

    This is an abridged edition of the author's previous two-volume work, Ring Theory, which concentrates on essential material for a general ring theory course while ommitting much of the material intended for ring theory specialists. It has been praised by reviewers:**""As a textbook for graduate students, Ring Theory joins the best....The experts will find several attractive and pleasant features in Ring Theory. The most noteworthy is the inclusion, usually in supplements and appendices, of many useful constructions which are hard to locate outside of the original sources....The audience of non

  10. 3-Substituted-7-(diethylamino)coumarins as molecular scaffolds for the bottom-up self-assembly of solids with extensive π-stacking

    Science.gov (United States)

    Arcos-Ramos, Rafael; Maldonado-Domínguez, Mauricio; Ordóñez-Hernández, Javier; Romero-Ávila, Margarita; Farfán, Norberto; Carreón-Castro, María del Pilar

    2017-02-01

    In this study, a set of molecular crystals derived from 3-substituted-7-(diethylamino)-2H-chromen-2-ones 1-8 were studied to sample the aggregation of coumarins into ordered solids. Crystals of parent compound 1a and its brominated derivative 2 were obtained and solved in the P-1 and C2/c space groups, respectively. All the crystalline coumarins studied display extensive π-stacking in the solid-state. Theoretical valence-conduction band gaps for derivatives 3b and 5 are close to crystalline rubrene, highlighting the importance of cooperativity and periodicity of π-stacking, in organic semiconductors; given their synthetic accessibility, electronic tunability and self-assembly via stacking, dipolar and H-bonding interactions, these systems arise as candidates for the bottom-up construction of organic crystals with extensive π-stacking and high polarizability.

  11. Planetary Rings

    CERN Document Server

    Tiscareno, Matthew S

    2011-01-01

    Planetary rings are the only nearby astrophysical disks, and the only disks that have been investigated by spacecraft. Although there are significant differences between rings and other disks, chiefly the large planet/ring mass ratio that greatly enhances the flatness of rings (aspect ratios as small as 1e-7), understanding of disks in general can be enhanced by understanding the dynamical processes observed at close-range and in real-time in planetary rings. We review the known ring systems of the four giant planets, as well as the prospects for ring systems yet to be discovered. We then review planetary rings by type. The main rings of Saturn comprise our system's only dense broad disk and host many phenomena of general application to disks including spiral waves, gap formation, self-gravity wakes, viscous overstability and normal modes, impact clouds, and orbital evolution of embedded moons. Dense narrow rings are the primary natural laboratory for understanding shepherding and self-stability. Narrow dusty...

  12. Derivation of a true (t → 0+) quantum transition-state theory. I. Uniqueness and equivalence to ring-polymer molecular dynamics transition-state-theory.

    Science.gov (United States)

    Hele, Timothy J H; Althorpe, Stuart C

    2013-02-28

    Surprisingly, there exists a quantum flux-side time-correlation function which has a non-zero t → 0+ limit and thus yields a rigorous quantum generalization of classical transition-state theory (TST). In this Part I of two articles, we introduce the new time-correlation function and derive its t → 0+ limit. The new ingredient is a generalized Kubo transform which allows the flux and side dividing surfaces to be the same function of path-integral space. Choosing this function to be a single point gives a t → 0+ limit which is identical to an expression introduced on heuristic grounds by Wigner in 1932; however, this expression does not give positive-definite quantum statistics, causing it to fail while still in the shallow-tunnelling regime. Positive-definite quantum statistics is obtained only if the dividing surface is invariant to imaginary-time translation, in which case the t → 0+ limit is identical to ring-polymer molecular dynamics (RPMD) TST. The RPMD-TST rate is not a strict upper bound to the exact quantum rate, but is a good approximation to one if real-time coherence effects are small. Part II will show that the RPMD-TST rate is equal to the exact quantum rate in the absence of recrossing.

  13. Apoptosis Induced by Photodynamic Therapy with Benzoporphyrin Derivative Monoacid Ring A and Exploration of its Potential Mechanism in Bladder Cancer Cells

    Institute of Scientific and Technical Information of China (English)

    Chuanshan Xu; Shiming Wu; Zhigang Wang; Lehua Yu; Qing Yang; Xiabo Zeng

    2005-01-01

    OBJECTIVE To investigate apoptosis induced by photodynamic therapy with benzoporphyrin derivative monoacid ring A (BPD-MA) and explore its potential mechanism in human bladder cancer cells.METHODS Photosensitization of BPD-MA was activated with a red light Laser (632.8nm) delivered at 10 mW/cm2 to give a total dose of 2.4 J/cm2.Cellular apoptosis was measured with flow cytometry analysis and an insitu terminal deoxyuridine nick end-labeling (TUNEL) assay. Changes in mitochondrial membrane potential (△ψm) were monitored by a flow cytometric method with Rhodamine 123 staining and the expression of bcl2 in BIU-87 cells was detected with immunocytochemical staining.RESULTS At 8 h following photodynamic treatment, the degree of apoptosis was significantly increased when analyzed with flow cytometry and TUNEL assay. Treatment of the BIU-87 cells by PDT with BPD-MA resulted in the collapse of the △m and a decrease of bcl-2 expression.CONCLUSION BPD-MA-mediated PDT can effectively induce apoptosis in BIU-87 cells. The mechanism probably is through a mitochondrial-initiated pathway.

  14. QSAR and 3D-QSAR studies of the diacyl-hydrazine derivatives containing furan rings based on the density functional theory

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    QSAR studies of 27 diacyl-hydrazine derivatives containing furan rings were conducted and compared with the DFT method and AM1-MOPAC method.q2 values of 0.61 and 0.40 validated the predictability and reliability of eq.(5) from the DFT method were higher than those of eq.(6) from the AM1-MOPAC method.The DFT-optimized conformations and ESP-fitting charges of the target compounds were also used for 3D-QSAR analysis,including CoMFA and CoMSIA.The leave-one-out cross-validation correlation coefficient and the good correlation between the predicted and experimental activities of excluded test compounds revealed that CoMFA and CoMSIA models were robust.The QSAR results were consistent with the 3D-QSAR results,indicating that the electrostatic and hydrophobic properties of the target compounds were significant to the biological activity.These models are useful tools for predicting the larvicidal activities of new compounds and designing new specific insect growth regulators.

  15. An Efficient One Pot Protocol to the Annulation of Face “d” of Benzazepinone Ring with Pyrazole, Isoxazole, and Pyrimidine Nucleus through the Corresponding Oxoketene Dithioacetal Derivative

    Directory of Open Access Journals (Sweden)

    Aditi Anand

    2014-01-01

    Full Text Available A highly facile single step approach to the annulation of face “d” of benzazepinone nucleus with pyrazole, isoxazole, and pyrimidine ring has been described. The annulation proceeded smoothly on the reaction of oxoketene dithioacetal derivative 3 with (i NH2–NH2·H2O, (ii NH2OH·HCl, (iii acetamidine hydrochloride, (iv guanidine nitrate, (v urea, and (vi thiourea which yielded the pyrazolo, isoxazolo, and pyrimido annulated analogues of benzazepinone 4–9, respectively, in acceptable yields. The 4-ketene dithioacetal analogue of 7-fluorobenzo[b]azepine-2,5-dione (3 was in turn obtained from the reaction of 7-fluoro-3,4-dihydro-1H-benzo[b]azepine-2,5-dione (2 (with CS2 + CH3I in presence of t-BuOK. 7-Fluoro-3,4-dihydro-1H-benzo[b]azepine-2,5-dione (2 resulted from the acylation of p-fluoroaniline with succinyl chloride followed by cyclocondensation of the later with polyphosphoric acid (PPA.

  16. Evaluation of vascular effects after photodynamic and photothermal therapies using benzoporphyrin derivative monoacid ring A on a rodent dorsal skinfold model

    Science.gov (United States)

    Smith, Tia K.; Choi, Bernard; Ramirez-San-Juan, Julio C.; Nelson, John S.; Kelly, Kristen M.

    2005-04-01

    Background and Objectives: Pulsed dye laser (PDL) irradiation is the standard clinical treatment for vascular lesions. However, PDL treatment of port wine stain birthmarks (PWS) is variable and unpredictable. Photodynamic therapy (PDT) using benzoporphyrin derivative monoacid ring A (BPD) and yellow light may induce substantial vascular effects and potentially offer a more effective treatment. In this study, we utilize a rodent dorsal skinfold model to evaluate the vascular effects of BPD-PDT at 576 nm as compared to PDL. Study Design/Materials and Methods: A dorsal skinfold window was created on the backs of female Sprague-Dawley rats, allowing epidermal and subdermal irradiation and subdermal imaging. One mg/kg BPD was administered intravenously via a jugular venous catheter. Study groups were: control (no BPD, no light), PDL (585 nm, τp 1.5 ms, 10 J/cm2), and PDT (BPD + continuous wave irradiation (CW) at 576nm, τp 16 min, 96 J/cm2). Vessels were imaged and assessed for damage using laser speckle imaging (LSI) before, immediately after, and 18 hours post-intervention. Results: Epidermal irradiation was accomplished without blistering, scabbing or ulceration. PDL and PDT resulted in similar reductions in vascular perfusion 18 hours post-intervention (34.6% and 33.4%, respectively). Conclusions: BPD-PDT can achieve safe and selective vascular effects and may offer an alternative therapeutic option for treatment of hypervascular skin lesions including PWS birthmarks.

  17. Planetary Rings

    Science.gov (United States)

    Cuzzi, Jeffrey N.

    1994-01-01

    Just over two decades ago, Jim Pollack made a critical contribution to our understanding of planetary ring particle properties, and resolved a major apparent paradox between radar reflection and radio emission observations. At the time, particle properties were about all there were to study about planetary rings, and the fundamental questions were, why is Saturn the only planet with rings, how big are the particles, and what are they made of? Since then, we have received an avalanche of observations of planetary ring systems, both from spacecraft and from Earth. Meanwhile, we have seen steady progress in our understanding of the myriad ways in which gravity, fluid and statistical mechanics, and electromagnetism can combine to shape the distribution of the submicron-to-several-meter size particles which comprise ring systems into the complex webs of structure that we now know them to display. Insights gained from studies of these giant dynamical analogs have carried over into improved understanding of the formation of the planets themselves from particle disks, a subject very close to Jim's heart. The now-complete reconnaissance of the gas giant planets by spacecraft has revealed that ring systems are invariably found in association with families of regular satellites, and there is ark emerging perspective that they are not only physically but causally linked. There is also mounting evidence that many features or aspects of all planetary ring systems, if not the ring systems themselves, are considerably younger than the solar system

  18. Ab Initio MO study on the nucleophilic oxirane ring opening of exo and endo Aflatoxin B{sub 1} 8,9-Oxide; Ekiso oyobi endo Aflatoxin B{sub 1} 8,9-Oxide no kyukaku kaikan hanno ni taisuru Ab Initio ho ni yoru kaiseki

    Energy Technology Data Exchange (ETDEWEB)

    Okajima, Toshiya; Hashikawa, Akane [Saga University, Saga (Japan). Department of Chemistry

    1999-08-10

    The difference of the reactivity for S{sub N}2 type oxirane ring opening of exo and endo Aflatoxin B{sub 1} (AFB{sub 1}) 8,9-oxide (exo-1 and endo-1, respectively) was analyzed with ab initio molecular orbital theory. All stationary points including transition-state structures were optimized with no geometry constraint at the RHF/3-21G basis set, and energies were evaluate at Becke3LYP/3-21G level based on the RHF/3-21G geometries. The calculation clarified the following three points: (1) the activation energy ({delta}E{sup {ne}}) for endo attacking of NH{sub 3} molecule (the reaction with exo derivatives containing exo-1) is considerably smaller than those for exo attacking (the reaction with endo ones containing endo-1), (2) the reactivity for nucleophilic oxirane ring opening is controlled by the distortion of LUMO{sub C-O} of oxirane ring, which is probably caused by exo/endo relationship between oxirane ring and five-membered dihydrofurano ring (B) with respect to A ring, and (3) the remaining part (inclusing coumarin skeleton) of AFB{sub 1} oxid has little influence on the geometry around the reaction center and the activation energy. (author)

  19. New sesquiterpene coumarins from the roots of Ferula flabelliloba.

    Science.gov (United States)

    Iranshahi, Mehrdad; Kalategi, Farhad; Sahebkar, Amirhossein; Sardashti, Alireza; Schneider, Bernd

    2010-02-01

    Three new sesquiterpene coumarins, namely, farnesiferone B (1), flabellilobin A (2) and flabellilobin B (3), together with nine known compounds, ligupersin A, 7-epi-gamma-eudesmol, persicasulfide A, conferdione, umbelliprenin, conferone, feselol, lehmferin and farnesiferol B were isolated from the roots of Ferula flabelliloba Rech. f. & Aell. (Apiaceae). The structures of these compounds were elucidated by various 1- and 2-D NMR techniques as well as HREIMS.

  20. SUPRAMITRAL RING

    Directory of Open Access Journals (Sweden)

    Rajesh G

    2011-11-01

    Full Text Available Supra mitral ring is a rare cause for congenital mitral valve obstr uction. The reported incidence of supramitral ring is 0.2-0.4% in general population and 8% in patients with congenital mitral valve disease. The condition is characterized by an abnormal ridge of connective tissue often circumferential in shape ,on the atrial side of the mitral valve encroaching on the orifice of the mitral valve. It may adhere to the leaflets of the valve and restrict their movements. Although a supramitral ring may be rarely nonobstructive, it often results in mitral valve inflow obstruction.

  1. Ring-Ringlet Interactions in Saturn's C Ring

    Science.gov (United States)

    Rappaport, N. J.

    1997-01-01

    The overall obejective of this work is to derive a theoretical model for the formation of gaps harboring isolated ringlets in order to explain the presence of such features in Saturn's C ring and Cassini division.

  2. Determinantal rings

    CERN Document Server

    Bruns, Winfried

    1988-01-01

    Determinantal rings and varieties have been a central topic of commutative algebra and algebraic geometry. Their study has attracted many prominent researchers and has motivated the creation of theories which may now be considered part of general commutative ring theory. The book gives a first coherent treatment of the structure of determinantal rings. The main approach is via the theory of algebras with straightening law. This approach suggest (and is simplified by) the simultaneous treatment of the Schubert subvarieties of Grassmannian. Other methods have not been neglected, however. Principal radical systems are discussed in detail, and one section is devoted to each of invariant and representation theory. While the book is primarily a research monograph, it serves also as a reference source and the reader requires only the basics of commutative algebra together with some supplementary material found in the appendix. The text may be useful for seminars following a course in commutative ring theory since a ...

  3. Inhibitory effect of new copper (Ⅱ) complex with coumarin derivatives on lung cancer cells A549 in vivo and vitro%新型香豆素类酰腙-铜配合物对肺腺癌A549细胞的体内外抑制作用

    Institute of Scientific and Technical Information of China (English)

    陆勤; 欧秋霞; 朱文娇; 朱涛峰

    2015-01-01

    目的:观察新型香豆素类酰腙—铜配合物(以下缩写为CCCD)在体内外对肺癌A549细胞的抑制作用,并探讨其机制。方法培养肺癌A549细胞,分别加入5、10、20、30、50、80、120、160μmol/L的CCCD,干预72 h后,采用MTT法,计算细胞生长抑制率( IR )。将A549细胞分为干预组、对照组,干预组分别加入10、20、40μmol/L CCCD,对照组加入PBS,采用流式细胞术检测各组细胞凋亡情况并计算细胞凋亡率,采用Western blot法检测各组细胞Caspase-3蛋白表达。取18只裸鼠建立肺癌荷瘤鼠模型,分为观察1组、观察2组、对照组,每组各6只,分别予尾静脉注射4、8 mg/kg CCCD及PBS,1次/周,共干预3周,干预结束后测算各组肿瘤体积并计算抑瘤率。随后处死各组裸鼠,取瘤体组织,应用TUNEL法检测各组肿瘤细胞凋亡情况并计算凋亡指数( AD)。结果加入5、10、20、30、50、80、120、160μmol/L CCCD 后, A549细胞 IR 分别为8.80%、16.52%、37.24%、55.75%、77.22%、87.16%、95.25%、98.70%,随着药物浓度增高,IR呈增高趋势。干预组加入10、20、40μmol/L CCCD后,细胞凋亡率均高于对照组(P均<0.05)。干预组Caspase-3蛋白表达高于对照组(P<0.05)。观察1组、观察2组、对照组AD分别为16.83%±8.44%、24.65%±11.24%、3.30%±2.12%,各组间比较P均<0.05。观察1组、观察2组抑瘤率分别为51.08%、56.78%。结论 CCCD在体内外均可抑制肺癌A549细胞的生长,促进细胞凋亡,其作用机制可能与经Caspase-3途径诱导细胞凋亡有关。%Objective To observe the inhibitory effect of a new copper (Ⅱ) complex with coumarin derivatives ( CCCD) on lung cancer cell line A549 in vivo and in vitro and to investigate the mechanism .Methods The lung cancer A549 cells were cultured and were treated with 5, 10

  4. Cave Rings

    Science.gov (United States)

    2010-10-13

    hypothesis, that cave rings are formed in the same manner as coffee rings[3], that is, due to the enhanced deposition at the edges of sessile drops ...ring’ is the deposit formed when a sessile drop of a solution containing dissolved particles, such as coffee or salt, dries. This was investigated by...who expanded on Deegan et al.[3] to find an exact form for the evaporation flux over a sessile drop . It turns out that solving 179 for the flux is

  5. Vascular rings.

    Science.gov (United States)

    Backer, Carl L; Mongé, Michael C; Popescu, Andrada R; Eltayeb, Osama M; Rastatter, Jeffrey C; Rigsby, Cynthia K

    2016-06-01

    The term vascular ring refers to congenital vascular anomalies of the aortic arch system that compress the esophagus and trachea, causing symptoms related to those two structures. The most common vascular rings are double aortic arch and right aortic arch with left ligamentum. Pulmonary artery sling is rare and these patients need to be carefully evaluated for frequently associated tracheal stenosis. Another cause of tracheal compression occurring only in infants is the innominate artery compression syndrome. In the current era, the diagnosis of a vascular ring is best established by CT imaging that can accurately delineate the anatomy of the vascular ring and associated tracheal pathology. For patients with a right aortic arch there recently has been an increased recognition of a structure called a Kommerell diverticulum which may require resection and transfer of the left subclavian artery to the left carotid artery. A very rare vascular ring is the circumflex aorta that is now treated with the aortic uncrossing operation. Patients with vascular rings should all have an echocardiogram because of the incidence of associated congenital heart disease. We also recommend bronchoscopy to assess for additional tracheal pathology and provide an assessment of the degree of tracheomalacia and bronchomalacia. The outcomes of surgical intervention are excellent and most patients have complete resolution of symptoms over a period of time. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Genotype-guided coumarin dosing: Where are we now and where do we need to go next?

    NARCIS (Netherlands)

    Baranova, Ekaterina V.; Verhoef, Talitha I; Asselbergs, Folkert W.; De Boer, Anthonius; Maitland-Van Der Zee, Anke-Hilse

    2015-01-01

    Introduction: A large proportion of the coumarin dose variability is explained by environmental factors and by common genetic variants in the VKORC1 and CYP2C9 genes. Genotype-guided coumarin dosing has been proposed for a more accurate prediction of the coumarin dose in order to reduce the incidenc

  7. Genotype-guided coumarin dosing : where are we now and where do we need to go next?

    NARCIS (Netherlands)

    Baranova, Ekaterina V; Verhoef, Talitha I; Asselbergs, Folkert W; de Boer, Anthonius; Maitland-van der Zee, Anke-Hilse

    2015-01-01

    INTRODUCTION: A large proportion of the coumarin dose variability is explained by environmental factors and by common genetic variants in the VKORC1 and CYP2C9 genes. Genotype-guided coumarin dosing has been proposed for a more accurate prediction of the coumarin dose in order to reduce the incidenc

  8. New Views of Jupiter's Rings

    Science.gov (United States)

    Burns, J. A.

    1998-09-01

    Jupiter's rings are the archetype of ethereal planetary rings (very-low optical-depth bands containing micron-sized "dust"). As a result of much improved observations by Galileo (Ockert-Bell* -- most citations are et al. and Icarus in press* or this meeting) and Keck (de Pater*), we now understand the nature of such rings. The ring has three components: a 104 km-thick toroidal halo (1.4-1.7 RJ; normal optical depth t = 10-6), a thin main ring (1.7-1.8 RJ; t = 10-6), and a pair of exterior gossamer rings (1.8-3.5RJ; t = 10-7). The main ring has patchy ( 20-30 percent) brightness. The ring is reddish and its particles satisfy a -2.5 differential power-law size distribution. Because particle lifetimes are brief, the rings must be continually regenerated, by collisions into parent bodies, which may be unseen or may be the known small ring-moons (Thomas*, Simonelli). The gossamer ring seems to be collisional ejecta derived from the ring-moons Amalthea and Thebe, and evolving inward by Poynting-Robertson drag (Burns). The particles drift through many electromagnetic resonances, clustering around synchronous orbit, which produce jumps in the particles' inclinations (Hamilton). The main ring is probably debris from Adrastea and Metis, which orbit in the equatorial plane. The halo particles are driven vertically by electromagnetic forces, which may be resonant (Schaffer & Burns) or not (Horanyi & Cravens). When halo orbits become highly distorted, particles are lost into Jupiter. Similar faint rings may be attendant to all small, close-in satellites (Showalter).

  9. Relationship between coumarin-induced hepatocellular toxicity and mitochondrial function in rats.

    Science.gov (United States)

    Tanaka, Yasuhiro; Fujii, Wataru; Hori, Hisako; Kitagawa, Yoshinori; Ozaki, Kiyokazu

    2016-04-01

    The manifestation of coumarin-induced hepatocellular toxicity may differ and depends on the frequency of administration to rats. A single coumarin dose induces hepatocellular necrosis while repeated doses induce only hepatocyte degeneration. However, the mechanism underlying these effects remains unclear. Therefore, we investigated the mechanism of coumarin-induced hepatotoxicity in rats. Coumarin was administered to male rats as a single dose or for 4 consecutive days, and samples were obtained 4 or 24 h after a single dose or 24 h after the repeated doses. A single coumarin dose significantly induced hepatocellular necrosis in rats; however, toxicity was attenuated after repeated dosing. With a single dose, hepatocellular necrosis was preceded by increased mitochondrial number and size and decreased mitochondrial function. An increased expression of granular cytochrome P450 (CYP) 2E1 protein was observed in the cytoplasm and mitochondria of coumarin-treated rats compared to the expression in the untreated controls. Nevertheless, repeated dosing showed mitochondrial function that was equivalent to that of the control while enlarged CYP2E1 protein droplets were distributed outside the mitochondria. These results suggest that mitochondrial function and CYP2E1 expression might be involved in coumarin-induced hepatocellular toxicity in rats. A reduction in mitochondrial CYP2E1 might be implicated in the acquisition of coumarin resistance after repeated doses.

  10. [Impending Coumarin-necrosis in a patient with heterozygous protein C deficiency type I].

    Science.gov (United States)

    Schulze, R; Behr, W; Wittwer, H; Harwix, S; Murmann, K; V Scheidt, W; Ehret, W; Schlimok, G

    2008-05-01

    Painful pink or magenta colored skin lesions characterized by a clear line of demarcation between the affected area and surrounding tissue appearing under therapy with coumarins may be a sign for evolving coumarin-necrosis. Immediate treatment with a protein C preparation in patients with protein C deficiency can prevent necrosis.

  11. Coumarins from Murraya paniculata var. zollingeri endemic to the Timor Islands.

    Science.gov (United States)

    Teshima, Naoko; Yamada, Hiromi; Ju-ichi, Motoharu; Uji, Tahan; Kinoshita, Takeshi; Ito, Chihiro

    2015-02-01

    Four new coumarins, murrangatin-1'-senecioate (1), 5-methoxypanial (2), mexoticin-2'-senecioate (3) and murralongic acid (4), were isolated from the leaves of Murraya paniculata var. zollingeri, together with 23 known coumarins. The structures of the new compounds were elucidated based on spectroscopic data. The taxonomic status of M. paniculata var. zollingeri is briefly discussed, along with its similarity to M. paniculata.

  12. Three New Coumarins from Micromelum integerrimum

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    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.

  13. Herbicidal Activity of Coumarin When Applied as a Pre-plant Incorporated into Soil

    Directory of Open Access Journals (Sweden)

    Amir-Hossein NAZEMI

    2015-06-01

    Full Text Available Due to having a short half-life and novel site of action, the herbicidal potential of natural compounds are lionized. Coumarin is a secondary metabolite from Lavandula sp., family Lamiacae. The impact of eight concentrations of coumarin (0, 100, 200, 400, 800, 1600, 3200 and 6400 ppm were separately used as a pre-plant incorporated into soil on six plant species under greenhouse conditions. Generally, coumarin had phytotoxic effect against all plant species. The phytotoxic effect was concentration-dependent. The high concentrations could inhibit the emergence of seedlings (probably by stopping germination of seeds. Based on ED50 parameter, the ranking of plant species for tolerance to coumarin was S. halepense > Z. mays > C. album > A. retroflexus > E. cruss-gali > P. oleracea. Based on selectivity index, coumarin at a concentration of 365.69 ppm can control P. oleracea without damaging Z. mays, whereas any concentration it cannot control other weeds without damaging Z. mays.

  14. The resolution of thermal oedema at various temperatures under coumarin treatment.

    Science.gov (United States)

    Piller, N B

    1975-02-01

    The treatment of thermal oedema with coumarin (a benzopyrone) has been found to be most effect when fast moving air of 20 degrees was blown over the burnt animals. Coumarin has two main effects: one is to cause vascular injury thus allowing extra protein and fluid into the tissues; the other is to stimulate phagocytosis, enzyme production and thus proteolysis and a subsequent removal of protein and fluid from the injured tissues. At lower temperatures the injurious nature of coumarin is prominent. At medium range temperatures the proteolytic actions of coumarin outweigh its injurious nature. Resolution thus proceeds much more rapidly. At high temperatures resolution is slowed. This is a consequence of the antioxidant effect of coumarin on adrenaline and ambient temperature on peripheral dilatation. The results obtained tie in well with those obtained by workers using water of equivalent temperature.

  15. Selected C7-substituted chromone derivatives as monoamine oxidase inhibitors.

    Science.gov (United States)

    Legoabe, Lesetja J; Petzer, Anél; Petzer, Jacobus P

    2012-12-01

    A series of C7-substituted chromone (1-benzopyran-4-one) derivatives were synthesized and evaluated as inhibitors of recombinant human monoamine oxidase (MAO) A and B. The chromones are structurally related to a series of C7-functionalized coumarin (1-benzopyran-2-one) derivatives which has been reported to act as potent MAO inhibitors. The results of the current study document that the chromones are highly potent reversible inhibitors of MAO-B with IC(50) values ranging from 0.008 to 0.370 μM. While the chromone derivatives also exhibit affinities for MAO-A, with IC(50) values ranging from 0.495 to 8.03 μM, they are selective for the MAO-B isoform. Structure-activity relationships (SAR) show that 7-benzyloxy substitution of chromone is suitable for MAO-B inhibition with tolerance for a variety of substituents and substitution patterns on the benzyloxy ring. It may be concluded that 7-benzyloxychromones are appropriate lead compounds for the design of reversible and selective MAO-B inhibitors. With the aid of modeling studies, potential binding orientations and interactions of selected chromone derivatives in the MAO-A and -B active sites are examined. Copyright © 2012 Elsevier Inc. All rights reserved.

  16. 3D QSAR studies on binding affinities of coumarin natural products for glycosomal GAPDH of Trypanosoma cruzi

    Science.gov (United States)

    Menezes, Irwin R. A.; Lopes, Julio C. D.; Montanari, Carlos A.; Oliva, Glaucius; Pavão, Fernando; Castilho, Marcelo S.; Vieira, Paulo C.; Pupo, M.^onica T.

    2003-05-01

    Drug design strategies based on Comparative Molecular Field Analysis (CoMFA) have been used to predict the activity of new compounds. The major advantage of this approach is that it permits the analysis of a large number of quantitative descriptors and uses chemometric methods such as partial least squares (PLS) to correlate changes in bioactivity with changes in chemical structure. Because it is often difficult to rationalize all variables affecting the binding affinity of compounds using CoMFA solely, the program GRID was used to describe ligands in terms of their molecular interaction fields, MIFs. The program VolSurf that is able to compress the relevant information present in 3D maps into a few descriptors can treat these GRID fields. The binding affinities of a new set of compounds consisting of 13 coumarins, for one of which the three-dimensional ligand-enzyme bound structure is known, were studied. A final model based on the mentioned programs was independently validated by synthesizing and testing new coumarin derivatives. By relying on our knowledge of the real physical data (i.e., combining crystallographic and binding affinity results), it is also shown that ligand-based design agrees with structure-based design. The compound with the highest binding affinity was the coumarin chalepin, isolated from Rutaceae species, with an IC50 value of 55.5 μM towards the enzyme glyceraldehyde-3-phosphate dehydrogenase (gGAPDH) from glycosomes of the parasite Trypanosoma cruzi, the causative agent of Chagas' disease. The proposed models from GRID MIFs have revealed the importance of lipophilic interactions in modulating the inhibition, but without excluding the dependence on stereo-electronic properties as found from CoMFA fields.

  17. Almost ring theory

    CERN Document Server

    2003-01-01

    This book develops thorough and complete foundations for the method of almost etale extensions, which is at the basis of Faltings' approach to p-adic Hodge theory. The central notion is that of an "almost ring". Almost rings are the commutative unitary monoids in a tensor category obtained as a quotient V-Mod/S of the category V-Mod of modules over a fixed ring V; the subcategory S consists of all modules annihilated by a fixed ideal m of V, satisfying certain natural conditions. The reader is assumed to be familiar with general categorical notions, some basic commutative algebra and some advanced homological algebra (derived categories, simplicial methods). Apart from these general prerequisites, the text is as self-contained as possible. One novel feature of the book - compared with Faltings' earlier treatment - is the systematic exploitation of the cotangent complex, especially for the study of deformations of almost algebras.

  18. Synthesis and Evaluation of Some Coumarin Containing Potential Antimicrobial Agents

    Directory of Open Access Journals (Sweden)

    Sayali D. Kudale

    2012-01-01

    Full Text Available A series of the Schiff’s bases incorporating coumarin and chalcone moeities, 3-(4-(4-(substituted phenylprop-1-ene-3-one phenylimino methyl-4-chloro-2h-chromen-2-one 4(a-g were synthesized as potential antimicrobial agents. These compounds were characterized on the basis of their spectral (IR, 1H NMR data and evaluated for antimicrobial activity in vitro against gram positive and gram negative bacteria and fungi. Compound 4b was found to be most active with an MIC of 20 µg/mL against all the tested organisms.

  19. Coumarin versus Chromone Monoamine Oxidase B Inhibitors: Quo Vadis?

    Science.gov (United States)

    Fonseca, André; Reis, Joana; Silva, Tiago; Matos, Maria João; Bagetta, Donatella; Ortuso, Francesco; Alcaro, Stefano; Uriarte, Eugenio; Borges, Fernanda

    2017-08-24

    Because of the lack of significant disease-modifying drugs for neurodegenerative disorders, a pressing need for new chemical entities endowed with IMAO-B still exists. Within this framework, and for the first time, a study was performed to compare coumarin- and chomone-3-phenylcarboxamide scaffolds. Compounds 10a and 10b were the most potent, selective, and reversible noncompetitive IMAO-B. The benzopyrone sp(2) oxygen atom was found to be position independent and a productive contributor for the ligand-enzyme complex stability.

  20. Novel fluorescent chemosensor for Ag+ based on coumarin fluorophore

    Institute of Scientific and Technical Information of China (English)

    Mao Xiang Wang; Xiang Ming Meng; Man Zhou Zhu; Qing Xiang Guo

    2008-01-01

    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/H20 (3:7, v:v) solution of CS1 gave a significantly quenched fluorescence. Other ions including Pb2+, Zn2+, Cu2+, Ca2+, Cd2+, Co2+, Mg2+, Mn2+, Hg2+, Ag+, Ni2+ induced no or much smaller spectral changes. This constitutes an ON-OFF Ag+-selective fluorescent chemosensor.

  1. Uncatalysed Production of Coumarin-3-carboxylic Acids: A Green Approach

    Directory of Open Access Journals (Sweden)

    Joel Martínez

    2016-01-01

    Full Text Available A green contribution in short reaction times with moderate yields to produce coumarin-3-carboxylic acids is offered. Five different modes to activate the reactions (microwave, near-infrared, mechanical milling, and ultrasound were compared with mantle heating in the presence or absence of ethanol, a green solvent. Near-infrared and microwave irradiations deliver the best yields in contrast to ultrasound and mechanical milling; moreover, these four processes offered shorter reaction times in comparison with the conventional mantle heating method. It is also important to highlight that the obtained molecules were produced without the requirement of a catalyst and two nonconventional energies forms are presented as new processes.

  2. Antiplatelet Aggregation Coumarins from the Leaves of Murraya omphalocarpa

    Directory of Open Access Journals (Sweden)

    Yang-Chang Wu

    2008-01-01

    Full Text Available Using a bioactivity-guided fractionation method, two coumarins: minumicrolineacetonide (1 and epimurpaniculol senecioate (2, were isolated from the leaves ofMurraya omphalocarpa Hayata (Rutaceae. Compound 1 had been previously synthesizedand was now isolated from natural sources for the first time, and compound 2, possessing anegative optical rotation value, is new. The structures and their stereochemistry were fullyelucidated on the basis of spectroscopic and X-ray crystallographic techniques. Bothcompounds 1 and 2 are active in the antiplatelet aggregation assay. Interestingly, thepossible acetonide artifact 1 displayed significant antiplatelet aggregation induced not onlyby AA and collagen but also by platelet activating factor (PAF.

  3. Topological rings

    CERN Document Server

    Warner, S

    1993-01-01

    This text brings the reader to the frontiers of current research in topological rings. The exercises illustrate many results and theorems while a comprehensive bibliography is also included. The book is aimed at those readers acquainted with some very basic point-set topology and algebra, as normally presented in semester courses at the beginning graduate level or even at the advanced undergraduate level. Familiarity with Hausdorff, metric, compact and locally compact spaces and basic properties of continuous functions, also with groups, rings, fields, vector spaces and modules, and with Zorn''s Lemma, is also expected.

  4. Screening of Natural Organic Volatiles from Prunus mahaleb L. Honey: Coumarin and Vomifoliol as Nonspecific Biomarkers

    Directory of Open Access Journals (Sweden)

    Mladenka Malenica Staver

    2011-03-01

    Full Text Available Headspace solid-phase microextraction (HS-SPME; PDMS/DVB fibre and ultrasonic solvent extraction (USE; solvent A: pentane and diethyl ether (1:2 v/v, solvent B: dichloromethane followed by gas chromatography and mass spectrometry (GC, GC-MS were used for the analysis of Prunus mahaleb L. honey samples. Screening was focused toward chemical composition of natural organic volatiles to determine if it is useful as a method of determining honey-sourcing. A total of 34 compounds were identified in the headspace and 49 in the extracts that included terpenes, norisoprenoids and benzene derivatives, followed by minor percentages of aliphatic compounds and furan derivatives. High vomifoliol percentages (10.7%–24.2% in both extracts (dominant in solvent B and coumarin (0.3%–2.4% from the extracts (more abundant in solvent A and headspace (0.9%–1.8% were considered characteristic for P. mahaleb honey and highlighted as potential nonspecific biomarkers of the honey’s botanical origin. In addition, comparison with P. mahaleb flowers, leaves, bark and wood volatiles from our previous research revealed common compounds among norisoprenoids and benzene derivatives.

  5. Synthesis of Novel Biologically Active s-Triazolo[3,4-b]-1,3,4-thiadiazole Derivatives

    Institute of Scientific and Technical Information of China (English)

    SUN,Yi-Feng

    2004-01-01

    @@ Heterocycles bearing a symmetrical triazole or 1,3,4-thiadiazole ring system are reported to show a broad spectrum of biological activities.[1,2] The 1,2,4-triazole nucleus has been recently incorporated into a wide variety of therapeutically interesting drugs including H1/H2 histamine receptor blockers, cholinesterase active agents, CNS stimulants, antianxiety and sedatives[3] Coumarins are nowadays an important group of organic compounds that used as bactericides, fungicides,anti-inflammatory, anticoagulant, anti-HIV and antitumour agents.[4,5] Keeping in view the biological importance of the above mentioned heterocyclic compounds and in continuation of our search for biologically active nitrogen and sulphur heterocycles, a series of s-triazolo[3,4-b]-1,3,4-thiadiazole derivatives was synthesized.

  6. D and E rings may not be indispensable for antofine: discovery of phenanthrene and alkylamine chain containing antofine derivatives as novel antiviral agents against tobacco mosaic virus (TMV) based on interaction of antofine and TMV RNA.

    Science.gov (United States)

    Wang, Ziwen; Wei, Peng; Liu, Yuxiu; Wang, Qingmin

    2014-10-29

    On the basis of the interaction of antofine and tobacco mosaic virus (TMV) RNA, a series of phenanthrene and alkylamine chain containing antofine derivatives 1-41 were designed, synthesized, and systematically evaluated for their antiviral activity against TMV. The results showed that most of these compounds exhibited good to excellent anti-TMV activity, which indicated that the D and E rings of antofine may not be indispensable. Phenanthrene is important for these compounds, but not the more the better. Phenanthrene, benzene rings, and alkylamine chain containing compounds exhibited good antiviral activity. The optimum compounds, 10, 18, and 19, displayed higher activity than precursor antofine and commercial ribavirin, thus emerging as new lead compounds. The novel concise structure provides another new template for antiviral studies.

  7. Ring interferometry

    CERN Document Server

    Malykin, Grigorii B; Zhurov, Alexei

    2013-01-01

    This monograph is devoted to the creation of a comprehensive formalism for quantitative description of polarized modes' linear interaction in modern single-mode optic fibers. The theory of random connections between polarized modes, developed in the monograph, allows calculations of the zero shift deviations for a fiber ring interferometer. The monograph addresses also the

  8. Expedient synthesis of coumarin-coupled triazoles via 'click chemistry' leading to the formation of coumarin-triazole-sugar hybrids.

    Science.gov (United States)

    Kumar, K Karthik; Kumar, R Mahesh; Subramanian, V; Das, T Mohan

    2010-11-02

    Coumarin-based triazoles were synthesized from 3-azidomethylcoumarin and a terminal acetylenic compound. Uncatalysed thermal conditions result in a mixture of both 1,4- and 1,5-regioisomers or the thermodynamically more stable 1,4-regioisomer, whereas the Cu(I)-catalysed reaction affords only the favourable 1,4-regioisomer. B3LYP/6-31G(d) level of theory has been used to calculate geometry and frequency features of the reactants, transition states (TSs) and products. Computational studies further reveal that 1,4-regioisomeric products are more favourable and also thermodynamically more stable compared to the 1,5-regioisomers.

  9. Low doping concentration studies of doped PVA-Coumarin nanocomposite films

    Science.gov (United States)

    Tripathi, J.; Tripathi, S.; Bisen, R.; Sharma, A.; Choudhary, A.; Shripathi, T.

    2016-05-01

    The observations of combination of Poly (vinyl) alcohol and Coumarin properties in nanocmposite films are reported. The X-ray diffraction measurements reveal nanocrystalline nature of PVA film, which remains nanocrystalline after doping Coumarin but along with PVA peaks, additional peak due to dopant crystallinity is seen. The absorption edge shows a double edge feature, where distinct bandgaps for PVA host and dopant Coumarin are obtained. However at a higher doping wt % of 1 and 2, the absorption is mainly dominated by Coumarin and single absorption edge is observed giving a bandgap equal to that of bulk Coumarin (3.3 eV). The composite formation affects the bonding of host drastically and is seen through the bond modification in FTIR spectra. The results suggest that doping below 2 wt% is advantageous as combination of PVA and Coumarin properties are obtained but at 2 wt %, the properties are dominated by mainly Coumarin and the signature of PVA from optical properties is completely lost.

  10. Gustatory Receptors Required for Avoiding the Toxic Compound Coumarin in Drosophila melanogaster

    Science.gov (United States)

    Poudel, Seeta; Lee, Youngseok

    2016-01-01

    Coumarin is a phenolic compound that mainly affects the liver due to its metabolization into a toxic compound. The deterrent and ovicidal activities of coumarin in insect models such as Drosophila melanogaster have been reported. Here we explore the molecular mechanisms by which these insects protect themselves and their eggs from this toxic plant metabolite. Coumarin was fatal to the flies in a dosage-dependent manner. However, coumarin feeding could be inhibited through activation of the aversive gustatory receptor neurons (GRNs), but not the olfactory receptor neurons. Furthermore, three gustatory receptors, GR33a, GR66a, and GR93a, functioned together in coumarin detection by the proboscis. However, GR33a, but not GR66a and GR93a, was required to avoid coumarin during oviposition, with a choice of the same substrates provided as in binary food choice assay. Taken together, these findings suggest that anti-feeding activity and oviposition to avoid coumarin occur via separate mechanisms. PMID:26912085

  11. Micropatterned coumarin polyester thin films direct neurite orientation.

    Science.gov (United States)

    McCormick, Aleesha M; Maddipatla, Murthy V S N; Shi, Shuojia; Chamsaz, Elaheh A; Yokoyama, Hiroshi; Joy, Abraham; Leipzig, Nic D

    2014-11-26

    Guidance and migration of cells in the nervous system is imperative for proper development, maturation, and regeneration. In the peripheral nervous system (PNS), it is challenging for axons to bridge critical-sized injury defects to achieve repair and the central nervous system (CNS) has a very limited ability to regenerate after injury because of its innate injury response. The photoreactivity of the coumarin polyester used in this study enables efficient micropatterning using a custom digital micromirror device (DMD) and has been previously shown to be biodegradable, making these thin films ideal for cell guidance substrates with potential for future in vivo applications. With DMD, we fabricated coumarin polyester thin films into 10×20 μm and 15×50 μm micropatterns with depths ranging from 15 to 20 nm to enhance nervous system cell alignment. Adult primary neurons, oligodendrocytes, and astrocytes were isolated from rat brain tissue and seeded onto the polymer surfaces. After 24 h, cell type and neurite alignment were analyzed using phase contrast and fluorescence imaging. There was a significant difference (ppolyester thin films has proven beneficial as an axon guidance platform for future nervous system regenerative strategies.

  12. Aurapten, a coumarin with growth inhibition against Leishmania major promastigotes

    Directory of Open Access Journals (Sweden)

    Napolitano H.B.

    2004-01-01

    Full Text Available Several natural compounds have been identified for the treatment of leishmaniasis. Among them are some alkaloids, chalcones, lactones, tetralones, and saponins. The new compound reported here, 7-geranyloxycoumarin, called aurapten, belongs to the chemical class of the coumarins and has a molecular weight of 298.37. The compund was extracted from the Rutaceae species Esenbeckia febrifuga and was purified from a hexane extract starting from 407.7 g of dried leaves and followed by four silica gel chromatographic fractionation steps using different solvents as the mobile phase. The resulting compound (47 mg of shows significant growth inhibition with an LD50 of 30 µM against the tropical parasite Leishmania major, which causes severe clinical manifestations in humans and is endemic in the tropical and subtropical regions. In the present study, we investigated the atomic structure of aurapten in order to determine the existence of common structural motifs that might be related to other coumarins and potentially to other identified inhibitors of Leishmania growth and viability. This compound has a comparable inhibitory activity of other isolated molecules. The aurapten is a planar molecule constituted of an aromatic system with electron delocalization. A hydrophobic side chain consisting of ten carbon atoms with two double bonds and negative density has been identified and may be relevant for further compound synthesis.

  13. Toxicogenomic analysis of pharmacological active coumarins isolated from Calophyllum brasiliense.

    Science.gov (United States)

    Gomez-Verjan, J C; Estrella-Parra, E A; Gonzalez-Sanchez, I; Rivero-Segura, N A; Vazquez-Martinez, R; Magos-Guerrero, G; Mendoza-Villanueva, D; Cerbón-Cervantes, M A; Reyes-Chilpa, R

    2015-12-01

    Calophyllum brasiliense (Calophyllaceae) is a tropical rain forest tree, mainly distributed in South and Central America. It is an important source of bioactive natural products like, for instance soulatrolide, and mammea type coumarins. Soulatrolide is a tetracyclic dipyranocoumarins and a potent inhibitor of HIV-1 reverse transcriptase and Mycobacterium tuberculosis. Mammea A/BA and A/BB coumarins, pure or as a mixture, are highly active against several leukemia cell lines, Trypanosoma cruzi and Leishmania amazonensis. In the present work, a toxicogenomic analysis of Soulatrolide and Mammea A/BA + A/BB (3:1) mixture was performed in order to validate the toxicological potential of this type of compounds. Soulatrolide or mixture of mammea A/BA + A/BB (3:1) was administered orally to male mice (CD-1) at dose of 100 mg/kg/daily, for 1 week. After this time, mice were sacrificed, and RNA extracted from the liver of treated animals. Transcriptomic analysis was performed using Affymetrix Mouse Gene 1.0 ST Array. Robust microarray analysis (RMA) and two way ANOVA test revealed for mammea mixture treatment 46 genes upregulated and 72 downregulated genes; meanwhile, for soulatrolide 665 were upregulated and 1077 downregulated genes. Enrichment analysis for such genes revealed that in both type of treatments genetic expression were mainly involved in drug metabolism. Overall results indicate a safety profile. The microarray data complies with MIAME guidelines and are deposited in GEO under accession number GSE72755.

  14. Toxicogenomic analysis of pharmacological active coumarins isolated from Calophyllum brasiliense

    Directory of Open Access Journals (Sweden)

    J.C. Gomez-Verjan

    2015-12-01

    Full Text Available Calophyllum brasiliense (Calophyllaceae is a tropical rain forest tree, mainly distributed in South and Central America. It is an important source of bioactive natural products like, for instance soulatrolide, and mammea type coumarins. Soulatrolide is a tetracyclic dipyranocoumarins and a potent inhibitor of HIV-1 reverse transcriptase and Mycobacterium tuberculosis. Mammea A/BA and A/BB coumarins, pure or as a mixture, are highly active against several leukemia cell lines, Trypanosoma cruzi and Leishmania amazonensis. In the present work, a toxicogenomic analysis of Soulatrolide and Mammea A/BA + A/BB (3:1 mixture was performed in order to validate the toxicological potential of this type of compounds. Soulatrolide or mixture of mammea A/BA + A/BB (3:1 was administered orally to male mice (CD-1 at dose of 100 mg/kg/daily, for 1 week. After this time, mice were sacrificed, and RNA extracted from the liver of treated animals. Transcriptomic analysis was performed using Affymetrix Mouse Gene 1.0 ST Array. Robust microarray analysis (RMA and two way ANOVA test revealed for mammea mixture treatment 46 genes upregulated and 72 downregulated genes; meanwhile, for soulatrolide 665 were upregulated and 1077 downregulated genes. Enrichment analysis for such genes revealed that in both type of treatments genetic expression were mainly involved in drug metabolism. Overall results indicate a safety profile. The microarray data complies with MIAME guidelines and are deposited in GEO under accession number GSE72755.

  15. Cytotoxic effects of mammea type coumarins from Calophyllum brasiliense.

    Science.gov (United States)

    Reyes-Chilpa, Ricardo; Estrada-Muñiz, Elizabet; Apan, Teresa Ramírez; Amekraz, Badia; Aumelas, Andre; Jankowski, Christopher K; Vázquez-Torres, Mario

    2004-08-13

    Calophyllum brasiliense (Clusiaceae) is a big tree from the Tropical Rain Forests of the American continent. The organic extracts from the leaves yielded coumarins of the mammea type: mammea A/BA, A/BB, B/BA, B/BB, C/OA, C/OB, B/BA cyclo F, B/BB cyclo F, and isomammeigin. The triterpenoids friedelin and canophyllol, as well as the biflavonoid amentoflavone, protocatechuic and shikimic acids, were also obtained. Most of the isolated compounds were tested in vitro against K562, U251, and PC3 human tumor cell lines. The coumarins were cytotoxic against the three cell lines, the highest activity was shown by mammea A/BA (IC50 = 0.04 to 0.59 microM). The mixtures of mammea A/BA + A/BB, mammea B/BA + B/BB and mammea C/OA + C/OB were also highly active (IC50 < 4.05 microM). Friedelin was cytotoxic only against PC3, and U251 lines. Inhibition of HIV-1 reverse transcriptase was also assayed in vitro; however, none of the tested compounds (250 microM) prevented the activity of this enzyme. Most of the isolated compounds were also inactive against fourteen bacterial strains; however mammea A/BA + A/BB, and mammea C/OA + C/OB inhibited the growth of Staphylococcus aureus, S. epidermidis and Bacillus subtilis.

  16. Fluorophores as Chemosensors for Sr(sup 2+) and Cs(sup +) Based on Calix[4]arenes and Coumarin Reporter Groups

    Energy Technology Data Exchange (ETDEWEB)

    Gorestzki, Gudrun; Brown, Gilbert M.; Bonnesen, Peter V.

    2003-09-10

    Fluorescent sensors are being developed for Cs + and Sr2+ which combine a molecular recognition element with an optical transduction element. Such sensors will be needed for real-time application in the characterization of nuclear waste and waste process streams. The fluorescent method is very important due to its high sensitivity and direct visual perception even in highly dilute solutions and its potential for remote application utilizing fiber optics. Crown ether bridged calix[4]arenes have been widely used as a three-dimensional platform for selective metal ion recognition. Coumarins show interesting photochemical and photophysical properties and are widely used in laser dye applications. These fluorescence probes increase their dipolar moment when excited. We will report the synthesis of calix[4]arene-crown-6 derivatives possessing 1,3-alternate conformation and incorporating a coumarin based fluorescence reporter group. Selectivity for Sr2+ over Cs + is obtained by using azacrowns and the sensitivity will be determined by varying the donor atom set as well as the substitution pattern of the coumarin.

  17. On SAP-rings

    OpenAIRE

    Zhixiang, Wu

    2006-01-01

    The rings whose simple right modules are absolutely pure are called right $SAP$-rings. We give a new characterization of right $SAP$ rings, right $V$ rings, and von Neumann regular rings. We also obtain a new decomposition theory of right selfinjective von Neumann regular rings. The relationships between $SAP$-rings, $V$-rings, and von Neumann regular rings are explored. Some recent results obtained by Faith are generalized and the results of Wu-Xia are strengthened.

  18. Novel microtubule-targeted agent 6-chloro-4-(methoxyphenyl) coumarin induces G2-M arrest andapoptosis in HeLa cells

    Institute of Scientific and Technical Information of China (English)

    Yi-ming MA; Yu-bo ZHOU; Chuan-ming XIE; Dong-mei CHEN; Jia LI

    2012-01-01

    To identify a novel coumarin analogue with the highest anticancer activity and to further investigate its anticancer mechanisms.Methods:The viability of cancer cells was investigated using the MTT assay.The cell cycle progression was evaluated using both flow cytometric and Western blotting analysis.Microtubule depolymerization was observed with immunocytochemistry in vivo and a tubu-lin depolymerization assay in vitro.Apoptosis was demonstrated using Annexin V/Propidium Iodide (PI) double-staining and sub-G1analysis.Results:Among 36 analogues of coumarin,6-chloro-4-(methoxyphenyl) coumarin showed the best anticancer activity (IC50 value about 200 nmol/L) in HCT116 cells.The compound had a broad spectrum of anticancer activity against 9 cancer cell lines derived from colon cancer,breast cancer,liver cancer,cervical cancer,leukemia,epidermoid cancer with IC5o value of 75 nmol/L-1.57 μmol/L but with low cytotocitity against WI-38 human lung fibroblasts (IC50 value of 12.128 μmol/L).The compound (0.04-10 μmol/L) induced G2-M phase arrest in HeLa cells in a dose-dependent manner,which was reversible after the compound was removed.The compound (10-300 μmol/L) induced the depolymerization of purified porcine tubulin in vitro.Finally,the compound (0.04-2.5 μmol/L) induced apoptosis of HeLa cells in dose- and time-dependent manners.Conclusion:6-Chloro-4-(methoxyphenyl) coumarin is a novel microtubule-targeting agent that induces G2-M arrest and apoptosis in HeLa cells.

  19. Inhibition of gastric H+,K+-ATPase activity by flavonoids, coumarins and xanthones isolated from Mexican medicinal plants.

    Science.gov (United States)

    Reyes-Chilpa, Ricardo; Baggio, Cristiane Hatsuko; Alavez-Solano, Dagoberto; Estrada-Muñiz, Elizabeth; Kauffman, Frederick C; Sanchez, Rosa I; Mesia-Vela, Sonia

    2006-04-21

    Medicinal plants are commonly used in Latin American folk medicine for the treatment of gastric problems. In order to understand the properties of some of their chemical constituents, four natural xanthones, an acetylated derivative, two coumarins (mammea A/BA and mammea C/OA) isolated from Calophyllum brasiliense Cambess and two flavonoids (minimiflorin and mundulin) isolated from Lonchocarpus oaxacensis Pittier, and the chalcone lonchocarpin isolated from Lonchocarpus guatemalensis Benth were tested for their activities on gastric H+,K+-ATPase isolated from dog stomach. All the compounds tested inhibited H+,K+-ATPase activity with varied potency. The xanthones inhibited the H+,K+-ATPase with IC50 values ranging from 47 microM to 1.6 mM. Coumarins inhibited H+,K+-ATPase with IC50 values of 110 and 638 microM. IC50 values for the flavonoids ranged from 9.6 to 510 microM among which minimiflorin was the most potent. The results suggest that H+,K+-ATPase is sensitive to inhibition by several types of structurally different natural compounds. The potency of the effects on gastric H+,K+-ATPase depends on the presence, position and number of hydroxyls groups in the molecule. Collectively, these results suggest a potential for important pharmacological and toxicological interactions by these types of natural products at the level of H+,K+-ATPase which may explain, at least in part, the gastroprotective properties, indicated by traditional medicine, of the plants from which these compounds were isolated.

  20. Divergent synthetic routes for ring expansion or cyclization from 1,4-allylic diol derivatives via gold(I) catalysis or zinc(II) mediation.

    Science.gov (United States)

    Zhu, Li-Li; Li, Xiao-Xiao; Zhou, Wen; Li, Xin; Chen, Zili

    2011-11-04

    A new efficient method was developed to transform cyclic alkanols into one-carbon higher homologated ketones using various esters as the leaving groups through gold-catalyzed allylic cation-promoted pinacol-type rearrangement. This reaction, coupled with oxy-Cope rearrangement, provided a new strategy to synthesize five-carbon homologated ring ketones. In addition, using ZnBr(2), 2,5-dihydrofuran products were obtained in moderate to good yields via an intramolecular cyclization process.

  1. The Use of Coumarins as Environmentally-Sensitive Fluorescent Probes of Heterogeneous Inclusion Systems

    Directory of Open Access Journals (Sweden)

    Brian D. Wagner

    2009-01-01

    Full Text Available Coumarins, as a family of molecules, exhibit a wide range of fluorescence emission properties. In many cases, this fluorescence is extremely sensitive to the local environment of the molecule, especially the local polarity and microviscosity. In addition, coumarins show a wide range of size, shape, and hydrophobicity. These properties make them especially useful as fluorescent probes of heterogeneous environments, such as supramolecular host cavities, micelles, polymers and solids. This article will review the use of coumarins to probe such heterogeneous systems using fluorescence spectroscopy.

  2. Supernumerary ring chromosomes derived from the long arm of chromosome 12 as the primary cytogenetic anomaly in a rare soft tissue chondroma.

    Science.gov (United States)

    Shadan, F F; Mascarello, J T; Newbury, R O; Dennis, T; Spallone, P; Stock, A D

    2000-04-15

    Supernumerary ring chromosomes varying with respect to both size and number were found as the primary cytogenetic anomaly in a rare benign soft tissue chondroma resected from the floor of the mouth of a 3-year-old girl. Reverse fluorescence in situ hybridization paint probes prepared by polymerase chain reaction from microdissected rings produced fluorescent signal over two large but discontinuous parts of the chromosome 12 long arm, subdivided into four regions. This case expands the spectrum of mesenchymal neoplasms in which ring chromosomes have been described as the primary genetic anomaly. A review of the literature reporting similar findings in other soft tissue tumors further supports the possibility that low-level amplification of chromosome 12 long-arm regions may contribute to abnormal cellular proliferation in a variety of mesenchymal tumors. Genes implicated in the control of the cell cycle such as sarcoma amplified sequence (SAS), the human homolog of the murine double-minute type 2 gene (MDM-2), proto-oncogenes CHOP/GADD153, GLI, A2MR, cyclin-dependent kinase (CDK4), and the high mobility group (HMGIC) gene implicated in mesenchymal tumorigenesis are all located on the long arm of chromosome 12. Chromosomal abnormalities involving the 12q13-q15 region are associated with a wide range of benign soft tissue tumors and sarcomas.

  3. Risk assessment of coumarin using the bench mark dose (BMD) approach: children in Norway which regularly eat oatmeal porridge with cinnamon may exceed the TDI for coumarin with several folds.

    Science.gov (United States)

    Fotland, T Ø; Paulsen, J E; Sanner, T; Alexander, J; Husøy, T

    2012-03-01

    Coumarin is a naturally occurring flavouring substance in cinnamon and many other plants. It is known that coumarin can cause liver toxicity in several species, and it is considered a non-genotoxic carcinogen in rodents. By using the bench mark dose approach we re-assessed coumarin toxicity and established a new TDI for coumarin of 0.07 mg/kg bw/day. Oral intake of coumarin is related to consumption of cinnamon-containing foods and food supplements. Cinnamon is a widely used spice in Norway, and can be used as topping on oatmeal porridge. Based on analyses of coumarin in Norwegian foods, intake calculations for children and adults were conducted, and a risk assessment of coumarin in the Norwegian population was performed. Intake estimates of coumarin show that small children eating oatmeal porridge several times a week sprinkled with cinnamon could have a coumarin intake of 1.63 mg/kg bw/day and may exceeding the TDI with several folds. Adults drinking cinnamon-based tea and consuming cinnamon supplements also can exceed TDI. The coumarin intake could exceed the TDI by 7- to 20-fold in some intake scenarios. Such large daily exceedances of TDI, even for a limited time period of 1-2 weeks, cause concern of adverse health effects. Copyright © 2011 Elsevier Ltd. All rights reserved.

  4. Anti-leishmanial and structure-activity relationship of ring substituted 3-phenyl-1-(1,4-di-N-oxide quinoxalin-2-yl-2-propen-1-one derivatives

    Directory of Open Access Journals (Sweden)

    Asunción Burguete

    2008-12-01

    Full Text Available A series of ring substituted 3-phenyl-1-(1,4-di-N-oxide quinoxalin-2-yl-2-propen-1-one derivatives were synthesized and tested for in vitro leishmanicidal activity against amastigotes of Leishmania amazonensis in axenical cultures and murine infected macrophages. Structure-activity relationships demonstrated the importance of a radical methoxy at position R3', R4' and R5'. (2E-3-(3,4,5-trimethoxy-phenyl-1-(3,6,7-trimethyl-1,4-dioxy-quinoxalin-2-yl-propenone was the most active. Cytotoxicity on macrophages revealed that this product was almost six times more active than toxic.

  5. Coumarin Compounds of Biebersteinia Multifida Roots Show Potential Anxiolytic Effects In Mice

    Directory of Open Access Journals (Sweden)

    Hamid Reza Monsef-Esfahani

    2013-06-01

    Full Text Available Background:Traditional preparations of the root of Biebersteinia multifida DC (Geraniaceae, a native medicinal plant of Irano-Turanian floristic region, have been used for the treatment of phobias as anxiolytic herbal preparation.Methods:We utilized the phobic behavior of mice in an elevated plus-maze as a model to evaluate the anxiolytic effect of the plant extract and bio-guided fractionation was applied to isolate the active compounds. Total root extract, alkaline and ether fraction were administered to mice at different doses 30 and 90 min prior to the maze test. Saline and diazepam were administered as negative and positive controls, respectively. The time spent in open and closed arms, an index of anxiety behavior and entry time, was measured as an index of animal activity.Results:The total root extract exhibited anxiolytic effect which was comparable to diazepam but with longer duration. This sustained effect of the crude extract was sustained for 90 min and was even more after injection of 45 mg/kg while the effect of diazepam had been reduced by 90 min. The anxiolytic effect factor was only present in the alkaline fraction and displayed its effect at lower doses than diazepam while pure vasicinone as the previously known alkaloid did not shown anxiolytic effect. The effect of the alkaline fraction was in a dose dependent manner starting at 0.2 mg/kg with a maximum at 1.0 mg/kg. Bio-guided fractionation using a variety of chromatographic methods led to isolation and purification of three coumarin derivatives from the bioactive fraction, including umbelliferone, scopoletin, and ferulic acid.Conclusion:For the first time, bio-guided fractionation of the root extract of B. multifida indicates significant sustained anxiolytic effects which led to isolation of three coumarin derivatives with well-known potent MAO inhibitory and anti-anxiety effects. These data contribute to evidence-based traditional use of B. multifida root for anxiety

  6. Quantitative DNA interstrand cross-link formation by coumarin and thymine: structure determination, sequence effect, and fluorescence detection.

    Science.gov (United States)

    Sun, Huabing; Fan, Heli; Peng, Xiaohua

    2014-12-01

    The coumarin analogues have been widely utilized in medicine, biology, biochemistry, and material sciences. Here, we report a detailed study on the reactivity of coumarins toward DNA. A series of coumarin analogues were synthesized and incorporated into oligodeoxynucleotides. A photoinduced [2 + 2] cycloaddition occurs between the coumarin moiety and the thymidine upon 350 nm irradiation forming both syn- and anti-cyclobutane adducts (17 and 18), which are photoreversible by 254/350 nm irradiation in DNA. Quantitative DNA interstrand cross-link (ICL) formation was observed with the coumarin moieties containing a flexible two-carbon or longer chain. DNA cross-linking by coumarins shows a kinetic preference when flanked by an A:T base pair as opposed to a G:C pair. An efficient photoinduced electron transfer between coumarin and dG slows down ICL formation. ICL formation quenches the fluorescence of coumarin, which, for the first time, enables fast, easy, and real-time monitoring of DNA cross-linking and photoreversibility via fluorescence spectroscopy. It can be used to detect the transversion mutation between pyrimidines and purines. Overall, this work provides new insights into the biochemical properties and possible toxicity of coumarins. A quantitative, fluorescence-detectable, and photoswitchable DNA cross-linking reaction of the coumarin moieties can potentially serve as mechanistic probes and tools for bioresearch without disrupting native biological environment.

  7. 8-或6-(3-氯苯甲酰)香豆素衍生物的合成、表征、生物活性及与牛血清白蛋白的相互作用%Synthesis, Characterization, Biological Activity and Interaction with Bovine Serum Albumin of 8-or 6-(3-Chlorobenzoyl)coumarin Derivatives

    Institute of Scientific and Technical Information of China (English)

    杨树平; 韩立军; 潘燕; 王大奇; 王南南; 王婷

    2013-01-01

    合成了2个新化合物7-羟基-8-(3-氯苯甲酰基)-4-甲基香豆素(1)和7-羟基-6-(3-氯苯甲酰基)-4-甲基香豆素(2).X射线单晶衍射分析表明,2个化合物的晶体同属于单斜晶系,P21/c空间群,化合物1:a=1.21527 (14) nm,b=1.01550(12) nm,c=1.5045 (2) nm,β=112.377 (2)°,V=1.7169 (4) nm3,Dc=1.396 g/cm3,Z=4,F(000)=752,R1=0.0415,wR2=0.0981 [I>2σ (I)],S=1.063;化合物2:a=2.0168(2) nm,b=0.76229(12) nm,c=2.25497(17) nm,β=123.987(6)°,V=0.8745(6) nm3,Dc=1.454g/cm3,Z=8,F(000)=1296,R1=0.0604,wR2 =0.1384[I>2σ(I)],S=0.948.抗菌实验结果表明,2个化合物对大肠杆菌(E.coli)、枯草杆菌(B.subtilis)和金色葡萄球菌(S.aureus)均有中等程度的抑制作用;体外抗氧化实验结果表明,2个化合物对超氧阴离子自由基(O-2·)、羟基自由基(·OH)和二苯代苦味肼基自由基(DPPH·)均有良好的清除能力.采用荧光光谱法研究了不同温度下2个化合物与牛血清白蛋白(BSA)的相互作用,结果表明,2个化合物对BSA的荧光猝灭均属于静态猝灭;热力学数据表明,化合物1(△H>0,△S>0,△G<0)与BSA主要以疏水作用力相结合,化合物2(△H<0,△S<0,△G<0)与BSA主要以氢键或范德华力相结合;BSA与化合物1和化合物2间的距离分别为2.59和2.38 nm,说明2个化合物与BSA之间可能发生了非辐射能量转移.%Two new compounds, 4-methyl-7-hydroxy-8-(3-chlorobenzoyl) coumarin(l) and 4-methyl-7-hy-droxy-6-(3-chlorobenzoyl)coumarin(2) , were synthesized and characterized by elemental analysis, infrared spectra, 1H NMR and single crystal X-ray diffraction methods. The crystals of compounds 1 and 2 belong to monoclinic system with space group P21/c, compound 1: a= 1. 21527(14) nm, b = 1.01550(12) run, c= 1.5045(2) nm,β = 112. 377(2)°, V=1.7169(4) nm3, Dc = 1. 396 g/cm3, Z = 4, F(000)=752, R1 = 0.0415, wR2 = 0.0981[I>2σ(I)], S= 1.063; compound2: a = 2. 0168(2) nm, b = 0.76229(12) nm, c = 2.25497(17) nm, β=123. 987(6)

  8. Comparison of tissue heat balance- and thermal dissipation-derived sap flow measurements in ring-porous oaks and a pine.

    Science.gov (United States)

    Renninger, Heidi J; Schäfer, Karina V R

    2012-01-01

    Sap flow measurements have become integral in many physiological and ecological investigations. A number of methods are used to estimate sap flow rates in trees, but probably the most popular is the thermal dissipation (TD) method because of its affordability, relatively low power consumption, and ease of use. However, there have been questions about the use of this method in ring-porous species and whether individual species and site calibrations are needed. We made concurrent measurements of sap flow rates using TD sensors and the tissue heat balance (THB) method in two oak species (Quercus prinus Willd. and Quercus velutina Lam.) and one pine (Pinus echinata Mill.). We also made concurrent measurements of sap flow rates using both 1 and 2-cm long TD sensors in both oak species. We found that both the TD and THB systems tended to match well in the pine individual, but sap flow rates were underestimated by 2-cm long TD sensors in five individuals of the two ring-porous oak species. Underestimations of 20-35% occurred in Q. prinus even when a "Clearwater" correction was applied to account for the shallowness of the sapwood depth relative to the sensor length and flow rates were underestimated by up to 50% in Q. velutina. Two centimeter long TD sensors also underestimated flow rates compared with 1-cm long sensors in Q. prinus, but only at large flow rates. When 2-cm long sensor data in Q. prinus were scaled using the regression with 1-cm long data, daily flow rates matched well with the rates measured by the THB system. Daily plot level transpiration estimated using TD sap flow rates and scaled 1 cm sensor data averaged about 15% lower than those estimated by the THB method. Therefore, these results suggest that 1-cm long sensors are appropriate in species with shallow sapwood, however more corrections may be necessary in ring-porous species.

  9. Boronate Derivatives of Functionally Diverse Catechols: Stability Studies

    Directory of Open Access Journals (Sweden)

    Kamal Aziz Ketuly

    2010-03-01

    Full Text Available Benzeneboronate of catecholic carboxyl methyl esters, N-acetyldopamine, coumarin and catechol estrogens were prepared as crystalline derivatives in high yield. Related catechol compounds with extra polar functional group(s (OH, NH2 do not form or only partially form unstable cyclic boronate derivatives.

  10. Selective electrochemical discrimination between dopamine and phenethylamine-derived psychotropic drugs using electrodes modified with an acyclic receptor containing two terminal 3-alkoxy-5-nitroindazole rings.

    Science.gov (United States)

    Doménech, Antonio; Navarro, Pilar; Arán, Vicente J; Muro, Beatriz; Montoya, Noemí; García-España, Enrique

    2010-06-01

    Electrochemical discrimination between dopamine and psychotropic drugs which have in common a skeletal structure of phenethylamine, can be obtained using acyclic receptors L(1) and L(2), containing two terminal 3-alkoxy-5-nitroindazole rings. Upon attachment to graphite electrodes, L(1) and L(2) exhibit a well-defined, essentially reversible solid state electrochemistry in contact with aqueous media, based on electrolyte-assisted reduction processes involving successive cation and anion insertion/binding. As a result, a distinctive, essentially Nernstian electrochemical response is obtained for phenethylammonium ions of methamphetamine (METH), p-methoxyamphetamine (PMA), amphetamine (AMPH), mescaline (MES), homoveratrylamine (HOM), phenethylamine (PEA) and dopamine (DA) in aqueous media.

  11. Derived logarithmic geometry I

    OpenAIRE

    Steffen, Sagave; Timo, Schurg; Gabriele, Vezzosi

    2016-01-01

    In order to develop the foundations of logarithmic derived geometry, we introduce a model category of logarithmic simplicial rings and a notion of derived log \\'etale maps and use this to define derived log stacks.

  12. Carrier transport and charge transfer properties in coumarin-doped bulk-heterojunction materials

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, T.; Maeda, T.; Yamashita, K. [Graduate School of Science and Technology, Kyoto Institute of Technology, Kyoto 606-8585 (Japan); Yanagi, H. [Graduate School of Materials Science, Nara Institute of Science and Technology, Nara 630-0192 (Japan)

    2012-12-15

    We have investigated photovoltaic properties of organic solar cells using polymer-fullerene bulk-heterojunction films doped with coumarin dyes. Whereas the coumarin molecules used in this study had similar absorption bands, evident difference was observed in the open-circuit voltage as well as in the short-circuit current. In particular, the doping of coumarin 307 was found to cause a distinct enhancement in the open-circuit voltage. On the other hand, the doping of coumarin 30 gave a serious degradation in the device performance. These results were strongly associated with calculated molecular energies of the doped dyes, especially with the highest occupied molecular orbital energy. (copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  13. Synthesis and Characterization of Coumarin-Containing Cyclic Polymer and Its Photoinduced Coupling/Dissociation.

    Science.gov (United States)

    Li, Min; Fan, Wei; Hong, Chunyan; Pan, Caiyuan

    2015-12-01

    Cyclic polystyrene (PS) with a pendant coumarin group is prepared by the combination of atom transfer radical polymerization and "click" chemistry. Fluorescence resonance energy transfer process is observed in the fluorescence measurement of coumarin-containing PS, and cyclic PS exhibits stronger emission than that of its linear precursor. When cyclic PS is irradiated under UV light at λ = 365 nm, 8-shaped PS is achieved due to the dimerization of pendant coumarin group. Subsequently, 8-shaped PS can be divided into single macrocycle under UV irradiation at λ = 254 nm via the photocleavage of coumarin dimer. The photoinduced coupling and dissociation are monitored by UV/vis spectra and gel permeation chromatography (GPC).

  14. L-Proline Catalyzed Solvent-Free Knoevenagel Condensation for the Synthesis of 3-Substituted Coumarins

    Institute of Scientific and Technical Information of China (English)

    KARADE Nandkishor. N.; GAMPAWAR Sumit V.; SHINDE Sandeep. V.; JADHAV Wamanrao. N.

    2007-01-01

    L-Proline was utilized as an efficient organo-catalyst for the environmentally benign synthesis of 3-substituted coumarins by the Knoevenagel condensation of substituted 2-hydroxybenzaldehydes with reactive methylene compounds under solvent free conditions.

  15. Rare Coumarins Induce Apoptosis, G1 Cell Block and Reduce RNA Content in HL60 Cells

    Directory of Open Access Journals (Sweden)

    Widelski Jarosław

    2017-02-01

    Full Text Available The rare coumarins stenocarpin, stenocarpin isobutyrate, oficinalin, oficinalin isobutyrate, 8-methoxypeucedanin and the known xanthotoxin, isoimperatorin, bergapten, peucedanin and 8–methoxyisoimperatorin were isolated from Peucedanum luxurians Tamamsch. (Apiaceae and identified by means of spectral data (1D and 2D NMR. Their immunomodulating activity was evaluated by flow cytometry and their influence on HL60 cells as well as on PHA-stimulated PBLs was tested. All tested coumarins induce apoptosis (maximal in the 48 h culture and decrease cell proliferation in a time- and dose-dependent manner, especially in HL60 cells. They also induce partial G1 block, but only in HL60 cells (at 100 µM concentrations. Dose-dependent reduction of RNA content was also found in G1 cells treated by the coumarins. All of the tested coumarins also possessed immunomodulatory activities. Bergapten and xanthotoxin were found to be the best candidates for further evaluation as anti-cancer drugs.

  16. Synthesis and functionalization of coumarin-containing copolymers for second order optical nonlinearities

    Science.gov (United States)

    Essaïdi, Zacaria; Krupka, Oksana; Iliopoulos, Konstantinos; Champigny, Emilie; Sahraoui, Bouchta; Sallé, Marc; Gindre, Denis

    2013-01-01

    The second-order nonlinear optical properties of photocross-linkable coumarin-based copolymers were investigated using the optical second harmonic generation (SHG) with the Maker fringes technique. High quality and transparent spin-deposited thin films of various methacrylic copolymers containing 4-methylcoumarin pendant chromophores were prepared and the coumarin units were ordered and oriented by the corona poling technique. Nonlinear optical investigations were performed using a picosecond Q-switched Nd:YAG laser working at the fundamental wavelength (λ = 1064 nm) and the second order nonlinear optical susceptibilities of the functionalized polymers were determined. The samples were irradiated using two wavelengths (λ = 254 nm and λ > 300 nm) promoting the reversible photo-induced dimerisation of coumarin moieties within the film. The latter is shown to have a significant impact on the nonlinear optical response of the corresponding material. A large SHG response of photocross-linkable coumarin-based copolymers is obtained.

  17. Assessment of Coumarin Levels in Ground Cinnamon Available in the Czech Retail Market

    Directory of Open Access Journals (Sweden)

    Jana Blahová

    2012-01-01

    Full Text Available The objective of this study was to determine the coumarin content of ground cinnamon purchased from retail markets in the Czech Republic. No sample was labelled with information on the botanical source, but, in some cases, the countries of origin were specified. For comparison, a single cinnamon sample imported directly from a plantation in Sri Lanka that came from Cinnamomum verum was analyzed. Results from 60 ground cinnamon samples comprising twelve brands confirmed a high content of coumarin, with mean levels ranging from 2 650 to 7 017 mg · kg−1. The high coumarin content confirmed that these cinnamon samples obtained from cassia cinnamon were in contrast to the sample from Sri Lanka, which was coumarin-free.

  18. Gas phase ion chemistry of coumarins: ab initio calculations used to ...

    African Journals Online (AJOL)

    Gas phase ion chemistry of coumarins: ab initio calculations used to justify ... and quadrupole mass spectrometer (qMS) coupled to a gas chromatograph is ... Ab Initio calculations, Electron ionization, Positive chemical ionization, Negative ...

  19. [Coumarins from Skimmia arborescens and its anti-inflammatory effect].

    Science.gov (United States)

    He, Lei; Yang, Shunli; Wu, Desong; Cui, Tao; Wei, Di; Ding, Zhongtao

    2012-03-01

    To investigate chemical constituents contained in Skimmia arborescens. The chemical constituents were separated by silica gel column chromatography, pharmadex LH-20, RP-C18, and 1H, 13C-NMR spectroscopic analysis were employed for the structural elucidation. Six coumarin compounds were separated from S. arborescens. Their structures were elucidated as umbelliferone (1), scopoletin (2), scopolin (3), nodakenetin (4), skimmin (5), 6, 7-dimethoxycoumarin (6), and all compounds were separated from the plant for the first time. Using the model of ear swelling caused by xylol of mice, the anti-inflammatory effect of its total extract was evaluated. The result indicated that middle and high dose groups of its total extract could obviously inhibit the ear swelling caused by xylol of mice.

  20. Superexciplex of Coumarin Molecules using Tunable Ti-Sapphire Laser

    Science.gov (United States)

    Al-Ghamdi, Attieh Ali; Al-Dwayyan, Abdullah S.; Masilamani, Vadivel; Al-Saud, Turki Saud M.; Al-Salhi, Mohammed Saleh

    2003-10-01

    Certain highly polar dye molecules exhibit an additional optical gain band under pulsed laser excitation, while there is no such band under steady-state continuous wave (CW) lamp excitation. This new band is not due to an excimer, an exciplex or a two-photon fluorescence band but stems from the formation of a new molecular complex in which two excited molecules remain associated with a solvent molecule acting as a bridge. In this paper, the characteristics of superexciplexes of four related coumarin molecules are presented. All molecules were excited using a tunable Ti-sapphire laser pulse 10 ns in width. The distinct difference between the amplified spontaneous emission (ASE) spectra obtained with tunable laser and tunable lamp excitation demonstrated that twisted intramolecular charge transfer (TICT) conformations might also assist in the formation of these superexciplexes.

  1. Costs and effectiveness of using coumarins before, during and after coronary angioplasty.

    Science.gov (United States)

    ten Berg, Jurrien M; Kelder, Johannas C; Plokker, Thys H W; van Hout, Ben A

    2002-01-01

    In the Balloon Angioplasty and Anticoagulation Study (BAAS), coumarins added to routine aspirin therapy before coronary angioplasty reduced cardiac events at the cost of a slightly higher risk of bleeding complications. To determine the cost effectiveness of coumarin treatment, based on the occurrence of both cardiac and bleeding events. Effectiveness was measured, applying two definitions, in terms of the number of events occurring at one year. In the first definition, the occurrence of death, myocardial infarction (MI), or stroke was assessed. The second definition also included revascularisations and major bleeding episodes as an event. Costs were limited to direct medical costs. Cost effectiveness was addressed by probability ellipses representing the point estimates and uncertainties surrounding both costs and effectiveness. At 1 year, death, MI or stroke occurred 1.1% less often when treating with aspirin plus coumarins rather than aspirin therapy alone. When revascularisations and major bleeding events were also included, the difference was 5.0%. Overall, the additional costs in relation to coumarin treatment were compensated by a reduction in repeat interventions. When including all costs, the savings associated with coumarin treatment were estimated at Euros 235 per patient after 1 year. The probability that coumarins are cost saving was estimated at 0.85. The probability that coumarins combine additional effectiveness with cost savings was estimated at 0.70 when survival free of MI or stroke as an effectiveness measure was considered, and at 0.83 when survival free of MI, stroke, revascularisation or major bleeding was considered. Coumarin therapy added to routine aspirin therapy before coronary angioplasty, and continued during follow-up, may not only be considered more effective but also cost saving relative to aspirin therapy alone.

  2. Electron Donor-Acceptor Quenching and Photoinduced Electron Transfer for Coumarin Dyes.

    Science.gov (United States)

    1983-10-31

    Mechanism of cousarin photodegradation . Ithe behavior of eoiuma dyes is water ad In aqueous detergent media,. and the effsects of medism aud, additives on...D-i36 345 ELECTRON DONOR-ACCEPTOR UENCHING AND PHOTOINDUCED i/i Ai ELECTRON TRANSFER FOR COUMARIN DYES (U) BOSTON UNIY MR DEPT OF CHEMISTRY G JONES...TYPE OF REPORT & PEIOD COVERED Electron Donor-acceptor Quenching and Photo- Technical, 1/1/82-10/31/82 induced Electron Transfer for Coumarin Dyes S

  3. Functionalized 4-Hydroxy Coumarins: Novel Synthesis, Crystal Structure and DFT Calculations

    Directory of Open Access Journals (Sweden)

    Olga Igglessi-Markopoulou

    2011-01-01

    Full Text Available A novel short-step methodology for the synthesis in good yields of functionalized coumarins has been developed starting from an activated precursor, the N-hydroxysuccinimide ester of O-acetylsalicylic acid. The procedure is based on a tandem C-acylation-cyclization process under mild reaction conditions. The structure of 3-methoxycarbonyl-4-hydroxy coumarin has been established by X-ray diffraction analysis and its geometry was compared with optimized parameters by means of DFT calculations.

  4. K stability and stability of chiral ring

    CERN Document Server

    Collins, Tristan C; Yau, Shing-Tung

    2016-01-01

    We define a notion of stability for chiral ring of four dimensional N=1 theory by introducing test chiral rings and generalized a maximization. We conjecture that a chiral ring is the chiral ring of a superconformal field theory if and only if it is stable. We then study N=1 field theory derived from D3 branes probing a three-fold singularity X, and show that the K stability which implies the existence of Ricci-flat conic metric on X is equivalent to the stability of chiral ring of the corresponding field theory.

  5. Photoinduced interaction of CdSe quantum dot with coumarins

    Energy Technology Data Exchange (ETDEWEB)

    El-Kemary, Maged, E-mail: elkemary@sci.kfs.edu.eg [Nanotechnology Center, Faculty of Science, Kafrelsheikh University, 33516 Kafrelsheikh (Egypt); Gaber, Mohamed; El-Sayed, Y.S. [Chemistry Department, Faculty of Science, University of Tanta, Tanta (Egypt); Gheat, Youssef [Nanotechnology Center, Faculty of Science, Kafrelsheikh University, 33516 Kafrelsheikh (Egypt); Chemistry Department, Faculty of Science, University of Tanta, Tanta (Egypt)

    2015-03-15

    Cadmium selenide (CdSe) quantum dots (QDs) were synthesized with a cubic shape having a diameter of ∼5.24 nm. The prepared CdSe QDs were characterized by using UV–visible, Fourier transform infrared (FTIR), powder X-ray diffraction (XRD) and transmission electron microscope (TEM) measurements. The UV–visible absorption spectra indicate that the optical band gap of CdSe QDs is ∼622 nm and the peak shift can mainly be due to the quantum size effects. The fluorescence decay kinetics for the synthesized QDs was followed by time-resolved fluorescence spectroscopy, and the spectra were analyzed in regard to a bi-exponential model to identify two lifetime values, that is, shorter-lifetime 1.37 ns (55%) and longer-lifetime 6.58 ns (45%). The interaction of coumarin 152 (C152) and coumarin 153 (C153) with QDs surface brings about further considerable changes in the absorption and fluorescence patterns. The calculated binding constant from fluorescence quenching method matches well with that determined from the absorption spectral changes. The static quenching mechanism was confirmed by large magnitude of K{sub SV} and unaltered fluorescence lifetime. - Highlights: • CdSe QDs were synthesized with a cubic shape having a diameter of ∼5.24 nm. • The UV–visible absorption spectra indicate that the optical band gap of CdSe QDs is ∼622 nm. • Picosecond fluorescence measurements of the QDs suggest bi-exponential function. • The calculated binding constant from fluorescence quenching method matches well with that determined from the absorption spectral changes. • The static quenching mechanism was confirmed by large magnitude of K{sub SV} and unaltered fluorescence lifetime.

  6. An asymmetric route to 2,3-epoxy-syn-1,4-cyclohexane diol derivatives using ring closing metathesis (RCM)

    Indian Academy of Sciences (India)

    Soumitra Maity; Subrata Ghosh

    2010-11-01

    An asymmetric route for the synthesis of highly functionalized 2,3-epoxy-syn-1,4-cyclohexane diol derivatives present in some polyketide natural products has been developed. The key step involves RCM of an appropriately constructed 1,7-dienol derived from D-mannitol to cyclohexane-1,4-diol followed by its stereoselective epoxidation.

  7. Femtosecond study of laser coloring soluble in water: the coumarins; Etude femtoseconde de colorants laser solubles dans l`eau: les coumarines

    Energy Technology Data Exchange (ETDEWEB)

    Cassara, L.

    1996-11-29

    This thesis concerns the study of four hydro soluble coumarins A.T.C., D.M.A.T.C., D.A.T.C. et C.H.O.S., analogues of classical coumarins C120, C311, C1 and C102. These molecules are made hydro soluble because of the substitution in position 4- of the methyl group by a polyether group. The mechanisms of deactivation are studied because of fluorescence methods (resolved in time and transient absorption) which allow to study the reactional dynamics of coumarins after luminous excitement. SEveral time scales, from a few femto seconds to the nanosecond have been approachable and have allowed investigations on different processes: relaxation S{sub n} {yields} S{sub 1}, solvation dynamics, orientational diffusion of the solution and deactivation process S{sub 1} {yields} S{sub 0} of radiative and non radiative relaxation in different solvents. (N.C.)

  8. [Determination of five coumarins in toys by high performance liquid chromatography-tandem mass spectrometry].

    Science.gov (United States)

    Yang, Rongjing; Wei, Biwen; Gao, Huan; Yu, Wenjia

    2012-02-01

    A rapid analytical method for the determination of five coumarins (coumarin, 7-methoxycoumarin, dihydrocoumarin, 7-methyl coumarin and 7-ethoxy-4-methyl coumarin) in toys by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) has been developed. After ultrasonic extraction in tetrahydrofuran, the samples were analyzed by HPLC-MS/MS in multi-reaction monitoring (MRM) mode. Acetonitrile and 0.1% acetic acid were used as the mobile phases with gradient elution. The linear ranges of calibration curves were 10 - 1 000 microg/L, and the limits of quantification (LOQ) (S/N > 10) were 2.0 microg/L for all the analytes, except that the LOQ for dihydrocoumarin was 5.0 microg/L. The recoveries of the five coumarins spiked in three types of samples were in the ranges of 93.2% - 105.8%, 97.3% - 103.2% and 96.8% - 102.9%, with the relative standard deviations in the ranges of 4.35% - 8.27%, 3.65% - 6.73% and 4.03% - 6.45%, respectively. The method was applied in the determination of 12 toy samples. The five analytes were found in 9 samples, and in some cases, the presence of quite high concentrations of these coumarins in the toys should be a matter of concern.

  9. Origami rings

    CERN Document Server

    Buhler, Joe; de Launey, Warwick; Graham, Ron

    2010-01-01

    Motivated by a question in origami, we consider sets of points in the complex plane constructed in the following way. Let $L_\\alpha(p)$ be the line in the complex plane through $p$ with angle $\\alpha$ (with respect to the real axis). Given a fixed collection $U$ of angles, let $\\RU$ be the points that can be obtained by starting with $0$ and $1$, and then recursively adding intersection points of the form $L_\\alpha(p) \\cap L_\\beta(q)$, where $p, q$ have been constructed already, and $\\alpha, \\beta$ are distinct angles in $U$. Our main result is that if $U$ is a group with at least three elements, then $\\RU$ is a subring of the complex plane, i.e., it is closed under complex addition and multiplication. This enables us to answer a specific question about origami folds: if $n \\ge 3$ and the allowable angles are the $n$ equally spaced angles $k\\pi/n$, $0 \\le k < n$, then $\\RU$ is the ring $\\Z[\\zeta_n]$ if $n$ is prime, and the ring $\\Z[1/n,\\zeta_{n}]$ if $n$ is not prime, where $\\zeta_n := \\exp(2\\pi i/n)$ is ...

  10. Synthesis and Characterization of New Thiazolidinones Containing Coumarin Moieties and Their Antibacterial and Antioxidant Activities

    Directory of Open Access Journals (Sweden)

    Alary Fabienne

    2012-08-01

    Full Text Available New coumarin derivatives, namely (2-(4-methyl-2-oxo-2H-chromen-7-yloxy-N-(4-oxo-2-phenylthiazolidin-3-ylacetamide, N-(2-(3-methoxyphenyl-4-oxothiazolidin-3-yl-2-(4-methyl-2-oxo-2H-chromen-7-yloxyacetamide, 2-(4-methyl-2-oxo-2H-chromen-7-yloxy-N-(4-oxo-2-(2,3,4trimethoxyphenylthiazolidin-3-ylacetamide and N-(2-(4-bromophenyl-4-oxothiazolidin-3-yl-2-(4-methyl-2-oxo-2H-chromen-7-yloxyacetamide were synthesized starting from 4-methyl-7-hydroxycoumarin. The structures of the obtained compounds were confirmed by analytical IR and NMR spectra to elucidate the different positions of protons and carbons and as well as theoretical studies (DFT/B3LYP. The new compounds were screened for antibacterial activity. Most of them are more active against E. coli S. aureus and B. subtilis than standard references.

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

    Institute of Scientific and Technical Information of China (English)

    CHEN Guo-jun; XUE Peng-chong; LU Ran; SONG Dong-po; BAO Chun-yan; XU Ting-hua; ZHAO Ying-ying

    2009-01-01

    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 organogeis 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 F%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.

  12. Inhibition of Mild Steel Corrosion in Hydrochloric Acid Solution by New Coumarin

    Directory of Open Access Journals (Sweden)

    Abdul Amir H. Kadhum

    2014-06-01

    Full Text Available A new coumarin derivative, N,N′-((2E,2′E-2,2′-(1,4-phenylenebis (methanylylidenebis(hydrazinecarbonothioylbis(2-oxo-2H-chromene-3-carboxamide PMBH, was synthesized and its chemical structure was elucidated and confirmed using spectroscopic techniques (Infrared spectroscopy IR, Proton nuclear  magnetic resonance, 1H-NMR and carbon-13 nuclear magnetic resonance 13C-NMR. The corrosion inhibition effect of PMBH on mild steel in 1.0 M HCl was investigated using corrosion potential (ECORR, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS, and electrochemical frequency modulation (EFM measurements. The obtained results indicated that PMBH has promising inhibitive effects on the corrosion of mild steel in 1.0 M HCl across all of the conditions examined. Scanning electron microscopy (SEM was used to investigate the morphology of the mild steel before and after immersion in 1.0 M HCl solution containing 0.5 mM of PMBH. Surface analysis revealed improvement of corrosion resistance in presence of PMBH.

  13. Inhibition viral RNP and anti-inflammatory activity of coumarins against influenza virus.

    Science.gov (United States)

    Wang, YuTao; Yan, Wen; Chen, QiaoLian; Huang, WanYi; Yang, Zifeng; Li, Xiong; Wang, XinHua

    2017-03-01

    Influenza viruses pose a severe threat to human health and a significant increase in antiviral drug-resistant among influenza viruses worldwide has been observed. Therefore, there is an urgent need to develop the new antiviral drugs, specifically from the natural products. In this study, the anti-viral and anti-inflammatory activities of coumarins against influenza A virus in vitro were investigated. One of the derivatives eleutheroside B1 showed a wide spectrum of anti- human influenza virus effect with the IC50 value of 64-125μg/ml in vitro, but it showed no effects against avian influenza virus. The time of addition was done and the results indicated that it had a potent antiviral effect when added at 0-6h, and also the virus yield was reduced by 60%. The influenza virus ribonucleoprotein was inhibited at 200μg/ml, and also the NP mRNA expression was inhibited at 50 and 200μg/ml. The expression level of cytokines and chemokines influenced by eleutheroside B1 was further demonstrated, the IL-6, CXCL-8, CCL-2 expression were all inhibited by the eleuthe roside B1 at concentration 200μg/ml. The findings of study suggest that eleutheroside B1 can be as potential agent to develop for the prevention and treatment of influenza A virus.

  14. The first zeolite with a tri-directional extra-large 14-ring pore system derived using a phosphonium-based organic molecule.

    Science.gov (United States)

    Yun, Yifeng; Hernández, Manuel; Wan, Wei; Zou, Xiaodong; Jordá, Jose L; Cantín, Angel; Rey, Fernando; Corma, Avelino

    2015-05-04

    A new germanosilicate zeolite (denoted as ITQ-53) with extra-large pores has been synthesised using tri-tertbutylmethylphosphonium cation as the organic structure directing agent (OSDA). Rotation electron diffraction (RED) was used to identify ITQ-53 from an initially-synthesised sample containing impurities, and to solve its structure. The structure was refined against PXRD data of pure ITQ-53 samples obtained after synthesis optimisation. ITQ-53 is the first example of extra-large pore zeolites with tri-directional interconnected 14 × 14 × 14-ring channels. It is stable up to at least 650 °C. The structure of ITQ-53 changes from monoclinic to orthorhombic upon calcination.

  15. Interannual variability of average minimum temperatures derived from tree rings in the mid-Qinling Mountains, China, for the past 138 years

    Science.gov (United States)

    Lei, Ying; Liu, Yu; Sun, Bo; Sun, Changfeng

    2016-10-01

    In this study, spruce tree rings from the southern slope of mid-Qinling Mountains were adopted to investigate the characteristics of average minimum temperatures during the past 138 years. Analysis showed that the interannual variability in radial growth of trees was positively correlated with the interannual variability of average minimum temperatures from previous December to current September ( VTM DS) in the study area during 1955-2010 ad. Based on the correlation analysis, the VTM DS were reconstructed for 1876-2013 ad with an explained variance of 42.5 % for the calibration period. Among the 22 dramatic changing years, extreme changes occurred more times when it was cooling, while the warming was comparatively gentle. Both the 10-year filtering of VTM DS series and the frequency of occurrences for those dramatic changing years showed a relatively stationary variation after the early 1950s. Over the last five decades, the accumulated VTM DS series showed an obvious warming trend, and the increase of the minimum temperature had contributed to the regional warming. The comparison of VTM DS and the dryness/wetness indices generally reflected cold-wet and warm-dry climate conditions in the study area. Significant positive correlations between the reconstructed VTM DS and the gridded minimum temperature indicated a regional representative of the temperature reconstruction, and positive correlations between VTM DS and sea surface temperature (SST) of the Indian Ocean and western Pacific regions suggested a possible linkage between the VTM DS variations and the Asian summer monsoon. Synchronous fluctuations in three tree-ring study series and connections of VTM DS with Arctic oscillation (AO) and El Niño-Southern Oscillation (ENSO) activities suggested that the minimum temperature variations in the TTH area responded sensitively to large-scale climate fluctuations and were the results of atmosphere-ocean interactions.

  16. Interannual variability of average minimum temperatures derived from tree rings in the mid-Qinling Mountains, China, for the past 138 years.

    Science.gov (United States)

    Lei, Ying; Liu, Yu; Sun, Bo; Sun, Changfeng

    2016-10-01

    In this study, spruce tree rings from the southern slope of mid-Qinling Mountains were adopted to investigate the characteristics of average minimum temperatures during the past 138 years. Analysis showed that the interannual variability in radial growth of trees was positively correlated with the interannual variability of average minimum temperatures from previous December to current September (VTM DS) in the study area during 1955-2010 AD. Based on the correlation analysis, the VTM DS were reconstructed for 1876-2013 AD with an explained variance of 42.5 % for the calibration period. Among the 22 dramatic changing years, extreme changes occurred more times when it was cooling, while the warming was comparatively gentle. Both the 10-year filtering of VTM DS series and the frequency of occurrences for those dramatic changing years showed a relatively stationary variation after the early 1950s. Over the last five decades, the accumulated VTM DS series showed an obvious warming trend, and the increase of the minimum temperature had contributed to the regional warming. The comparison of VTM DS and the dryness/wetness indices generally reflected cold-wet and warm-dry climate conditions in the study area. Significant positive correlations between the reconstructed VTM DS and the gridded minimum temperature indicated a regional representative of the temperature reconstruction, and positive correlations between VTM DS and sea surface temperature (SST) of the Indian Ocean and western Pacific regions suggested a possible linkage between the VTM DS variations and the Asian summer monsoon. Synchronous fluctuations in three tree-ring study series and connections of VTM DS with Arctic oscillation (AO) and El Niño-Southern Oscillation (ENSO) activities suggested that the minimum temperature variations in the TTH area responded sensitively to large-scale climate fluctuations and were the results of atmosphere-ocean interactions.

  17. Development of a coumarin-furan conjugate as Zn2 + ratiometric fluorescent probe in ethanol-water system

    Science.gov (United States)

    Li, Chao-rui; Li, Si-liang; Yang, Zheng-yin

    2017-03-01

    In this study, a novel coumarin-derived compound bearing the furan moiety called 7-diethylamino-3-formylcoumarin (2‧-furan formyl) hydrazone (1) has been designed, synthesized and evaluated as a Zn2 + ratiometric fluorescent probe in ethanol-water system. This probe 1 showed good selectivity and high sensitivity towards Zn2 + over other metal ions investigated, and a decrease in fluorescence emission intensity at 511 nm accompanied by an enhancement in fluorescence emission intensity at 520 nm of this probe 1 was observed in the presence of Zn2 + in ethanol-water (V : V = 9 : 1) solution, which provided ratiometric fluorescence detection of Zn2 +. Additionally, the ratiometric fluorescence response of 1 to Zn2 + was nearly completed within 0.5 min, which suggested that this probe 1 could be utilized for sensing and monitoring Zn2 + in environmental and biological systems for real-time detection.

  18. Study on the interaction between gliadins and a coumarin as molecular model system of the gliadins-anthocyanidins complexes.

    Science.gov (United States)

    Tozzi, Silvia; Zanna, Nicola; Taddei, Paola

    2013-12-15

    To clarify the conformational changes of gliadins (Glia) upon complexation with anthocyanidins (in particular cyanidin, Cya), the interaction of Glia with a coumarin derivative (3-ethoxycarbonylcoumarin, 3-EcC), having a benzocondensed structure similar to that of Cya, has been investigated by NMR, IR, and Raman spectroscopy under acidic and neutral conditions. Raman spectra showed that both molecules produce a similar effect on the Glia structure, i.e. an increase in the α-helix conformation and a decrease in β-sheet and β-turns content. In the presence of both molecules, this effect is more marked; the spectroscopic results showed that both Cya and 3-EcC interact with Glia and 3-EcC favors the complex formation with Glia. The results obtained in this study provide new insights into anthocyanidins-Glia interactions and may have relevance to human health, in the field of the attempts to modify gluten proteins to decrease allergen immunoreactivity.

  19. Solvation dynamics of coumarin 153 embedded in AOT + phenol organogels studied by time-resolved fluorescence spectroscopy

    Science.gov (United States)

    Nishiyama, Katsura; Takata, Kei; Watanabe, Keiichi; Shigematsu, Hirotake

    2012-03-01

    We investigate solvation dynamics of organogel utilizing ps-ns fluorescence spectroscopy. The organogel studied in this Letter comprises bis(2-ethylhexyl) sulfosuccinate (AOT) and p-chlorophenol in the m-xylene solvent, that produce an organogel architecture with self-assembly. Within the organogel, an emitting probe, coumarin 153 (C153), is embedded. We then obtain dynamic response functions of solvation derived from the time-resolved fluorescence spectra of C153. We propose that total energy of the C153-organogel system relaxes with a relaxation time of 3.9 ns, whereas the entire rearrangement of the organogel structure around C153 is achieved with that of 6.1 ns, respectively.

  20. Early and late effects of coumarin therapy started before percutaneous coronary intervention

    Science.gov (United States)

    ten Berg, J.M.; Kelder, J.C.; Suttorp, M.J.; Mast, E.G.; Bal, E.T.; Ernst, J.M.P.G.; Plokker, H.W.M.

    2002-01-01

    Background Coronary angioplasty frequently creates a thrombogenic surface with subsequent mural thrombosis that may lead to acute complications and possibly stimulates the development of restenosis. Whether coumarins can prevent these complications is unclear. Methods In the Balloon Angioplasty and Anticoagulation Study (BAAS), the effect of coumarins started before the procedure on early and late outcome was studied. Patients were randomised to aspirin only or to aspirin plus coumarins. Half of the patients were randomised to undergo six-month angiographic follow-up. Study medication was started one week before coronary angioplasty and the target international normalised ratio (INR) was 2.1-4.8 during angioplasty and six-month follow-up. 'Optimal' anticoagulation was defined as an INR in the target range for at least 70% of the follow-up time. In addition, cost-effectiveness of coumarin treatment was measured. Results At one year death, myocardial infarction, target-lesion revascularisation and stroke were observed in 14.3% of the 530 patients randomised to aspirin plus coumarin versus in 20.3% of the 528 patients randomised to aspirin alone (relative risk 0.71; 95% CI 0.54-0.93). The incidence of major bleedings and false aneurysms during hospitalisation was 3.2% and 1.0%, respectively, (relative risk 3.39; 95% CI 1.26-9.11). Optimal anticoagulation was an independent predictor of late thrombotic events (relative risk, 0.33; 95% CI, 0.19-0.57). Quantitative coronary analysis was performed of 301 lesions in the ASA group and of 297 lesions in the coumarin group. At six months, the minimal luminal diameter was similar in the ASA and coumarin group. However, optimal anticoagulation was an independent predictor of angiographic outcome at six months. Optimal anticoagulation led to a 0.21 mm (95% CI: 0.05-0.37) larger MLD as compared with suboptimal anticoagulation whereas aspirin use led to a 0.12 mm (95% CI -0.28-0.04) smaller MLD. When including all costs, the

  1. Ring Model for Pneumatic Tires

    Institute of Scientific and Technical Information of China (English)

    危银涛; 范成建; 管迪华

    2002-01-01

    This paper reviews the state-of-the-art of the ring modeling method for tires, emphasizing the differences among the various tire ring models. A general tire ring model was then developed including all the nonlinear terms in the ring strain and the initial stresses induced by the internal pressure and rotation. The general equations of motion were derived from the Hamilton principle whth the geometric parameters for the model directly obtained from the tire design. The physical parameters were calculated from experimental mode parameters. A numerical example is given for a 195/70 R14-type tire. The analysis shows that the predicted natural frequencies and the tire mode shape agree well with experimental results.

  2. Effects of Different Coumarin- 3-Carboxamide Agents on Scopolamine Induced Learning and Memory Deficit in Mice

    Directory of Open Access Journals (Sweden)

    Samaneh Ghanei Nasab

    2017-06-01

    Full Text Available Introduction: It has been shown that three new synthetic coumarins-3-carboxamides including 3-fluorobenzilchloride, 4-fluorobenzilchloride and 2-hidroxy-3 metoxybenzaldehyde, have acetylcholinesterase inhibitory activity. This study was performed to estimate ameliorating effect of these new coumarin-3-carboxamides on memory impairments induced by scopolamine (1 mg/kg, induced prolongation in mice. Methods: 30 male mice were divided into five groups, 6 mice in each group. Three experiment groups received coumarins-3- carboxamides (10 mg/kg body weight 30 min before scopalamin injection and two other groups considered as normal (saline-treated groups and finally one negative control (scopalamin only group. The experiment groups were treated with coumarins of 3-fluorobenzilchloride, 4-fluorobenzilchloride and 2-hidroxy-3 metoxybenzaldehyde. The passive avoidance test was performed in an automatic conventional shuttle box set-up. The stepped down latency and number of errors was recorded. Results: With reference to saline-treated group, scopolamine-treated mice demonstrated impairment of learning and memory as a reduction of latency and an increased numbers of errors in step-down testp < 0.01. Treated mice receiving these coumarins at the dose of 10 mg/kg showed an increase in the number of avoidances on the memory tests compared to the scopolamine group (p < 0.01. Conclusion: The study has demonstrated some therapeutic effects of coumarin-3-carboxamides on learning and memory deficit induced by scopolamine. Further investigation is needed to explore whether coumarin-3-carboxamides could be beneficial for memory impairment in Alzheimer’s disease in which cholinergic deficit is one of the hallmarks. 

  3. Increasing aridity threats to Himalayan alpine ecosystems? A millenial history of hydroclimate from the Tibetan plateau derived from a δ18O tree-ring network

    Science.gov (United States)

    Griessinger, J.

    2015-12-01

    The Tibetan plateau (TP) plays an important role as an elevated heat source responsible for the establishment of the Asias monsoonal systems. Besides the Indian Summer Monsoon (ISM), also the East Asian Summer Monsoon (EASM) is triggering the regional precipitation regimes during the vegetation period from May to September. Within recent decades, fundamental climate changes on the southeastern part of the TP were detected leading to substantial changes within the regional hydrological budget and affecting local ecosystems. By using a spatial network of multicentennial to 1.5 millenial year old tree-ring δ18O time-series from the southeastern part of the TP, the regional climate history as well as the late Holocene monsoonal variability will be presented. Since the main climatically sensitive periods like the Medieval Warm Period and the Little Ice Age are displayed in all chronologies, their typical hydroclimatological characteristics and impacts will be discussed especially in regard to the recent warming trend on the TP and the responsible climatic triggers. Arising from these results, regional impacts and differences of the proposed hydrological changes will be discussed. In addition, first results of a comparison between proxy-based (δ18O) and model-based (re-analysis datasets) trajectory calculations will be presented, trying to give insights in the origin and impact of air masses for the most striking last three decades on the southeastern part of the TP.

  4. Prime rings with PI rings of constants

    CERN Document Server

    Kharchenko, V K; Rodríguez-Romo, S

    1996-01-01

    It is shown that if the ring of constants of a restricted differential Lie algebra with a quasi-Frobenius inner part satisfies a polynomial identity (PI) then the original prime ring has a generalized polynomial identitiy (GPI). If additionally the ring of constants is semiprime then the original ring is PI. The case of a non-quasi-Frobenius inner part is also considered.

  5. Synthesis and In Vitro Antiproliferative Activity of Novel Phenyl Ring-Substituted 5-Alkyl-12(H)-quino[3,4-b][1,4]benzothiazine Derivatives.

    Science.gov (United States)

    Zięba, Andrzej; Latocha, Małgorzata; Sochanik, Aleksander; Nycz, Anna; Kuśmierz, Dariusz

    2016-11-04

    A novel series of tetracyclic quinobenzothiazine derivatives was synthetized. Compounds containing a substituent (hydroxyl, methyl, phenyl, piperidyl, or piperazinyl) in positions 9 and 11 were obtained by cyclization of suitable 4-aminoquinolinium-3-thiolates. Quinobenzothiazine 10-O-substituted derivatives were obtained by alkylating the hydroxyl group in position 10 of the parent (quinobenzothiazine) system. Antiproliferative activity of the synthesized compounds was studied using cultured neoplastic cells (MDA-MB-231, SNB-19, and C-32 cell lines). Four selected compounds were investigated in more detail for cytotoxicity and antiproliferative effect. Transcriptional activity of genes regulating cell cycle (TP53), apoptosis (BAX, BCL-2), as well as proliferation (H3) were assessed. Finally, the ability of the selected compounds to bind DNA was checked in the presence of ethidium bromide.

  6. Synthesis and In Vitro Antiproliferative Activity of Novel Phenyl Ring-Substituted 5-Alkyl-12(H-quino[3,4-b][1,4]benzothiazine Derivatives

    Directory of Open Access Journals (Sweden)

    Andrzej Zięba

    2016-11-01

    Full Text Available A novel series of tetracyclic quinobenzothiazine derivatives was synthetized. Compounds containing a substituent (hydroxyl, methyl, phenyl, piperidyl, or piperazinyl in positions 9 and 11 were obtained by cyclization of suitable 4-aminoquinolinium-3-thiolates. Quinobenzothiazine 10-O-substituted derivatives were obtained by alkylating the hydroxyl group in position 10 of the parent (quinobenzothiazine system. Antiproliferative activity of the synthesized compounds was studied using cultured neoplastic cells (MDA-MB-231, SNB-19, and C-32 cell lines. Four selected compounds were investigated in more detail for cytotoxicity and antiproliferative effect. Transcriptional activity of genes regulating cell cycle (TP53, apoptosis (BAX, BCL-2, as well as proliferation (H3 were assessed. Finally, the ability of the selected compounds to bind DNA was checked in the presence of ethidium bromide.

  7. On the nonlinear modeling of ring oscillators

    KAUST Repository

    Elwakil, Ahmed S.

    2009-06-01

    We develop higher-order nonlinear models of three-stage and five-stage ring oscillators based on a novel inverter model. The oscillation condition and oscillation frequency are derived and compared to classical linear model analysis. Two important special cases for five-stage ring oscillators are also studied. Numerical simulations are shown. © 2009 World Scientific Publishing Company.

  8. A prodrug approach to the use of coumarins as potential therapeutics for superficial mycoses.

    Directory of Open Access Journals (Sweden)

    Derry K Mercer

    Full Text Available Superficial mycoses are fungal infections of the outer layers of the skin, hair and nails that affect 20-25% of the world's population, with increasing incidence. Treatment of superficial mycoses, predominantly caused by dermatophytes, is by topical and/or oral regimens. New therapeutic options with improved efficacy and/or safety profiles are desirable. There is renewed interest in natural product-based antimicrobials as alternatives to conventional treatments, including the treatment of superficial mycoses. We investigated the potential of coumarins as dermatophyte-specific antifungal agents and describe for the first time their potential utility as topical antifungals for superficial mycoses using a prodrug approach. Here we demonstrate that an inactive coumarin glycone, esculin, is hydrolysed to the antifungal coumarin aglycone, esculetin by dermatophytes. Esculin is hydrolysed to esculetin β-glucosidases. We demonstrate that β-glucosidases are produced by dermatophytes as well as members of the dermal microbiota, and that this activity is sufficient to hydrolyse esculin to esculetin with concomitant antifungal activity. A β-glucosidase inhibitor (conduritol B epoxide, inhibited antifungal activity by preventing esculin hydrolysis. Esculin demonstrates good aqueous solubility (<6 g/l and could be readily formulated and delivered topically as an inactive prodrug in a water-based gel or cream. This work demonstrates proof-of-principle for a therapeutic application of glycosylated coumarins as inactive prodrugs that could be converted to an active antifungal in situ. It is anticipated that this approach will be applicable to other coumarin glycones.

  9. Properties of the Triplet State of Coumarin Substituted Compounds

    Science.gov (United States)

    Bryantseva, N. G.; Gadirov, R. M.; Nikonov, S. Yu.; Sokolova, I. V.

    2015-03-01

    The absorption spectra of the triplet excited state of coumarin sensitizers are investigated both theoretically and experimentally. The most intense triplet-triplet (TT) absorption bands are determined. The experimental spectra of the T-T absorption are compared with the theoretical T-T transitions. The phosphorescence spectra of five compounds are measured at a temperature of 77 K. The quantum phosphorescence yield is determined by the method of comparison with an etalon (8-methoxypsoralen). The phosphorescence lifetime is determined for the examined molecules at a temperature of 77 K. For 3,4-phenyl-4',5'-cyclohexylpsoralen, 4'-methyl-3,4-cycloheptylpsoralen, and 4'5'-dimethyl-3,4-cyclohexylpsoralen compounds, this time is equal to 1.1, 1.25, and 2.5 s, respectively. The main energy deactivation channel for all examined compounds is the phosphorescence. The positions of the lower excited triplet states, calculated by the quantum-chemical method of intermediate neglect of differential overlap with spectroscopic parameterization (INDO/S), are confirmed by the available experimental data.

  10. Radical theory of rings

    CERN Document Server

    Gardner, JW

    2003-01-01

    Radical Theory of Rings distills the most noteworthy present-day theoretical topics, gives a unified account of the classical structure theorems for rings, and deepens understanding of key aspects of ring theory via ring and radical constructions. Assimilating radical theory's evolution in the decades since the last major work on rings and radicals was published, the authors deal with some distinctive features of the radical theory of nonassociative rings, associative rings with involution, and near-rings. Written in clear algebraic terms by globally acknowledged authorities, the presentation

  11. The ring of the narcissist.

    Science.gov (United States)

    Shengold, L

    1995-12-01

    The author has not attempted a complete exposition of the meaning of rings--which can refer to and symbolise many aspects of relationships with other human beings from 'transitional objects' of early development (Winnicott) to all sorts of bonds of loyalty, friendship, and love in the life of the child and the adult. He stresses the meanings of the ring from the point of view of early narcissistic development--the 'body ego' time of early development in which symbolism (in Freud's sense) develops. The clinical and literary examples therefore illustrate the use of rings as magical narcissistic symbols--part subject and part object--derived developmentally from the body ego and ultimately from the body sphincters. Endowed with these regressive primitive meanings, rings are felt to have magical powers that can either preserve or destroy, and that can control emotions in the self and in others. In the course of ordinary or pathological narcissistic regressions, rings (consciously associated with many positive feelings and achievements) also partake, in so far as they are 'Freudian' symbols, of qualities associated with developmentally early defensive mechanisms and modes of psychic functioning (projection, introjection; idealisation, devaluation). In the cases cited, rings seemed specifically associated with (and to symbolise) sphincteric (largely anal) narcissistic defensiveness--the mind functioning as an emotional sphincteric counterpart primarily deadening and distancing affect but intermittently letting through primitive rage and primal polymorphous perverse sexual impulses.

  12. BODIPY-Coumarin Conjugate as an Endoplasmic Reticulum Membrane Fluidity Sensor and Its Application to ER Stress Models.

    Science.gov (United States)

    Lee, Hoyeon; Yang, Zhigang; Wi, Youngjin; Kim, Tae Woo; Verwilst, Peter; Lee, Yun Hak; Han, Ga-In; Kang, Chulhun; Kim, Jong Seung

    2015-12-16

    An endoplasmic reticulum (ER) membrane-selective chemosensor composed of BODIPY and coumarin moieties and a long alkyl chain (n-C18) was synthesized. The emission ratio of BODIPY to coumarin depends on the solution viscosity. The probe is localized to the ER membrane and was applied to reveal the reduced ER membrane fluidity under ER stress conditions.

  13. Cassia Cinnamon as a source of Coumarin in cinnamon-flavored food and food supplements in the United States

    Science.gov (United States)

    Cinnamon is one of the most popular flavoring agents in the United States. Some cinnamon varieties and cinnamon flavored food sold in US could be potential sources of coumarin. Coumarin is banned from food in the United States due to its potential adverse side effects. An ultra-performance liquid ch...

  14. Transport of the Coumarin Metabolite 7-Hydroxycoumarin Glucuronide Is Mediated via Multidrug Resistance-Associated Proteins 3 and 4

    NARCIS (Netherlands)

    Wittgen, Hanneke G. M.; van den Heuvel, Jeroen J. M. W.; van den Broek, Petra H. H.; Siissalo, Sanna; Groothuis, Geny M. M.; de Graaf, Inge A. M.; Koenderink, Jan B.; Russel, Frans G. M.

    2012-01-01

    Coumarin (1,2-benzopyrone) is a natural compound that has been used as a fragrance in the food and perfume industry and could have therapeutic usefulness in the treatment of lymphedema and different types of cancer. Several previous pharmacokinetic studies of coumarin have been performed in humans,

  15. Transport of the coumarin metabolite 7-hydroxycoumarin glucuronide is mediated via multidrug resistance-associated proteins 3 and 4.

    NARCIS (Netherlands)

    Wittgen, H.G.M.; Heuvel, J.J.M.W. van den; Broek, P.H.H. van den; Siissalo, S.; Groothuis, G.M.; Graaf, I.A. de; Koenderink, J.B.; Russel, F.G.M.

    2012-01-01

    Coumarin (1,2-benzopyrone) is a natural compound that has been used as a fragrance in the food and perfume industry and could have therapeutic usefulness in the treatment of lymphedema and different types of cancer. Several previous pharmacokinetic studies of coumarin have been performed in humans,

  16. Transport of the Coumarin Metabolite 7-Hydroxycoumarin Glucuronide Is Mediated via Multidrug Resistance-Associated Proteins 3 and 4

    NARCIS (Netherlands)

    Wittgen, Hanneke G. M.; van den Heuvel, Jeroen J. M. W.; van den Broek, Petra H. H.; Siissalo, Sanna; Groothuis, Geny M. M.; de Graaf, Inge A. M.; Koenderink, Jan B.; Russel, Frans G. M.

    Coumarin (1,2-benzopyrone) is a natural compound that has been used as a fragrance in the food and perfume industry and could have therapeutic usefulness in the treatment of lymphedema and different types of cancer. Several previous pharmacokinetic studies of coumarin have been performed in humans,

  17. Transport of the coumarin metabolite 7-hydroxycoumarin glucuronide is mediated via multidrug resistance-associated proteins 3 and 4.

    NARCIS (Netherlands)

    Wittgen, H.G.M.; Heuvel, J.J.M.W. van den; Broek, P.H.H. van den; Siissalo, S.; Groothuis, G.M.; Graaf, I.A. de; Koenderink, J.B.; Russel, F.G.M.

    2012-01-01

    Coumarin (1,2-benzopyrone) is a natural compound that has been used as a fragrance in the food and perfume industry and could have therapeutic usefulness in the treatment of lymphedema and different types of cancer. Several previous pharmacokinetic studies of coumarin have been performed in humans,

  18. Identification of coumarin as the sensitizer in a patient sensitive to her own perfume but negative to the fragrance mix

    DEFF Research Database (Denmark)

    Mutterer, V; Giménez Arnau, E; Lepoittevin, J P;

    1999-01-01

    obtained was afterwards tested on the patient using a ROAT and/or a patch test. Only 1 fraction gave a positive ROAT result. This fraction was analyzed and found to contain coumarin and ethyl vanillin. Coumarin, one of the most widely used fragrance compounds that is not present in the fragrance mix...

  19. Rare biscoumarins and a chlorogenic acid derivative from Erycibe obtusifolia.

    Science.gov (United States)

    Liu, Jian; Feng, Ziming; Xu, Jianfu; Wang, Yinghong; Zhang, Peicheng

    2007-07-01

    Three coumarins, 7,7'-dihydroxy-6,6'-dimethoxy-3,3'-biscoumarin (1), 7,7'-dihydroxy-6,6'-dimethoxy-8,8'-biscoumarin (2) and 7-O-[4'-O-(3'',4''-dihydroxycinnamyl)-beta-d-glucopyranosyl]-6-methoxycoumarin (3), and a chlorogenic acid derivative, methyl-3-O-(4''-hydroxy-3'',5''-dimethoxybenzoyl)-chlorogenate (4) were isolated from the roots of Erycibe obtusifolia along with four known coumarins, scopoletin (5), scopolin (6), cleomiscosin A (7) and cleomiscosin B (8). Their structures were elucidated by spectroscopic methods. Among them, compounds (1) and (2) are rare carbon-carbon linked symmetrical biscoumarins.

  20. Synthesis and biological evaluation of novel formyl-pyrazoles bearing coumarin moiety as potent antimicrobial and antioxidant agents.

    Science.gov (United States)

    Nagamallu, Renuka; Kariyappa, Ajay Kumar

    2013-12-01

    A series of coumarin appended formyl-pyrazoles 14-18 were synthesized by a simple and accessible approach. The reaction of 8-acetyl-4-methyl-7-hydroxy coumarin 3 and phenyl hydrazine hydrochlorides 4-8 produces the intermediate compounds 8-acetyl-4-methyl-7-hydroxy coumarin hydrazones 9-13. The reaction of compounds 9-13 and DMF in the presence of POCl3 yielded formyl-pyrazoles bearing coumarin moiety 14-18 in good yield. The synthesized new compounds 14-18 and the intermediates 8-acetyl-4-methyl-7-hydroxy coumarin hydrazones 9-13 prepared were screened in vitro for their antibacterial, antifungal antioxidant activities. The compounds 12 and 17 having chloro substitution exhibited promising antifungal and antibacterial activity against the different organisms tested. The compound 17 showed remarkable DPPH radical scavenging ability. Copyright © 2013 Elsevier Ltd. All rights reserved.

  1. Synthesis and photochemical properties of PEGylated coumarin-caged ceramides for cell studies.

    Science.gov (United States)

    Kim, Young Ah; Day, Jenna; Lirette, Carol Ann; Costain, Willard J; Johnston, Linda J; Bittman, Robert

    2016-01-01

    Caged ceramide analogues (C6-, C16-, C18-, C22- and C24-Cer) have been prepared by introducing a hydrophilic coumarin-based cage bearing a short polyethylene glycol (PEG) chain. (6-Bromo-7-mTEGylated-coumarin-4-yl)methyl (Btc) caged ceramide showed efficient photo-uncaging to release the parent ceramide upon direct exposure to 350 nm UV light; in contrast (7-mTEGylated-coumarin-4-yl)methyl (Tc) caged ceramide was photolysed more slowly. In preliminary experiments, Btc-caged ceramides were taken up by cells and their photolysis led to decreases in cell viability, but not to activation of caspase enzymes, suggesting that either reactive oxygen species or an alternate caspase-independent pathway may be responsible for the decreases in cell viability caused by photolysis of caged ceramides.

  2. Antifungal Activity of Coumarin from Ageratum conyzoides L. Leaves on Candida albicans cells

    Directory of Open Access Journals (Sweden)

    Gunawan Pamudji Widodo

    2012-07-01

    Full Text Available The aim of this study was to identify the antifungal activity of coumarin isolated from Ageratum conyzoides L. leaves and to observe its influence on Candida albicans cells by scanning electron microscope (SEM and transmission electron microscope (TEM. Antifungal activity testing by disk diffusion method showed coumarin was active toward pathogenic fungus, Candida albicans with the MIC value of coumarin of 125 g mL-1. The influence of this substance on C. albicans cells was observed by scanning and transmission electron microscopies. The result showed that this compound damaged the cell by pores formation on the cell wall. The death of cells occurred due to leakage and necrotic of cytoplasmic content.

  3. Effect of anisotropic and isotropic solvent on the dipole moment of coumarin dyes.

    Science.gov (United States)

    Zakerhamidi, M S; Ghanadzadeh, A; Moghadam, M

    2011-03-01

    The ground state (μ(g)) and the excited state (μ(e)) dipole moments of two coumarin laser dyes, coumarin 440 and 460, were studied at room temperature in various solvents, viz., general solvents, alcohols and liquid crystals at 298 K. In this work, we report dipole moment of laser dyes in different anisotropic (liquid crystal) and isotropic environments for understanding the effects of environments on the molecular dipole moment and comparing them. Ground and excited state dipole moments of coumarin dyes were evaluated by means of solvatochromic shift method. It was observed that dipole moment values of excited states (μ(e)) were higher than the corresponding ground state values (μ(g)) in all media.

  4. The essential role of coumarin secretion for Fe acquisition from alkaline soil.

    Science.gov (United States)

    Clemens, Stephan; Weber, Michael

    2016-01-01

    Plant productivity is limited by the scarcity of the essential micronutrient iron particularly in alkaline soils. The root secretion of phenolics has long been recognized as a component of the acidification-reduction strategy to acquire iron (strategy I). However, very little molecular insight into this process was available until recently several research groups independently discovered the important role of coumarins for the growth of Arabidopsis thaliana under Fe-limited conditions. Genome-wide analyses of iron deficiency responses, mutant screening and metabolomics experiments all converged on the finding that the synthesis and root exudation of scopoletin, esculetin and other coumarins is essential for iron uptake from substrates with low iron availability. Here we describe the evidence supporting this conclusion and discuss important questions that now have to be addressed in order to better understand the mechanistic basis of coumarin-dependent iron uptake and its significance within the plant kingdom.

  5. Probe dependent anomalies in the solvation dynamics of coumarin dyes in dimethyl sulfoxide-glycerol binary solvent: confirming the local environments are different for coumarin dyes.

    Science.gov (United States)

    Koley, Somnath; Kaur, Harveen; Ghosh, Subhadip

    2014-10-28

    The solvation dynamics of coumarin dyes in dimethyl sulfoxide (DMSO)-glycerol (GLY) binary mixtures were studied across the GLY concentrations. Three coumarin dyes with widely different hydrophobicities were used for probing the entire polarity regions of this solvent mixture. Multiple anomalous concentration regions with significantly slow solvation times were detected from all three coumarin dyes. However, their precise positions were found to be probe molecule dependent. The solvation dynamics of the moderately hydrophobic dye coumarin 480 (C480) maintain a plateau region with a similar solvation time (∼550 ps) with the increase in GLY concentration until X(GLY) (the mole fraction of glycerol) reaches 0.5. This plateau region is followed by a sudden slowdown (to ∼975 ps) on the addition of more GLY to the DMSO-GLY mixture, and then this slow region persists from X(GLY)∼ 0.55 to 0.65 (peak at 0.6). On further addition of GLY (X(GLY) > 0.7), the solvation dynamics again become slower to ∼828 ps (at X(GLY)∼ 0.8) from ∼612 ps (at X(GLY)∼ 0.7). For very high GLY-content samples (X(GLY) > 0.85), the solvation times remain similar on further changes of the GLY concentrations. In contrast to C480, the most hydrophobic dye coumarin 153 (C153) shows a linear increase of solvation time in the DMSO-GLY mixture, from 102 ps (at X(GLY)∼ 0.1) to 946 ps (at X(GLY)∼ 0.9) with increase in GLY concentration, except for the concentration region, X(GLY)∼ 0.45-0.55 (peak at 0.5), where a substantial slowdown of the solvation time is observed. The highly hydrophilic probe coumarin 343 (C343) demonstrates multiple concentration regions (X(GLY)∼ 0.05-0.10, 0.25-0.35 and 0.55-0.65) where the solvation dynamics are significantly retarded. The presence of probe dependent anomalies in the DMSO-GLY mixture is a clear indication of there being different locations of probe molecules within this solvent mixture. We assume that the slowing-down of the solvation time could

  6. Synthesis of New Branched Polysaccharide by Ring-Opening Polymerization of Anhydro-deoxyglucose Derivative and the Subsequent Glycosylation of the Polysaccharide Derivative; Musui deokishigukoru yudotai no kaikan jugo oyobi porima eno tofuka ni yoru shinki bunshi taso no gosei

    Energy Technology Data Exchange (ETDEWEB)

    Hatanaka, Ken`ichi.; Ota, Sanae.; Kasuya, M.C.Z.; Kanno, Ken`ichi. [Tokyo Institute of Technology, Tokyo (Japan). Department of Biomolecular Engineering

    1998-11-10

    1,6-Anhydro-2-deoxy-glucose derivatives having two kinds of protective groups were polymerized and copolymerized in order to synthesize branched polysaccharides. Deoxy-glucose monomers showed high polymerizability. The obtained polymer was selectively deprotected and then glucosylated to give 2-deoxy-(1{yields}6)-{alpha}-D-glucopyranan with glucose branch at C-3. In the present report, it is firstly described that the comb-shaped branched polysaccharide (100% branching) was synthesized by the glycosylation of the polysaccharide derivative. (author)

  7. Stirling engine piston ring

    Science.gov (United States)

    Howarth, Roy B.

    1983-01-01

    A piston ring design for a Stirling engine wherein the contact pressure between the piston and the cylinder is maintained at a uniform level, independent of engine conditions through a balancing of the pressure exerted upon the ring's surface and thereby allowing the contact pressure on the ring to be predetermined through the use of a preloaded expander ring.

  8. Birth Control Ring

    Science.gov (United States)

    ... Loss Surgery? A Week of Healthy Breakfasts Shyness Birth Control Ring KidsHealth > For Teens > Birth Control Ring A A A What's in this article? ... español Anillo vaginal anticonceptivo What Is It? The birth control ring is a soft, flexible, doughnut-shaped ring ...

  9. Solvation of coumarin6 studied by vibrational spectroscopy and density functional theory

    Science.gov (United States)

    Singh, Randhir; Sathe, Vasant; Sharma, Amit; Kaur, Sarvpreet; Saini, G. S. S.

    2016-02-01

    Effect of solvation on coumarin6 dye has been studied with density functional theory (DFT). Optimized structure of the dye has been obtained in various solvents and frequencies of various vibrational bands have been calculated in these solvents. Calculations predict shift in the frequency of certain bands in the solvents. Similar shifts have been observed experimentally in the vibrational spectra of the dye in solvents. In order to ascertain the origin of these shifts, the interactions of solvent molecules with the coumarin6 molecule have been studied using various tools of DFT like donor-acceptor interactions, Molecular Electrostatic potential (MEP) and HOMO-LUMO analysis etc.

  10. Cyclization of ortho-hydroxycinnamates to coumarins under mild conditions: A nucleophilic organocatalysis approach

    Directory of Open Access Journals (Sweden)

    Florian Boeck

    2012-09-01

    Full Text Available (E-Alkyl ortho-hydroxycinnamates cyclize to coumarins at elevated temperatures of 140–250 °C. We find that the use of tri-n-butylphosphane (20 mol % as a nucleophilic organocatalyst in MeOH solution allows cyclization to take place under much milder conditions (60–70 °C. Several coumarins were prepared, starting from ortho-hydroxyarylaldehydes, by Wittig reaction with Ph3P=CHCO2Me to (E-methyl ortho-hydroxycinnamates, followed by the phosphane catalyzed cyclization.

  11. Actin Rings of Power.

    Science.gov (United States)

    Schwayer, Cornelia; Sikora, Mateusz; Slováková, Jana; Kardos, Roland; Heisenberg, Carl-Philipp

    2016-06-20

    Circular or ring-like actin structures play important roles in various developmental and physiological processes. Commonly, these rings are composed of actin filaments and myosin motors (actomyosin) that, upon activation, trigger ring constriction. Actomyosin ring constriction, in turn, has been implicated in key cellular processes ranging from cytokinesis to wound closure. Non-constricting actin ring-like structures also form at cell-cell contacts, where they exert a stabilizing function. Here, we review recent studies on the formation and function of actin ring-like structures in various morphogenetic processes, shedding light on how those different rings have been adapted to fulfill their specific roles.

  12. Alternative loop rings

    CERN Document Server

    Goodaire, EG; Polcino Milies, C

    1996-01-01

    For the past ten years, alternative loop rings have intrigued mathematicians from a wide cross-section of modern algebra. As a consequence, the theory of alternative loop rings has grown tremendously. One of the main developments is the complete characterization of loops which have an alternative but not associative, loop ring. Furthermore, there is a very close relationship between the algebraic structures of loop rings and of group rings over 2-groups. Another major topic of research is the study of the unit loop of the integral loop ring. Here the interaction between loop rings and group ri

  13. Growth inhibition and apoptosis induced by osthole, a natural coumarin, in hepatocellular carcinoma.

    Directory of Open Access Journals (Sweden)

    Lurong Zhang

    Full Text Available BACKGROUND: Hepatocellular carcinoma (HCC is one of the most commonly diagnosed tumors worldwide and is known to be resistant to conventional chemotherapy. New therapeutic strategies are urgently needed for treating HCC. Osthole, a natural coumarin derivative, has been shown to have anti-tumor activity. However, the effects of osthole on HCC have not yet been reported. METHODS AND FINDINGS: HCC cell lines were treated with osthole at various concentrations for 24, 48 and 72 hours. The proliferations of the HCC cells were measured by MTT assays. Cell cycle distribution and apoptosis were determined by flow cytometry. HCC tumor models were established in mice by subcutaneously injection of SMMC-7721 or Hepa1-6 cells and the effect of osthole on tumor growths in vivo and the drug toxicity were studied. NF-κB activity after osthole treatment was determined by electrophoretic mobility shift assays and the expression of caspase-3 was measured by western blotting. The expression levels of other apoptosis-related genes were also determined by real-time PCR (PCR array assays. Osthole displayed a dose- and time-dependent inhibition of the HCC cell proliferations in vitro. It also induced apoptosis and caused cell accumulation in G2 phase. Osthole could significantly suppress HCC tumor growth in vivo with no toxicity at the dose we used. NF-κB activity was significantly suppressed by osthole at the dose- and time-dependent manner. The cleaved caspase-3 was also increased by osthole treatment. The expression levels of some apoptosis-related genes that belong to TNF ligand family, TNF receptor family, Bcl-2 family, caspase family, TRAF family, death domain family, CIDE domain and death effector domain family and CARD family were all increased with osthole treatment. CONCLUSION: Osthole could significantly inhibit HCC growth in vitro and in vivo through cell cycle arrest and inducing apoptosis by suppressing NF-κB activity and promoting the expressions of

  14. Growth Inhibition and Apoptosis Induced by Osthole, A Natural Coumarin, in Hepatocellular Carcinoma

    Science.gov (United States)

    Zhang, Lurong; Jiang, Guorong; Yao, Fei; He, Yan; Liang, Guoqiang; Zhang, Yinsheng; Hu, Bo; Wu, Yan; Li, Yunsen; Liu, Haiyan

    2012-01-01

    Background Hepatocellular carcinoma (HCC) is one of the most commonly diagnosed tumors worldwide and is known to be resistant to conventional chemotherapy. New therapeutic strategies are urgently needed for treating HCC. Osthole, a natural coumarin derivative, has been shown to have anti-tumor activity. However, the effects of osthole on HCC have not yet been reported. Methods and Findings HCC cell lines were treated with osthole at various concentrations for 24, 48 and 72 hours. The proliferations of the HCC cells were measured by MTT assays. Cell cycle distribution and apoptosis were determined by flow cytometry. HCC tumor models were established in mice by subcutaneously injection of SMMC-7721 or Hepa1-6 cells and the effect of osthole on tumor growths in vivo and the drug toxicity were studied. NF-κB activity after osthole treatment was determined by electrophoretic mobility shift assays and the expression of caspase-3 was measured by western blotting. The expression levels of other apoptosis-related genes were also determined by real-time PCR (PCR array) assays. Osthole displayed a dose- and time-dependent inhibition of the HCC cell proliferations in vitro. It also induced apoptosis and caused cell accumulation in G2 phase. Osthole could significantly suppress HCC tumor growth in vivo with no toxicity at the dose we used. NF-κB activity was significantly suppressed by osthole at the dose- and time-dependent manner. The cleaved caspase-3 was also increased by osthole treatment. The expression levels of some apoptosis-related genes that belong to TNF ligand family, TNF receptor family, Bcl-2 family, caspase family, TRAF family, death domain family, CIDE domain and death effector domain family and CARD family were all increased with osthole treatment. Conclusion Osthole could significantly inhibit HCC growth in vitro and in vivo through cell cycle arrest and inducing apoptosis by suppressing NF-κB activity and promoting the expressions of apoptosis

  15. C ring may be dispensable for β-carboline: Design, synthesis, and bioactivities evaluation of tryptophan analog derivatives based on the biosynthesis of β-carboline alkaloids.

    Science.gov (United States)

    Huang, Yuanqiong; Liu, Yongxian; Liu, Yuxiu; Song, Hongjian; Wang, Qingmin

    2016-02-01

    According to our previous work and the latest research on the biosynthesis of β-carboline, and using the reverse thinking strategy, tryptophan, the biosynthesis precursor of β-carboline alkaloids, and their derivatives were synthesized, and their biological activities and structure-activity relationships were studied. This bioassay showed that these compounds exhibited good inhibitory activities against tobacco mosaic virus (TMV); especially (S)-2-amino-3-(1H-indol-3-yl)-N-octylpropanamide (4) (63.3±2.1%, 67.1±1.9%, 68.7±1.3%, and 64.5±3.1%, 500μg/mL) exhibited the best antiviral activity both in vitro and in vivo. Compound 4 was chosen for the field trials and the acute oral toxicity test, the results showed that the compound exhibited good anti-TMV activity in the field and low acute oral toxicity. We also found that these compounds showed antifungal activities and insecticidal activities.

  16. Novel dabigatran derivatives with a fluorine atom at the C-2 position of the terminal benzene ring: Design, synthesis and anticoagulant activity evaluation.

    Science.gov (United States)

    Yang, Haoran; Liu, Qianqian; Gao, Xiaodong; Ren, Yujie; Gao, Yonghong

    2017-01-27

    This manuscript describes the preparation of dabigatran derivatives and their inhibitory potentials toward human thrombin. Among the tested compounds, 7c, 7k, 7m and 7o, with IC50 values of 1.54, 0.84, 1.18 and 1.42 nM, exhibited comparable inhibitory activity to dabigatran (IC50 = 1.20 nM). The in vivo anti-thrombotic activity of compounds 7c and 7o in SD rats was studied. Results showed that intravenously administering the two compounds significantly inhibited the growth of thrombus with an inhibition rate of (84.24 ± 1.53)% and (84.57 ± 0.45)%, which were comparable to that of dabigatran (85.07 ± 0.61)%. Furthermore, the docking simulation of active compounds (7k and 7m) provided a potential binding model. Results indicated that these compounds could be further investigated to determine their anticoagulant activities. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  17. Bunch transverse emittance increase in electron storage rings

    Institute of Scientific and Technical Information of China (English)

    GAO Jie

    2009-01-01

    In this paper a theoretical framework to estimate the bunch transverse emittance growing in electron storage rings due to short range transverse wakefield of the machine is established. New equilibrium emittance equations are derived and applied to explain the experimentally obtained results in ATF damping ring. This equation will be useful for linear collider damping ring design.

  18. Influence of ZnO nanoparticles on Coumarin-503 and Coumarin-540 dye mixture for energy transfer distributed feedback dye lasers

    Science.gov (United States)

    Vijayaraghavan, G. V.; Basheer Ahamed, M.

    2016-07-01

    Using organic dyes Coumarin-503 (C503) and Coumarin-540 (C540) as donor and acceptor dyes, respectively, and Nd-YAG as pumping source (355 nm), an energy transfer-distributed feedback dye laser (ETDFDL) was constructed and its characteristics studied. Theoretical studies such as critical transfer radius (Ro), critical concentration (Co), and half quenching concentration (C1/2) were carried out using the absorption and fluorescence spectra of donor and acceptor dyes. On varying the input pump energy to the nanoparticle-incorporated ETDFDL and keeping the acceptor and donor dye concentrations constant, the lasing output obtained was found to be higher than that without the use of nanoparticles. This enhancement was due to the size, shape, and coupling between nanoparticles with the dye mixture. Tunability in the range of 435-553 nm was obtained for both donor (C503) and acceptor (C540) DFDL as a function of the angle of interfering beams of the pump laser.

  19. Cassia cinnamon as a source of coumarin in cinnamon-flavored food and food supplements in the United States.

    Science.gov (United States)

    Wang, Yan-Hong; Avula, Bharathi; Nanayakkara, N P Dhammika; Zhao, Jianping; Khan, Ikhlas A

    2013-05-08

    Coumarin as an additive or as a constituent of tonka beans or tonka extracts is banned from food in the United States due to its potentially adverse side effects. However, coumarin in food from other natural ingredients is not regulated. "True Cinnamon" refers to the dried inner bark of Cinnamomum verum. Other cinnamon species, C. cassia, C. loureiroi, and C. burmannii, commonly known as cassia, are also sold in the U.S. as cinnamon. In the present study, coumarin and other marker compounds were analyzed in authenticated cinnamon bark samples as well as locally bought cinnamon samples, cinnamon-flavored foods, and cinnamon-based food supplements using a validated UPLC-UV/MS method. The experimental results indicated that C. verum bark contained only traces of coumarin, whereas barks from all three cassia species, especially C. loureiroi and C. burmannii, contained substantial amounts of coumarin. These species could be potential sources of coumarin in cinnamon-flavored food in the U.S. Coumarin was detected in all locally bought cinnamon, cinnamon-flavored foods, and cinnamon food supplements. Their chemical profiles indicated that the cinnamon samples and the cinnamon in food supplements and flavored foods were probably Indonesian cassia, C. burmannii.

  20. On JB-Rings

    Institute of Scientific and Technical Information of China (English)

    Huanyin CHEN

    2007-01-01

    A ring R is a QB-ring provided that aR + bR = R with a, b ∈ R implies that there exists a y ∈ R such that a+by ∈ R-1q. It is said that a ring R is a JB-ring provided that R/J(R) is a QB-ring, where J(R) is the Jacobson radical of R. In this paper, various necessary and sufficient conditions, under which a ring is a JB-ring, are established. It is proved that JB-rings can be characterized by pseudo-similarity. Furthermore, the author proves that R is a J B-ring iff so is R/J(R)2.

  1. Statistical Correlations Between Near-Infrared Luminosities and Ring Sizes in Field Ringed Galaxies

    Science.gov (United States)

    Wu, Wentao

    2008-01-01

    Statistically complete samples of inner-pseudo-, inner-, and outer-ringed galaxies can be extracted from the Catalog of Southern Ringed Galaxies. Redshifts and near-infrared (NIR) photometric data are available for the samples, allowing the derivation of the statistical correlations between the total NIR luminosities (L NIR) and the projected ring major axes in the physical scale (D) for these galaxies. For any of the three types of rings, the correlations are approximately L NIR vprop D 1.2 among the early-type ringed galaxies (the most commonly observed ringed galaxies). The correlations among late-type ringed galaxies appear significantly different. The results contradict the previous suggestion by Kormendy (1979, ApJ, 227, 714), who gave LB vprop D 2 (LB : B-band galaxy luminosity). The relations can be used in future to test theoretical simulations of dynamical structures of ringed galaxies as well as those of ring formation under the framework of cosmological models. Currently the results indicate at most small differences in the relative contributions of disk components to total galaxy masses and in the initial disk velocity dispersions between commonly observed ringed galaxies of similar type. The correlations also suggest a new approach to effectively use ring sizes as tertiary cosmological distance indicators, to help enhance the reliability of the measurement of the Hubble Constant.

  2. Allosteric Partial Inhibition of Monomeric Proteases. Sulfated Coumarins Induce Regulation, not just Inhibition, of Thrombin

    Science.gov (United States)

    Verespy III, Stephen; Mehta, Akul Y.; Afosah, Daniel; Al-Horani, Rami A.; Desai, Umesh R.

    2016-01-01

    Allosteric partial inhibition of soluble, monomeric proteases can offer major regulatory advantages, but remains a concept on paper to date; although it has been routinely documented for receptors and oligomeric proteins. Thrombin, a key protease of the coagulation cascade, displays significant conformational plasticity, which presents an attractive opportunity to discover small molecule probes that induce sub-maximal allosteric inhibition. We synthesized a focused library of some 36 sulfated coumarins to discover two agents that display sub-maximal efficacy (~50%), high potency (150-fold). Michaelis-Menten, competitive inhibition, and site-directed mutagenesis studies identified exosite 2 as the site of binding for the most potent sulfated coumarin. Stern-Volmer quenching of active site-labeled fluorophore suggested that the allosteric regulators induce intermediate structural changes in the active site as compared to those that display ~80–100% efficacy. Antithrombin inactivation of thrombin was impaired in the presence of the sulfated coumarins suggesting that allosteric partial inhibition arises from catalytic dysfunction of the active site. Overall, sulfated coumarins represent first-in-class, sub-maximal inhibitors of thrombin. The probes establish the concept of allosteric partial inhibition of soluble, monomeric proteins. This concept may lead to a new class of anticoagulants that are completely devoid of bleeding. PMID:27053426

  3. Pathological and biochemical evaluation of coumarin and chlorophyllin against aflatoxicosis in rat.

    Science.gov (United States)

    Abdel-Latif, Mohamed S; Elmeleigy, Khaled M; Aly, Tahany A A; Khattab, Marwa S; Mohamed, Sara M

    2017-02-09

    Aflatoxin contamination of animal diet has adverse effects on animal health and productivity. This study was performed to investigate the effect of using coumarin and/or chlorophyllin in rat diet against aflatoxicosis. Fifty-four rats were assigned into 7 groups (6 rats each). G1 was a negative control. G2 received water with coumarin 0.5%. G3 received water with chlorophyllin 0.5%. G4 received water with coumarin 0.5% and chlorophyllin 0.5%. G5-8 fed aflatoxin B1 1000ppb in diet. Group 6-8 were administered similar treatments as G2-4. The experiment ended after 8 weeks. Random glucose, total lipid, total cholesterol, total triglycerides, total protein, serum ALT, AST, creatinine, and urea were measured. Histopathology of liver, kidney and pancreas and immunohistochemical staining of placental glutathione-S-transferase (GST-P) in liver were performed. The glucose serum level, cholesterol, AST, and ALT were elevated in G5 compared to G6-8. The liver and kidney lesions in G5 included vacuolation and necrosis which subsided in G6-8. The necrosis and inflammatory cells infiltration in the pancreas of G5 were absent in G6-8. GST-P positive hepatocytes were abundant in G5, few in G6 and absent in G7 and G8. In conclusion, the chlorophyllin and coumarin possessed protective and anti-carcinogenic effect against aflatoxicosis in rats.

  4. Coumarin fluorometry to quantitatively detectable OH radicals in ultrasound aqueous medium.

    Science.gov (United States)

    Hirano, Kohsuke; Kobayashi, Takaomi

    2016-05-01

    When ultrasound (US) was exposed to aqueous coumarin solution in air atmosphere, the UV-visible and fluorescence spectra of the probe were measured at different US exposure times. The US exposure was carried out at 43 kHz and 500 kHz with different out-put power. It was found that the 500 kHz US produced umbelliferone fluorescence, while the 43 kHz US had no fluorescence. In addition, the coumarin absorbance at 270 nm maximum was decreased with in cases of the US exposure time. In contrary, the fluorescent intensity of umbelliferone at 460 nm increased with increasing of US exposure time. This exhibited that the coumarin probe was converted to umbelliferone by the US exposure, when the 500 kHz US was operated. This was facted that the coumarin framework was caused with addition of OH groups which was generated by the 500 kHz US. Therefore, the umbelliferone fluorescent became a probe to estimate OH radical in US medium. Furthermore, the chemo-fluorometry showed that the emission maximum of the formed umbelliferone could probe the bulk pHs in the US aqueous medium.

  5. Ferulone A and ferulone B: two new coumarin esters from Ferula orientalis L. roots.

    Science.gov (United States)

    Razavi, Seyed Mehdi; Nahar, Lutfun; Talischi, Hamideh; Sarker, Satyajit Dey

    2016-10-01

    Ferula orientalis (Apiaceae) is a well-known perennial herb growing wild in Iran used in traditional medicine. To perform phytochemical studies, dried ground roots of F. orientalis were sequentially Soxhlet-extracted using n-hexane, dichloromethane and methanol. A combination of vacuum liquid chromatography and preparative thin-layer chromatographic analyses were performed to isolate coumarin esters. The structures of the isolated compounds were elucidated by spectroscopic means, and in vitro free-radical-scavenging property was determined by the DPPH assay. Two new coumarin esters, 7-O-(4,8,12,16-tetrahydroxy-4,8,12,16-tetramethyl-heptadecanoyl)-coumarinand 7-O-(4-hydroxy-4,8,12-trimethyl-trideca-7,11-dienoyl)-coumarin, named ferulone A and ferulone B, respectively, were isolated from the n-hexane extract of the roots of F. orientalis. Both compounds showed a low level of free-radical-scavenging property with the RC50 values of 0.252 and 0.556 mg/mL for compounds 1 and 2, respectively, as opposed to that of the positive control (quercetin) 0.004 mg/mL. This is the first report on the purification of coumarin esters from the genus Ferula.

  6. An Injectable PEG-BSA-Coumarin-GOx Hydrogel for Fluorescence Turn-on Glucose Detection.

    Science.gov (United States)

    Srinivasan, Gayathri; Chen, Jun; Parisi, Joseph; Brückner, Christian; Yao, Xudong; Lei, Yu

    2015-11-01

    Diabetes mellitus is a chronic metabolic disorder, requiring vigilant monitoring of blood glucose levels. In this study, an injectable fluorescent enzymatic hydrogel was designed for rapid glucose detection. The leakage-free glucose-responsive hydrogel was constructed by the covalent linkage of a multi-arm poly-(ethylene glycol) (PEG), bovine serum albumin (BSA), glucose oxidase (GOx), and 4-(aminomethyl)-6,7-dimethoxycoumarin (Coumarin-NH2). The GOx serves as glucose-recognition element and the pH-sensitive Coumarin-NH2 as a fluorescence turn-on reporter. The material properties of the fluorescent hydrogel were systematically characterized which show high elasticity with good mechanical strength. Upon the addition of glucose, the as-developed fluorescent hydrogel shows a fast response time, good sensitivity, and good reproducibility at physiological pH and ambient temperature. The glucose-sensing mechanism is based on the oxidation of the glucose by GOx that generates protons to change the local pH. Consequently, protonation of the covalently immobilized and pH-sensitive Coumarin-NH2 turns on the fluorescence of the coumarin. The fluorescence hydrogel developed holds great promise as an injectable, implantable glucose-sensing biomaterials for in vivo continuous glucose monitoring.

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

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    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.

  8. The coumarin herniarin as a sensitizer in German chamomile [Chamomilla recutita (L.) Rauschert, Compositae

    DEFF Research Database (Denmark)

    Paulsen, Evy; Otkjaer, Aksel; Andersen, Klaus E

    2010-01-01

    (7-methoxycoumarin), which is one of the possible coumarin allergens in chamomile. PATIENTS/MATERIALS/METHODS: Between 1991 and 2009, selected patients with known or suspected Compositae contact allergy were patch tested with herniarin 1% petrolatum. RESULTS: Among 36 patients tested, there was one...

  9. Differential morphological, cytological and biochemical responses of two rice cultivars to coumarin

    Science.gov (United States)

    Plants are often exposed to allelochemicals in the environment produced by neighboring plants. Coumarin is a common allelochemical produced by many higher plants. Two cultivars (susceptible BS-2000 and less susceptible BR-41) of rice (Oryza sativa L.) were selected to compare their differential root...

  10. Synthesis of a Novel Blue—light—emitting Polymer Material Bearing Coumarin Pendants

    Institute of Scientific and Technical Information of China (English)

    ZhiYunLU; TongSuoYUAN; 等

    2002-01-01

    A novel blue luminescent polymer bearing coumarin pendants was prepared. Its luminescent properties were determined indicating that it had strong blue fluorescent properies and good film formation ability. This novel polymer can be used as a blue organic electroluminescent material (OELM) in organic electroluminescent devices.

  11. Antifungal Activity of Coumarin Mammeisin Isolated from Species of the Kielmeyera Genre (Family: Clusiaceae or Guttiferae

    Directory of Open Access Journals (Sweden)

    Helcio Cassemiro Marcondes

    2015-01-01

    Full Text Available Coumarin mammeisin isolated from Kielmeyera elata was evaluated for its toxicity and antifungal activities. The toxicity of mammeisin was investigated by utilizing the Artemia salina methodology to determine its LD50 value. The minimum inhibitory concentration (MIC of fungi Candida sp. was assessed for mammeisin, presenting equivalent activity to ketoconazole but displaying better results than fluconazole.

  12. Increased Bleeding Risk With Concurrent Use of Selective Serotonin Reuptake inhibitors and Coumarins

    NARCIS (Netherlands)

    Schalekamp, Tom; Klungel, Olaf H; Souverein, Patrick C; de Boer, Anthonius

    2008-01-01

    BACKGROUND: Treatment with vitamin K antagonists (coumarins) is associated with an increased risk of bleeding. Because use of selective serotonin reuptake inhibitors (SSRIs) is also associated with an increased risk of bleeding, we assessed the odds ratio (OR) of abnormal bleeding associated with SS

  13. Statement on the safety of glucosamine for patients receiving coumarin anticoagulants

    DEFF Research Database (Denmark)

    Tetens, Inge

    2011-01-01

    The European Food Safety Authority (EFSA) asked the Panel on Dietetic Products, Nutrition and Allergies to provide a scientific statement on the safety of glucosamine for patients receiving coumarin anticoagulants. More than 40 case reports have been collected by drug-monitoring agencies that sho......The European Food Safety Authority (EFSA) asked the Panel on Dietetic Products, Nutrition and Allergies to provide a scientific statement on the safety of glucosamine for patients receiving coumarin anticoagulants. More than 40 case reports have been collected by drug-monitoring agencies...... that showed in some patients being prescribed coumarin anticoagulants, especially warfarin, that the International Normalised Ratio (INR) increased after they began taking glucosamine, which indicated an increase in the coagulation time. In most cases the increased INR values were symptomless but in some...... cases haemorrhage occurred in a variety of organs, and in one case this resulted in a persistent vegetative state. The evidence for an interaction between glucosamine and coumarin anticoagulants is strengthened by the observation that in the majority of cases the INR began to fall to normal values when...

  14. Neurological outcome in school-age children after in utero exposure to coumarins

    NARCIS (Netherlands)

    Wesseling, J; Van Driel, D; Smrkovsky, M; Van der Veer, E; Geven-Boere, LM; Sauer, PJJ; Touwen, BCL

    2001-01-01

    The effect of prenatal exposure to coumarins (acenocoumarol, phenprocoumon) on neurological outcome was assessed in a cohort of 306 children aged 7-15 years. Findings were compared with those in a non-exposed cohort of 267 children, matched for sex, age, and demographic region. We used a neurologica

  15. The effect of high pressure on the luminescent properties of coumarin 153

    CERN Document Server

    Li Hong; He Li Ming; Wu Shi Kang; Li Yi; Yang Guo Qiang

    2002-01-01

    A dual-fluorescence emitting behaviour of coumarin 153 powder has been detected at high pressure while at ambient pressure the dye exhibits only single-band emission. Because of the strong electron-withdrawal group at site 7, these two fluorescent peaks can be ascribed to local excited state emission and charge transfer state emission, respectively.

  16. Control of an Unusual Photo-Claisen Rearrangement in Coumarin Caged Tamoxifen through an Extended Spacer.

    Science.gov (United States)

    Wong, Pamela T; Roberts, Edward W; Tang, Shengzhuang; Mukherjee, Jhindan; Cannon, Jayme; Nip, Alyssa J; Corbin, Kaitlin; Krummel, Matthew F; Choi, Seok Ki

    2017-02-17

    The use of coumarin caged molecules has been well documented in numerous photocaging applications including for the spatiotemporal control of Cre-estrogen receptor (Cre-ERT2) recombinase activity. In this article, we report that 4-hydroxytamoxifen (4OHT) caged with coumarin via a conventional ether linkage led to an unexpected photo-Claisen rearrangement which significantly competed with the release of free 4OHT. The basis for this unwanted reaction appears to be related to the coumarin structure and its radical-based mechanism of uncaging, as it did not occur in ortho-nitrobenzyl (ONB) caged 4OHT that was otherwise linked in the same manner. In an effort to perform design optimization, we introduced a self-immolative linker longer than the ether linkage and identified an optimal linker which allowed rapid 4OHT release by both single-photon and two-photon absorption mechanisms. The ability of this construct to actively control Cre-ERT2 mediated gene modifications was investigated in mouse embryonic fibroblasts (MEFs) in which the expression of a green fluorescent protein (GFP) reporter dependent gene recombination was controlled by 4OHT release and measured by confocal fluorescence microscopy and flow cytometry. In summary, we report the implications of this photo-Claisen rearrangement in coumarin caged compounds and demonstrate a rational linker strategy for addressing this unwanted side reaction.

  17. Valorisation des plantes médicinales à coumarines des marchés de ...

    African Journals Online (AJOL)

    SARAH

    30 janv. 2015 ... Résultats : Au total, 38 espèces végétales à coumarines dont 25 herbacées et 13 ligneuses ont ... These species are mostly cultivated and leaves, fruits and seeds are generally used for ... substances naturelles, organiques et.

  18. Non-cytotoxic antibacterial silver-coumarin complex doped sol-gel coatings.

    Science.gov (United States)

    Jaiswal, Swarna; Bhattacharya, Kunal; Sullivan, Maeve; Walsh, Maureen; Creaven, Bernadette S; Laffir, Fathima; Duffy, Brendan; McHale, Patrick

    2013-02-01

    Microbial colonisation on clinical and industrial surfaces is currently of global concern and silane based sol-gel coatings are being proposed as potential solutions. Sol-gels are chemically inert, stable and homogeneous and can be designed to act as a reservoir for releasing antimicrobial agents over extended time periods. In the present study, silver nitrate (AgN) and a series of silver coumarin complexes based on coumarin-3-carboxylatosilver (AgC) and it is 6, 7 and 8 hydroxylated analogues (Ag6, Ag7, Ag8) were incorporated into sol-gel coatings. The comparative antibacterial activity of the coatings was determined against meticillin resistant Staphylococcus aureus (MRSA) and multidrug resistance Enterobacter cloacae WT6. The percentage growth inhibitions were found in the range of 9.2 (±2.7)-66.0 (±1.2)% at low silver loadings of 0.3% (w/w) with E. cloacae being the more susceptible. Results showed that among the Ag coumarin complexes, the Ag8 doped coating had the highest antibiofilm property. XPS confirmed the presence of silver in the nanoparticulate state (Ag(0)) at the coating surface where it remained after 4 days of exposure to bacterial culture. Comparative cytotoxicity studies revealed that the Ag-complex coatings were less toxic than the AgN coating. Thus, it can be concluded that a sol-gel matrix with Ag-coumarin complexes may provide non-toxic surfaces with antibacterial properties.

  19. Increased Bleeding Risk With Concurrent Use of Selective Serotonin Reuptake inhibitors and Coumarins

    NARCIS (Netherlands)

    Schalekamp, Tom; Klungel, Olaf H; Souverein, Patrick C; de Boer, Anthonius

    2008-01-01

    BACKGROUND: Treatment with vitamin K antagonists (coumarins) is associated with an increased risk of bleeding. Because use of selective serotonin reuptake inhibitors (SSRIs) is also associated with an increased risk of bleeding, we assessed the odds ratio (OR) of abnormal bleeding associated with

  20. Sesquiterpene coumarins from the roots of Ferula sinkiangensis and Ferula teterrima.

    Science.gov (United States)

    Yang, Jun-Rong; An, Zheng; Li, Zhi-Hong; Jing, Song; Qina, Hai-Lin

    2006-11-01

    Three new natural sesquiterpene coumarins, isofeterin (1), lehmannolol (3), sinkianone (4), and one known compound, lehmannolone (2), were isolated from the roots of Ferula teterrima and Ferula sinkiangensis. Their chemical structures were established on the basis of spectroscopic analysis, including X-ray crystallography and CD spectrum measurements for determining the absolute configuration of compound 2.